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Osteoporotic vertebral compression fractures (OVCF) are common in elderly patients and may cause local kyphosis due to the vertebral collapse and wedging. Balloon kyphoplasty (BKP) with polymethyl methacrylate is widely used to relieve back pain and restore the height and kyphosis of the destroyed vertebra Johnell (Osteoporos Int 17(12):1726-33, 2006); Wasnich (Bone 18: 179S-183S, 1996); Finnern (Osteoporos Int 14:429-436, 2003). However, the influence of BKP on global sagittal alignment (GSA) in patients with OVCF remains unclear.To systematically evaluate the relevant literature regarding the influence of BKP on the global spinal sagittal alignment using the following radiological parameters: Pelvic Incidence (PI), Pelvic Tilt (PT), Lumbar Lordosis (LL), Thoracic Kyphosis (TK), Sagittal Vertical Axis (SVA) and Spinosacral Angle (SSA). Visual Analogue Score (VAS) was also recorded.A systematic review of the English language literature dating up until August 2022, was undertaken utilising the PRISMA guidelines.Of a total of 548 articles, 4 studies met the inclusion criteria (4 level III evidence) and were analyzed. Overall, 201 patients of mean age 73.8 years (69-77) had acute OVCF of one or more vertebra. The male to female ratio was 51:128. The number of fractured vertebrae was 235 (average of 1.17 fractured vertebrae per patient). Their pre-operative radiological parameters on standing x-rays showed a mean PI of 56°, PT 24.1°, LL 44.4°, TK 42.3°, PI-LL 11.7°, SVA 4.9 cm, LL/TK 1 and SSA 114.8°. The average VAS was 7.6 (2.6-10). All the patients underwent BKP and their radiological parameters on standing x-rays post operatively showed a mean PI of 55.3°, PT 23.1°, LL 45.1°, TK 41.4°, PI-LL 10.3°, SVA 4.29 cm, LL/TK 1.07 and SSA 116.8°. Their average VAS post BPK was 2.36 (0-4.8).A statistical analysis comparing the pre/post-operative GSA (111 patients, 3 studies with standard deviations) showed no statistical difference in PT (24.1° vs. 23.5°, P = 0.93), TK (42.3° vs. 42.4°, P = 0.57), PI-LL (14.4° vs.12.4°, P = 0.4), SVA (6.1 cm vs. 5.5 cm, P = 0.19) SSA (114.8° vs. 116.7° P = 0.36). VAS was significantly reduced post BKP (7.1 vs. 2.5 P = 0.004).Performing BKP procedures does not significantly affect the global sagittal alignment in patients with osteoporotic vertebral compression fractures. There was however, a significant improvement in pain scores in patients undergoing BKP at 1 or more levels.

The anterior petrosectomy, also known as the Kawase approach, and the retrosigmoid intradural suprameatal approach (RISA) have both been used to reduce the petrous apex and access the petroclival region. Our goal was to compare the volumes and 3-dimensional shapes of bony resection obtained through each approach while trying to resemble realistic surgical settings.Five cadaveric specimens totaling 10 sides were dissected and analyzed. In every specimen, 1 side was used for the Kawase approach while the opposite side was used for the RISA. Petrosectomy volumes were assessed by comparing preoperative and postoperative thin-sliced computed tomography scans.Petrosectomy volumes were significantly larger through the Kawase approach than through the RISA (0.82 ± 0.11 vs. 0.49 ± 0.07 cmThe Kawase approach invariably results in larger volumes of bony removal than the RISA operative variant, and the volume of petrosectomy that is spatially congruent is only partially identical. The Kawase corridor is best suited for middle fossa lesions that extend into the posterior fossa, while the RISA is suitable for pathologies mainly residing in the posterior fossa and extending into the Meckel cave.

Background High-grade glioma (HGG) patients present with variable impairment in neurocognitive function (NCF). Based on that, isocitrate dehydrogenase 1 (IDH1) wild-type HGGs are more aggressive than IDH1 mutant-type ones, we hypothesized that patients with IDH1 wild-type HGG would exhibit more severe NCF deficits than their IDH1 mutant counterparts. Methods NCF was assessed by Mini Mental Status Exam (MMSE), Trail Making Test (TMT), Digit Span (DS), and Controlled Word Association Test (COWAT) tests in 147 HGG patients preoperatively. Results Analyses between IDH1 groups revealed a significant difference on MMSE concentration component (p ≤ .01), DS (p ≤ .01), TMTB (p ≤ .01), and COWAT (p ≤ .01) scores, with the IDH1 wild group performing worse than the IDH1 mutant one. Age and tumor volume were inversely correlated with MMSE concentration component (r = −4.78, p < .01), and with MMSE concentration (r = −.401, p < .01), TMTB (r = −.328, p < .01), and COWAT phonemic scores (r = −.599, p < .01), respectively, but only for the IDH1 wild-type group. Analyses between age-matched subsamples of IDH1 groups revealed no age effect on NCF. Tumor grade showed nonsignificance on NCF (p > .05) between the 2 IDH1 mutation subgroups of grade IV tumor patients. On the contrary, grade III group showed a significant difference in TMTB (p < .01) and DS backwards (p < .01) between IDH1 subgroups, with the mutant one outperforming the IDH1 wild one. Conclusions Our findings indicate that IDH1 wild-type HGG patients present greater NCF impairment, in executive functions particularly, compared to IDH1 mutant ones, suggesting that tumor growth kinetics may play a more profound role than other tumor and demographic parameters in clinical NCF of HGG patients.

Despite the heterogeneity of chronic lower back pain aetiologies, cluneal nerve entrapment remains underdiagnosed and poorly understood with few studies discussing the efficacy of its surgical release.The current study opts to conduct a systematic review reporting on the efficacy of cluneal nerve surgical decompression in patients with an established diagnosis who fail conservative treatment. We aimed to systematically evaluate the literature regarding the clinical outcomes, recurrence of symptoms and revision rates of surgical intervention.A systematic review of the English language literature dating up until May 2022 was undertaken according to the PRISMA guidelines. Isolated case reports were excluded.Of a total of 54 articles, 4 studies met the inclusion criteria (three were level IV evidence and one level III evidence) and were analyzed. Overall, 98 patients of mean age 61 years, (range 17-86) underwent cluneal nerve release with a mean follow-up of 25.5 months (6-58 months). There was significant improvement in symptoms post operatively in the 4 studies. No systemic or local complications were encountered during the surgeries. Four articles reported on revision surgery for recurrent symptoms in 8 patients out of 98 with a rate of 8.2%. Of the reoperated patients, 7/8 had new branches released that were not addressed initially and 1 had neurectomy for an adhered pre-released branch.This systematic review demonstrated that cluneal nerve decompression has been performed in a total of 98 patients with significant clinical improvement, zero systemic and local complications and revision rates of 8.2% of the cases.

Purpose The DRAF III procedure has been used for access to the lateralmost part of the frontal sinus. We sought to identify anatomical and radiological measurements as well as modifications that predict the lateral limits of visualization and surgical access after this procedure. Methods Seven cadaver heads were imaged with computed tomography scan. The distance from midline to the medial orbital wall (MOWD), midline to the lateral end of the frontal sinus (MLD), the sum of MLDs (SMLD), interorbital distance (IOD) and the shortest anteroposterior distance of the frontal recess (APD) were utilized. The ratios MLD/MOWD, and SMLD/IOD were calculated. The same distances were measured on 41 CT scans. Orbital transposition (OT) and partial resection of the piriform aperture (PAR) were performed; the visualization and reach were assessed. The angle of insertion was measured before and after the modifications. Results Only the ratio MLD/MOWD was consistently predictive of access to the lateral, superior and posterior wall of the frontal sinus. Following the modifications, a visualization of 100% laterally was achieved with the 30- and 45 degree endoscopes and every lateral recess could be reached with the 70 degree suction. A mean increase of the angle of insertion of 25.3 and 59.6% was recorded after OT and PAR, respectively. Conclusions IOD rather than APD defines the limits of the Draf III approach to the lateral frontal sinus and MLD/MOWD ratio can serve as a useful preoperative tool. Along to the already described OT, PAR increases visualization and reach of the lateral frontal sinus.

Background Aim of the present study is to investigate whether preoperative neurocognitive status is prognostically associated with overall survival (OS) in newly diagnosed glioblastoma (GBM) patients. Methods Ninety patients with dominant-hemisphere IDH-wildtype GBM were assessed by Mini Mental Status Exam (MMSE), Trail Making Test (TMT) A and B parts and Control Word Association Test (COWAT) phonemic and semantic subtests. Demographics, Karnofsky Performance Scale (KPS), tumor parameters, type of surgery and adjuvant therapy data were available for patients. Results According to Cox proportional hazards model the neurocognitive variables of TMT B (p Conclusions Our study demonstrates that neurocognitive status at baseline -prior to treatment- is an independent prognostic factor for OS in wildtype GBM patients, adding another prognostic tool to assist physicians in selecting the best treatment plan.

Neuro-imaging studies demonstrate simultaneous activation of the human precuneus and temporal pole, both in resting-state conditions and during a diverse array of higher-order functions. Despite remarkable advances in neuroscience research, the precise underlying structural connectivity remains unclear. Here, we investigate the connectivity of the precuneus and temporal pole through fiber micro-dissections in human hemispheres. We show the direct axonal connectivity between the posterior precuneus area POS2 and the areas 35 and TI of the temporal pole via the fifth subcomponent of the cingulum. This finding enhances the neuroanatomical knowledge regarding the connectivity of the posteromedial cortices, facilitates the detailed anatomo-functional integration in normal and pathological brain function, and suggests an axonal connectivity unique within the human brain supporting the differences in neural networks between species.

Visuospatial neglect possesses significant heterogeneity in clinical features and neuroanatomical substrates. Behavioral dissociations on different neglect tasks have been reported in the past, and the investigation of their respective anatomical correlates at cortical and, to a lesser degree, subcortical levels has been attempted in stroke studies. We report a patient with a neoplasm occupying the right ventral post-central gyrus and anterior supramarginal gyrus. The patient was admitted preoperatively with dissociation on the performance of neglect tasks, showing clinical deficits in the line bisection task and clock drawing, but not on the cancelation task. The patient underwent an awake craniotomy for tumor excision. Intraoperative visuospatial mapping was employed by applying direct electrical stimulation (DES) to the supramarginal gyrus and the ventral branch of the superior longitudinal fasciculus (SLF III) during the line bisection task. According to our findings, DES was ineffective at the cortical level, but it induced strong rightward bias when applied subcortically at the SLF III. By combining our preoperative and intraoperative anatomical and clinical data, we suggest that the posterior part of the SLF III might have a distinct role in the perceptual component of neglect. Our findings are discussed within the context of previous literature supporting the notion that particular behavioral features of spatial neglect are mediated by different white-matter connections.

This study opts to investigate the thus far ill-defined intra-hemispheric topography, morphology, and connectivity of the extrapyramidal fibers that originate from the frontoparietal cortex and project to the tegmental area and to explore structural correlations to the pyramidal pathway. To this end, twenty normal adult, formalin-fixed cerebral hemispheres were studied through the fiber micro-dissection technique. Stepwise and in-tandem medial to lateral and lateral to medial dissections were carried out in all specimens. The cortical termination of the fibers under investigation was carefully defined, and their entry zone at the tegmental area was meticulously recorded. We consistently identified the corticotegmental tract (CTT) as a distinct fiber pathway lying in the white matter of the genu and posterior limb of the internal capsule and travelling medial to the corticospinal tract (CST) and lateral to the thalamic radiations. The CTT exhibits a fan-shaped configuration and can be classified into three discrete segments: a rostral one receiving fibers from BA8 (pre-SMA, frontal eye fields, dorsal prefrontal cortex), a middle one arising from areas BA4 and BA6 (primary motor cortex and premotor cortex), and a caudal one stemming from areas BA1/2/3 (somatosensory cortex). The anatomical location, configuration, trajectory, and axonal connectivity of this tract are attuned to the descending component of the extrapyramidal system, and therefore, it is believed to be implicated in locomotion, postural control, motor inhibition, and motor modification. Our results provide further support on the emerging concept of a dynamic, parallel, and delocalized theory for complex human motor behavior.

Meningioma is one of the most frequent primary central nervous system tumors. While magnetic resonance imaging (MRI), is the standard radiologic technique for provisional diagnosis and surveillance of meningioma, it nevertheless lacks the prima facie capacity in determining meningioma biological aggressiveness, growth, and recurrence potential. An increasing body of evidence highlights the potential of machine learning and radiomics in improving the consistency and productivity and in providing novel diagnostic, treatment, and prognostic modalities in neuroncology imaging. The aim of the present article is to review the evolution and progress of approaches utilizing machine learning in meningioma MRI-based sementation, diagnosis, grading, and prognosis. We provide a historical perspective on original research on meningioma spanning over two decades and highlight recent studies indicating the feasibility of pertinent approaches, including deep learning in addressing several clinically challenging aspects. We indicate the limitations of previous research designs and resources and propose future directions by highlighting areas of research that remain largely unexplored. LEVEL OF EVIDENCE: 5 TECHNICAL EFFICACY STAGE: 2.

Idiopathic intracranial hypertension denotes raised intracranial pressure in the absence of an identifiable cause and presents with symptoms relating to elevated ICP, namely headaches and visual deterioration. Treatment of IIH aims at reducing intracranial pressure, relieving headache and salvaging patients' vision. Surgical interventions are recommended for medically refractory IIH and include CSF diversion techniques, optic nerve sheath fenestration, bariatric surgery and venous sinus stenting. Prospective studies on the surgical options for IIH are scant and no evidence-based guidelines for the surgical management of medically refractory IIH have been established. A search in Cochrane Library, MEDLINE and EMBASE from 1 January 1985 to 19 April 2019 for controlled or observational studies on the surgical treatment of IIH (defined in accordance with the modified Dandy or the modified Friedman criteria) in adults yielded 109 admissible studies. VSS improved papilledema, visual fields and headaches in 87.1%, 72.7% and 72.1% of the patients respectively, with a 2.3% severe complication rate and 11.3% failure rate. CSF diversion techniques diminished papilledema, visual field deterioration and headaches in 78.9%, 66.8% and 69.8% of the cases and are associated with a 9.4 severe complication rate and a 43.4% failure rate. ONSF ameliorated papilledema, visual field defects and headaches in 90.5, 65.2% and 49.3% of patients. Severe complication rate was 2.2% and failure rate was 9.4%. This is currently the largest systematic review for the available operative modalities for IIH. VSS provided the best results in headache resolution and visual outcomes, with low failure rates and a very favourable complication profile. In light of this, VSS ought to be regarded as the first-line surgical modality for the treatment of medically refractory IIH.

OBJECTIVEThe aim of this study was to investigate the anatomical consistency, morphology, axonal connectivity, and correlative topography of the dorsal component of the superior longitudinal fasciculus (SLF-I) since the current literature is limited and ambiguous.METHODSFifteen normal, adult, formalin-fixed cerebral hemispheres were studied through a medial to lateral fiber microdissection technique. In 5 specimens, the authors performed stepwise focused dissections of the lateral cerebral aspect to delineate the correlative anatomy between the SLF-I and the other two SLF subcomponents, namely the SLF-II and SLF-III.RESULTSThe SLF-I was readily identified as a distinct fiber tract running within the cingulate or paracingulate gyrus and connecting the anterior cingulate cortex, the medial aspect of the superior frontal gyrus, the pre–supplementary motor area (pre-SMA), the SMA proper, the paracentral lobule, and the precuneus. With regard to the morphology of the SLF-I, two discrete segments were consistently recorded: an anterior and a posterior segment. A clear cleavage plane could be developed between the SLF-I and the cingulum, thus proving their structural integrity. Interestingly, no anatomical connection was revealed between the SLF-I and the SLF-II/SLF-III complex.CONCLUSIONSStudy results provide novel and robust anatomical evidence on the topography, morphology, and subcortical architecture of the SLF-I. This fiber tract was consistently recorded as a distinct anatomical entity of the medial cerebral aspect, participating in the axonal connectivity of high-order paralimbic areas.

Three-dimensional relationships within the limbic and paralimbic areas are often hard to grasp. Relevant anatomical structures exhibit a complicated architecture and connectivity and therefore surgical approaches targeting lesions or functional resections in this area pose a distinct challenge.To provide an educational, comprehensive, systematic and stepwise manual for the dissection and illustration of major limbic structures since there is a gap in the pertinent literature. Further, we aim to offer a thorough yet simplified roadmap for laboratory and intraoperative dissections.Twenty (20) normal adult, formalin-fixed cerebral hemispheres were studied through the fiber dissection technique and under the microscope. Stepwise and in tandem medial to lateral and lateral to medial dissections were performed in all specimens aiming to reveal the morphology and spatial relationships of major limbic and paralimbic areas.Fourteen (14) consecutive, discrete and easily reproducible laboratory anatomical steps are systematically described to reveal the intricate anatomy of the limbic and paralimbic structures and their main connections.This study offers for the first time in the pertinent literature a focused, step-by-step laboratory manual for the dissection and illustration of the limbic and paralimbic structures. The overreaching goal is to supplement the novice and experienced anatomist and neurosurgeon with a thorough and systematic reference to facilitate laboratory or intraoperative dissections.

ΣΚΟΠΟΣ: Σκοπός της παρούσας διατριβής είναι η μελέτη της αρχιτεκτονικής, της μορφολογίας και της συσχετιστικής ανατομίας των δεματίων λευκής ουσίας που εμπλέκονται στη συνδεσιμότητα του κινητικού και προκινητικού φλοιού καθώς και της επικουρικής και προ-εκπικουρικής περιοχής. ΜΕΘΟΔΟΣ: Τριάντα (30) ημισφαίρια υγειών ενηλίκων μονιμοποιημένα σε φορμόλη μελετήθηκαν με χρήση της μεθόδου παρασκευής της λευκής ουσίας κατά Klingler. Οι εν λόγω βήμα προς βήμα παρασκευές ολοκληρώθηκαν με κατεύθυνση από έξω προς τα έσω και από έσω προς τα έξω. ΑΠΟΤΕΛΕΣΜΑΤΑ: Αναζητήθηκε η υποφλοιώδης αρχιτεκτονική, η χωρική συσχέτιση και η συνδεσιμότητα τεσσάρων κυρίως μείζονων δεματίων: Α) Το ραχιαίο τμήμα του άνω επιμήκους δεματίου (SLF-I) ανευρέθηκε σταθερά στην έσω επιφάνεια του ημισφαιρίου να συνδέει το προσφηνοειδές λόβιο, την επικουρική και προ-επικουρική κινητική περιοχή. Β) Το Μετωπιαίο Επίμηκες Δεμάτιο(FLS) παρατηρήθηκε σταθερά ως μια πρόσθια συνέχεια του 2ου και 3ου τμήματος του άνω επιμήκους δεματίου(SLF II& SLF III). Το εν λόγω δεμάτιο συνδέει τον προκινητικό με τον προμετωπιαίο φλοιό. Γ) Το Μέτωπο-Κερκοφόρο Δεμάτιο (FCT) ένα ριπιδοειδές σύστημα ινών λευκής ουσίας, καταγράφηκε να συμμετέχει στη συνδεσιμότητα του προμετωπιαίου και προκινητικού φλοιού με την κεφαλή και το σώμα του κερκοφόρου πυρήνα. Δ) Το Φλοιο-καλυπτρικό δεμάτιο (CTT) ανευρέθηκε σταθερά να συνδέει τη μεσεγκεφαλική καλύπτρα με τον κινητικό/προκινητικό φλοιό και τον φλοιό της οπίσθιας κεντρικής έλικας. Κατά τις παρασκευές των εν λόγω δεματίων δεν παρατηρήθηκαν ημισφαιρικές ασυμμετρίες. Τέλος πρότυπα υποτμηματοποίησης προτάθηκαν για όλα τα δεμάτια. ΣΥΜΠΕΡΑΣΜΑΤΑ: Η συνδεσιμότητα και η λειτουργική εξειδίκευση των κινητικών και προκινητικών περιοχών του ανθρώπινου εγκεφάλου παραμένει σε μεγάλο βαθμό ασαφής καθώς ο μεγαλύτερος όγκος πληροφοριών προέρχεται από μελέτες σε πειραματόζωα και δεσμιδογραφικές μελέτες. Χρησιμοποιώντας την τεχνική Παρασκευής της λευκής ουσίας κατά Klingler ως βασική μέθοδο διερεύνησης, η παρούσα μελέτη παρέχει δεδομένα και στοιχεία για την λεπτή ανατομία των σχετιζόμενων με τις παραπάνω περιοχές δεματίων.

Background There is a lack of definite anatomical landmarks for the inferior extension of the standard retrosigmoid approach. Objective To evaluate whether the posterior condylar emissary vein (PCEV) can be used as an intraoperative landmark for optimizing the surgical corridor. Methods We performed the standard retrosigmoid approach on 5 formalin fixed and latex injected cadaveric specimens and measured the distance between the PCEV near its bony canal and the vertebral artery (VA). In addition, vascular reconstructions of thin sliced preoperative CT scans were studied in 40 patients and the relationship between these two vessels was evaluated. An illustrative case is also included. Results The PCEV was consistently identified on both sides of cadaveric specimens and in 87, 5% and 82, 5% of the left and right sides of the included CT scans respectively. The average distance between the part of the PCEV near its osseous canal and the VA was measured to be between 8,4mm and 8,6mm in the specimens and between 9,2mm and 9,3mm in the CT scans. This distance offers a safe and effective plane of dissection during the standard retrosigmoid approach and allows easy access to the foramen magnum. Conclusion The PCEV near its bony canal proved to be an easy, straightforward, safe and effective operative landmark with which the surgeon can extend the soft tissue dissection and bony exposure towards the foramen magnum. This maneuver provides ample access to the cisterna magna for CSF drainage and increases visibility and surgical maneuvrebility to the entire CP angle.

International audience; Τhe middle longitudinal fasciculus (MdLF) was initially identified in humans as a discrete subcortical pathway connecting the superior temporal gyrus (STG) to the angular gyrus (AG). Further anatomo-imaging studies, however, proposed more sophisticated but conflicting connectivity patterns and have created a vague perception on its functional anatomy. Our aim was, therefore, to investigate the ambiguous structural architecture of this tract through focused cadaveric dissections augmented by a tailored DTI protocol in healthy participants from the Human Connectome dataset. Three segments and connectivity patterns were consistently recorded: the MdLF-I, connecting the dorsolateral Temporal Pole (TP) and STG to the Superior Parietal Lobule/Precuneus, through the Heschl's gyrus; the MdLF-II, connecting the dorsolateral TP and the STG with the Parieto-occipital area through the posterior transverse gyri and the MdLF-III connecting the most anterior part of the TP to the posterior border of the occipital lobe through the AG. The lack of an established termination pattern to the AG and the fact that no significant leftward asymmetry is disclosed tend to shift the paradigm away from language function. Conversely, the theory of "where" and "what" auditory pathways, the essential relationship of the MdLF with the auditory cortex and the functional role of the cortical areas implicated in its connectivity tend to shift the paradigm towards auditory function. Allegedly, the MdLF-I and MdLF-II segments could underpin the perception of auditory representations; whereas, the MdLF-III could potentially subserve the integration of auditory and visual information.

The superficial anatomy of the occipital lobe has been described as irregular and highly complex. This notion mainly arises from the variability of the regional sulco-gyral architecture. Our aim was to investigate the prevalence, morphology, and correlative anatomy of the sulci and gyri of the occipital region in cadaveric specimens and to summarize the nomenclature used in the literature to describe these structures. To this end, 33 normal, adult, formalin-fixed hemispheres were studied. In addition, a review of the relevant literature was conducted with the aim to compare our findings with data from previous studies. Hence, in the lateral occipital surface, we recorded the lateral occipital sulcus and the intraoccipital sulcus in 100%, the anterior occipital sulcus in 24%, and the inferior occipital sulcus in 15% of cases. In the area of the occipital pole, we found the transverse occipital sulcus in 88% of cases, the lunate sulcus in 64%, the occipitopolar sulcus in 24%, and the retrocalcarine sulcus in 12% of specimens. In the medial occipital surface, the calcarine fissure and parieto-occipital sulcus were always present. Finally, the basal occipital surface was always indented by the posterior occipitotemporal and posterior collateral sulci. A sulcus not previously described in the literature was identified on the supero-lateral aspect of the occipital surface in 85% of cases. We named this sulcus "marginal occipital sulcus" after its specific topography. In this study, we offer a clear description of the occipital surface anatomy and further propose a standardized taxonomy for clinical and anatomical use.

Background Atypical rhabdoid teratoid tumors are very rare embryonal tumors that typically affect children younger than 3 years old and are encountered intracranially. Case Description Here, we describe the case of a 19-year-old woman who presented with gait disturbances and coccydynia. Imaging revealed a cauda equina mass. The tumor was partially resected. Histology reported loss of SMARCB1/INI1 expression and therefore the diagnosis of atypical rhabdoid teratoid was established. The patient underwent radiation treatment, but within 3 months 2 relapses were manifested. Conclusions Atypical rhabdoid teratoids are exceptionally rare in adults and are seldom found in spine; only 8 such cases have been reported in the medical literature. They are invariantly characterized by multiple relapses and dismal prognosis. The clinician must be attentive of leptomeningeal disseminations and 22q11 deletion–associated comorbidities.

Background The presence of a caroticoclinoid bar (CCB) has been implicated in both transcranial and endonasal surgery. Its morphology reflects differences in the microsurgical anatomy of the parasellar area and its manipulation during anterior or middle clinoidectomy can result in internal carotid artery injury. Although adjustment of the surgical technique according to the CCB anatomic variants is required for safe surgical access to the paraclinoid region, a review indicated the lack of a systematic assortment of reported data regarding the prevalence of the CCB. Thus, our objective was to systematically review and document the prevalence of the CCB and its anatomic variations. Methods Three databases were systematically reviewed using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement through August 2018 to identify relevant studies. Results A total of 27 reports (7521 subjects or specimens, 14,449 sides) were included in the present meta-analysis. The overall pooled prevalence of the CCB was 32.6% (95% confidence interval [CI], 26.6%–38.8%) when measured in the subjects or specimens and 23.6% (95% CI, 19.7%–27.6%) when measured in each side. The overall prevalence of the CCB reported from imaging studies was 23.1% (95% CI, 8.9%–41.4%) for the subjects/specimens and 18.7% (95% CI, 12.6%–25.7%) for each side. The presence of the CCB was slightly more prevalent (P = 0.050) on the right side. Conclusions Our results showed a considerable prevalence of the CCB, with lower prevalence rates found among imaging studies. Although meticulous preoperative investigation is mandatory, surgeons treating patients with parasellar pathologic entities should always be vigilant regarding the CCB.

OBJECTIVE: To provide an educational, comprehensive, systematic and stepwise manual for the dissection and illustration of major limbic structures since there is a gap in the pertinent literature. Further, we aim to offer a thorough yet simplified roadmap for laboratory and intraoperative dissections.METHODS: Twenty (20) normal adult, formalin-fixed cerebral hemispheres were studied through the fiber dissection technique and under the microscope. Stepwise and in tandem medial to lateral and lateral to medial dissections were performed in all specimens aiming to reveal the morphology and spatial relationships of major limbic and paralimbic areas RESULTS: Twelve (12) consecutive, discrete and easily reproducible laboratory anatomical steps are systematically described to reveal the intricate anatomy of the structures of the limbic system.CONCLUSION: Surgical approaches for lesions or functional resections in and around limbic areas pose a challenging task for the neurosurgeon. By employing the fiber dissection technique, we were able to provide a stepwise and thorough laboratory guide for the gradual dissection and better comprehension of the morphology and spatial relationships of this specific system. Anatomical manuals like the present study raise interest and enrich anatomical knowledge on complex cerebral areas with the overarching goal to inform surgical practice.

Background Recent studies advocate a connectivity pattern wider than previously believed of the uncinate fasciculus that extends to the ventrolateral and dorsolateral prefrontal cortices. These new percepts on the connectivity of the tract suggest a more expansive role for the uncinate fasciculus. Our aim was to shed light on this controversy through fiber dissections. Methods Twenty normal adult human formalin-fixed cerebral hemispheres were used. Focused dissections on the insular, orbitofrontal, ventromedial, ventrolateral, and dorsolateral prefrontal areas were performed to record the topography of the frontal terminations of the uncinate fasciculus. Results Three discrete fiber layers were consistently disclosed: the first layer was recorded to terminate at the posterior orbital gyrus and pars orbitalis, the second layer at the posterior two thirds of the gyrus rectus, and the last layer at the posterior one third of the paraolfactory gyrus. The insular apex was documented as a crucial landmark regarding the topographic differentiation of the uncinate and occipitofrontal fasciculi (i.e., fibers that travel ventrally belong to the uncinate fasciculus whereas those traveling dorsally are occipitofrontal fibers). Conclusions The frontal terminations of the uncinate fasciculus were consistently documented to project to the posterior orbitofrontal area. The area of the insular apex is introduced for the first time as a crucial surface landmark to effectively distinguish the stems of the uncinate and occipitofrontal fasciculi. This finding could refine the spatial resolution of awake subcortical mapping, especially for insular lesions, and improve the accuracy of in vivo diffusion tensor imaging protocols.

Grade II gliomas are slow growing tumours that usually affect younger patients. The mainstream treatment modality at present is surgical. The role of radiation therapy in the management of grade II gliomas has been the subject of considerable debate. Radiation therapy has a proven potential to prolong progression free and overall survival in high-risk patients, but may also produce long-term cognitive deficits. Since grade II glioma patients are expected to live several years, retention of cognitive capacity and quality of life is an equally important endpoint as prolonging progression free survival. Our overarching goal is to critically review the available evidence on the possible neuropsychological effects of postoperative radiotherapy in adult grade II glioma patients. We performed a systematic literature search in Medline, Embase and Cochrane databases up to 1st of May 2020 for studies assessing the cognitive effects of radiation therapy on grade II glioma patients. Eleven studies meeting our inclusion criteria provide either negative or contradictory data regarding the cognitive domains affected, while major confounding variables remain incompletely addressed. The available evidence does not adequately support the notion that current radiation therapy protocols independently produce substantial cognitive decline in grade II glioma patients and therefore it would be premature to argue that radiation associated cognitive morbidity outweighs the benefit of prolonged survival. A large prospective study incorporating a full battery of neuropsychological testing, sufficiently long-term follow-up period and tight control of confounders is due to provide high quality data.

This study opts to investigate the thus far ill-defined intra-hemispheric topography, morphology, and connectivity of the extrapyramidal fibers that originate from the frontoparietal cortex and project to the tegmental area and to explore structural correlations to the pyramidal pathway. To this end, twenty normal adult, formalin-fixed cerebral hemispheres were studied through the fiber micro-dissection technique. Stepwise and in-tandem medial to lateral and lateral to medial dissections were carried out in all specimens. The cortical termination of the fibers under investigation was carefully defined, and their entry zone at the tegmental area was meticulously recorded. We consistently identified the corticotegmental tract (CTT) as a distinct fiber pathway lying in the white matter of the genu and posterior limb of the internal capsule and travelling medial to the corticospinal tract (CST) and lateral to the thalamic radiations. The CTT exhibits a fan-shaped configuration and can be classified into three discrete segments: a rostral one receiving fibers from BA8 (pre-SMA, frontal eye fields, dorsal prefrontal cortex), a middle one arising from areas BA4 and BA6 (primary motor cortex and premotor cortex), and a caudal one stemming from areas BA1/2/3 (somatosensory cortex). The anatomical location, configuration, trajectory, and axonal connectivity of this tract are attuned to the descending component of the extrapyramidal system, and therefore, it is believed to be implicated in locomotion, postural control, motor inhibition, and motor modification. Our results provide further support on the emerging concept of a dynamic, parallel, and delocalized theory for complex human motor behavior.

OBJECTIVEThe authors sought to investigate the very existence and map the topography, morphology, and axonal connectivity of a thus far ill-defined subcortical pathway known as the fronto-caudate tract (FCT) since there is a paucity of direct structural evidence regarding this pathway in the relevant literature.METHODSTwenty normal adult cadaveric formalin-fixed cerebral hemispheres (10 left and 10 right) were explored through the fiber microdissection technique. Lateral to medial and medial to lateral dissections were carried out in a tandem manner in all hemispheres. Attention was focused on the prefrontal area and central core since previous diffusion tensor imaging studies have recorded the tract to reside in this territory.RESULTSIn all cases, the authors readily identified the FCT as a fan-shaped pathway lying in the most medial layer of the corona radiata and traveling across the subependymal plane before terminating on the superolateral margin of the head and anterior part of the body of the caudate nucleus. The FCT could be adequately differentiated from adjacent fiber tracts and was consistently recorded to terminate in Brodmann areas 8, 9, 10, and 11 (anterior pre–supplementary motor area and the dorsolateral, frontopolar, and fronto-orbital prefrontal cortices). The authors were also able to divide the tract into a ventral and a dorsal segment according to the respective topography and connectivity observed. Hemispheric asymmetries were not observed, but instead the authors disclosed asymmetry within the FCT, with the ventral segment always being thicker and bulkier than the dorsal one.CONCLUSIONSBy using the fiber microdissection technique, the authors provide sound structural evidence on the topography, morphology, and connectional anatomy of the FCT as a distinct part of a wider frontostriatal circuitry. The findings are in line with the tract’s putative functional implications in high-order motor and behavioral processes and can potentially inform current surgical practice in the fields of neuro-oncology and functional neurosurgery.

Idiopathic normal pressure hydrocephalus (INPH) diagnosis is challenging as it can be mimicked by other neurological conditions, such as neurodegenerative dementia and motor syndromes. Additionally, outcomes after lumbar puncture (LP) tap test and shunt treatment may vary due to the lack of a common protocol in INPH assessment. The present study aimed to assess whether a post-LP test amelioration of frontal cognitive dysfunctions, characterizing this syndrome, can differentiate INPH from similar neurological conditions and whether this improvement can predict INPH post–shunt outcomes. Seventy-one consecutive patients referred for INPH suspicion and LP testing, were enrolled. According to the consensus guidelines criteria, 29 patients were diagnosed as INPH and 42 were assigned an alternative diagnosis (INPH-like group) after reviewing clinical, neuropsychological and imaging data, and before LP results. A comprehensive neuropsychological assessment for frontal executive, upper extremity fine motor functions, aphasias, apraxias, agnosias and gait evaluation were administered at baseline. Executive, fine motor functions and gait were re-examined post-LP test in all patients and post-shunt placement in INPH patients. Of the INPH patients, 86.2% showed cognitive amelioration in the post-LP test; in addition, all but one (97%) presented with neurocognitive and gait improvement post-shunt. Verbal phonological fluency and finger tapping task post-LP improvement predicted positive clinical outcome post-shunt. None of the INPH-like group presented with neurocognitive improvement post-LP. Post-LP amelioration of verbal fluency and finger tapping deficits can differentiate INPH from similar disorders and predict positive post-shunt clinical outcome in INPH. This becomes of great importance when gait assessment is difficult to perform in clinical practice.

Background Recent analysis on the epidemiology of traumatic brain injury (TBI) within Europe indicates an increase in fall-related injuries and in the incidence of hospitalization among older adults as well as a decrease in contribution of road traffic accidents (RTA). Given the paucity of recent national data, we analyzed TBI-related admissions from the Athens Head Trauma Registry during the largest part of the past decade (2010-2018), a period marked by a profound national socioeconomic crisis. Methods Demographic and clinical data of admitted TBI patients were collected and analyzed statistically. Results The mean age of patients (N=2042, 68% men) was 59 years (median 64 years). Patient age showed an upward trend across the study period. Most cases were mild, while moderate and severe injuries were indicated in, 11% and 20%, respectively. Falls were the predominant cause of injury (46% of cases), followed by RTA (38%). An upward trend in the frequency of fall-related injury was apparent across the study period; RTA-related injury frequency displayed a downward trend during the second part of the study period. Assault-related injury accounted for 6%. Surgery took place in 11% of cases. In-hospital mortality (IHM) was 21%. Fall-related mortality contributed to 56% of total IHM; RTA-related mortality contributed to 30%. The mean length of hospital stay was 13 days (median: 5 days). Conclusions The present findings suggest a shift in the epidemiologic profile of TBI patients in Greece with a rise in the proportion of elderly patients, a concomitant increase in fall-related injuries and a reduction in RTA-related injury. They also highlight fall-related injury as the predominant cause of IHM. Our results point towards the urgent need for the intensification of fall prevention strategies, continuing medical education as well as public information campaigns on the risks of geriatric fall-related injury.

Idiopathic intracranial hypertension denotes raised intracranial pressure in the absence of an identifiable cause and presents with symptoms relating to elevated ICP, namely headaches and visual deterioration. Treatment of IIH aims at reducing intracranial pressure, relieving headache and salvaging patients' vision. Surgical interventions are recommended for medically refractory IIH and include CSF diversion techniques, optic nerve sheath fenestration, bariatric surgery and venous sinus stenting. Prospective studies on the surgical options for IIH are scant and no evidence-based guidelines for the surgical management of medically refractory IIH have been established. A search in Cochrane Library, MEDLINE and EMBASE from 1 January 1985 to 19 April 2019 for controlled or observational studies on the surgical treatment of IIH (defined in accordance with the modified Dandy or the modified Friedman criteria) in adults yielded 109 admissible studies. VSS improved papilledema, visual fields and headaches in 87.1%, 72.7% and 72.1% of the patients respectively, with a 2.3% severe complication rate and 11.3% failure rate. CSF diversion techniques diminished papilledema, visual field deterioration and headaches in 78.9%, 66.8% and 69.8% of the cases and are associated with a 9.4 severe complication rate and a 43.4% failure rate. ONSF ameliorated papilledema, visual field defects and headaches in 90.5, 65.2% and 49.3% of patients. Severe complication rate was 2.2% and failure rate was 9.4%. This is currently the largest systematic review for the available operative modalities for IIH. VSS provided the best results in headache resolution and visual outcomes, with low failure rates and a very favourable complication profile. In light of this, VSS ought to be regarded as the first-line surgical modality for the treatment of medically refractory IIH.

OBJECTIVEThe purpose of this study was to investigate the morphology, connectivity, and correlative anatomy of the longitudinal group of fibers residing in the frontal area, which resemble the anterior extension of the superior longitudinal fasciculus (SLF) and were previously described as the frontal longitudinal system (FLS).METHODSFifteen normal adult formalin-fixed cerebral hemispheres collected from cadavers were studied using the Klingler microdissection technique. Lateral to medial dissections were performed in a stepwise fashion starting from the frontal area and extending to the temporoparietal regions.RESULTSThe FLS was consistently identified as a fiber pathway residing just under the superficial U-fibers of the middle frontal gyrus or middle frontal sulcus (when present) and extending as far as the frontal pole. The authors were able to record two different configurations: one consisting of two distinct, parallel, longitudinal fiber chains (13% of cases), and the other consisting of a single stem of fibers (87% of cases). The fiber chains’ cortical terminations in the frontal and prefrontal area were also traced. More specifically, the FLS was always recorded to terminate in Brodmann areas 6, 46, 45, and 10 (premotor cortex, dorsolateral prefrontal cortex, pars triangularis, and frontal pole, respectively), whereas terminations in Brodmann areas 4 (primary motor cortex), 47 (pars orbitalis), and 9 were also encountered in some specimens. In relation to the SLF system, the FLS represented its anterior continuation in the majority of the hemispheres, whereas in a few cases it was recorded as a completely distinct tract. Interestingly, the FLS comprised shorter fibers that were recorded to interconnect exclusively frontal areas, thus exhibiting different fiber architecture when compared to the long fibers forming the SLF.CONCLUSIONSThe current study provides consistent, focused, and robust evidence on the morphology, architecture, and correlative anatomy of the FLS. This fiber system participates in the axonal connectivity of the prefrontal-premotor cortices and allegedly subserves cognitive-motor functions. Based in the SLF hypersegmentation concept that has been advocated by previous authors, the FLS should be approached as a distinct frontal segment within the superior longitudinal system.

Angiosarcoma-related cerebral metastases have only been recorded in a few case reports and case series and have not been systematically reviewed to date. Our objective was therefore to perform a systematic literature review on cases of angiosarcomas metastasizing to the brain to inform current practice. All three major libraries—PubMed/MEDLINE, Embase, and Cochrane—were systematically searched, until January 2019. Articles in English reporting angiosarcoma-related cerebral metastases via hematogenous route were included. Our search yielded 45 articles (38 case reports, 5 retrospective studies, 1 case series and 1 letter to the editor), totaling 48 patients (mean age 47.9 years). The main primary site was the heart. The mean time of diagnosis of cerebral metastases following primary tumor identification was 4.9 months. In 15 cases, the brain was the only metastatic site. In cases of multiple extracerebral metastases, the most common sites were the lung and bone. Acute intracerebral supratentorial hemorrhage was the most common presenting radiological feature. Treatment strategies were almost equally divided between the surgical (with or without adjuvant treatment) and the medical arm. Mean overall survival was 7.2 months while progression-free survival was 1.5 months. To our knowledge, this is the first systematic literature review on angiosarcoma-related cerebral metastases. This pathology proves to be an extremely rare clinical entity and carries a poor prognosis, and no consensus has been reached regarding treatment.

The sledge runner fasciculus (SRF) has been recently identified as a discrete fiber tract of the occipital lobe and has been allegedly implicated in the axonal connectivity of cortical areas conveying spatial navigation and visuospatial imagery. However, detailed knowledge regarding its anatomic and tractographic morphology is lacking. We thus opted to investigate the anatomy and connectivity of the SRF through cadaveric dissections and DTI studies. Twenty normal, adult, cerebral, cadaveric hemispheres treated with the Klingler’s method were dissected through the fiber microdissection technique and 35 healthy participants from the MGH-USC Adult Diffusion Dataset (Human Connectome available dataset) underwent a tailored DTI protocol aiming to investigate the structural architecture of the SRF. SR was identified as a discrete fiber pathway, just under the U fibers of the medial occipital lobe, exhibiting a dorsomedial–ventrolateral trajectory and connecting the cortical areas of the anterior cuneus, anterior lingula, isthmus of the cingulum and posterior parahippocampal gyrus. The topography of the SR in relation to adjacent fiber pathways such as the cingulum, major forceps and stratum calcarinum is clearly delineated. Dissection and tractographic findings showed a good correspondence regarding SR topography, morphology and axonal connectivity. Our results support the hypothesis that the SRF is involved in the structural axonal connectivity of cerebral areas that strongly activate during spatial navigation and visuospatial imagery. Furthermore detailed anatomo-imaging evidence is provided on the microanatomic architecture of this newly discovered fiber tract.

OBJECTIVEThe authors investigated the specific topographic relationship of the optic radiation fibers to the roof and floor of the ventricular atrium because the current literature is ambiguous.METHODSThirty-five normal, adult, formalin-fixed cerebral hemispheres and 30 focused MRI slices at the level of the atrium were included in the study. The correlative anatomy of the optic radiation with regard to the atrial roof and floor was investigated in 15 specimens, each through focused fiber microdissections. The remaining 5 hemispheres were explored with particular emphasis on the trajectory of the collateral sulcus in relation to the floor of the atrium. In addition, the trajectory of the collateral sulcus was evaluated in 30 MRI scans.RESULTSThe atrial roof was observed to be devoid of optic radiations in all studied hemispheres, whereas the atrial floor was seen to harbor optic fibers on its lateral part. Moreover, the trajectory of the intraparietal sulcus, when followed, was always seen to correspond to the roof of the atrium, thus avoiding the optic pathway, whereas that of the collateral sulcus was found to lead to either the lateral atrial floor or outside the ventricle in 88% of the cases, therefore hitting the visual pathway.CONCLUSIONSOperative corridors accessing the ventricular atrium should be carefully tailored through detailed preoperative planning and effective use of intraoperative navigation to increase patient safety and enhance the surgeon’s maneuverability. The authors strongly emphasize the significance of accurate anatomical knowledge.

AimsTo study anaplastic lymphoma kinase (ALK) protein expression and possible underlying gene alterations in glioblastoma (GBM), correlating them with clinical outcome.MethodsWe studied ALK immunohistochemical expression and fluorescent in situ hybridisation (FISH)-detected ALK gene alterations in 51 GBMs (46 isocitrate dehydrogenase-1 (IDH1)R132H-negative and 5 IDH-mutant (IDH1R132H-positive)). We compared two anti-ALK antibodies and immunohistochemical detection systems (5Α4/Nichirei Biosciences, D5F3/Ventana). The results were correlated with tumour cell proliferation and clinical outcome.ResultsIntense granular cytoplasmic ALK immunostaining was observed in 10/51 (19.61%) GBM and correlated with high Ki67 proliferation index; only 1 in 10 ALK-positive cases displayed multiple alk gene signals by FISH. Moderate ALK immunostaining was observed in 21 (41.17%), weak immunostaining in 5 (9.80%) while 15 (29.42%) cases were negative. p53 was expressed in 26/51 GBM (50.9%) (10% cut-off). IDH1R132H-negative GBM showed higher ALK expression compared with IDH-mutant GBM (65.2% vs 20%). ALK overexpression was more common in older patients but did not correlate with other clinicopathological variables or patient overall survival.ConclusionsALK overexpression can be identified in up to 70% of GBMs and does not correlate with underlying alk gene amplification. Despite being more common in rapidly growing, clinically aggressive GBM, ALK overexpression did not show correlation with prognosis in this study.

Gestation is a period of significant physiological changes that can severely affect the function of many systems, including the cardiovascular. The deviation from the standard that occurs during pregnancy may cause the deterioration of pre-existent cardiovascular diseases or the appearance of new ones. In this review we will present the most common congenital and acquired cardiovascular diseases, their clinical expression and therapeutic procedures according to the latest international guidelines.