Five-Year Serial Brain MRI Analysis of Military Members Exposed to Chronic Sub-Concussive Overpressures.

BACKGROUND: The Canadian Special Operations Forces Command conducts explosives operations and training which exposes members to explosive charges at close proximity. This 5-year longitudinal trial was conducted in follow-up to our initial trial which examined military breachers with MRI and EEG pre and post blast exposure. PURPOSE: To examine brain MRI findings in military personnel exposed to multiple repeated blast exposures. STUDY TYPE: Five-year longitudinal prospective trial. POPULATION: Ninety-two males aged 23-42 with an average of 9.4 years of blast exposure. FIELD STRENGTH/SEQUENCE: 3 T brain MRI/T1-weighted 3D with reconstruction in three planes, T2-weighted, T2-weighted fluid attenuated inversion recovery (FLAIR) 3D with reconstruction in three planes, T2-weighted gradient spin echo (GRE), saturation weighted images, DWI and ADC maps, diffusion tensor imaging. ASSESSMENT: All MRI scans were interpreted by the two neuroradiologists and one neuroradiology Fellow in a blinded fashion using a customized neuroradiology reporting form. STATISTICAL TESTS: Matching parametric statistics represented the number of participants whose brain parameters improved or deteriorated over time. Odds ratio (OR) and 95% confidence intervals (CI) were computed using log regression modeling to determine volume loss, white matter lesions, hemosiderosis, gliosis, cystic changes and enlarged Virchow Robin (VR) spaces. A Kappa (κ) statistic with a 95% CI was calculated to determine rater variability between readers. RESULTS: A significant deterioration was observed in volume loss (OR = 1.083, 95% CI 0.678-1.731, permutation test), white matter changes (OR: 0.754, 95% CI 0.442-1.284, permutation test), and enlargement of VR spaces (OR: 0.775, 95% CI 0.513-1.171). Interrater reliability was low: κ = 0.283, 0.156, and 0.557 for volume loss, white matter changes, and enlargement of VR spaces, respectively. DATA CONCLUSION: There were significant changes in brain volume, white matter lesions, and enlargement of VR spaces. EVIDENCE LEVEL: 2 TECHNICAL EFFICACY: Stage 2.

Gamma Knife Stereotactic Radiosurgery for Cerebral Cavernous Malformations: Meta-Analysis of Reconstructed Time-to-Event Data.

INTRODUCTION: Cavernomas are vascular lesions with a genetic heritage that can be spotted on the central nervous system. Whenever these lesions are localized in eloquent regions, surgical resection is not recommended. In this type of situation, Gamma Knife stereotactic radiosurgery (GKSRS) could be a feasible option for treating patients. Thus, we aimed to explore the outcomes associated with this procedure. METHODS: We performed a systematic review and meta-analysis of reconstructed time-to-event data based on Kaplan-Meier curves. A thorough search was conducted on PubMed, Cochrane, Web of Science, and Embase databases targeting papers that provided information regarding hemorrhagic outcomes associated with GKSRS through Kaplan-Meier curves. RESULTS: After a systematic search in the specific databases, seven studies were included in this review. Notably, a total of 1,071 patients had 1,104 cavernomas treated by GKSRS. Assessment of short-term and long-term post-procedure outcomes was performed, with the estimated overall events-free rate at 2 years being 89.8% (95% CI: 87.7-91.5), while, at 10 years, the estimated overall events-free rate was 71.3% (95% CI: 67.2-75.1). CONCLUSION: GKSRS seems to be a good alternative for the control of symptomatic events in early and long-term follow-up, despite the need for further investigation provided by future studies.

Radiation-induced cavernoma in pediatric CNS tumors: a systematic review and treatment paradigm.

PURPOSE: This retrospective systematic literature review aimed to summarize available data regarding epidemiology, etiology, presentation, investigations, differentials, treatment, prevention, monitoring, complications, and prognosis for radiation-induced cavernous malformations (RICMs) in pediatric patients. METHODOLOGY: Review conducted per PRISMA guidelines. Google Scholar, PubMed, Trip Medical Database, and Cochrane Library searched utilizing a keyphrase, articles filtered per inclusion/exclusion criteria, duplicates excluded. Based on criteria, 25 articles identified, 7 further excluded from the systematic data but included in discussion (5 × insufficient data, 2 × other systematic reviews). RESULTS: Many studies did not contain all explored data. 2487 patients reviewed, 325 later found to have RICM (143 male, 92 female). Mean age at irradiation 7.6 years (range 1.5-19). Mean total radiation dose 56 Gy (12-112). Most common indications for radiation-medulloblastoma 133x, astrocytoma 23x, ependymoma 21x, germinoma 19x. Mean age at RICM diagnosis 18 years (3.6-57). Mean latency to RICM 9.9 years (0.25-41). Most common anatomic locations-temporal 36, frontal 36, parietal 13, basal ganglia 16, infratentorial 20. Clinical presentation-incidental 270, seizures 19, headache 11, focal neurological deficit 7, other 13. 264 patients observed, 34 undergone surgery. RICM bled in 28 patients. Mean follow-up 11.7 years (0.5-50.3). Prognostic reporting highly variable. CONCLUSIONS: From our data, pediatric RICMs appear to display slight male predominance, present about 10 years after initial irradiation in late teen years, and present incidentally in majority of cases. They are mostly operated on when they bleed, with incidental lesions mostly being observed over time. Further prospective detailed studies needed to draw stronger conclusions.

Brainstem cavernous hemangioma with improvement of Holmes tremor on excision.

An 8-year-old boy presenting with left-angle paralysis, tremor in upper and lower extremities, and diplopia was diagnosed with hemorrhage from a mesencephalic cavernous hemangioma. He underwent hemangiomectomy through the occipital transtentorial approach 4 weeks post-hemorrhage, after which Holmes tremor (HT) markedly reduced. A year later, hemangioma has not recurred; he is now independent in his daily activities. Early intervention in the subacute stage allows for the complete removal of brainstem cavernomas (BSCs), with minimal risk of complications or sequelae. Proper timing and surgical approach for BSCs can prevent re-bleeding and improve HT after an initial hemorrhage, without any lasting negative consequences.

Surgical management of lobar cerebral cavernous malformations in children: a single-center experience.

PURPOSE: We aimed to determine the surgical indications and postoperative outcomes among pediatric patients with lobar cerebral cavernous malformations (CCMs). METHODS: We retrospectively reviewed pediatric patients operated on for lobar CCM between March 2010 and August 2021. Indications for surgery included (1) intracranial hemorrhage, (2) symptomatic superficially located lesion, and (3) asymptomatic CCM in non-eloquent area in case of strong parental preferences. Patients presenting with seizures were assessed using Engel Epilepsy Surgery Outcome Scale. RESULTS: Twenty-one patients were included. The predominant symptoms were seizures (57.1%), headaches (33.3%), and focal neurological deficits (23.8%). Patients were qualified for surgery due to symptomatic intracranial hemorrhage (47.6%), drug-resistant epilepsy (28.6%), and focal neurological deficits (9.5%). Three patients (14.3%) were asymptomatic. A gross total resection of CCM with the surrounding hemosiderin rim was achieved in all patients. The mean follow-up was 52 months. No patient experienced surgery-related complications. In all individuals with a preoperative first episode of seizures or focal neurological deficits, the symptoms subsided. All six patients with drug-resistant epilepsy improved to Engel classes I (67%) and II (33%). CONCLUSION: Surgical removal of symptomatic lobar CCMs in properly selected candidates remains a safe option. Parental preferences may be considered a sole qualifying criterion for asymptomatic lobar CCM excision.

Giant brainstem cavernoma in pediatrics: diagnosis and treatment-case report.

INTRODUCTION: Brain cavernomas or cavernous angiomas are a rare vascular malformation in the general population, even more so in pediatric patients. Their incidence in this group is less than 5% of all vascular malformations. They are typically found in the cerebral hemispheres in cortico-subcortical locations and, more rarely, in the brainstem. OBJECTIVE: To describe the diagnosis, treatment, and follow-up of a case involving a pediatric patient with a giant cavernoma in the brainstem at J.P. Garrahan Hospital. MATERIALS AND METHODS: The clinical history of the case was retrieved from the database of J.P. Garrahan Pediatric Hospital. Additionally, a literature search was conducted in high-impact factor journals using the PubMed database. CONCLUSION: Both the authors of this study and experts consulted through the literature agree that, given the eloquence of the affected area and its challenging accessibility, close monitoring and an expectant approach are advisable for such patients. Nevertheless, when the onset of the case warrants it, surgical intervention is deemed necessary in emergency situations and following the acute phase for complete resolution of the pathology.

Optochiasmatic Cavernomas: Updated systematic review and proposal of a novel classification with surgical approaches.

Cavernomas are histologically benign vascular malformations found at different sites in the brain. A rare site for such cavernomas, however, is the anterior optic pathway, comprising the optic nerve, chiasma, and optic tract-called optochiasmatic cavernomas (OCC). These lesions usually present with sudden onset or progressive vision loss, headache, and features mimicking pituitary apoplexy. In this paper, we describe a case of OCC operated at our center. We carry out an updated review of literature depicting cases of OCC, their clinical presentation, management, and postoperative complications. We also propose a novel classification system based on lesion location and further analyze these cavernoma types with respect to the surgical approach used and visual outcome. A 30-year-old lady had presented with a 3-week history of progressive bilateral vision loss and headache. Based on imaging, she was suspected to have a cavernous angioma of the chiasma and left optic tract. Due to progressive vision deterioration, the lesion was surgically excised using pterional craniotomy. Postoperatively, her visual symptoms improved, but she developed diabetes insipidus. Clinical and radiological follow-up has been done for 18 months after surgery. A total of 81 cases have been described in the literature, including the present case. Chiasmal apoplexy is the most common presentation. Surgical excision is the standard of care. Our analysis based on lesion location shows the most appropriate surgical approach to be used for each cavernoma type. Visual outcome correlates with the preoperative visual status. Visual outcome is good in patients presenting with acute chiasmal apoplexy, and when complete surgical excision is performed. The endonasal endoscopic approach was found to provide the best visual outcome. In addition to preoperative visual status, complete surgical excision predicts favorable visual outcomes in OCC. Our proposed classification system guides the appropriate surgical approach required for a particular location of the cavernoma.

Stereotactic radiosurgery for intracranial cavernous malformations of the deep-seated locations: systematic review and meta-analysis.

OBJECTIVE: To determine the outcomes of stereotactic radiosurgery (SRS) for deep-seated (brainstem, basal ganglia, thalamus, cerebellar peduncle) intracranial cavernous malformations (ICMs). METHODS: A systematic review and meta-analysis was performed according to PRISMA and MOOSE guidelines. The main outcomes were comparing pre- and post-SRS hemorrhage rates, using the pooled risk ratios (RR) as the measure of effect. Additionally, the study assessed lesion volume changes and radiation-injury incidence. RESULTS: Data of 850 patients across 14 studies were included in the meta-analysis. The pooled RR of all deep-seated ICMs show a decrease in hemorrhage rate after SRS compared to pre-SRS over the total follow-up period (RR =0.13), initial 2 years (RR =0.22), and after 2 years (RR =0.07). For 9 studies that reported hemorrhage rate of the brainstem only, the pooled RR shows a decrease of hemorrhage rate after SRS compared to pre-SRS over the total follow-up period (RR =0.13), initial 2 years (RR =0.19), and after 2 years (RR =0.07). Volumetric regression was achieved in 44.25% and stability in 56.1%. The pooled incidence of symptomatic and permanent radiation injury was 9% (95% CI, 7-11) and 3% (95% CI, 0-1.9%), respectively. CONCLUSION: SRS appears effective in reducing hemorrhage rates for deep-seated ICMs. The risk of symptomatic radiation injury is low. Given the high risk of surgical morbidity, SRS is a reasonable treatment option for patients with deep-seated ICMs with at least one prior hemorrhage.

[Thrombosis of portal cavernoma]. / Thrombose du cavernome porte.

Portal cavernoma thrombosis is a complication of portal cavernoma. We describe the case of a 74-year-old patient who presented to the emergency department with abdominal pain. The computed tomography scan showed a mass from the head of the pancreas to the hepatic hilum not enhanced after injection of iodinated contrast. There was no dilatation of the bile ducts. Abdominal magnetic resonance ruled out a tumour and confirmed a portal cavernoma thrombosis. In 50 % of cases the etiology of the portal cavernoma is unknown. It is often asymptomatic. It may be discovered in case of complications of portal hypertension. In rare cases the portal cavernoma can compress the bile ducts. To our knowledge, portal cavernoma thrombosis has only been described in one article. It is important to search for a thrombophilic disorder when such a complication is found. We share this case report in order to raise awareness in the medical community about this rare complication.

La thrombose de cavernome portal est une complication du cavernome porte. Nous décrivons le cas d'un patient de 74 ans qui s'est présenté aux urgences pour des douleurs abdominales. La tomodensitométrie montrait un syndrome de masse de la tête du pancréas jusqu'au hile hépatique non rehaussé après injection de produit de contraste iodé. Il n'y avait pas de dilatation des voies biliaires. Une imagerie par résonance magnétique abdominale a permis d'infirmer l'hypothèse d'une masse tumorale et d'affirmer une thrombose du cavernome porte. Dans 50 % des cas, l'étiologie du cavernome portal est inconnue. Il est souvent asymptomatique. Il peut être découvert en cas de complications à la suite d'une hypertension portale. Dans de rares cas, le cavernome portal peut comprimer les voies biliaires. À notre connaissance, la thrombose de cavernome portal n'a été décrite que dans un seul article. Il est important de rechercher un désordre thrombophilique quand une telle complication est retrouvée. Nous partageons ce cas clinique afin de sensibiliser la communauté médicale à cette rare complication.

Acute acalculous cholecystitis with portal cavernoma: A case report with literature review.

Portal cavernoma cholangiopathy (PCC) refers to morphological changes in the intrahepatic, extrahepatic biliary system, along with the gallbladder (GB), induced by portal cavernoma (PC). Acute acalculous cholecystitis (AAC) represents an infrequent clinical manifestation of PCC. Given the inadequacy of documentation within medical literature, AAC may go undiagnosed among patients with PC presenting symptoms of right upper quadrant pain. The current study aims to report a case of acute acalculous cholecystitis secondary to portal cavernoma, focusing on radiological findings, with a brief review of literature.

Thoracic root-related intradural extramedullary cavernoma presenting with subarachnoid hemorrhage: illustrative case.

BACKGROUND: Just 5% of all cavernomas are located in the spine. Thoracic root-related subtypes are the rarest, with a total of 14 cases reported in the literature to date. Among them, only 4 presented with subarachnoid hemorrhage (SAH). OBSERVATIONS: A 65-year-old female presented after an ictus of headache with no neurological deficits. Computed tomography (CT) demonstrated sulcal SAH, with the remainder of the workup nondiagnostic for etiology. Three weeks later, she re-presented with acute thoracic back pain and thoracic myelopathy. CT and magnetic resonance imaging suggested dubiously a T9-10 disc herniation with spinal cord compression. Surgical decompression and resection were then planned. Intraoperative ultrasound (IUS) demonstrated an intradural extramedullary lesion, confirmed to be cavernoma. Complete resection was achieved, and the patient was discharged a few days postoperatively to inpatient rehabilitation. LESSONS: Although spine imaging is deemed to be low yield in the evaluation of cryptogenic SAH, algorithms can be revisited even in the absence of spine-related symptoms. Surgeons can be prepared to change the initial surgical plan, especially when preoperative imaging is unclear. IUS is a powerful tool to assess the thecal sac after its exposure and to help guide this decision, as in this rare entity.

Endoscopic Endonasal Approach to the Orbit: A Case Series and Clinical Experience Emphasizing the Advantages of the Ipsilateral Mononostril Technique.

BACKGROUND: Lesions situated within the orbit pose significant challenges in management due to the confined space they occupy and their proximity to critical anatomical structures. The objective of our study is to assess the feasibility of the ipsilateral endoscopic endonasal approach for orbital cavernous hemangiomas and to comprehend the surgical anatomy of the orbital apex and inferomedial orbital structures. METHODS: Thirteen patients (8 women, 5 men), with ages ranging from 25 to 54 years (mean 35.2 ± 8.3 years), with orbital cavernous hemangioma who underwent surgery via the ipsilateral mononostril endoscopic endonasal approach between August 2018 and August 2023 were retrospectively evaluated. Demographic characteristics, clinical data, radiographic images, and clinical outcomes of the patients were collected from digital medical records. RESULTS: The left orbit was more commonly affected (9 left, 4 right). The average postoperative follow-up duration was 22.2 months (range: 6-50 months). Among the 13 cases of orbital cavernous hemangioma, 1 (7.7%) was located in the extraconal compartment, and 12 (92.3%) were situated in the intraconal compartment. Complete surgical resection of the tumor was successfully achieved in all patients. CONCLUSIONS: Our study highlights the potential advantages of employing a purely ipsilateral mononostril endoscopic endonasal approach for orbital surgery, particularly for accessing the orbital apex and managing medial and inferomedial orbital lesions. This technique holds promise for reducing morbidity and enhancing outcomes, especially when combined with careful patient selection, preoperative planning, and advanced endoscopic skills.

Spinal intradural extramedullary cavernoma: A case report.

INTRODUCTION: Cavernomas are rare vascular lesions that can occur anywhere along the neuraxis. However, they are most commonly found in the cerebral hemispheres. Spinal cavernomas are more uncommon and intradural extramedullary cavernomas are the most uncommon as they constitute only 3 % of spinal cavernomas. PRESENTATION: A 36-year-old female presented to our neurosurgical clinic with a history of back pain radiating to the left side of the chest with left lower extremity paresthesia and ataxia without urinary disturbance. Neurological exam showed left-sided hypoesthesia below the T9 dermatome in addition to increased patellar and Achilles reflexes on the left side. MRI showed a homogeneous intradural extramedullary mass which was hyperintense on T1 and hypointense on T2 and it was surgically resected. Pathological examination confirmed the diagnosis of intradural extramedullary cavernoma. DISCUSSION: Intradural extramedullary cavernomas are extremely rare lesions that arise within the area located between the inner surface of the dura and the pial surface of the spinal cord. Up until 2022 only 40 cases of intradural extramedullary cavernomas were reported in the literature. MRI is the preferred imaging modality and pathology is the golden standard for diagnosis. Surgical resection showed very promising results and it is considered the golden standard for treating this condition. However, surgery should be performed urgently to give an optimal outcome. CONCLUSION: Clinicians should consider this condition in their differential diagnoses when faced with progressive spinal root compression symptoms, sudden onset myelopathy, or progressive subarachnoid hemorrhage.

Assessing the Relationship between Surgical Timing and Postoperative Seizure Outcomes in Cavernoma-Related Epilepsy: A Single-Institution Retrospective Analysis of 63 Patients with a Review of the Literature.

Background: Patients with supratentorial cavernous malformations (SCMs) commonly present with seizures. First-line treatments for cavernoma-related epilepsy (CRE) include conservative management (antiepileptic drugs (AEDs)) and surgery. We compared seizure outcomes of CRE patients after early (≤6 months) vs. delayed (>6 months) surgery. Methods: We compared outcomes of CRE patients with SCMs surgically treated at our large-volume cerebrovascular center (1 January 2010-31 July 2020). Patients with 1 sporadic SCM and ≥1-year follow-up were included. Primary outcomes were International League Against Epilepsy (ILAE) class 1 seizure freedom and AED independence. Results: Of 63 CRE patients (26 women, 37 men; mean ± SD age, 36.1 ± 14.6 years), 48 (76%) vs. 15 (24%) underwent early (mean ± SD, 2.1 ± 1.7 months) vs. delayed (mean ± SD, 6.2 ± 7.1 years) surgery. Most (32 (67%)) with early surgery presented after 1 seizure; all with delayed surgery had ≥2 seizures. Seven (47%) with delayed surgery had drug-resistant epilepsy. At follow-up (mean ± SD, 5.4 ± 3.3 years), CRE patients with early surgery were more likely to have ILAE class 1 seizure freedom and AED independence than those with delayed surgery (92% (44/48) vs. 53% (8/15), p = 0.002; and 65% (31/48) vs. 33% (5/15), p = 0.03, respectively). Conclusions: Early CRE surgery demonstrated better seizure outcomes than delayed surgery. Multicenter prospective studies are needed to validate these findings.

Acute management of ruptured cavernous malformation of the optic nerve: illustrative case.

BACKGROUND: A cavernous malformation of the optic nerve (CMON) is a rare condition that often presents with an abrupt decline in vision. Acute management of ruptured optic nerve cavernous malformations is generally surgical, although the timing of surgery is controversial. OBSERVATIONS: A 47-year-old female experienced the sudden loss of vision in her left eye. Examination showed that this eye was nearly blind, and her right eye had a temporal field defect. Neuroimaging showed hemorrhage in her left optic nerve and optic chiasm. She was taken to the operating room on an emergent basis where the optic canal was decompressed, the hemorrhage was evacuated, and a vascular malformation with features of a cavernoma was removed from the optic nerve. Over the next 2 days, the vision in her right eye significantly recovered. LESSONS: CMONs remain rare, and it is unlikely that enough cases can be gathered to form a larger trial to compare the role and timing of surgery. On the basis of our experience with this case, the authors recommend that acute CMON-related hematomas should be treated as a surgical emergency and managed with acute optic nerve decompression, hematoma evacuation, and cavernoma resection to improve chances of vision recovery and prevent further vision loss.

Adhesive arachnoiditis, subarachnoid hemorrhage, and intradural extramedullary thoracic cavernoma: illustrative case.

BACKGROUND: Spinal arachnoiditis can result from various factors, including spinal subarachnoid hemorrhage (sSAH). In this paper, the authors describe a case of intradural extramedullary cavernoma with an initial presentation of subarachnoid hemorrhage leading to multilevel spinal arachnoiditis to discuss the pathophysiology and optimal treatment strategy. OBSERVATIONS: Spinal intradural extramedullary cavernoma manifesting with sSAH is a rare clinical presentation; therefore, there is no clear strategy for the management of sSAH. Spinal arachnoiditis is a result of chronic inflammation of the pia arachnoid layer due to hematomyelia. No effective treatment that interrupts this inflammatory cascade and would also prevent the development of spinal arachnoiditis has been described to date. LESSONS: Lumbar drainage could aid in sSAH management, relieve spinal cord compression, and restore the normal spinal cerebrospinal fluid circulation gradient. It could help to clear the blood degradation products rapidly and prevent early inflammatory arachnoiditis development. Mini-invasive intrathecal endoscopic adhesiolysis appears to be a reasonable approach for reducing the risk of aggravating spinal arachnoiditis with a mechanical-surgical stimulus. Whether a conservative approach should be applied in these patients with mild myelopathy symptoms is still debatable.

Hypertrophic olivary degeneration secondary to a Guillain Mollaret triangle cavernoma: Two case report.

Hypertrophic olivary degeneration (HOD) is a rare form of transsynaptic degeneration. It is caused by a damage at the Guillain-Mollaret triangle (GMT), which is defined by three anatomical structures: the dentate nucleus, the red nucleus, and the inferior olivary nucleus (ION). Clinically, it may be revealed by palatal myoclonus. On MRI, it appears as a unilateral or bilateral enlargement of the inferior olivary nucleus which shows a high signal intensity on T2-weighted images, with sometimes a cerebellar atrophy. Here we report 2 cases of healthy patients which present hemorrhagic brainstem cavernomas, complicated later by the development of palatal myoclonus and cerebellar ataxia, with MRI features corresponding to an (HOD) secondary to a (GMT) cavernoma. The purpose is to explain the mechanism of (HOD) subsequent to lesion in (GMT), and to describe magnetic resonance imaging features.

Microsurgical Resection for Cavernous Malformation of the Uncus: 3D-Operative Video.

Cavernous malformations (CMs) are rare and often oligosymptomatic vascular lesions. The main symptoms include seizure and focal neurologic deficits.1-3 Depending on the symptomatology, location, size, and risk factors for bleeding, like the presence of a developmental venous anomaly, CMs can be highly morbid. Thus surgical resection may be considered. Deep-seated and eloquent CMs, like those in the uncus, can be challenging.4,5 In Video 1, we present a 23-year-old male adult who developed focal seizures (i.e., oral automatisms) after an episode of sudden intense headache 1 year ago. His neurologic examination was unremarkable. The patient consented to the procedure and publication of his image. Nevertheless, his magnetic resonance images showed an uncal 2-cm Zabramski type I CM. We exposed the insula and its limen through a right pterional craniotomy and transsylvian corridor. During the video, we discuss the surgical nuances to access and resect this CM lesion en bloc while preserving important vascular structures and white matter tracts. Postoperative neuroimaging demonstrated total resection. In postoperative day 1, the patient had 1 episode of generalized seizure and evolved with contralateral hemiparesis. The patient had a good recovery and was discharged on postoperative day 21. At the 6-month follow-up, the patient had no new epileptic events and presented complete weakness improvement. Through this minimally invasive and well-known surgical corridor, we preserve the mesial and lateral portion of the temporal lobe, reducing the risk of lesions to the Meyer loop and limbic association area.

Axial Sections of Brainstem Safe Entry Zones and Clinical Importance of Intrinsic Structures: A Review.

Brainstem surgery is more difficult and riskier than surgeries in other parts of the brain due to the high density of critical tracts and cranial nerves nuclei in this region. For this reason, some safe entry zones into the brainstem have been described. The main purpose of this article is to bring on the agenda the significance of the intrinsic structures of the safe entry zones to the brainstem. Having detailed information about anatomic localization of these sensitive structures is important to predict and avoid possible surgical complications. In order to better understand this complex anatomy, we schematically drew the axial sections of the brainstem showing the intrinsic structures at the level of 9 safe entry zones that we used, taking into account basic neuroanatomy books and atlases. Some illustrations are also supported with intraoperative pictures to provide better surgical orientation. The second purpose is to remind surgeons of clinical syndromes that may occur in case of surgical injury to these delicate structures. Advanced techniques such as tractography, neuronavigation, and neuromonitorization should be used in brainstem surgery, but detailed neuroanatomic knowledge about safe entry zones and a meticulous surgery are more important. The axial brainstem sections we have drawn can help young neurosurgeons better understand this complex anatomy.

A small frontal lobe cavernoma presenting with headache mimicking migraine and complex focal seizure: A case report.

Cavernoma, or cerebral cavernous angioma, are hamartomatous lesions formed by sinusoidal vascular spaces without cerebral parenchyma in between. Cavernoma is a rare disorder that is diagnosed infrequently and incidentally, so it is called incidentaloma. However, cavernoma can present with seizures, headaches, and other focal neurological deficits, with seizures being the most frequent presentation. Cavernoma is angiographically concealed, and it's diagnosis is challenging. So, the cavernoma is diagnosed based on an MRI. We present the rare case of a patient who presented with a complex focal seizure and migraine-like headache caused by a small frontal lobe cavernoma.