Hippocampal sclerosis and epilepsy surgery in neurofibromatosis type 1: case report of a 3-year-old child explored by SEEG and review of the literature.

PURPOSE: Epilepsy associated with neurofibromatosis type 1 (NF1) is infrequent and usually controlled with anti-epileptic drugs. However, in some drug-resistant patients a presurgical evaluation should be considered. Hippocampal sclerosis (HS) is one of the rare causes of epilepsy in neurofibromatosis type 1, which can lead to surgery. METHODS: We present a three-year-old child with refractory epilepsy associated with several structural brain abnormalities but normal hippocampi on brain MRI and a heterozygous variant in the NF1 gene (c.2542G > A). A complete presurgical evaluation was performed including stereo-electroencephalography (SEEG). RESULTS: Usual seizures were recorded, and the seizure onset zone was delineated in the anterior hippocampus. Pathological examination performed after a tailored mesio-temporal resection confirmed hippocampal sclerosis, and the child achieved seizure freedom with 2 years of follow-up. CONCLUSION: This rare pediatric case illustrates that NF1 may be associated with early-onset refractory epilepsy secondary to MRI-negative HS, supporting the major role of SEEG in the presurgical evaluation of patients with extended cortical malformations.

Microsurgical Transcranial Approach of 112 Paraoptic Meningiomas: A Single-Center Case Series.

BACKGROUND: Predictors of visual outcomes after optic nerve decompression are controversial. OBJECTIVE: To identify the predictors of poor visual outcomes after surgery of meningiomas responsible of a compressive optic neuropathy. METHODS: We focused on paraoptic meningiomas (POMs), which gathered tuberculum sellae meningiomas (TSMs) and anterior clinoid meningiomas (ACMs) responsible for visual impairment or threatening visual function, that underwent surgery at our institution between January 2009 and December 2015 and analyzed the clinical and radiological findings of our patients. RESULTS: Among 112 patients who underwent surgery for a POM, a preoperative visual deficit was present in 108 patients (96.4%). Six months after surgery, 79 patients (70.5%) had a visual improvement, 15 patients (13.4%) had an unchanged vision, and 18 patients (16.1%) had deteriorated vision. A preoperative visual deficit of 6 mo or more was a strong predictor of poor visual outcome after surgery (P = .034). Poor visual outcome after surgery was not significantly related to the size of the tumor (P = .057), the age of the patient (P = .94), or the tumor extension into the optic canal (P = .47). CONCLUSION: The duration of preoperative visual deficit was found to be a strong predictor of poor visual outcomes after surgery in POMs Other predictors of poor visual outcomes are still needed and are currently under evaluation in a prospective study at our institution.

Invasive evaluation in children (SEEG vs subdural grids).

Designed from the 60s to the 80s for adults, and despite the development of many new techniques, invasive explorations still have indications in children with focal drug-resistant epilepsy. The main types are stereoelectroencephalography (SEEG) and subdural explorations (SDE). They provide precise information on the localization of the epileptogenic zone (EZ), its relationships with eloquent cortex, and the feasibility of performing a tailored surgical resection. Thermocoagulations, which are a diagnostic and therapeutic tool, can be performed using SEEG electrodes. Both techniques are feasible in children, with an age limitation for SEEG (which requires a bone thickness above 2 mm). The complication rate is higher with SDE. Opposed for a long time and never compared in a systematic study, they should presently be considered complementary. The indications cannot be directly inferred from those for adults, as there are pediatric particularities in the seizures' semiology, functional areas, imaging and urgent situations. We successively discuss the choice in individual cases of SEEG or SDE respectively, the specific problematic in infancy and early childhood, the schema in SEEG for cryptogenic epilepsies (in particular insular), the particularities of polymicrogyria and deeply located lesions, and finally, SEEG designed for thermocoagulations. Future improvements should include more accurate implantation schemas thanks to advanced non-invasive explorations and possibilities to perform SEEG in infants.

Seizure outcome and prognostic factors for surgical management of hypothalamic hamartomas in children.

PURPOSE: Hypothalamic hamartomas (HH) are rare benign lesions frequently associated with gelastic seizures early in life. Epilepsy can progress to multiple seizure types with cognitive impairment and behavioural disturbance, leading in some cases to epileptic encephalopathy. METHODS: We reviewed a retrospective series of 112 children treated in a single center, between 1998 and 2017. RESULTS: According to Delalande's HH classification, type1 was found in 2 patients, type 2 in 67, type 3 in 31, and type 4 in 12 patients. Stereotactic endoscopic disconnection was performed in 92 % of the procedures. Median age at diagnosis was 40 months and 7.6 years at surgery. Median time between diagnosis and surgery was 31 months and median follow up 4.1 years. For all HH types, 77.6 % of the patients had a favourable outcome (Engel I + II outcome score) with 57.1 % seizure-free (Engel I). The best outcome was obtained in patients with type 2 HH, (68.7 % Engel I and 85.1 % Engel I + II). The overall complication rate was 8.3 %, which is in line with previous series. Patients with isolated gelastic seizures had a better outcome (Engel I + II in 90 %), as compared to those with other seizure types (p = 0.07). A short delay between hamartoma diagnosis and surgery was a statistically significant factor for a good outcome (p = 0.03). CONCLUSION: Patients with HH and drug-resistant epilepsy should be early identified in order to propose surgical treatment without delay. Endoscopic disconnection is a safe and efficacious surgical option with good seizure outcome and immediate treatment results.

Posterior Fossa Craniectomy with Endovascular Therapy of Giant Fusiform Basilar Artery Aneurysms: A New Approach to Consider?

BACKGROUND: The prognosis of unruptured giant basilar artery (BA) aneurysms is very poor. No treatment has shown efficacy in survival. This pilot case-control study examines the overall survival (OS) benefit of combined surgical and endovascular management of giant BA aneurysms. METHODS: Combined treatment including posterior fossa craniectomy followed by endovascular treatment was performed in 3 patients with giant BA aneurysms. OS of the 3 patients was compared with a control group of 6 patients (ratio 1:2) treated with the endovascular procedure only. RESULTS: The mean survival time was 32.6 months in the craniectomy group (SD 9.01, 95% confidence interval [14.9, 50.3]) and 3.5 months in the control group (SD = 2.08, 95% confidence interval [0.001, 7.6]; Mantel-Cox test P < 0.04). At mean follow-up of 36.5 months (SD 10.2), 2 of 3 patients had a favorable outcome with a Glasgow Outcome Scale score of 5. Univariate analysis determined that women had a statistically higher OS than men (33.7 months vs. 3.058 months for men; log-rank test P = 0.011). A similar outcome was obtained in the presence of a circulating posterior communicating artery (P = 0.03) and in the presence of an endovascular right vertebral artery occlusion (P = 0.022). CONCLUSIONS: Our study suggests that preventive posterior fossa craniectomy increases significantly OS of patients with giant BA aneurysms.

Poor Prognosis and Challenging Treatment of Optic Nerve Malignant Gliomas: Literature Review and Case Report Series.

BACKGROUND: Malignant optic glioma of adulthood is a rare, invasive neoplasm of the anterior visual pathway. In this article, the clinical features of a case series of 3 malignant optic nerve glioblastomas (World Health Organization grade IV) are presented, and the modalities of treatment and their associated survivals are discussed through a review of the existing literature to date. METHODS: A retrospective case series study was led for 3 patients diagnosed with primary optic nerve and chiasm glioblastoma, coming from 2 referral neurosurgical centers. An electronic search was conducted on MEDLINE via PUBMED, COCHRANE, from October 1973 to April 2016. Cohort, case reports, and case series were screened for investigating treatment and overall survival (OS) of malignant optic nerve gliomas. Pooled means and 95% confidence intervals of OS for each treatment were generated. RESULTS: From our retrospective case series, all patients had initial visual impairment (2 women and 1 man). The histologic diagnosis was done by biopsy. The patients' mean age was 67.3 years (standard deviation [SD] 18.5). The disease was rapidly lethal for all patients: median OS was 5 months (SD: 15.1). Two patients underwent chemotherapy by single cure of temozolomide, while the third one was treated with a radiochemotherapy protocol. Due to the fact that there is no gold standard treatment as first-choice treatment, a large heterogeneity in first-choice oncologic treatment is observed. However, we did not find any significant differences for OS between World Health Organization grade III and grade IV optic gliomas. CONCLUSION: Malignant optic glioma is a rare and fatal disease in adults. Despite the modalities of treatment, the treatment outcomes remain unsatisfactory. There is no significant difference in the median OS of patients with malignant optic nerve, as compared with those diagnosed with other supratentorial glioblastoma. Chemoradiotherapy with temozolomide currently remains the best treatment in terms of OS. Advances in the understanding of tumor biology have yet failed to translate into effective treatment regimens.

From the Skin to the Brain: Pathophysiology of Colonization and Infection of External Ventricular Drain, a Prospective Observational Study.

Ventriculostomy-related infection (VRI) is a serious complication of external ventricular drain (EVD) but its natural history is poorly studied. We prospectively tracked the bacteria pathways from skin towards ventricles to identify the infectious process resulting in ventriculostomy-related colonization (VRC), and VRI. We systematically sampled cerebrospinal fluid (CSF) on a daily basis and collected swabs from both the skin and stopcock every 3.0 days for microbiological analysis including in 101 neurosurgical patient. Risk factors for positive event defined as either VRC or VRI were recorded and related to our microbiological findings. A total of 1261 CSF samples, 473 skin swabs, and 450 stopcock swabs were collected. Skin site was more frequently colonized than stopcock (70 (60%) vs 34 (29%), p = 0.023), and earlier (14 ±1.4 vs 24 ±1.5 days, p<0.0001). Sixty-one (52%) and 32 (27%) skin and stopcock sites were colonized with commensal bacteria, 1 (1%) and 1 (1%) with pathogens, 8 (7%) and 1 (1%) with combined pathogens and commensal bacteria, respectively. Sixteen positive events were diagnosed; a cutaneous origin was identified in 69% of cases. The presence of a pathogen at skin site (6/16 vs 4/85, OR: 11.8, [2.5-56.8], p = 0.002) and CSF leakage (7/16 vs 6/85, OR 10 [2.4-41.2], p = 0.001)) were the two independent significant risk factors statistically linked to positive events occurrence. Our results suggest that VRC and VRI mainly results from an extra-luminal progression of pathogens initially colonizing the skin site where CSF leaks.

Endoscopic third ventriculostomy for idiopathic aqueductal stenosis.

BACKGROUND: Idiopathic aqueductal stenosis is a cause of noncommunicating hydrocephalus, which actual treatment with endoscopic third ventriculostomy (ETV) could assess without any interference with the etiology. The results of ETV in this indication therefore could be interpreted as the result of the surgical procedure alone, without any additional factors related to the etiology of the cerebrospinal fluid pathway obstruction, such as hemorrhage, infection, brain malformations, or brain tumors or cysts. METHODS: After a brief description of pathogenesis of hydrocephalus in aqueductal stenosis, the authors review the literature for studies on ETV, extrapolating patients with idiopathic aqueductal stenosis in infancy, childhood, and adulthood. Differences in outcome between patients treated with ETV and patients treated with ventriculoperitoneal shunt (VPS) are also reviewed. RESULTS: The overall success rates of ETV range between 23% to 94%, with a mean of 68%; when only patients affected by obstructive triventricular hydrocephalus secondary to aqueductal stenosis are considered, the success rate is actually quite homogeneous and stable, being above 60% at any age, even if a trend in lower success rate in very young infants (younger than 6 months of age) is noticeable. The few reports on intellectual outcome failed to demonstrate differences between ETV and VPS. CONCLUSIONS: Several issues, such as the cause of failures in well-selected patients, long-term outcome in infants treated with ETV, effects of persistent ventriculomegaly on neuropsychological developmental, remain unanswered. Larger and more detailed studies are needed.

Accuracy of external ventricular drainage catheter placement.

BACKGROUND: External ventricular drainage (EVD) is a freehand neurosurgical procedure performed routinely using the anatomical landmarks. OBJECTIVE: The aim of this study was to determine the accuracy of EVD catheter freehand placement. MATERIALS AND METHODS: Pre-operative and post-operative computed tomography scans for 66 consecutive EVDs performed in 56 adult patients (26 men, 30 women) in 2008 were retrospectively reviewed. Etiologies of acute hydrocephalus were subarachnoid or intraventricular haemorrhage (43 cases) or miscellaneous (13 cases). Pre-operative lateral ventricular volume, position of the burr hole, length of the catheter and its sagittal and coronal angular variations from a theoretical trajectory were measured. RESULTS: The EVD was placed on the right (53 cases) or left (13 cases) side. The mean pre-operative lateral ventricular volume was 51 cc (10-118 cc). The average distance from the burr hole to the midline was 28 mm (10-49 mm) and to the supra-orbital ridge was 101 mm (75-125 mm). The mean intracranial catheter length was 60 mm (from 39-102 mm). Only 50% of the EVDs in the coronal plane and 40% in the sagittal plane were placed with an angular variation of ±5° to the target. The tip was placed outside of the ventricles in three cases; 13 catheters crossed the midline, and five intracranial minor haemorrhages were detected. CONCLUSION: Freehand placement of EVDs does not have sufficient accuracy and may lead to drainage dysfunctions. This data suggests that a guidance system for EVD's would be required.

Intracranial cerebrospinal fluid spaces imaging using a pulse-triggered three-dimensional turbo spin echo MR sequence with variable flip-angle distribution.

OBJECTIVE: To assess the three-dimensional turbo spin echo with variable flip-angle distribution magnetic resonance sequence (SPACE: Sampling Perfection with Application optimised Contrast using different flip-angle Evolution) for the imaging of intracranial cerebrospinal fluid (CSF) spaces. METHODS: We prospectively investigated 18 healthy volunteers and 25 patients, 20 with communicating hydrocephalus (CH), five with non-communicating hydrocephalus (NCH), using the SPACE sequence at 1.5T. Volume rendering views of both intracranial and ventricular CSF were obtained for all patients and volunteers. The subarachnoid CSF distribution was qualitatively evaluated on volume rendering views using a four-point scale. The CSF volumes within total, ventricular and subarachnoid spaces were calculated as well as the ratio between ventricular and subarachnoid CSF volumes. RESULTS: Three different patterns of subarachnoid CSF distribution were observed. In healthy volunteers we found narrowed CSF spaces within the occipital aera. A diffuse narrowing of the subarachnoid CSF spaces was observed in patients with NCH whereas patients with CH exhibited narrowed CSF spaces within the high midline convexity. The ratios between ventricular and subarachnoid CSF volumes were significantly different among the volunteers, patients with CH and patients with NCH. CONCLUSION: The assessment of CSF spaces volume and distribution may help to characterise hydrocephalus.