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Although numerous articles have been published not only on the classification of thoracic outlet syndrome (TOS) but also on diagnostic standards, timing, and type of surgical intervention, there still remains some controversy because of the lack of level 1 evidence. So far, attempts to generate uniform reporting standards have not yielded conclusive results. OBJECTIVE: To systematically review the body of evidence and reach a consensus among neurosurgeons experienced in TOS regarding anatomy, diagnosis, and classification. METHODS: A systematic literature search on PubMed/MEDLINE was performed on February 13, 2021, yielding 2853 results. Abstracts were screened and classified. Recommendations were developed in a meeting held online on February 10, 2021, and refined according to the Delphi consensus method. RESULTS: Six randomized controlled trials (on surgical, conservative, and injection therapies), 4 “guideline” articles (on imaging and reporting standards), 5 observational studies (on diagnostics, hierarchic designs of physiotherapy vs surgery, and quality of life outcomes), and 6 meta-analyses were identified. The European Association of Neurosurgical Societies’ section of peripheral nerve surgery established 18 statements regarding anatomy, diagnosis, and classification of TOS with agreement levels of 98.4 % (±3.0). CONCLUSION: Because of the lack of level 1 evidence, consensus statements on anatomy, diagnosis, and classification of TOS from experts of the section of peripheral nerve surgery of the European Association of Neurosurgical Societies were developed with the Delphi method. Further work on reporting standards, prospective data collections, therapy, and long-term outcome is necessary.

Objective Intraneural perineurioma is a rare tumor entity. It is a benign, very slow growing peripheral nerve sheath tumor that typically occurs in children and young adults. Motor deficits and muscle atrophy are classic presenting symptoms, while sensory deficits are rare at the onset of the disease. Recommended treatment strategies are lacking. We have evaluated the clinical follow-up and our experience with treatment of this rare entity. Methods A total of 30 patients with intraneural perineuriomas were assessed retrospectively. Demographic data, clinical symptoms, diagnostic examinations, therapy strategies, and clinical outcome were analyzed. Descriptive statistical methods were used for evaluation. Results The mean age was 22 years. Eleven women and 19 men were affected. The lesion occurred in the area of the upper extremity in 16 patients and in the area of the lower extremity in 14 patients. The most frequently affected nerve was the sciatic nerve, followed by the radial nerve. All patients showed a motor deficit to some extent. Seventy percent (n = 21) revealed atrophy, 43.3% (n = 13) had sensitive deficits, and 17% (n = 5) suffered of pain. Fascicle biopsies were performed in 26 patients (87%). In four patients (13%), the tumor was completely resected and then reconstructed via nerve grafts. Seventy percent of the patients (n = 21) received a magnetic resonance imaging (MRI) within 5 years postoperatively, in which no progress was shown. Conclusions To diagnose perineurioma, it is essential to take a biopsy of an enlarged, nonfunctional fascicle. Furthermore, a long-distance epineuriotomy to decompress the hypertrophic fascicle is reasonable. To preserve the nerves' residual function, a complete resection is not recommended. Results after grafting are poor. One reason for this might be residual tumor cells along the nerve that cannot be visualized. Malignant transformation is not yet reported and tumor growth is stable for years.

A 2016 published randomized multicenter phase III trial of prophylactic nimodipine treatment in vestibular schwannoma surgery showed only a tendency for higher hearing preservation rates in the treatment group. Gender was not included in statistical analysis at that time. A retrospective analysis of the trial considering gender, preoperative hearing, and nimodipine treatment was performed. The treatment group received parenteral nimodipine from the day before surgery until the seventh postoperative day. The control group was not treated prophylactically. Cochlear nerve function was determined by pure-tone audiometry with speech discrimination preoperatively, during in-patient care, and 1 year after surgery and classified according to the Gardner-Robertson grading scale (GR). Logistic regression analysis showed a statistically significant effect for higher hearing preservation rates (pre- and postoperative GR 1–4) in 40 men comparing the treatment (n = 21) and the control (n = 19) groups (p = 0.028), but not in 54 women comparing 27 women in both groups (p = 0.077). The results were also statistically significant for preservation of postoperative hearing with pre- and postoperative GR 1–3 (p = 0.024). There were no differences in tumor sizes between the treatment and the control groups in men, whereas statistically significant larger tumors were observed in the female treatment group compared with the female control group. Prophylactic nimodipine is safe, and an effect for hearing preservation in 40 men with preoperative hearing ability of GR 1–4 was shown in this retrospective investigation. The imbalance in tumor size with larger tumors in females of the treatment group may falsely suggest a gender-related effect. Further investigations are recommended to clarify whether gender has impact on nimodipine’s efficacy.

Objective Owing to technical development of specific fluorophore filters, the neurosurgical application of sodium fluorescein (SF) has regained value in brain tumor surgery. The aim of this study was to determine the usefulness of SF during nerve biopsies. Methods This single-center study included 5 cases of nerve biopsies performed under microscope-based fluorescence with SF performed between March 2016 and February 2017. SF was applied intravenously (1 mg/kg body weight). After microsurgical dissection of the involved nerve segment, fluorescence-guided fascicular biopsy was performed. Selection of target fascicles was at the surgeon's discretion and took into account nerve stimulation for preservation of motor function and fluorescence intensity. Correlation to histopathologic examination was examined. Video analysis of intraoperative images comparing target fascicles with intense fluorescent response to adjacent fascicles of the same nerve segment was performed using ImageJ. Results All patients had motor or sensory deficits. Magnetic resonance imaging findings were similar, depicting long segments of gadolinium enhancement (minimum 11.7 cm). Each biopsy sample was positive resulting in diverse histopathologic results. Digital image analysis revealed a statistically significant difference of the complementary color green (P = 0.0473). Conclusions Magnetic resonance imaging is the gold standard in diagnostic work-up of peripheral nerve disorders. Longitudinal nerve thickening with positive contrast enhancement is an unspecific magnetic resonance imaging finding. Various pathologies, such as tumors and inflammatory lesions, may cause this morphologic phenomenon. Nerve biopsies may be needed for diagnostic work-up. Intraoperative SF may help to depict the most affected fascicles and identify target fascicles for biopsy and increase diagnostic certainty of nerve biopsies.

Mammals differ in their regeneration potential after traumatic injury, which might be caused by species-specific regeneration programs. Here, we compared murine and human Schwann cell (SC) response to injury and developed an ex vivo injury model employing surgery-derived human sural nerves. Transcriptomic and lipid metabolism analysis of murine SCs following injury of sural nerves revealed down-regulation of lipogenic genes and regulator of lipid metabolism, including Pparg (peroxisome proliferator-activated receptor gamma) and S1P (sphingosine-1-phosphate). Human SCs failed to induce similar adaptations following ex vivo nerve injury. Pharmacological PPARg and S1P stimulation in mice resulted in up-regulation of lipid gene expression, suggesting a role in SCs switching towards a myelinating state. Altogether, our results suggest that murine SC switching towards a repair state is accompanied by transcriptome and lipidome adaptations, which are reduced in humans., publishedVersion

OBJECTIVEIn clinical routines, neuroprotective strategies in neurosurgical interventions are still missing. A pilot study (n = 30) and an analogously performed Phase III trial (n = 112) pointed to a beneficial effect of prophylactic nimodipine and hydroxyethyl starch (HES) in vestibular schwannoma (VS) surgery. Considering the small sample size, the data from both studies were pooled.METHODSThe patients in both investigator-initiated studies were assigned to 2 groups. The treatment group (n = 70) received parenteral nimodipine (1–2 mg/hour) and HES (hematocrit 30%–35%) from the day before surgery until the 7th postoperative day. The control group (n = 72) was not treated prophylactically. Facial and cochlear nerve functions were documented preoperatively, during the inpatient care, and 1 year after surgery.RESULTSPooled raw data were analyzed retrospectively. Intent-to-treat analysis revealed a significantly lower risk for hearing loss (Class D) 12 months after surgery in the treatment group compared with the control group (OR 0.46, 95% CI 0.22–0.97; p = 0.04). After exclusion of patients with preoperative Class D hearing, this effect was more pronounced (OR 0.38, 95% CI 0.17–0.83; p = 0.016). Logistic regression analysis adjusted for tumor size showed a 4 times lower risk for hearing loss in the treatment group compared with the control group (OR 0.25, 95% CI 0.09–0.63; p = 0.003). Facial nerve function was not significantly improved with treatment. Apart from dose-dependent hypotension (p < 0.001), the study medication was well tolerated.CONCLUSIONSProphylactic nimodipine is safe and may be recommended in VS surgery to preserve hearing. Prophylactic neuroprotective treatment in surgeries in which nerves are at risk seems to be a novel and promising concept.Clinical trial registration no.: DRKS 00000328 (https://drks-neu.uniklinik-freiburg.de/drks_web/)

Objective We designed this study using super-selective intraoperative cervical nerve root stimulation aiming to support decision making about complete or partial contralateral C7 (cC7) nerve root transfer in patients with multiple cervical root avulsion injury. Methods Super-selective intraoperative stimulations of anterior, lateral, medial and posterior aspect of C5–C8 nerve roots were performed. Compound muscle action potentials (CMAP) were recorded in the lateral part of the deltoid (DM), long head of biceps brachii (BCM), brachioradial (BRM), long head of triceps brachii (TCM), and extensor digitorum communis (EDC) muscle. Muscle strength was documented immediately after cC7 transfer procedures and on scheduled follow-up visits according to the Medical Research Council (MRC) scale. Results In the DM, stimulation of the posterior aspect of C5 resulted in the largest CMAP amplitudes (2.0 mV ± 1.9; 80% ± 28.3). The BCM CMAPs induced by the different aspects of C6 all revealed homogenous stimulation results. Stimulation of the lateral aspect of C7 induced the largest amplitude of TCM CMAPs (1.3 mV ± 1.0; 67.1% ± 43.3). CMAP amplitudes of individual muscles and individual contributions of cervical nerve roots to the TCM varied between subjects. Overall donor side morbidity was low, no permanent motor deficit occurred. Conclusion A super-selective intraoperative cervical nerve root stimulation may help minimize donor side morbidity in transfer procedures. Individual differences of cervical nerve root innervation pattern need to be addressed in future electrophysiological studies. Significance Our study outlines individual differences of cervical nerve root innervation pattern.

Background Injury to the brachial plexus is a devastating condition, with severe impairment of upper extremity function resulting in distinct disability. There are no systematic reports on epidemiology, causative mechanisms, treatment strategies. or outcomes of iatrogenic brachial plexus injury (iBPI). Methods We screened all cases of iatrogenic nerve injuries recorded between 2007 and 2017 at a single specialized institution. Mechanism of iBPI, type of previous causative intervention, location and type of the lesion as well as the type of revision surgery and functional patient outcome were analyzed. Results We identified 14 cases of iBPI, which all presented with significant impairment of upper extremity motor function (at least 1 muscle Medical Research Council grade 0). Neuropathic pain was present in most patients (11/14). Orthopedic shoulder procedures such as rotator cuff fixation, arthroplasty, and repositioning of a clavicle fracture accounted for iBPI in 7 of 14 patients. Other reasons for iBPI were resection or biopsy of a peripheral nerve sheath tumor in 3 patients or lymph node situated at the cervicomediastinal area in 2 patients. Mechanisms also included transaxillary rib resection in one and sternotomy in another patient. The treatment of iBPI was conducted according to each individual's needs and included neurolysis in 4, nerve grafting in 9, and nerve transfers in 1 patient. We found improved symptoms after treatment in most patients (11/14). Conclusions Most common causes for iBPI were shoulder surgery and resection or biopsy of peripheral nerve sheath tumor and lymph nodes. Early referral to specialized peripheral nerve centers may help to improve functional patient outcome.

Evidence of a high interobserver variability of the subjective House-Brackmann facial nerve grading system (HBGS) would justify cost- and time-consuming technological enhancements of objective classifications for facial nerve paresis. A total of 112 patients were recruited for a randomized multi-center trial to investigate the efficacy of prophylactic nimodipine treatment in vestibular schwannoma (VS) surgery. For the present investigation both treatment groups were pooled for the assessment of facial nerve function preoperatively, in the early postoperative course and 1 year after the surgery. Facial nerve function was documented photographically at rest and in motion and classified according to the HBGS by three independent observers (neurosurgeon, neurologist, ENT) and by the investigator of each center. Interobserver variability was considerably different with respect to the three time points depending upon the severity of facial nerve paresis. Preoperative facial nerve function was normal or only mildly impaired (HB grade I or II) and was assessed consistently in 97%. Facial nerve function deteriorated during the early postoperative course and was subsequently documented without dissent in only 36%, with one grade difference in 45%, two grade difference in 17% and three grade difference in 2%. One year after surgery, facial nerve function predominantly improved resulting in a consistent assessment in 66%. Differing ratings were observed in 34% with one grade deviation in 88% and of two grades in 12%. Patients with differing ratings of two or more grades exhibited considerably worse facial nerve function (p

OBJECT A pilot study of prophylactic nimodipine and hydroxyethyl starch treatment showed a beneficial effect on facial and cochlear nerve preservation following vestibular schwannoma (VS) surgery. A prospective Phase III trial was undertaken to confirm these results. METHODS An open-label, 2-arm, randomized parallel group and multicenter Phase III trial with blinded expert review was performed and included 112 patients who underwent VS surgery between January 2010 and February 2013 at 7 departments of neurosurgery to investigate the efficacy and safety of the prophylaxis. The surgery was performed after the patients were randomly assigned to one of 2 groups using online randomization. The treatment group (n = 56) received parenteral nimodipine (1–2 mg/hr) and hydroxyethyl starch (hematocrit 30%–35%) from the day before surgery until the 7th postoperative day. The control group (n = 56) was not treated prophylactically. RESULTS Intent-to-treat analysis showed no statistically significant effects of the treatment on either preservation of facial nerve function (35 [67.3%] of 52 [treatment group] compared with 34 [72.3%] of 47 [control group]) (p = 0.745) or hearing preservation (11 [23.4%] of 47 [treatment group] compared with 15 [31.2%] of 48 [control group]) (p = 0.530) 12 months after surgery. Since tumor sizes were significantly larger in the treatment group than in the control group, logistic regression analysis was required. The risk for deterioration of facial nerve function was adjusted nearly the same in both groups (OR 1.07 [95% CI 0.34–3.43], p = 0.91). In contrast, the risk for postoperative hearing loss was adjusted 2 times lower in the treatment group compared with the control group (OR 0.49 [95% CI 0.18–1.30], p = 0.15). Apart from dose-dependent hypotension (p < 0.001), no clinically relevant adverse reactions were observed. CONCLUSIONS There were no statistically significant effects of the treatment. Despite the width of the confidence intervals, the odds ratios may suggest but do not prove a clinically relevant effect of the safe study medication on the preservation of cochlear nerve function after VS surgery. Further study is needed before prophylactic nimodipine can be recommended in VS surgery.

The prevalence of arachnoid cysts (AC) is considerably increased in psychiatric patients, suggesting a possible causal relationship between AC and certain psychiatric disorders. Neurosurgery of AC in psychiatric disorders is, however, not recommended if no accompanying neurological symptoms or signs of increased intracranial pressure are present. In two cases of slow onset personality disorder in persons suffering from so-called asymptomatic AC, we performed AC neurosurgery beyond established rules. Both comparisons before and after neurosurgery of psychopathology and the following long-term course support in retrospect that both cases might be re-diagnosed as having suffered from 'minor' organic personality disorders before AC neurosurgery, which improved thereafter. The two cases did not initially appear to fulfill the established criteria for organic personality disorders either according to ICD-10 or DSM-IV, but in retrospect satisfied most criteria. In themselves, the personality disorders appeared not very severe, but had considerable relevance for the patients' lives. The established rules for AC neurosurgery should be reconsidered at least when therapy-resistant psychiatric disorders are observed in AC sufferers.

OBJECTIVE: Little is known about patient satisfaction and disability after brachial plexus surgery. Would patients undergo the procedure again, if they knew the current result beforehand ? How do they rate their result and their disability? METHODS: Of 319 plexus patients who had undergone surgery between 1995 and 2005, 199 received a 65-item questionnaire. Measurement instruments included a new plexus-specific outcome questionnaire (Ulm Questionnaire) with categories of satisfaction, functionality, pain, comorbidities, and work; and the disability of the arm, shoulder, and hand questionnaire (DASH; scale, 0-100). RESULTS: Of 99 returned questionnaires, 70 were returned in a useful form for evaluation. The results of patients with C5-C6 lesions (21 of 70) are as follows: 90% (19 of 21) would undergo surgery again, 95% (20 of 21) were satisfied with the result, and 86% (18 of 21) subjectively improved. The mean DASH score was 41 (standard deviation [SD], 24). The results of patients with C5-C7 lesions (6 of 70) are as follows: 50% (3 of 6) were satisfied and would undergo surgery again, and 67% (4 of 6) improved. The mean DASH score was 46 (SD, 13). The results of patients with C5-T1 lesions (43 of 70) are as follows: 67% (29 of 43) would undergo surgery again, 81 % (35 of 42) were satisfied, and 74% (32 of 43) reported improvement. The mean DASH score was 58 (SD, 26). The overall mean DASH score was 52 (SD, 26). Pain since the injury was prevalent in 86% of patients (60 of 70), back pain in 53%, and depression/anxiety in 21 %. Fifty-two percent of those who worked before their injury (27 of 53 patients) remained unemployed or incapacitated for work. Forty-five percent of previous workers (24 of 53) returned to their former occupation. Occupational retraining was successful for 70% of patients (16 of 23). The mean duration until return to work was 9 months overall and 5 months for those who returned to their previous occupation. CONCLUSION: Eighty-seven percent of patients were satisfied with the results and 83% would undergo the procedure again. Despite a high satisfaction rate, patients remained considerably disabled, and half of the previous workers did not return to work. Occupational retraining is effective.

In the hands of the inexperienced, endoscopic carpal tunnel release bears a substantial risk for neurovascular injury. For those thoroughly trained in this technique, it is a fast and elegant but also more expensive way to achieve carpal tunnel release. If performed uneventfully, it minimizes trauma and avoids a substantial palmar skin incision. The authors think that some basic considerations are useful to prevent complications. This article focuses on some points that are relevant to the safe use of this technique.

As long as humans have been medically treated, unfortunate cases of inadvertent injury to nerves afflicted by the therapist have occurred. Most microsurgically treated iatrogenic nerve injuries occur directly during an operation. Certain nerves are at a higher risk than others, and certain procedures and regions of the body are more prone to sustaining nerve injury. A high degree of insecurity regarding the proper measures to take can be observed among medical practitioners. A major limiting factor in successful treatment is delayed referral for evaluation and reconstructive surgery. This article on iatrogenic nerve injuries intends to focus on relevant aspects of management from a nerve surgeon's perspective.

The aim of this study is to analyse short- and long-term results after surgical treatment of foramen magnum meningiomas and to identify the possible advantages of the posterior suboccipital approach over lateral and anterior approaches. Between 1992 and 2006, 16 patients with foramen magnum meningiomas were operated on in our institution, and in all cases a posterior suboccipital approach was utilised with lateral extension of the bone opening according to the position of the tumour. In 14 patients, intraoperative monitoring of the lower cranial nerves was performed. Localisation of the tumours was ventral (3), ventrolateral (10), dorsal (1) and dorsolateral (2). Mean age of the patients was 61 years (ranging from 40 to 85 years). Preoperative and postoperative function was classified according to the McCormick scale. We found in eight patients a postoperative upgrading of at least one grade, in five patients an unchanged status and a deterioration in only two patients. Complete removal of the tumour was possible in 14 cases (Simpson 1-2). The follow-up period varied from 24 to 119 months (mean 43.5 months), during this time there were no recurrences. Removal of foramen magnum meningiomas can be performed safely today with the use of microsurgical techniques and intraoperative monitoring. In our experience, the posterior suboccipital approach is suitable for the majority of these tumours.

OBJECTIVE Facial nerve paresis and hearing loss are common complications after vestibular schwannoma surgery. Experiments with facial nerves of the rat and retrospectively analyzed clinical studies showed a beneficial effect of vasoactive treatment on the preservation of facial and cochlear nerve functions. This prospective and open-label randomized pilot study is the first study of a prophylactic vasoactive treatment in vestibular schwannoma surgery. METHODS Thirty patients were randomized before surgery. One group (n = 14) received a vasoactive prophylaxis consisting of nimodipine and hydroxyethylstarch which was started the day before surgery and was continued until the seventh postoperative day. The other group (n = 16) did not receive preoperative medication. Intraoperative monitoring, including acoustic evoked potentials and continuous facial electromyelograms, was applied to all patients. However, when electrophysiological signs of a deterioration of facial or cochlear nerve function were detected in the group of patients without medication, vasoactive treatment was started immediately. Cochlear and facial nerve function were documented preoperatively, during the first 7 days postoperatively, and again after long-term observation. RESULTS Despite the limited number of patients, our results were significant using the Fisher's exact test (small no. of patients) for a better outcome after vestibular schwannoma surgery for both hearing (P = 0.041) and facial nerve (P = 0.045) preservation in the group of patients who received a prophylactic vasoactive treatment. CONCLUSION Prophylactic vasoactive treatment consisting of nimodipine and hydroxyethylstarch shows significantly better results concerning preservation of the facial and cochlear nerve function in vestibular schwannoma surgery. The prophylactic use is also superior to intraoperative vasoactive treatment.

The diagnostic workup and surgical therapy for peripheral nerve tumors and tumorlike lesions are challenging. Magnetic resonance imaging is the standard diagnostic tool in the preoperative workup. However, even with advanced pulse sequences such as diffusion tensor imaging for MR neurography, the ability to differentiate tumor entities based on histological features remains limited. In particular, rare tumor entities different from schwannomas and neurofibromas are difficult to anticipate before surgical exploration and histological confirmation. High-resolution ultrasound (HRU) has become another important tool in the preoperative evaluation of peripheral nerves. Ongoing software and technical developments with transducers of up to 17–18 MHz enable high spatial resolution with tissue-differentiating properties. Unfortunately, high-frequency ultrasound provides low tissue penetration. The authors developed a setting in which intraoperative HRU was used and in which the direct sterile contact between the ultrasound transducer and the surgically exposed nerve pathology was enabled to increase structural resolution and contrast. In a case-guided fashion, the authors report the sonographic characteristics of rare tumor entities shown by intraoperative HRU and contrast-enhanced ultrasound.

Iatrogenic nerve lesions (INLs) are an integral part of peripheral neurology and require dedicated neurologists to manage them. INLs of peripheral nerves are most frequently caused by surgery, immobilization, injections, radiation, or drugs. Early recognition and diagnosis is important not to delay appropriate therapeutic measures and to improve the outcome. Treatment can be causative or symptomatic, conservative, or surgical. Rehabilitative measures play a key role in the conservative treatment, but the point at which an INL requires surgical intervention should not be missed or delayed. This is why INLs require close multiprofessional monitoring and continuous re-evaluation of the therapeutic effect. With increasing number of surgical interventions and increasing number of drugs applied, it is quite likely that the prevalence of INLs will further increase. To provide an optimal management, more studies about the frequency of the various INLs and studies evaluating therapies need to be conducted. Management of INLs can be particularly improved if those confronted with INLs get state-of-the-art education and advanced training about INLs. Management and outcome of INLs can be further improved if the multiprofessional interplay is optimized and adapted to the needs of the patient, the healthcare system, and those responsible for sustaining medical infrastructure.

Neurogenesis in the adult human brain occurs within two principle neurogenic regions, the hippocampus and the subventricular zone (SVZ) of the lateral ventricles. Recent reports demonstrated the isolation of human neuroprogenitor cells (NPCs) from these regions, but due to limited tissue availability the knowledge of their phenotype and differentiation behavior is restricted. Here we characterize the phenotype and differentiation capacity of human adult hippocampal NPCs (hNPCs), derived from patients who underwent epilepsy surgery, on various feeder cells including fetal mixed cortical cultures, mouse embryonic fibroblasts (MEFs) and PA6 stromal cells. Isolated hNPCs were cultured in clonal density by transferring the cells to serum-free media supplemented with FGF-2 and EGF in 3% atmospheric oxygen. These hNPCs showed neurosphere formation, expressed high levels of early neuroectodermal markers, such as the proneural genes NeuroD1 and Olig2, the NSC markers Nestin and Musashi1, the proliferation marker Ki67 and significant activity of telomerase. The phenotype was CD15low/-, CD34-, CD45- and CD133-. After removal of mitogens and plating them on poly D-lysine, they spontaneously differentiated into a neuronal (MAP2ab+), astroglial (GFAP+), and oligodendroglial (GalC+) phenotype. Differentiated hNPCs showed functional properties of neurons, such as sodium channels, action potentials and production of the neurotransmitters glutamate and GABA. Co-culture of hNPCs with fetal cortical cultures, MEFs and PA6 cells increased neurogenesis of hNPCs in vitro, while only MEFs and PA6 cells also led to a morphological and functional neurogenic maturation. Together we provide a first detailed characterization of the phenotype and differentiation potential of human adult hNPCs in vitro. Our findings reinforce the emerging view that the differentiation capacity of adult hNPCs is critically influenced by non-neuronal mesodermal feeder cells.

Object.Surgical therapy for traumatic brachial plexus lesions is still a great challenge in the field of peripheral nerve surgery. The aim of this study was to present the results of different surgical interventions in patients with this lesion type.Methods.One hundred thirty-four patients with traumatic brachial plexus lesions underwent surgery between January 1991 and September 1999. In more than 50% of the patients, injury was caused by a motorbike accident. Patients underwent surgery a mean of 6.3 months posttrauma. The following surgical techniques were applied: neurolysis for nerve lesions in continuity (27 cases), grafting for lesions in discontinuity (149 cases), and neurotization for root avulsions (67 cases). Sixty-five patients were evaluated for at least 30 months (mean follow up 42.1 months) after surgery.Function was graded using the Louisiana State University Health Sciences Center classification system. Only 2% of the patients had Grade 3 or better function preoperatively, increasing to 52% postoperatively. The effect of surgical measures on the functional results for different muscles were compared (supra- or infraspinatus, deltoid, biceps, and triceps muscles); the best results were obtained for biceps muscle function (57% of patients with Medical Research Council Grades M3–M5 function). Graft reconstruction yielded a better outcome than neurotization. Surgery within 5 months posttrauma clearly resulted in improved recovery of motor function compared with later interventions. Sural nerve grafts (monofascicular nerves) showed better results.Conclusions.The results of neurosurgical interventions for brachial plexus lesions are satisfactory, especially when the operation is performed between 3 and 6 months after trauma.

Spinal hematoma has been described in autopsies since 1682 and as a clinical diagnosis since 1867. It is a rare and usually severe neurological disorder that, without adequate treatment, often leads to death or permanent neurological deficit. Epidural as well as subdural and subarachnoid hematomas have been investigated. Some cases of subarachnoid spinal hematoma may present with symptoms similar to those of cerebral hemorrhage. The literature offers no reliable estimates of the incidence of spinal hematoma, perhaps due to the rarity of this disorder. In the present work, 613 case studies published between 1826 and 1996 have been evaluated, which represents the largest review on this topic to date. Most cases of spinal hematoma have a multifactorial etiology whose individual components are not all understood in detail. In up to a third of cases (29.7%) of spinal hematoma, no etiological factor can be identified as the cause of the bleeding. Following idiopathic spinal hematoma, cases related to anticoagulant therapy and vascular malformations represent the second and third most common categories. Spinal and epidural anesthetic procedures in combination with anticoagulant therapy represent the fifth most common etiological group and spinal and epidural anesthetic procedures alone represent the tenth most common cause of spinal hematoma. Anticoagulant therapy alone probably does not trigger spinal hemorrhage. It is likely that there must additionally be a "locus minoris resistentiae" together with increased pressure in the interior vertebral venous plexus in order to cause spinal hemorrhage. The latter two factors are thought to be sufficient to cause spontaneous spinal hematoma. Physicians should require strict indications for the use of spinal anesthetic procedures in patients receiving anticoagulant therapy, even if the incidence of spinal hematoma following this combination is low. If spinal anesthetic procedures are performed before, during, or after anticoagulant treatment, close monitoring of the neurological status of the patient is warranted. Time limits regarding the use of anticoagulant therapy before or after spinal anesthetic procedures have been proposed and are thought to be safe for patients. Investigation of the coagulation status alone does not necessarily provide an accurate estimate of the risk of hemorrhage. The most important measure for recognizing patients at high risk is a thorough clinical history. Most spinal hematomas are localized dorsally to the spinal cord at the level of the cervicothoracic and thoracolumbar regions. Subarachnoid hematomas can extend along the entire length of the subarachnoid space. Epidural and subdural spinal hematoma present with intense, knife-like pain at the location of the hemorrhage ("coup de poignard") that may be followed in some cases by a pain-free interval of minutes to days, after which there is progressive paralysis below the affected spinal level. Subarachnoid hematoma can be associated with meningitis symptoms, disturbances of consciousness, and epileptic seizures and is often misdiagnosed as cerebral hemorrhage based on these symptoms. Most patients are between 55 and 70 years old. Of all patients with spinal hemorrhage, 63.9% are men. The examination of first choice is magnetic resonance imaging. The treatment of choice is surgical decompression. Of the patients investigated in the present work, 39.6% experienced complete recovery. The less severe the preoperative symptoms are and the more quickly surgical decompression can be performed, the better are the chances for complete recovery. It is therefore essential to recognize the relatively typical clinical presentation of spinal hematoma in a timely manner to allow correct diagnostic and therapeutic measures to be taken to maximize the patient's chance of complete recovery.

Carpal tunnel syndrome is by far the most common peripheral nerve compression syndrome, affecting approximately one in every six adults to a greater or lesser extent. Splitting the flexor retinaculum to treat carpal tunnel syndrome is the second most common specialized surgical procedure in Germany. Cubital tunnel syndrome is rarer by a factor of 13, and the other compression syndromes are rarer still.This review is based on publications retrieved by a selective literature search of PubMed and the Cochrane Library, along with current guidelines and the authors' clinical and scientific experience.Randomized controlled trials have shown, with a high level of evidence, that the surgical treatment of carpal tunnel syndrome yields very good results regardless of the particular technique used, as long as the diagnosis and the indication for surgery are well established by the electrophysiologic and radiological findings and the operation is properly performed. The success rates of open surgery, and the single-portal and dual-portal endoscopic methods are 91.6%, 93.4% and 92.5%, respectively. When performed by experienced hands, all these procedures have complication rates below 1%. The surgical treatment of cubital tunnel syndrome has a comparably low complication rate, but worse results overall. Neuro-ultrasonography and magnetic resonance imaging (neuro-MRI) are increasingly being used to complement the diagnostic findings of electrophysiologic studies.Evidence-based diagnostic methods and treatment recommendations are now available for the two most common peripheral nerve compression syndromes. Further controlled trials are needed for most of the rarer syndromes, especially the controversial ones.

Iatrogenic nerve injuries can result from direct surgical trauma, mechanical stress on a nerve due to faulty positioning during anesthesia, the injection of neurotoxic substances into a nerve, and other mechanisms. Treating physicians should know the risk factors and the procedure to be followed when an iatrogenic nerve injury arises.This review is based on pertinent articles retrieved by a selective search in PubMed and on the authors' own data from the years 1990-2012.In large-scale studies, 25% of sciatic nerve lesions that required treatment were iatrogenic, as were 60% of femoral nerve lesions and 94% of accessory nerve lesions. Osteosyntheses, osteotomies, arthrodeses, lymph node biopsies in the posterior triangle of the neck, carpal tunnel operations, and procedures on the wrist and knee were common settings for iatrogenic nerve injury. 340 patients underwent surgery for iatrogenic nerve injuries over a 23-year period in the District Hospital of Günzburg (Neurosurgical Department of the University of Ulm). In a study published by the authors in 2001, 17.4% of the traumatic nerve lesions treated were iatrogenic. 94% of iatrogenic nerve injuries occurred during surgical procedures.A thorough knowledge of the anatomy of the vulnerable nerves and of variants in their course can lessen the risk of iatrogenic nerve injury. When such injuries arise, early diagnosis and planning of further management are the main determinants of outcome. If adequate nerve regeneration does not occur, surgical revision should optimally be performed 3 to 4 months after the injury, and 6 months afterward at the latest. On the other hand, if postoperative high resolution ultrasound reveals either complete transection of the nerve or a neuroma in continuity, surgery should be performed without any further delay. If the surgeon becomes aware of a nerve transection during the initial procedure, then either immediate end-to-end suturing or early secondary management after three weeks is indicated.

Whereas cranial neuronavigation is widely accepted as a helpful tool, larger series of the in vivo application of spinal neuronavigation do not exist. In the following we report our 4-year experience with spinal navigation in 75 consecutive cases for dorsal transpedicular screw placement. Seventy-five patients were planned for operation employing anatomical reference points defined on a 2-mm high resolution CT. We used single vertebra registration and surface matching. With the above methods, the mean registration deviation ranged from 0.18 mm (cervical spine) to 0.31 mm (lumbar spine). All our screws in the upper cervical spine were navigated correctly (17 patients), thus improving markedly the surgical outcome. The results were not as promising in the lumbar area. In only 84% was navigation reliable. The reason was the lack of a practicable tracking tool. Spinal neuronavigation based on anatomical reference points is able to improve the results in transpedicular screwing, especially in the cervical spine. The lack of a practicable tracking tool still hinders its use in routine clinical application.

Purpose Identification of the precentral gyrus can be difficult in patients with brain tumors. The purpose of the current study was to evaluate the clinical usefulness of functional MRI (fMRI) in identifying motor cortex and speech areas as a part of preoperative neurosurgical planning. Method fMRI was performed using a 1.5 T MR unit in 41 patients with brain tumors. The motor paradigm was finger tapping and foot movement, whereas the language paradigm consisted of a two word semantic test. Statistical analysis of the data was done using the Kolmogorow-Smirnow test. Plots of signal intensities over time were created. Results The precentral gyrus was identified in 38 of 41 patients. In two patients, fMRI was not of acceptable quality due to motion artifacts. Speech areas were localized in 33 patients. In a typical clinical setting, the value of the method was graded “high.” Conclusion fMRI`s efficacy in the preoperative localization of language and motor areas is high. The method should become a routine adjunct for preoperative evaluation of brain tumors in the near future.

Fourteen patients with traumatic brachial plexus injuries underwent intradural inspection of cervical nerve roots to evaluate radiological and intra-operative electrophysiological findings concerning cervical nerve root avulsion from the spinal cord. Four neurosurgeons of our department assessed independently from each other both myelography and CT-myelography concerning intradural nerve root lesions. Each neurosurgeon assessed a total of 26 cervical nerve roots. Two investigators assessed 6/26 and 2 investigators 7/26 nerve roots falsely concerning ventral or/and dorsal root lesions compared with the findings on intradural inspection (23% and 27% false findings). There was a considerable variance concerning the assessibility and findings among the 4 neurosurgeons. Reconstructive surgery was performed after a mean interval of 6.5 months following trauma and 2 weeks following intradural inspection. After exposure of the brachial plexus and the cervical nerve roots in question via a ventral approach, 13 cervical nerve roots were stimulated electrically close to the neuroforamen and cortical evoked potentials (root-SEPs) were recorded from the contralateral postcentral region. All 5 roots with SEPs were intact (no root lesion) and all 8 roots without SEPs showed interrupted (ventral or/and dorsal) rootlets on intradural inspection. Our results demonstrate that false radiological findings concerning root lesions are possible. Intra-operative root-SEPs seem to be a useful aid for evaluation of cervical nerve root lesions. However, more electrophysiological data are necessary to ascertain, if this modality is able to replace intradural inspection in unclear radiological cases in the future.

Objective: To determine the neurological outcome in patients with laminar fractures associated with dural tears and nerve root entrapment, operated upon for thoracic and lumbar spine injuries. Patient population: Out of 103 patients operated upon consecutively for thoracic and lumbar spine injuries during the period 1990 to 1994 inclusive, 24 (23.3%) patients had laminar fractures out of whom 3 (2.9%) had an associated dural tear and an other 17 (16.5% or 70.8% of the total patients with laminar fractures) had an associated dural tear and nerve root entrapment. Results: Twelve (70.5%) patients had injury at the thoraculumbar junction, 13 (76.5%) had Magerl's type A3 or above, 10 (58.8) had a kyphotic angle deformity greater than 5°. Seven (41.1%) had their spinal canal's sagittal diameter reduced by at least 50% and two had dislocations. Nine (52.9%) had initial neurological deficits. Four (50%) out of 8 patients with no initial neurological deficits (Frankel E) worsened to Frankel D. However, one patient among the 3 with initial Frankel A improved to Frankel C while both patients with initial Frankel C usefully improved to final Frankel grades D and E respectively. Two of the four patients with initial Frankel D improved to Frankel E, the other 2 remaining unchanged. All in all five patients' neurological status improved, 4 worsened and 8 remained unchanged after neurosurgical treatment. Conclusions: Vertical laminar fractures with dural tears and nerve root entrapment represent a special group of thoracic and lumbar spine injuries that carry a poor prognosis. However, special operative precautions lead to significant improvement in some of them although a majority remain unchanged or even worsened.

OBJECTIVE: Fifty-eight percent of patients who had undergone surgery for ulnar neuropathy at the elbow experienced pain after surgery. Severe pain, mostly radiating from the elbow into the hand, is the main indication for subsequent surgery. METHODS: During a period of 5.5 years, 25 patients underwent 28 operations for ulnar nerve entrapment at the elbow and experienced excruciating pain after surgery. Ten patients had undergone a simple decompression and 15 had undergone a nerve transposition. Seven patients underwent surgery at our hospital, whereas 18 patients underwent their primary surgery at other institutions. Various surgical techniques were used during the subsequent surgery, such as external or internal neurolysis, epineurectomy, anterior transposition, and subsequent transfer of the nerve back into the sulcus. RESULTS: The average follow-up after the last procedure was 17 months (2-55 mo). All five patients with subsequent transfer of the ulnar nerve into the sulcus became pain-free, whereas only two of five patients who had secondary intramuscular transposition for subluxation became free of pain. Results after internal neurolysis were unsatisfactory. Only one of six patients was free of pain after secondary surgery. Results after three or four procedures are approximately similar to the results after the first subsequent surgery. CONCLUSION: Simple and less extensive techniques for subsequent surgery have relatively good results in this complicated condition. Although our small number of patients does not allow us to draw general conclusions, we think our report makes a contribution because of the few reports in the literature dealing with the results of subsequent surgery for ulnar nerve neuropathy.

The results of 58 dorsal root entry zone (DREZ) thermocoagulation procedures in 51 patients are reported. The postoperative analgesic effect was judged by the patients as being good (more than 75% pain reduction), fair (25–75% pain reduction) or poor (less than 25% pain reduction). Of the 14 patients who underwent surgery for pain due to cervical root avulsion, 10 (77%) had permanently good (8) or fair (2) pain relief after a mean follow up period of 76 months, another 2 (15%) experienced recurrence to the pre-operative level (initially 1 good, 1 fair) after more than 2 and 4 years, respectively. Twenty two paraplegics were operated upon, 3 of whom twice, for intractable pain. After a mean observation time of 54 months, continuing pain relief was reported by 12 (55%) patients (11 good, 1 fair), and one (initially fair) had recurrent pain after 8 months. All 3 (early) re-operations remain successful for an average period of 75 months. Poor results were seen especially in cases of associated spinal cord cysts (5 out of 7), despite combined drainage, and in patients with diffuse pain distribution (5 out of 6). Continuous marked improvement for longer periods (mean follow up: 52 months) after DREZ lesions was reported only by 2 out of 10 patients with postherpetic neuralgia (12 procedures) and by 1 out of 5 with painful states due to radiation-induced brachial plexopathy (2), previous surgery (2) and malignant tumour infiltration of the brachial plexus (1). Three patients died postoperatively due to acute cardiac failure (2) and pulmonary embolism (1). Major complications, especially permanent gait disturbances were observed in 6 patients (12%) following primary procedures and in 2 out of 7 patients after re-operations, most of them suffering from postherpetic neuralgia. Minor neurological deficits were noted in 9 cases (18%). DREZ lesions revealed to be an effective procedure in patients with pain related to root avulsion and paraplegia. In contrast, it seems to be less successful for painful states due to other plexus lesions or postherpetic neuralgia.

Surgical treatment of nerve lesions in continuity remains difficult, even in the most experienced hands. The regenerative potential of those injuries can be evaluated by intraoperative electrophysiological studies and/or intraneural dissection. The present study examines the value of intraoperative high-frequency ultrasound as an imaging tool for decision making in the management of traumatic nerve lesions in continuity.Intraoperative high-frequency ultrasound was applied to 19 traumatic or iatrogenic nerve lesions of differing extents. The information obtained was correlated with intraoperative electrophysiological, microsurgical intraneural dissection, and histopathological findings in resected nerve segments.The intraoperative application of high-resolution, high-frequency ultrasound enabled morphological examination of nerve lesions in continuity, with good image quality. The assessment of the severity of the underlying nerve injury matched perfectly with the judgment obtained from intraoperative electrophysiological studies. Both intraneural nerve dissection and neuropathological examination of the resected nerve segments confirmed the sonographic findings. In addition, intraoperative ultrasound proved to be very time efficient.With intraoperative ultrasound, the extent of traumatic peripheral nerve lesions can be examined morphologically for the first time. It is a promising, noninvasive method that seems capable of assessing the type (intraneural/perineural) and grade of nerve fibrosis. Therefore, in combination with intraoperative neurophysiological studies, intraoperative high-resolution ultrasound may represent a major tool for noninvasive assessment of the regenerative potential of a nerve lesion.

Objective In this study, we compare different surgical procedures regarding the functional outcome of traumatic peroneal nerve lesions. Methods In a retrospective study, 48 patients with traumatic lesions (17 iatrogenic) of the peroneal nerve were evaluated. Twenty-two patients presented with lesions in continuity displaying regenerative potential by nerve action potential recording. In these cases, surgery was restricted to either external (12/) or interfascicular neurolysis (10/). Twenty-two cases had no regenerative potential (10/) or showed discontinuity (12/) and thus were reconstructed with autologous sural nerve grafts. In four cases, a reconstructive procedure was intraoperatively abandoned as a result of the large extent of the lesion. Results Thirty-six patients with an adequate follow-up period of at least 18 months were included in this study. Among those with external neurolysis, 73% (eight out of 11) showed a good functional outcome, obviating the need for a kick-up foot brace (M >or= 4). In the interfascicular neurolysis group, 71% (five out of seven) exhibited a similar outcome. In the grafted group, however, only 28% (five out of 18) obtained a functionally useful result dependent on graft length. A graft length under 6 cm led to a functionally useful outcome in 44% of patients (four out of nine) compared with 11% (one out of nine) when the graft length was greater than or equal to 6 cm. In six patients, muscle-tendon transfers were performed, resulting in strong, useful foot lift. Conclusion Peroneal nerve lesions lacking regenerative signs should be explored. A functionally useful result (M >or=4) was achieved in 72% of the patients with either external or internal neurolysis and in 28% of the patients after a nerve graft procedure. Patients in whom nerve surgery failed to reconstitute useful foot lift need to be evaluated for their suitability to undergo a tendon transfer procedure.

The aneurysmal subarachnoid hemorrhage (SAH) is a syndrom with an extremely complex pathophysiological course. Although treatment outcomes in patients with intracranial aneurysms of the circle of Willis and SAH have improved over time, the mortality and morbidity rates remain unacceptably high. The clinical course and the outcome were evaluated in a group of patients who underwent surgery.Patient characteristics, including age, sex, preexisting medical conditions, aneurysm location and size, time to admission, admission neurological status, computerized tomography and angiography findings were analyzed to determine relationship to outcome. A total of 67 patients with the intracranial aneurysms were treated by the microsurgical technique for a direct aneurysm surgery. The data were analyzed in two aspects: the overall management and the surgical results.An occlusion of aneurysm neck was done in 97% and 3% of patients were treated by aneurysm wrapping. There was a significant relationship between the neurological status on admission and the outcome (p0.005). Out of 67 patients, 50% had a good result, 16% were moderately disabled, 18% were severely disabled, and 12% were dead at the six month post-SAH evaluation. The results were significantly better according to the better neurological status on admission (p = 0.0001).The disastrous natural history of subarachnoid hemorrhage secondary to ruptured intracranial aneurysm has largely remained unaffected by even the best medical and surgical care because of the natural history of the disease, as well as mistakes in diagnosis and delays in treatment. Among the patients who were underwent surgery, 50% returned to their premorbid state, and 12% died. The factors associated with poor results were direct effects of the initial hemorrhage, vasospasm and rebleeding. Although the results of management of patients with ruptured aneurysms seem to be improved with time, there is opportunity for substantial additional improvement.

✓In this article the authors attempt to raise awareness of the pitfalls and controversial issues in nerve tumor surgery. In a case-guided format, examples of ambiguous findings, inappropriate tumor removal, repeated surgery, and nerve repairs are provided. The authors also discuss the need to establish a correct diagnosis preoperatively and to avoid the erroneous identification of malignant peripheral nerve sheath tumors (MPNSTs). They emphasize that not all of the principles of soft tissue sarcoma treatment protocols are applicable to MPNST. A situation of repeated surgery for supposedly malignant tumor is described, and an outline of the indications for, and an approach to, repair after lesion removal is given.

Global gene expression profiling was performed using RNA from adult human hippocampus-derived neuroprogenitor cells (NPCs) and multipotent frontal cortical fetal NPCs compared with adult human mesenchymal stem cells (hMSCs) as a multipotent adult stem cell control, and adult human hippocampal tissue, to define a gene expression pattern that is specific for human NPCs. The results were compared with data from various databases. Hierarchical cluster analysis of all neuroectodermal cell/tissue types revealed a strong relationship of adult hippocampal NPCs with various white matter tissues, whereas fetal NPCs strongly correlate with fetal brain tissue. However, adult and fetal NPCs share the expression of a variety of genes known to be related to signal transduction, cell metabolism and neuroectodermal tissue. In contrast, adult NPCs and hMSCs overlap in the expression of genes mainly involved in extracellular matrix biology. We present for the first time a detailed transcriptome analysis of human adult NPCs suggesting a relationship between hippocampal NPCs and white matter-derived precursor cells. We further provide a framework for standardized comparative gene expression analysis of human brain-derived NPCs with other stem cell populations or differentiated tissues. Disclosure of potential conflicts of interest is found at the end of this article.

Management of conducting neuroma-in-continuity in primary surgery for obstetrical brachial plexus palsy (OBPP) is still discussed controversially. We present our experience with intraoperative neurophysiological recordings in the management of lesions in continuity in OBPP.A series of ten children with lesions in continuity of the upper brachial plexus is presented. Due to recordable compound nerve action potentials (CNAPs) and muscle response to motor stimulation across the neuroma, five children underwent external neurolysis of neuroma only (neurolysis group). Due to lack of recordable CNAPs or muscle response, resection of neuroma and interpositional nerve grafting were performed in another five children (resection and grafting group). Functional recovery after at least 30 months of follow-up was assessed.There was a marked difference in functional recovery between the neurolysis and the resection and grafting group. Especially, recovery of shoulder function was disappointing after external neurolysis of conducting neuroma-in-continuity. At the end of follow-up, results of shoulder and elbow function after resection of neuroma followed by interpositional nerve grafting were better without exception.Intraoperative neurophysiological recordings face certain difficulties when used in small children with OBPP. Due to overoptimistic assessment of prognosis after intraoperative CNAP recordings and motor stimulation, the functional results after neurolysis of conducting neuroma-in-continuity are disappointing. Resection of neuroma-in-continuity, conducting or not, offers the best opportunity for maximal functional recovery of the compromised upper limb in OBPP. The role of intraoperative neurophysiological techniques should be confined to the diagnosis of root avulsions.

Surgical decompression and internal fixation of the injured spine have become standard procedures in the management of thoracic and lumbar spine fractures, but their effectiveness on neurological recovery remains controversial. We report on 169 consecutive patients with thoracic and lumbar spine fractures who were treated by reduction, fusion, and internal fixation using transpedicular screw-rod systems. Open decompression was carried out in 67 (39.6%) of them, including all 42 patients (25%) who presented with initial neurological deficits. At least 8 months following surgery, 30 (71%) had neurologically improved by one to three grades on the Frankel scale. Thirteen (59%) out of 22 patients whose initial deficits had been classified as "motor useless" (Frankel grades A to C) could walk, at least with support. Thirteen out of 20 patients with posttraumatic deficit Frankel D ("motor useful") improved to full recovery (Frankel E). In six (3.6%) patients (all from the group of the 127 patients without initial neurological deficits), permanent slight postoperative neurological impairment of one Frankel grade (E to D) was seen, among them two (1.2%) with new minor motor deficit. Neurological outcome was significantly better (p

From January 1999 to May 2003, 316 aneurysms were treated, among them 40 patients (12.7%) over 65 years with subarachnoid haemorrhage (SAH). The results of this sub-group are presented. Mean age was 71 years (range 65–83 years), 40% of the patients were in (Hunt & Hess) grade I–III and 60% grade IV–V. Eighty-five percent of the aneurysms were located in the anterior circulation (35% ACom aneurysms). Nineteen aneurysms were coiled (all basilar tip and small-based ACom aneurysms), two among them subsequently clipped after coil compaction, 18 were initially clipped (most of MCA and all broad-based ACom aneurysms), two wrapped and one trapped. A total of 66.7% of the patients with coiled and 60.0% with clipped aneurysms had been hospitalized in poor condition (Hunt & Hess IV–V). The average follow-up period was 16 months. Overall, 35% of patients fully recovered, 5% returned to normal activity with some deficit, 33% remained dependent and 27% died. All seven patients with MCA aneurysms and intracerebral haematoma were clipped, but died or remained vegetative. Ten of 17 coiled patients (58.8%) had a favourable outcome, compared to 4/11 (36.4%) in the clip group, but two primarily coiled aneurysms rebleld due to coil compaction. The outcome is dependent on the primary Hunt & Hess grade. A total of 48.5% of SAH patients without intracerebral bleeding fully recovered, even patients in poor primary grade. Additional intracerebral haemorrhage is linked to a bad outcome. As primary procedure, the less traumatic coiling seems to be superior to clipping primarily. Better Hunt & Hess grades have a statistically significant chance for a promising outcome.

Objective The goals of the study were to investigate the value of intraoperative electrically evoked nerve action potentials (NAPs) in the surgical treatment of traumatic peripheral nerve injuries (nerve lesions in continuity). Methods Sixty-four patients with 76 traumatic nerve lesions in continuity were investigated intraoperatively by stimulating and recording NAP from the whole nerve across the suspected lesion site. Among the 76 nerves (nerve lesions) were 43 with incomplete and 33 with complete loss of function. In cases (nerves) with complete loss of function (n = 33), the surgical procedure (external neurolysis, internal neurolysis, or nerve repair) was performed according to the microscopic aspect of the nerve and the result of the intraoperative electrophysiological testing. In cases (nerves) with incomplete loss of function (n = 43), the surgical procedure was performed solely according to the microscopic aspect of the nerve and independently from the result of the intraoperative electrophysiological testing. Results Of 43 nerves with incomplete loss of function, we were able to record reproducible NAPs in 41 (95%) across the lesion site, thus demonstrating a high reliability of the method. Of 33 nerves with complete loss of function, a reproducible NAP could be recorded only in 3. Assuming an axonotmetic lesion in regeneration, we did nothing else on the nerve with excellent clinical results (full recovery). Of the remaining nerves with no NAP, 24 showed a caliber shift of the nerve (in 20 cases a thickening of the nerve, suggesting a neuroma in continuity). A grafting procedure was performed, and the histological evaluation revealed a neurotmetic lesion. However, in six patients with no NAP, there was no clear caliber shift of the nerve. The epineurium was opened and an internal neurolysis performed showing fascicles in continuity. Three patients had good and three had partial (but useful) recovery. Conclusions In nerve lesions in continuity with complete loss of nerve function, intraoperative NAPs are able to detect axonotmetic lesions in regeneration. Thus, unnecessary further surgical procedures can be avoided. On the other end of the spectrum, no recordable NAP together with a caliber shift of the nerve (suggesting a neuroma in continuity) may facilitate the surgeon's decision for a grafting procedure without a time-consuming internal neurolysis. But there is also evidence from our data that not every nerve lesion in continuity without a NAP needs to be grafted.

Intra-operative direct root-SEPs combined with evoked muscle action potentials (EMAPs) from neck muscles are presented as helpful tools for evaluation of anterior and/or posterior spinal root avulsion from the spinal cord during surgical management of brachial plexus stretch injuries.

✓ Suprascapular nerve entrapment (SNE) in the suprascapular notch is a rare entity that must be considered in the differential diagnosis of radicular pain, as well as that of shoulder discomfort. Over a period of 10 years (1985–1995), the authors treated 28 cases of SNE in 27 patients by surgical decompression of the nerve. One patient underwent operation bilaterally within 5 years. Five patients presented with a history of trauma to the shoulder region. In three patients, a ganglion cyst was the origin of the nerve lesion. In 16 patients, the nerve problem was primarily related to athletic activities. Eight of these patients were professional volleyball players. In the remaining three patients, there was no relationship between the nerve lesion and trauma or athletic activities. Twenty-one patients (22 cases) complained of pain located over the suprascapular notch. Seventeen patients had paresis and atrophy of both the supraspinatus (SS) and infraspinatus (IS) muscles. In 10 patients only the IS muscle was involved. One patient exhibited a sensory deficit over the posterior portion of the shoulder. Electromyography was performed in all cases. The mean follow-up period in the 25 cases (24 patients) that could be evaluated was 20.8 months (range 3–70 months). Nineteen of 22 cases with preoperative pain could be evaluated. Sixteen of these patients were completely free of pain after surgery and three patients found their pain had improved. Motor function in the SS muscle improved in 86.7% and motor function in the IS muscle in 70.8% of cases. Atrophy of the SS muscle resolved in 80.7% and atrophy of the IS muscle in 50% of cases. Surgical treatment of SNE is indicated after failed conservative treatment and in cases of atrophy of the SS and IS muscles. The authors recommend the posterior approach, which minimizes risks and complications and produces good postoperative results.

High-resolution ultrasonography is a noninvasive, readily applicable imaging modality, capable of depicting real-time static and dynamic morphological information concerning the peripheral nerves and their surrounding tissues. Continuous progress in ultrasonographic technology results in highly improved spatial and contrast resolution. Therefore, nerve imaging is possible to a fascicular level, and most peripheral nerves can now be depicted along their entire anatomical course. An increasing number of publications have evaluated the role of high-resolution ultrasonography in peripheral nerve diseases, especially in peripheral nerve entrapment. Ultrasonography has been shown to be a precious complementary tool for assessing peripheral nerve lesions with respect to their exact location, course, continuity, and extent in traumatic nerve lesions, and for assessing nerve entrapment and tumors. In this article, the authors discuss the basic technical considerations for using ultrasoniography in peripheral nerve assessment, and some of the clinical applications are illustrated.

Schwannomas, tumors originating from Schwann cells, represent a frequent neurological tumor and can occur both in a genetic disorder called neurofibromatosis type 2 (NF2) and sporadically. In both cases the genetic background is identical as all schwannomas are caused by biallelic mutations in the tumor suppressor gene NF2 coding for merlin. Mutations in this gene have also been found to be responsible for 50% to 60% of spontaneous and 100% of the NF2 associated meningiomas. The NF2 gene product, merlin, links transmembrane proteins to the cytoskeleton and is involved in intracellular signaling processes. It has previously been shown that reexpression of wild-type merlin in primary human schwannoma cells leads to an increase in the number of apoptotic cells. Here, we report in vivo and in vitro evidence that the basal apoptosis rate of primary human schwannoma cells is reduced in comparison to that of normal Schwann cells, supporting the idea that in this benign tumor type, apoptosis has a role in tumorigenesis.