How to understand an enlarged Meckel's cave? An anatomical study.

PURPOSE: Dilatation of the trigeminal cavum, or Meckel's cave (MC), is usually considered a radiological sign of idiopathic intracranial hypertension. However, the normal size of the trigeminal cavum is poorly characterized. In this study, we describe the anatomy of this meningeal structure. METHODS: We dissected 18 MCs and measured the length and width of the arachnoid web and its extension along the trigeminal nerve. RESULTS: Arachnoid cysts were clearly attached to the ophthalmic (V1) and maxillary (V2) branches until they entered the cavernous sinus and foramen rotundum, respectively, without extension to the skull base. Arachnoid cysts were close to the mandibular branch toward the foramen ovale, with a median anteromedial extension of 2.5 [2.0-3.0] mm, lateral extension of 4.5 [3.0-6.0] mm, and posterior extension of 4.0 [3.2-6.0] mm. The trigeminal cavum arachnoid had a total width of 20.0 [17.5-25.0] mm and length of 24.5 [22.5-29.0] mm. CONCLUSION: Our anatomical study revealed variable arachnoid extension, which may explain the variability in size of the trigeminal cavum in images and calls into question the value of this structure as a sign of idiopathic intracranial hypertension. The arachnoid web extends beyond the limits described previously, reaching almost double the radiological size of the cavum, particularly at the level of V3 afference of the trigeminal nerve. It is possible that strong adhesion of the arachnoid to the nerve elements prevents the formation of a true subarachnoid space that can be visualized by magnetic resonance imaging.

Bilateral spheno-orbital meningiomas: surgical management, progression, and recurrence.

OBJECTIVE: Bilateral spheno-orbital meningiomas (bSOMs) are a rare entity among meningiomas. These tumors are benign and predominantly affect women. They represent 4% of spheno-orbital meningiomas (SOMs) and are poorly described in the literature. This study aimed to describe the characteristics, risk factors, evolution, and management of bSOMs. METHODS: Twenty patients with bSOMs were enrolled in a multicentric descriptive study including 15 neurosurgical departments. RESULTS: In this study, the authors found that bSOMs affected exclusively women, with a mean age of 50 years. Approximately 65% of patients were on progestin therapy. The mean follow-up in this series was 55 months. Clinically, visual symptoms were predominant: proptosis was present in 17 of 20 patients (85%; 7 unilateral, 10 bilateral), and a decrease in visual acuity was observed in 11 of 20 patients (55%; 6/10 to 9/10 in 6 patients, 3/10 to 5/10 in 1 patient, and < 3/10 in 4 patients). Contrary to unilateral SOMs, the authors identified that intracranial hypertension was a common presentation (25%) of bSOMs. Surgical management with gross-total resection was the gold standard treatment. Recurrences only occurred following subtotal resection in 36% to 60% of patients, with a median time of 50 to 54 months after surgery. Visual improvement or stability was observed in 75% of cases postoperatively. Progesterone receptor expression levels were 70% to 100% in 10 of 11 (91%) cases. CONCLUSIONS: Bilateral SOMs are usually found in female patients and are strongly associated with hormone replacement therapy. Early surgical management with gross-total resection is the most effective treatment in terms of recurrence and improves visual acuity. Given the slow progressive nature of bSOMs and their time to recurrence, which can be up to 10 years, long-term follow-up of patients is essential.

Effect of microorganisms isolated by preoperative osseous sampling on surgical site infection after autologous cranioplasty: A single-center experience.

PURPOSE: The most frequent postoperative complication in autologous cranioplasty (AC) is infection. European recommendations include osseous sampling before cryogenic storage of a bone flap. We evaluated the clinical impact of this sampling. METHODS: All patients who underwent decompressive craniectomy (DC) and AC in our center between November 2010 and September 2021 were reviewed. The main outcome was the rate of reoperation for infection of the cranioplasty. We evaluated risk factors for bone flap infection, rate of reoperation for any reason (hematoma, skin erosion, cosmetic request, or bone resorption), and radiological evidence of bone flap resorption. RESULTS: A total of 195 patients with a median age of 50 (interquartile range: 38.0-57.0) years underwent DC and AC between 2010 and 2021. Of the 195 bone flaps, 54 (27.7%) had a positive culture, including 48 (88.9%) with Cutibacterium acnes. Of the 14 patients who underwent reoperation for bone flap re-removal for infection, 5 and 9 had positive and negative bacteriological cultures, respectively. Of patients who did not have bone flap infection, 49 and 132 had positive and negative bacteriological cultures, respectively. There were no significant differences between patients with and without positive bacteriological culture of bone flaps in the rates of late bone necrosis and reoperation for bone flap infection. CONCLUSIONS: A positive culture of intraoperative osseous sampling during DC is not associated with a higher risk of re-intervention after AC.

When to discharge patients following a neuronavigation-assisted brain biopsy for supratentorial lesion? A single-center experience.

OBJECTIVE: Most brain biopsies are performed using the frame-based stereotactic technique and several studies describe the time taken and rate of complications, often allowing an early discharge. In comparison, neuronavigation-assisted biopsies are performed under general anesthesia and their complications have been poorly described. We examined the complication rate and determined which patients will worsen clinically. METHODS: All adults who underwent a neuronavigation-assisted brain biopsy for a supratentorial lesion from Jan, 2015, to Jan, 2021, in the Neurosurgical Department of the University Hospital Center of Bordeaux, France, were analyzed retrospectively in accordance with the Strengthening the Reporting of Observational studies in Epidemiology (STROBE) statement. The primary outcome of interest was short-term (7 days) clinical deterioration. The secondary outcome of interest was the complication rate. RESULTS: The study included 240 patients. The median postoperative Glasgow score was 15. Thirty patients (12.6 %) showed acute postoperative clinical worsening, including 14 (5.8 %) with permanent neurological worsening. The median delay was 22 h after the intervention. We examined several clinical combinations that allowed early postoperative discharge. A preoperative Glasgow prognostic score of 15, Charlson Comorbidity Index ≤ 3, preoperative World Health Organization Performance Status ≤ 1, and no preoperative anticoagulation or antiplatelet treatment predicted postoperative worsening (negative predictive value, 96.3 %). CONCLUSION: Optical neuronavigation-assisted brain biopsies might require longer postoperative observation than frame-based biopsies. Based on strict preoperative clinical criteria, we consider to plan postoperative observation for 24 h a sufficient hospital stay for patients who undergo these brain biopsies.

Cauda Equina Syndrome: Poor Recovery Prognosis Despite Early Treatment.

STUDY DESIGN: A prospective patient's database operated on a cauda equina syndrome (CES). OBJECTIVE: The aim of our study was to identify prognosis factors for favorable functional recovery after CES. SUMMARY OF BACKGROUND DATA: CES is a neurologic impairment of variable symptoms associating urinary, bowel, and sexual dysfunctions with or without motor or sensitive deficits caused by nerve root compression of the cauda equina. The definition of CES remains debated, as well as the prognosis factors for favorable functional recovery and the benefit of early surgery. METHODS: One hundred forty patients were included between January 2010 and 2019. Univariate and multivariate cox proportional hazard regression models were conducted. RESULTS: The patients were young with a median age of 46.8 years (range 18-86 yrs). At presentation, 60% were affected by a motor deficit, 42.8% a sensitive deficit, 70% urinary dysfunctions, and 44% bowel dysfunctions. The mean follow-up was 15.5 months. Bilateral motor deficit (P = 0.017) and an initial deficit severity of 0 to 2 (P = 0.001) represented prognosis factors of poor motor recovery. Initial anal incontinence (P = 0.007) was associated with poor bowel recovery. Only 32.8% of the patients went back to work. Initial motor deficit (P = 0.015), motor sequelae (P = 0.001), sphincter dysfunctions sequelae (P = 0.02), and long LOS (P = 0.02) were poor return-to-work prognosis factors. Time to surgery within an early timing < 24 or 48 hours or later did not represent a prognosis factor of recovery in CES. Incomplete versus complete CES did not show better recovery. CONCLUSION: CES remains a profound disabling syndrome with poor functional prognosis: in the long run, few patients go back to work. The main prognosis factors established in our series regarded the initial severity of deficits whether motor or sphincteral. Early or later surgical cauda equina decompression did not show to represent a prognosis factor for functional recovery.Level of Evidence: 4.

Spinal Dural Arteriovenous Fistulas: Clinical Outcome After Surgery Versus Embolization: A Retrospective Study.

OBJECTIVE: Spinal dural arteriovenous fistulas (SDAVFs) are rare vascular spinal malformations. According to the reported data, surgery seems to result in better occlusion rates than endovascular treatment. However, the post-treatment evolution of neurological symptoms stratified by the treatment remains unknown. The main objective of the present study was to compare the clinical outcomes for patients according to the treatment method. METHODS: The data from 63 patients with SDAVFs from 2000 to 2017 at 4 academic neurosurgical departments were retrospectively analyzed. Preoperative and postoperative examination neurological status was assessed using the Aminoff-Logue scale (ALS), which evaluates gait and micturition disturbances. Initial occlusion, late recurrence, and complications of the 2 techniques were also reviewed. RESULTS: Patients who had undergone surgery and embolization improved clinically on the ALS (P = 0.0009), and no significant differences were found between the 2 techniques. Subgroup analysis using the ALS showed that patients who had undergone surgery and embolization without late recurrence improved (P < 0.0001 and P = 0.0334, respectively) and that patients who had undergone surgery or embolization with late recurrence did not improve. The initial occlusion rate was in favor of surgery, with 91.3% versus 70% for endovascular treatment (P = 0.050). The late recurrence rate was higher for embolization (21.4% vs. 9.1% for surgery; P = 0.28). CONCLUSIONS: Surgery can be proposed as first-line treatment of SDAVFs after multidisciplinary discussion between neurosurgeons and neuroradiologists. The development of late recurrence negatively affects the neurological outcome of patients.