How to reduce the complication rate of multiple burr holes surgery in moyamoya angiopathy.

PURPOSE: This study is aimed at analyzing clinical outcome, absence of stroke recurrence, revascularization, and complications and long-term follow-up in the surgical treatment of moyamoya angiopathy (MMA) using the multiple burr holes (MBH) technique with dura opening and arachnoid preservation as a single procedure. To the best of our knowledge, this is the first to describe an MBH technique with arachnoid preservation. METHOD: We retrospectively reviewed all patients operated from June 2001 to March 2021, for a symptomatic and progressive MMA operated with opening of the dura but arachnoid preservation. Clinical examinations were obtained in all patients, and radiological monitoring was performed by cerebral 3D-magnetic resonance angiography (MRA) with perfusion or single-photon emission computed tomography (SPECT) with acetazolamide. RESULTS: In total, 21 consecutive patients (6 children and 15 adults) were included with a mean age of 7.4 years in the pediatric group and 36.9 years in the adult group. Initial presentation was permanent ischemic stroke in 15 cases, transient ischemic attack (TIA) in 5 cases, and cerebral hemorrhage in one case. The MBH with dura opening and arachnoid preservation was performed bilaterally in 9 cases (43%) and unilaterally in 12 cases (57%). One patient died due to intraoperative bilateral ischemic stroke. Of the 20 other patients, 30% demonstrated clinical stability and 70% showed partial or complete recovery. Although one patient experienced a perioperative stroke, we did not observe any pseudomeningocele or postoperative ischemic stroke (IS) recurrence in all surviving cases during the average follow-up period of 55.5 months (range: 1-195). These outcomes emphasize the importance of preoperative monitoring to ensure the effectiveness and safety of the intervention. Postoperative angiography studies showed revascularization in 96.3% of treated hemispheres (100% in the adult group vs 80% in the pediatric group). CONCLUSIONS: Our results on this small cohort suggest that the MBH technique with opening of the dura and arachnoids preservation can prevent recurrent strokes and reduce the risk of pseudomeningocele.

Ectopic sphenoidal ACTH-secreting adenoma revealed by 11C Methionine PET scan: case report.

BACKGROUND: Ectopic ACTH pituitary adenomas (EAPA), located outside the sella turcica and deriving from cellular remnants of Rathke's pouch are a very rare cause of Cushing's syndrome (CS). The diagnosis is often difficult and delayed, even after comprehensive work-up. To our knowledge, we report for the first time an ectopic corticotroph tumor of the posterior wall of the sphenoid sinus, leading to false positive results of bilateral inferior petrosal sinus sampling (BIPPS) and which was finally localized by a co-registered11 C Methionine PET/MR imaging. CASE PRESENTATION: A 48-year-old woman was referred for a high clinical suspicion of ACTH-dependent CS. Biological testing comprising low dose dexamethasone suppression and CRH stimulation tests were indicative of pituitary Cushing's disease, but comprehensive pituitary MRI did not reveal any pituitary adenoma. BIPSS confirmed however a central origin of ACTH secretion (central-to-peripheral ACTH ratio > 100) and revealed a significant right-to-left gradient (6.2), leading to a first right-sided exploratory hypophysectomy, that did not cure the patient. BIPSS images were reviewed and revealed preferential drainage of the left pituitary to the right petrosal sinus, leading us to a left sided exploratory hypophysectomy, which was again unsuccessful. A11 C Methionine PET/MRI was performed and revealed a hypermetabolic lesion adjacent to the posterior wall of the sphenoidal sinus. After surgical resection, this polypoid mass was identified as an ectopic ATCH-secreting pituitary adenoma expressing ACTH and T-Pit and complete remission of hypercortisolism was observed. CONCLUSIONS: In conclusion, we report a case of ACTH-dependent Cushing's syndrome, caused by an ectopic corticotroph adenoma located in the sphenoidal sinus, which perfectly mimicked the biological features of a classical pituitary ACTH adenoma on a comprehensive hormonal evaluation including BIPPS, and the features of a benign naso-sinusal polyp at MRI. We report for the first time a key role of11 C Methionine PET co-registered to high resolution MRI for localizing ectopic adenomas, efficiently guiding surgical removal and leading to complete remission of hypercortisolism.

Holmes tremor in a monocentric series of resected brainstem cavernomas.

OBJECT: Several scientific papers report clinical symptoms, indications, complications and outcomes of brainstem cavernous malformation (BSCM) surgery without reporting on the occurrence of postoperative Holmes tremor (HT). Our purpose is to report our experience with HT in a monocentric series of resected brainstem cavernomas. METHODS: We reviewed all the BSCM surgical records between 2002 and 2018 at Saint-Luc University Hospital's Department of Neurosurgery, Brussels and selected patients developing HT postoperatively. Patients' demographics, symptoms, pre- and postoperative imaging, recurrence and complications were analysed. A PubMed literature review was performed to compare our results with those in the existing literature. RESULTS: In a total series of 18 resected BSCM, 5 patients: 1 male and 4 females, with a median age of 51 years (range 29-59 years), developed HT. The median preoperative mRS score was 2 (range 1-4). GTR was achieved in all patients without surgery-related death. BSCM were located in the mesencephalon in 4 patients (80%) who developed HT. Tremor was noticed between ten days and one year after surgery. One patient saw significant improvements to the point of stopping treatment. The median follow-up period was 2 years (range 1-14 years). At the last follow-up, 40% of our patients showed a worse mRS score, 40% stayed unchanged, and 20% improved. CONCLUSION: We are reporting an original single-center series of patients suffering from HT after BSCM surgery. The risk for HT after surgery is significant for midbrain BSCM. A spontaneous favorable evolution is possible.

Functional Prognostic value of optical coherence tomography in optic chiasmal decompression: A preliminary study.

PURPOSE: To assess the predictive value for functional recovery of Ganglion Cell Complex Layer (GCC) and Retinal Nerve Fiber Layer (RNFL) measurements obtained by Optical Coherence Tomography (OCT) in patients undergoing chiasmal decompression and to define potential OCT thresholds for visual recovery. METHODS: We measured preoperative GCC and RNFL thickness in patients with a sellar and/or perisellar tumor compressing the optic chiasm. Visual recovery was defined as recovery of mean deviation (MD) and pattern standard deviation (PSD) using Humphrey visual field testing after 12 successful decompressions (24 eyes). Receiver operating characteristic curve (ROC) analysis was used to identify the best thresholds. RESULTS: Robust global and focal OCT thresholds were found. Superior GCC≥63µm had the best functional prognostic value (AUC=1) for visual improvement. Mean GCC ≥ 67µm and mean RNFL≥75µm also had excellent predictive values (AUC>0.9). CONCLUSION: In this preliminary study, significant preoperative OCT thresholds for early visual recovery after chiasmal decompression were identified, mainly regarding GCC measurements. Further studies on larger cohorts with closely scheduled follow-up could refine our results.

Anterior thalamic nucleus deep brain stimulation for refractory epilepsy: Preliminary results in our first 5 patients.

OBJECTIVES: Deep brain stimulation (DBS) of the anterior thalamic nucleus (ATN) has been recognized to be an efficient treatment of refractory epilepsy (RE). However, ATN targeting is difficult and up to 8% of lead misplacement is reported. Our objective is to report our surgical procedure based on MRI targeting and our clinical results. PATIENTS AND METHODS: Our first five consecutive patients (4M, 1F, mean age: 42.8 years) treated by DBS of ATN between March and October 2016 were included. The mean duration of their epilepsy was 29 years. Four patients had already vagal nerve stimulation and 2 mammillary body stimulation. Stereotactic coordinates were calculated using distal segment of mammillothalamic tract as landmark. All procedures were performed under general anesthesia with intraoperative control of lead position using a robotic 3D fluoroscopy and image fusion with the preoperative MRI. RESULTS: No complications or lead misplacement was observed. The mean 3D distance between the planned target and location of the lead was 1.8 mm. Each patient was followed up at least one year (15+3months). The stimulation parameters were: 140Hz, 90m/s and 5 Volts with one minute ON/five minutes OFF cycle. The mean reduction of seizure frequency reached -52.5% (+32.2) at 6-months but decreased to -24.5% (+65.7) at the last follow-up due to some adverse events not related to stimulation. CONCLUSION: No complication, no lead misplacement and the improvement in our first patients, previously not help by multiple medications or surgeries, are encouraging.

Multiple subpial transections and magnetic resonance imaging.

INTRODUCTION: Multiple subpial transection (MST) has been applied to the treatment of refractory epilepsy when epileptogenic zone involves eloquent areas since 1989. However, there is a lack of data evaluating the effect of this surgical technique on the cortex as measured by Magnetic Resonance Imaging (MRI). PATIENTS AND METHODS: Ten consecutive patients (3F/7M, average age: 18.5 years) were operated on using radiating MST (average: 39; min: 19, max: 61) alone (n=3) or associated with another technique (n=7). Seven patients underwent a post-operative 3.0T MRI while 3 had a 1.5T MRI. Three patients had an early post-operative MRI and 7 a late MRI, among which 3 previously had an intraoperative MRI. RESULTS: The MR sequences that allowed the best assessment of MST-induced changes were T2 and T2*. The traces of MST are more visible on late MRI. These discrete non-complicated stigmas of MST were observed in all 10 studied patients: on the intraoperative MRI they are seen as micro-hemorrhagic spots (hypo-T2), on the early postoperative MRI as a discreet and limited cortical edema whether associated or not with micro-hemorrhagic spots and on the late MRI as liquid micro-cavities (hyper-T2) surrounded with a fine border of hemosiderin. CONCLUSIONS: MST-induced cerebral lesions are best visualized in T2-sequences, mainly on the late postoperatively MRIs. On all the MRI examinations in this study, the MST are only associated with limited modifications of the treated cortical regions.

Myelopathy secondary to a spinal cord compression induced by C2 nerve tumors during head rotation.

INTRODUCTION: It is well known that nerve root tumors developing in the spinal canal can be responsible for spinal cord compression leading to myelopathy and neurological deficits. We report the case of a patient with bilateral C2 neurofibromas presenting with a myelopathy of the upper cervical spine with no spinal cord compression on standard magnetic resonance imaging. The spinal cord compression occurred between the cervical neurofibromas only during head rotation. CASE REPORT: A patient with bilateral neurofibromas of the C2 nerve roots showed a progressive neurological deterioration with an intramedullary MRI hypersignal without visible compression. Only an additional MRI carried-out with the head in rotation demonstrated the tumoral dynamic compression. A review of the literature showed that only two similar cases had previously been reported. The largest C2 tumor was completely removed uneventfully. CONCLUSION: Dynamic compression of the spinal cord in patients with bilateral C2 nerve root tumors must be routinely investigated even if the standard MRI shows no compression.

Partial cauda equina syndrome after an uneventful minimally invasive microdiscectomy in a patient with Crohn's disease.

Cauda equina syndrome is a serious condition resulting from dysfunction of the lumbosacral nerve roots and characterized by impairment of bladder, bowel, sexual and lower limb functions. We report the case of a 48-year-old woman who had Crohn's disease for more than twenty years. The patient was undergoing immunotherapy with infliximab and developed a partial cauda equina syndrome after an uneventful minimally invasive microdiscectomy (L5-S1) that completely cured her sciatica. A postoperative magnetic resonance imaging examination showed root clumping but no compressive lesion. We discuss a possible relationship between the cauda equina syndrome and the patient's active Crohn's disease, treatment and surgery.

Application of a three-dimensional graft of autologous osteodifferentiated adipose stem cells in patients undergoing minimally invasive transforaminal lumbar interbody fusion: clinical proof of concept.

BACKGROUND: The authors applied a scaffold-free osteogenic three-dimensional (3D) graft made of adipose-derived mesenchymal stem cells (AMSCs) in patients undergoing minimally invasive transforaminal lumbar interbody fusion (MI-TLIF). METHODS: Three patients (two patients and one patient with 1 and 2 levels, respectively) with degenerative spondylolisthesis underwent MI-TLIF with 3D graft made of AMSCs. To obtain the AMSCs, fatty tissue was collected from the abdomen by lipoaspiration and differentiated afterwards in our Cell/Tissue bank. Clinical outcomes, including the Oswestry Disability Index (ODI) and visual analog scale (VAS) as well as fusion status were assessed preoperatively and up to 12 months postoperatively. RESULTS: At 12 months, all four operated AMSC levels could be assessed (n = 4). Grade 3 fusion could be confirmed at two levels out of four. Mean VAS score improved from 8.3 to 2 and ODI also improved from 47 to 31%. No donor site complication was observed. The final AMSC osteogenic product was stable, did not rupture with forceps manipulation, and was easily implanted directly into the cage with no marked modification of operating time. CONCLUSIONS: A scaffold-free 3D graft made of AMSCs can be manufactured and used as a promising alternative for spinal fusion procedures. Nevertheless, further studies of a larger series of patients are needed to confirm its effectiveness.

Evaluation of a clip-reinforced wrapping technique with collagen-impregnated Dacron for intracranial aneurysms inaccessible to other treatment.

OBJECTIVE: To describe our clip-reinforced wrapping technique (CRW) with collagen-impregnated Dacron and report our experience in intracranial aneurysms (IA) untreatable by coil embolization (CE) or surgical clipping (SC). METHODS: Between July 2003 and November 2010, CRW was performed on 20 IAs in 18 patients using a collagen-impregnated Dacron fabric (Hemashield(®), USA) fixed with a clip around the parent vessel and the IA. RESULTS: Two patients (11%) died of complications from their subarachnoid hemorrhage and preexisting conditions. In the remaining 16 patients, after an average follow-up of 45 months (min: 27, max: 77), 16 (89%) out of the 18 treated aneurysms were no longer visible and two were reduced and stable. CONCLUSION: Our preliminary results suggest that CRW with Hemashield could be an accurate and safe alternative technique for some IA without any other treatment option. IMPLICATIONS: Description of an alternative surgical technique for otherwise untreatable intracranial aneurysms.

Invasive EEG in refractory epilepsy: insertion of subdural grids through linear craniectomy reduces complications and remains effective.

OBJECTIVE: To evaluate our technique of implanting subdural grids by linear craniectomy under computer-assisted navigation for invasive electroencephalography in medically refractory epilepsy. MATERIAL AND METHOD: We report results from our first 38 consecutive patients with medically refractory epilepsy who underwent subdural grids implantation by linear craniectomy. For each case, a preoperative MRI was performed for navigation followed by a postoperative MRI for localization control of the intracranial electrode contacts. A linear skin incision, adapted to the depth and type of subdural electrode (strip or grid) and compatible with possible subsequent therapeutic surgery, was carried out. One or two linear craniectomies (maximal length 6cm, width 1cm) were then drilled with a bevel. The dura mater was incised under microscopic guidance to avoid opening the arachnoid. The required subdural electrodes were then slipped subdurally through each linear craniectomy (letter-box technique). RESULTS: Forty-one invasive electroencephalographies were performed with 28 (68%) bilateral. For all invasive electroencephalographies, at least one subdural grid was implanted. Sixty-one subdural grids were implanted in total, 52 with 20 contacts and nine with 32 contacts. No cerebrospinal fluid leakage, no infection, no neurological deficit and no permanent complications were observed. Three subdural grids (5%) were not positioned exactly as planned but this had no consequence for the invasive electroencephalography analysis. CONCLUSION: The implantation of 61 consecutive subdural grids for invasive electroencephalography through linear craniectomies was associated with no transient or permanent complications in this population. This letter-box technique appears to be practical and safe without limiting explorative efficacy.

Glioblastoma surgery with and without intraoperative MRI at 3.0T.

BACKGROUND: Gross total or near total resection (GTR/NTR; resection ≥95%) of glioblastoma (GBM) seems correlated with a longer survival. Intraoperative MRI (ioMRI) is one method to evaluate the extent of resection (EOR) in order to improve it during the same anesthesia. We compared GBM resections using a 3.0T ioMRI and then without considering the EOR, safety, survival and discussed the indications for using this expensive modality. METHODS: Between March 2006 and November 2011, 56 GBM resections were performed using an ioMRI, and 38 without (control group). The only criterion in order to have access to the ioMRI was its availability. We compared the variables EOR, Karnofsky Performance Scale scores and survival in both groups. RESULTS: In the ioMRI group, 15 patients (26.8%) underwent an immediate second resection increasing the GTR rate of 10.7% and the GTR/NTR rate of 8.9%. There was a significant difference between the use of an ioMRI and the control group in reaching a larger EOR (P=0.049, Fisher's exact test). The effect of using the ioMRI or not on the overall survival, with EOR as covariate, was not significant (P=0.147, Likelihood ratio test). However, the EOR alone had a significant effect on survival (P=0.049, Wald test), with a shorter survival for the patients with a partial resection (PR) than a GTR/NTR (Hazard ratio=1.6, 95% CI HR: 1.00-2.69), with a median overall survival of 15.26 months (95% CI: 12.34-19.08) for the GTR/NTR subgroup versus 10.26 months (95% CI: 6.64-15.82) for the PR subgroup. Multivariate regression analysis also identified age, sex and adjuvant chemotherapy as factors significantly associated with overall survival. CONCLUSIONS: A 3.0T ioMRI improved the quality of resection by 17.8% and increased the GTR/NTR rate by 8.9% up to 73.2% without additional morbidity. A GTR/NTR improves survival duration by about 50%. Thus, it remains reasonable to increase the EOR to reach GTR/NTR using an intraoperative control. However, ioMRI should be limited to the cases for which a GTR/NTR seems preoperatively possible.

Spontaneous submucosal sphenoidal fistula discovered intraoperatively. A case report.

BACKGROUND AND IMPORTANCE: Skull base spontaneous cerebrospinal fluid fistulas have been recently recognized as secondary to pseudotumor cerebri. In most cases, they occur in the ethmoid region and the sphenoid bone which is much less affected. Regardless of their etiology, the clinical manifestation of skull base fistulas is usually the same and includes a rhinorrhea and less frequently an otorrhea. We report a case of a cryptic sphenoid cerebrospinal fluid fistula discovered intraoperatively during the excision of a pituitary ACTH-secreting microadenoma (2mm in diameter). CLINICAL PRESENTATION: A 54-year-old female was admitted to our neurosurgery department for Cushing's disease due to a pituitary microadenoma. Six months prior to admission, she complained of severe fatigue, polyphagia and weight gain. Clinical examination revealed central obesity with a body mass index of 45kg/m(2) and other symptoms suggestive of Cushing's disease. Hormonal tests and a MR scan revealed a pituitary ACTH-secreting microadenoma. During the operative procedure via a transnasal approach, her nasal and sphenoid sinus mucosa appeared unusually edematous. After removal of the latter in order to approach the sellar floor, a millimetric hole in the bone at the level of the optic groove was visualized which let out cerebrospinal fluid under pressure without interruption. The microadenoma was macroscopically completely removed without any cerebrospinal fluid coming from the pituitary surgical cavity. The closing procedure of the sphenoid groove millimetric opening was performed by injecting fibrin glue and a lumbar drain was placed indwelling for four days. CONCLUSION: This case report describes a cryptic sphenoid submucosal cerebrospinal fluid fistula in a patient with Cushing's syndrome. This type of case raises the question of the natural evolution of the skull base cerebrospinal fluid fistula from its formation to an externalization such as rhinorrhea.

Recurrent acute subdural bleeding as a rare complication of a hemorrhagic non malignant meningioma.

We report the case of a 66-year-old male patient who presented acute and sub-acute subdural hematomas complicating a grade I meningioma. In the absence of trauma, detection of a subdural hematoma necessitates an etiologic research, in particular the exclusion of a vascular anomaly or a tumour. Subdural bleeding as a complication of a non malignant meningioma is a very rare and threatening situation and requires prompt surgical removal of the tumor.

Percutaneous pedicle screw implantation for refractory low back pain: from manual 2D to fully robotic intraoperative 2D/3D fluoroscopy.

Many surgical treatments for chronic low back pain that is refractory to medical treatments focus on spine stabilization. One of the main surgical procedures consists of placing an interbody cage with bone grafts associated with pedicle screws [2, 25, 30]. This technique can be performed using different approaches: a large open posterior approach, tubular approaches (minimal open) or percutaneously (minimally invasive percutaneous or MIP) [5, 28]. One of the main difficulties is to precisely locate the screws into the pedicle avoiding especially infero-medial pedicle breaches. This difficulty is even great- er when working percutaneously. This paper focuses on percutaneously placed pedicle screws (PPS), reports the use of a robotic multi-axis 2D/3D fluoros- copy to enhance the accuracy of pedicle screw placement and reviews other strategies and results reported in the literature.

[Indications and surgical treatments for failed coiled aneurysms]. / Indications et traitement chirurgical des anévrismes intracrâniens après recanalisation ou embolisation incomplète.

The possibility of treating intra-cranial aneurysms (ICA) through an endovascular approach is a great progress. But, as any technique, it has its own limitations. Multidisciplinary neurovascular teams are regularly confronted with ICA where embolization is a poor option or even failed (a residue of more than 5% at six months follow-up or after recanalization). Another potential failure is a coil extrusion into the parent vessel with thrombo-embolic risks. Our team and others in the world developed strategies to manage these complex cases. After a brief review of the literature, we describe our experience and present a modified Gurian classification. This classification allows a better identification of the various failed coiled aneurysms types and their potential surgical treatments.

Surgical indications and techniques for failed coiled aneurysms.

For two decades, endovascular coiling has revolutionized the treatment of intracranial aneurysms. However, as with all techniques, it has limitations and endovascular radiologists and neurosurgeons are regularly confronted by what we call "failed" coiled aneurysms. Failed coiled aneurysms can occur in different situations: a) presence of a significant remnant at the end of an endovascular procedure; b) recanalization of an initially satisfactory occlusion; and c) coil extrusion deemed too thrombogenic or threatening the blood flow in the parent vessel. We and other teams around the world have developed strategies to manage these difficult cases. Here, we compare our own experience with other reports in the literature.

Intra-operative 3.0 T magnetic resonance imaging using a dual-independent room: long-term evaluation of time-cost, problems, and learning-curve effect.

We present a short and comprehensive report of our 39-month experience using a 3.0 T intra-operative magnetic resonance imaging (ioMRI) neurosurgical-MR twin room, including a description of the problems encountered and the associated time-delays. Forty-seven problems were experienced during the 189 ioMRI procedures (two ioMRI were performed in five of the 184 surgical procedures) performed in the 39-month period, including a blocked transfer table, failure of anesthetic monitoring material, and specific MRI-related problems, such as head and coil positioning difficulties, artefacts, coil malfunctions and other technical difficulties. None of these problems prevented the ioMRI procedure from taking place or affected image interpretation, but they sometimes caused a significant delay. Fifteen (32%) of these problems occurred during the initial learning curve period. The mean duration of the ioMRI procedure was 75 min, which decreased slightly with experience, although an average waiting-for-access time of 24 min could not be avoided. These results illustrate that although performing ioMRI at 3.0 T with the dual room is a challenging procedure, it remains safe and feasible and associated with only minor dysfunctions while offering optimal image quality and standard surgical conditions.

Intraoperative 3T MR imaging for spinal cord tumor resection: feasibility, timing, and image quality using a "twin" MR-operating room suite.

We assessed feasibility, safety, and timing of an original intraoperative MR procedure in 3 cases of resection of spinal cord glioma by using a clinical 3T MR system connected to an adjacent operating room in a design being coined "twin" or "dual" MR-operating room suite.