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Objective With the exponential growth of coronavirus 2019 (COVID-19) related literature, we aimed to identify and characterize the 100 most cited COVID-related articles in the field of neurology and neurosurgery. Methods In March 2021, we performed a title-specific search of the Scopus database using the terms (“neurology” or “neurologic” or “neurosurgery” or “neurosurgical”) and “COVID” as our search query term without date restrictions. The top 100 most cited English-language articles were obtained and reviewed. Results Our search yielded 9,648 articles published from December 2019 to March 2021. Bibliometric analysis of the top 100 articles found that (1) the most cited article had a citation count of 1741 and was the first to report on the detailed neurologic manifestations of the disease; (2) Neurology had the most number of publications; (3) the majority of the primary authors were neurologists, but 35% came from non-neuroscience specialties; (4) the United States of America, Italy, United Kingdom, China, and Germany were the top contributors, with a combined total of 77%; (5) most of the publications were correspondence or editorial articles; and (6) most articles discussed the neurologic manifestations and complications of patients with COVID-19. Conclusions This study has identified the top 100 most cited neurologic or neurosurgical COVID-19-related articles published to date. This list can be used to identify high impact studies that will help healthcare practitioners in clinical decision making and researchers in navigating key areas of study and guiding future research.

Background The coexistence of intracranial arteriovenous malformation (AVM) and meningioma in a single patient is seldom reported, so the clinical profile, optimal management, and outcomes of these patients are mostly unknown. Methods We performed a systematic review of the SCOPUS and PubMed databases for case reports and case series on patients with both intracranial AVMs and meningiomas. Data on demographics, clinical characteristics, surgical management, and outcomes were collected. Results A total of 18 cases were reported in the literature, including the present case. The mean age at presentation was 54 years (range of 15–70 years), with no gender predilection. Most of the meningiomas and AVMs were frontal in location, and more than half of the lesions were contiguous. The most common presenting symptoms were seizures (67%), headache (44%), and weakness (33%). Majority of the patients underwent single stage meningioma and AVM excision (44%), followed by staged meningioma excision then AVM excision (17%) and meningioma excision only (17%). In all, 94% (17/18) of the meningiomas were excised compared to 72% (13/18) of the AVMs. Outcomes were reported in 15 patients; 80% were favorable, but there were 2 deaths and 1 tumor recurrence after 5 years. Conclusion The coexistence of an intracranial AVM with a meningioma is recognized but rarely reported in the literature. Individualized treatment should be employed in managing patients with concurrent lesions, and outcomes are generally favorable due to the benign nature of both these entities.

Objective Hydranencephaly is a congenital central nervous system disorder characterized by the complete or near-complete absence of the cerebral cortex and basal ganglia. Because of its rarity, data on the clinical features and survivorship remain sparse. We aim to determine the clinical features and survivorship of a cohort of patients with hydranencephaly. Methods We performed a retrospective cohort study of all patients diagnosed with hydranencephaly at our institution from 2008 to 2018. Data on demographics, clinical features, presence of comorbidities, surgical operations performed, and status on last follow-up were collected. Survival curves were generated using Kaplan-Meier analysis. Results Fifty patients were included in the cohort, who had a median age at diagnosis of 4 months and a female predilection. The most common clinical manifestations were macrocephaly (92%) and seizures or myoclonic movements. Infection was present in 36% of cases, endocrinopathies in 22%, dysmorphisms in 20%, and cardiac disease in 8%. Twenty patients underwent shunt insertion, with half developing a postoperative complication at a mean follow-up of 14.9 months. The median survival of the cohort was not reached at 7.5 years. Among the patients with follow-up, characteristics were similar between the surgical and nonsurgical groups, except for the greater incidence of infections in the nonsurgical group. The survival curves among the groups were significantly different, with a hazard ratio of 3.731 in the nonsurgical group. Conclusions In this large single-center retrospective cohort of patients with hydranencephaly, novel findings are presented regarding the clinical manifestations and survivorship of this condition.

Objective Chondroblastoma is an uncommon benign neoplasm of cartilaginous origin usually involving the long bones. The temporal bone is a rare location for this tumor. The clinical profile, optimal medical and surgical management, and outcomes of treatment for temporal bone chondroblastoma remain unknown. Methods We performed a systematic review of the SCOPUS, PubMed, and CENTRAL databases for case reports and case series on patients with histopathologically proven temporal bone chondroblastoma. Data on demographics, clinical manifestation, surgical management, adjuvant treatment, and outcome on last follow-up were collected. Results A total of 100 cases were reported in the literature, including one described in the current study. The mean age of patients was 42.3 years (range, 2–85 years), with a slight male predilection (1.3:1). The most common clinical manifestations were otologic symptoms (e.g., hearing loss [65%], tinnitus, and otalgia) and a palpable mass. Surgical excision was performed in all cases, with gross total excision achieved in 58%. Radiation therapy was performed in 18% of cases, mostly as adjuvant treatment after subtotal excision. There were no deaths at a median follow-up of 2 years. Among the patients with detailed status on follow-up, 58% had complete neurologic recovery, 38% had partial recovery, and 4% had progression of symptoms as a result of tumor recurrence. Conclusions Temporal bone chondroblastoma has a distinct clinical profile from chondroblastoma of long bones. Surgery is the mainstay of treatment, and radiation therapy may be given after subtotal excision. Outcomes are generally favorable after treatment.

Background Determining the cost of hospitalization for acute stroke is important in the appropriate allocation of resources for public health facilities and in the cost effectiveness analysis of interventions. Despite being the second leading cause of mortality in the Philippines, there are no published data on the cost of stroke in the country. Aim The study aims to determine the in-hospitalization cost for stroke (IHCS) in a tertiary public hospital in the Philippines and identify the factors influencing IHCS. Methods The study was a retrospective review of the medical and billing records of the hospital. Adult patients admitted for acute stroke between 1 June 2017 and 31 May 2018 were included in the analysis. After the mean cost of stroke was determined, multivariate logistic regression analysis was done to determine demographic and clinical characteristics that were predictive of stroke cost. Results A total of 863 patient records were analyzed. The median in-hospitalization cost for stroke was PHP 17,141.50 or US$329.52. Independent determinants of higher cost include male sex (p = 0.021), stroke type (hemorrhagic stroke, p = 0.001; subarachnoid hemorrhage, p Conclusion The study provided current data on the in-hospitalization cost of acute stroke in a public tertiary hospital in the Philippines. Male sex, stroke type, lower GCS on admission, surgical intervention, intravenous thrombolysis, infection, length of hospital stay, and mechanical ventilation were independent predictors of cost.

Background: Cough is one of the most common symptoms of coronavirus disease 2019 (COVID-19) infection. This relatively benign symptom may lead to serious sequelae, especially in postoperative neurosurgical patients. Case Description: Here, we report a case of bone flap displacement, pseudomeningocele formation, and consequent cerebrospinal fluid leak in a patient with COVID-19 infection who recently underwent craniotomy for excision of cerebral metastasis. We highlight the pathophysiologic mechanisms of cough that may cause increased intracranial pressure (ICP), leading to the postoperative morbidity. Conclusion: Aside from additional risks to the patient’s health and increased treatment costs, these complications also lead to subsequent delays in the management of the underlying disease. Symptomatic treatment of cough is advised to prevent complications resulting from increased ICP.

Background Despite multimodality treatment, the prognosis of glioblastoma (GBM) has remained poor. Intraoperative radiation therapy (IORT) offers additional local control by directly applying a radiation source to the resection margin, where most recurrences occur. Methods We performed a systematic review on the oncologic outcomes and toxicities of IORT for GBM in the era of modern external beam radiation therapy (EBRT) and chemotherapy with temozolamide. Results Four studies representing 123 patients were included. Majority (81%) were newly diagnosed, and gross total resection was reported in 13–80% of cases. IORT modalities included electrons from a linear accelerator (LINAC) and photons from a 50-kV x-ray device. Median doses were from 12.5 to 20 Gy for electron-based studies and 10–25 Gy for photon-based studies. Adjuvant treatment consisted of 46–60 Gy post-operative EBRT in electron-based studies and the Stupp protocol in photon-based studies. Complications included radiation necrosis (2.8–33%), infection, hematoma, perilesional edema, and wound dehiscence. Median time to local recurrence was 9.9–16 months and the reported overall progression-free survival was 11.2–12.2 months. Median overall survival was 13–14.2 months for the electron-based studies and 13.8–18 months for the photon-based studies. Conclusion IORT resulted in improved local control and comparable overall survival rates with the Stupp protocol. Although photon-based IORT had better results than electron IORT, this may be due to improvements in other forms of adjuvant treatment rather than the IORT modality itself. The overall effect of IORT on GBM treatment is still inconclusive due to the small number of patients and heterogeneous reporting of data.

Background: Decompressive hemicraniectomy (DH) has been performed for some cases of acute ischemic stroke in patients with coronavirus disease 2019 (COVID-19) infection, but there is little information about the clinical course and outcomes of these patients. Case Description: We report a case of a 36-year-old woman with COVID-19 infection who developed stroke like symptoms while under home quarantine. Cranial CT scan showed an acute left internal carotid artery (ICA) infarct. She subsequently underwent an emergent left DH. Despite timely surgical intervention, she succumbed to chronic respiratory failure. A systematic review of SCOPUS and PubMed databases for case reports and case series of patients with COVID-19 infection who similarly underwent a DH for an acute ischemic infarct was performed. There were eight other reported cases in the literature. The patients’ age ranged from 33 to 70 years (mean 48), with a female predilection (2:1). Respiratory preceded neurologic symptoms in 83% of cases. The ICA was the one most commonly involved in the stroke, and the mean NIHSS score was 20. DH was performed at a mean of 1.8 days post-ictus. Only four out of the nine patients were reported alive at the time of writing. The most common cause of death was respiratory failure (60%). Conclusion: Clinicians have to be cognizant of the neurovascular complications that may occur during the course of a patient with COVID-19. DH for acute ischemic stroke associated with the said infection was reported in nine patients, but the outcomes were generally poor despite early surgical intervention.

Background The busy and demanding work schedule of neurosurgeons suggests that they might have type A behavior patterns (TABPs). TABPs are also associated with multiple diseases; hence, their early identification could lead to behavioral changes and disease prevention. We aimed to determine the presence of TABPs among neurosurgeons and trainees in the Philippines and the association between demographic and clinical factors and TABPs. Methods An online survey was sent to neurosurgeons and neurosurgical trainees in the Philippines. Data on age, sex, comorbid conditions, smoking, alcohol use, training institution, level of residency training, and place of practice were obtained. The modified Bortner scale was used to determine TABPs. Univariate and multiple regression analyses were used for analysis. Results A total of 102 individuals (41 neurosurgeons and 61 trainees) completed the survey. Most of the respondents were men (74%), with a mean age of 36 years. The Bortner scores were normally distributed. TABPs were significantly associated with female sex (P = 0.0006) in the entire cohort. However, the trainee cohort also exhibited a significant association between TABPs and training in a public institution (P = 0.0027). Conclusion The presence of TABPs followed a normal distribution among neurosurgeons and neurosurgical trainees in the Philippines. A significant association was found between TABPs and female sex for both neurosurgeons and trainees, and training in a public institution was significantly associated with TABPs only among the trainees.

Background There is geographic variability in the clinical profile and outcomes of non-traumatic intracerebral hematoma (ICH) in the young, and data for the Philippines is lacking. We aimed to describe this in a cohort from the Philippines, and identify predictors of mortality. Methods We performed a retrospective study of all patients aged 19–49 years with radiographic evidence of non-traumatic ICH admitted in our institution over five years. Data on demographics, risk factors, imaging, etiologies, surgical management, in-hospital mortality, and discharge functional outcomes were collected. Multivariate logistic regression analysis was done to determine factors predictive of mortality. Results A total of 185 patients were included, which had a mean age of 40.98 years and a male predilection (71.9%). The most common hematoma location was subcortical, but it was lobar for the subgroup of patients aged 19-29 years. Overall, the most common etiology was hypertension (73.0%), especially in patients aged 40-49. Conversely, the incidence of vascular lesions and thrombocytopenia was higher in patients aged 19-29. Surgery was done in 7.0% of patients. The rates of mortality and favorable functional outcome at discharge were 8.7% and 35.1%, respectively. Younger age (p = 0.004), higher NIHSS score on admission (p=0.01), higher capillary blood glucose on admission (p=0.02), and intraventricular extension of hematoma (p = 0.01) predicted mortality. Conclusions In the Philippines, the most common etiology of ICH in young patients was hypertension, while aneurysms and AVM's were the most common etiology in the subgroup aged 19 – 29 years. Independent predictors of mortality were identified.

Background Tuberculomas affecting the peripheral nerve are exceedingly rare. As such, little has been reported about their clinical features, treatment, and outcomes. Methods We report the case of a 10-year-old male patient with histopathologically proven tuberculoma presenting preoperatively as a peripheral nerve tumor. We also performed a systematic review of the SCOPUS and PubMed databases for case reports and case series documenting patients with histopathologically confirmed peripheral nerve tuberculoma and discussed clinical features and treatment outcomes. Results A total of 7 cases of peripheral nerve tuberculomas were reported in the literature, including the current case. The mean age was 21.4 years with no sex predilection. The ulnar nerve was involved in all cases. The most common clinical manifestations were hand weakness, atrophy, ulnar clawing, and hypoesthesia. The classic histopathologic features of caseous necrosis, epithelioid granulomas, and Langhans giant cells were seen in all cases, while staining for acid fast bacilli was positive in only one case. All patients underwent nerve exploration and lesion resection, and were given antitubercular treatment lasting between 3 and 18 months. Treatment resulted in complete recovery in 43% of cases and partial improvement of neurologic deficits in 57%. Conclusions Tuberculoma of the peripheral nerve is a rare manifestation of tuberculous disease, with a predilection for the ulnar nerve. Current management includes nerve exploration, lesion resection, and antitubercular treatment, which often results in good neurologic recovery.

BACKGROUND The Philippine General Hospital, a public national referral center, sees 60–80 pediatric brain tumor cases per year. Historically, the rate of post-operative ventriculitis has been high, resulting in treatment delays and poor outcomes. Starting in July 2019, as a means to decrease infections, patients were provided standardized bathing and wound care kits and caregivers were trained to follow a bathing and wound care protocol. METHODS This quality improvement study included patients younger than 18 years who underwent craniotomy at PGH were enrolled. The type of surgery, length of surgery, existence of post-operative CNS infection, length of stay and total cost of care was collected. The outcome of these interventions are analyzed 6 months after implementation. RESULTS Thirty-two 32 patients were included, with mean age of 7 years (1–16). The surgeries performed were: tumor resection (n=20), ventriculo-peritoneal shunt insertion (VPS) (n=3), endoscopic third ventriculostomy (n=3), resection with tube ventriculostomy (n=3), Ommaya reservoir placement (n=2), and resection with shunt (n=1). Median surgery time was 4 hours (1–10). Three patients (9.4%) developed ventriculitis. No surgical site infections occurred. Compared to historical controls, a lower rate of infections was noted (9.4% vs. 15.5%, runchart analysis). Patients without post-operative infections had a shorter length of stay (median 14 vs 48 days, p CONCLUSION Implementation of simple hygiene interventions effectively lowered post-operative CNS infections and hospital costs in a public hospital setting. Incorporation of these into standard clinical practices is urgently needed.

Background Neurosurgical trainees have a heavy workload and poor quality of life, resulting in high rates of burnout and attrition. Consequently, wellness programs have been used by various training institutions to combat this situation. Objective We aimed to identify and describe wellness programs available for neurosurgical trainees in their training institutions, the outcome measures used to assess them, and their efficacy. Methods A systematic review of the literature was made following PRISMA guidelines. Results Six studies were included in the review, describing wellness programs from 9 institutions. All programs except 1 used exercise as the core component. The other components included physical and mental well-being lectures, team-building activities, and cultural excursions. Most institutions used piloted satisfaction and perception questionnaires to assess efficacy. Trainee perceptions of wellness programs were generally positive, but the responses on validated questionnaires and surveys were mixed. Barriers to the program included lack of institutional support, time constraints, fatigue, and feelings of guilt in prioritizing wellness over patient care. Conclusions There is a paucity of literature regarding trainee wellness in neurosurgery. A few training programs have instituted wellness initiatives for trainees, and the feedback was generally positive. However, objective measures of efficacy such as validated questionnaires and scales yielded mixed results.

Objectives Intraventricular rupture of brain abscess (IVROBA) is one of the most dreaded complications of pyogenic brain abscess due to its high mortality rate. Because of its relative infrequency and poor outcome, the optimal management of this condition remains to be determined. Patients and Methods We report the case of a 5-year old female with a presumptive diagnosis of IVROBA who was discharged with good neurologic outcome after completing intravenous antibiotic treatment and undergoing insertion of an external ventricular drain (EVD) and later, a ventriculoperitoneal (VP) shunt. We also performed a systematic review of the SCOPUS and PubMed databases for case reports and series documenting patients who survived after undergoing treatment for IVROBA. Results A total of 24 cases of IVROBA survivors were reported in the literature, including the present case. The median age was 48.5 years (range: 5–71), with a male predilection (3:1). The most common location of the brain abscesses was temporal while the most common route of spread was hematogenous. Surgery was performed in 92% of cases, with EVD being the most common surgical procedure. Twenty nine percent of cases required a VP shunt. The duration of systemic antibiotic treatment ranged from 31 to 180 days (median: 56 days) while intraventricular antibiotics were given for 8–42 days (median: 14 days). Conclusion The management of IVROBA in this series varied widely, with surgery playing an important role. Although IVROBA is still a devastating complication of intracranial abscess, a good neurologic outcome may still be possible with treatment.

Hydranencephaly is a congenital condition characterized by the complete or near-complete absence of the cerebral cortex and basal ganglia, while central diabetes insipidus (CDI) is a condition characterized by the inability to concentrate urine due to a deficiency in antidiuretic hormone (ADH). CDI is known to occur in midline congenital malformations such as holoprosencephaly and septo-optic dysplasia, but its association with hydranencephaly is less well-established. We reported two cases of hydranencephaly complicated by CDI. We also performed a systematic review of the SCOPUS and PubMed databases for case reports and case series of patients with hydranencephaly and CDI, and compiled data on the clinical features and treatment options. Seven cases of hydranencephaly complicated by CDI were identified from the systematic review in addition to the two cases reported here, resulting in a total of nine cases. The patients’ age ranged from 4 days to 4 years, and there was a female sex predilection (3.5:1). Patients most commonly presented with macrocephaly, developmental delay, and seizures, with dysmorphic features noted in 33%. In addition to CDI, other endocrinologic derangements included hypothyroidism (22%), hypocortisolemia (22%), and panhypopituitarism (22%). CDI was treated using sublingual or oral desmopressin while hypopituitarism was treated with the appropriate hormone replacement therapy. Insertion of a ventriculoperitoneal (VP) shunt was reported in 44% of cases. The case reports and systematic review suggest a previously unknown association between hydranencephaly and CDI. Clinicians managing cases of hydranencephaly are advised to have a high index of suspicion for CDI in patients presenting with the characteristic signs and symptoms.

Pituitary abscess is a rare condition. It can present with hormonal deficiencies and may affect reproductive health. We present a case of a 43-year-old female presenting with bitemporal hemianopsia and amenorrhea. Imaging of the pituitary showed a sellar-suprasellar mass 2.6 x 2.4 x 1.8 cm with an enhancing nodular component. Pre-operative diagnosis was pituitary adenoma with panhypopituitarism and compression of the optic chiasm. The patient underwent transsphenoidal excision of the tumor. Intraoperative findings revealed purulent fluid consistent with pituitary abscess. There was immediate improvement of vision post operatively. She did not develop diabetes insipidus. Gram stain showed polymorphonuclear (PMN) cells 0-1 per oil immersion field (OIF) and Gram-positive cocci 0-1 per OFI, however there was no growth on culture. The abscess was also negative for acid-fast bacilli and was negative on polymerase chain reaction. Histopathologic evaluation showed benign cyst contents. The patient was treated with ceftriaxone 2 grams every 12 hours for 14 days and was eventually discharged with prednisone and levothyroxine. Pituitary abscess is an important differential diagnosis for sellar and suprasellar masses. There are no specific clinical and radiologic features that will enable a preoperative diagnosis of pituitary abscess.

Background Neurocutaneous melanosis is a rare phakomatosis characterized by large or multiple pigmented nevi and melanosis of the leptomeninges. It is often complicated by hydrocephalus due to melanotic deposits interfering with cerebrospinal fluid reabsorption in the basal cisterns or causing foraminal or aqueductal obstruction. In 10% of cases, it will be associated with the Dandy-Walker complex. Case Description We present the case of a 6-year-old girl with multiple congenital hairy nevi presenting with generalized tonic-clonic seizures, headache, and vomiting. Neuroimaging showed a communicating hydrocephalus associated with the Dandy-Walker variant, melanotic deposits in the amygdalae, thalami, and cortical sulci, and abnormal leptomeningeal enhancement. After undergoing ventriculoperitoneal shunt insertion, the symptoms of increased intracranial pressure abated. However, she again showed deterioration 1 month postoperatively due to progressive leptomeningeal spread suspicious for malignant degeneration. Conclusion The results of the present case and the findings from a review of related data suggest that shunt insertion (ventriculoperitoneal or cystoperitoneal) is an effective palliative measure for patients with neurocutaneous melanosis with associated hydrocephalus. Despite treatment, however, the prognosis of these patients remains poor owing to malignant progression and leptomeningeal spread of lesions, in particular, in cases associated with the Dandy-Walker complex.

Traumatic neuroma in continuity (NIC) results in profound neurological deficits, and its management poses the most challenging problem to peripheral nerve surgeons today. The absence of a clinically relevant experimental model continues to handicap our ability to investigate ways of better diagnosis and treatment for these disabling injuries. Various injury techniques were tested on Lewis rat sciatic nerves. Optimal experimental injuries that consistently resulted in NIC combined both intense focal compression and traction forces. Nerves were harvested at 0, 5, 13, 21, and 65 days for histological examination. Skilled locomotion and ground reaction force (GRF) analysis were performed up to 9 weeks on the experimental (n=6) and crush-control injuries (n=5). Focal widening, disruption of endoneurium and perineurium with aberrant intra- and extrafascicular axonal regeneration and progressive fibrosis was consistently demonstrated in 14 of 14 nerves with refined experimental injuries. At 8 weeks, experimental animals displayed a significantly greater slip ratio in both skilled locomotor assessments, compared to nerve crush animals (p

Background Autologous nerve grafts remain the only proven means of bridging lengthy gaps in peripheral nerve. However, there is very little literature on a reliable long (> 5 cm) nerve autograft animal model. Objective To establish a reproducible long nerve gap and autograft animal model that is clinically relevant but not cost prohibitive. Methods The extent of nerve regeneration and electrophysiological recovery after segmental repair of a long nerve defect was evaluated with a sheep model. Thirteen Suffolk sheep were used. An 18-cm segment of radial sensory nerve was harvested from the forelimb, trimmed, divided into 2 equal segments of 7 cm each, and microsurgically repaired to a surgically created defect of 5 cm in the median nerve within the same forelimb. Electrophysiological studies were performed on 6 sheep at 6 months and 6 sheep at 9 months. Samples of the grafted segments were obtained for histology, immunohistochemistry, and morphometric analyses. Electric studies were also performed on an uninjured median nerve of a control animal in tissue that was similarly harvested and processed. Results At 6 and 9 months, all sheep had recordable robust nerve action potentials. Nerve conduction velocity and amplitude were slightly decreased compared with control, but the difference was statistically insignificant. Histomorphometric assessment demonstrated that the autografts contained a large number of regenerating axons through graft fascicles in all animals. Conclusion The median nerve in the sheep forelimb is a reproducible and reliable model for assessing regeneration through long peripheral nerve grafts.

Surgery for parasagittal and falcine meningiomas requires meticulous preservation of the cortical veins that surround the tumour; thus, knowledge of the relevant venous anatomy would be extremely helpful during surgery. This study utilises virtual reality technology to determine the number, size and disposition of the veins in relation to the tumour in 8 patients with parasagittal and falcine meningiomas. The same data were also collected from the scans of 8 normal subjects and compared with the data from the meningioma patients. Our results show that the average number of veins is comparable in the tumour and control groups, and that the number of veins on either side does not differ significantly for both groups. On measurement, the size of the veins is approximately the same on either side of the superior sagittal sinus for both the control and the tumour groups. It was also observed that regardless of size, most of the parasagittal and falcine meningiomas demonstrated no significant anatomical distortion effects on the adjacent venous structures, with the exception of one parasagittal meningioma with invasion of the superior sagittal sinus and concomitant engulfment of the draining veins. Data from a larger population would have to be collected in order to determine the effect of the growth of these tumours on the surrounding venous anatomy. With virtual reality technology, the parasagittal veins are clearly discerned, and knowing their location and relationship to the tumour would contribute towards safe and effective surgery.

OBJECTIVE Benign extracerebral lesions such as meningiomas may cause hemiparesis by compression and deviation without infiltrating the white matter. We used magnetic resonance diffusion tensor imaging and diffusion tensor tractography to investigate the effects of benign extracerebral lesions on the corticospinal tract (CST). METHODS Thirteen patients with extracerebral lesions (11 benign meningiomas and 2 benign cysts) underwent magnetic resonance diffusion tensor imaging and diffusion tensor tractography of the CST using fiber assignment by continuous tractography. The CST was reconstructed and assessed by comparing the ipsilateral and unaffected contralateral fibers. The tumor volume, relative fractional anisotropy, fiber deviation, relative fiber number, and relative fiber per voxel were compared between patients without and with temporary presurgical hemiparesis. RESULTS Seven patients without hemiparesis and five patients with temporary hemiparesis were analyzed; one patient had permanent weakness and was excluded from analysis. There was no significant difference in the tumor volume, relative fractional anisotropy, presence of cerebral edema, or CST deviation between groups. In patients with temporary hemiparesis, the median relative fiber number (mean, 0.35 +/- 0.32) and relative fiber per voxel (mean, 0.49 +/- 0.14) were significantly reduced compared with patients without hemiparesis (0.92 +/- 0.55, P = 0.04; and 0.96 +/- 0.28, P < 0.01, respectively). CONCLUSION In patients with benign extracerebral lesions, reduction in fiber number and fiber per voxel, but not fiber deviation, correlated with temporary hemiparesis. Clinical recovery was possible even if the CST fibers detected by diffusion tensor tractography were reduced by benign extracerebral lesions.

Gliomas are intrinsic brain tumours that are frequently associated with cerebral oedema. As such, keyhole approaches may not be appropriate because if the craniotomy is small, intraoperative cerebral oedema may occur, resulting in cortical compression at the bone edge. This would lead to further neurological deficit, especially if the swollen brain is located in eloquent areas. In awake craniotomy, worsening of such a deficit would mandate premature cessation of surgery and lead to a less than ideal extent of resection. Two such cases of intraoperative brain swelling are described to illustrate this point. The authors suggest doing a larger craniotomy for glioma patients undergoing awake surgery to prevent compression of normal brain at the craniotomy edge and to allow for a more complete resection by providing access to the tumour even if intraoperative swelling does occur.

A 22-year-old man presented with a one year history of rightsided shoulder pain, hand weakness and tingling, and purplish discoloration of the upper extremity upon abduction. He had congenital pseudarthrosis of the right clavicle since childhood. Aside from an obvious deformity characterized by asymmetry of the shoulders and a palpable bony depression over the right clavicle, the patient had been previously asymptomatic. Physical examination revealed the musculoskeletal deformities as described, as well as prominent veins over his right shoulder, arm, and chest. With arm elevation, his right arm became dusky and his radial pulse diminished. Neurologically, the patient had no deficits except for mild weakness (Grade 4+/5) of the ulnarinnervated intrinsic muscles of the right hand. The clinical findings were consistent with a combined neurogenic and vascular form of thoracic outlet syndrome.

A m t r p t t p i S imilar to other tissues in the body, the brachial plexus and other peripheral nerves are also at risk for iatrogenic injury. There are few data in the literature regarding the prevaence of iatrogenic injury in peripheral nerves, but these injuries o occur and are almost always clinically symptomatic. Iatrogenic actors accounted for 11.2% of all peripheral nerve injuries in a arge series, with the sciatic nerve most commonly affected and ntramuscular injection the most common etiology (3). In a ubgroup analysis, iatrogenic lesions of the brachial plexus ccounted for 0.4% of all nerve injuries or 6.6% of all brachial lexus lesions (3). In another series dealing exclusively with rachial plexus injuries, 9% of cases were due to operative or atrogenic trauma (2). The prevalence of iatrogenic nerve injuries anged from 15%–17.4% in other studies (1, 4), but the number f brachial plexus injuries was not specified. The brachial plexus as not in the list of the top three nerves injured by iatrogenic eans, however (1, 4). As for the literature on brachial plexus njury secondary to thoracic endoscopic surgery, Skoro et al. have lready reviewed this in their article.