Management and Outcome of Recurring Low-Grade Intramedullary Astrocytomas.

Intramedullary astrocytomas (IMAs) are the second most frequent intramedullary tumors in adults. Low-grade IMAs (LG-IMA, WHO grade I and II) carry a better prognosis than high-grade IMAs (HG-IMAs). However, adjuvant treatment of LG-IMAs by radiotherapy (RT) and/or chemotherapy (CT) as well as treatment of tumor recurrences remains controversial. The aim of our study was to evaluate the postoperative outcome of LG-IMAs and the management of recurring tumors. We retrospectively reviewed a series of patients operated on for IMA from 1980 to 2022 in a single neurosurgical department. We retrieved 40 patients who received surgery for intramedullary astrocytomas, including 30 LG-IMAs (22 WHO grade I; 5 WHO grade II; 3 "low-grade") and 10 HG-IMAs (4 WHO grade III; 5 WHO grade IV; 1 "high-grade"). Of the patients with LG-IMAs, the extent of surgical resection was large (gross or subtotal resection >90%) in 30% of cases. Immediate postoperative radiotherapy and/or chemotherapy was proposed only to patients who underwent biopsy (n = 5), while others were initially followed-up. Over a median follow-up of 59 months (range = 13-376), 16 LG-IMA (53.3%) recurred with a mean delay of 28.5 months after surgery (range = 3-288). These included seven biopsies, five partial resections (PR), four subtotal resections (STR) but no gross total resections (GTR). Progression-free survival for LG-IMAs was 51.9% at 3 years and 35.6% at 5 and 10 years; overall survival was 96.3% at 3 years; 90.9% at 5 years and 81.9% at 10 years. There were no significant differences in terms of OS and PFS between WHO grade I and grade II tumors. However, "large resections" (GTR or STR), as opposed to "limited resections" (PR and biopsies), were associated with both better OS (p = 0.14) and PFS (p = 0.04). The treatment of recurrences consisted of surgery alone (n = 3), surgery with RT and/or CT (n = 2), RT with CT (n = 3), RT alone (n = 2) or CT alone (n = 2). In conclusion, although LG-IMAs are infiltrating tumors, the extent of resection (GTR or STR), but not WHO grading, is the main prognostic factor. The management of recurring tumors is highly variable with no conclusive evidence for either option.

A Staged Approach for Surgical Management of Basilar Invagination.

BACKGROUND AND OBJECTIVES: Patients with basilar invagination (BI) can be treated with several surgical options, ranging from simple posterior decompression to circumferential decompression and fusion. Here, we aimed at examining the indications and outcomes associated with these surgical strategies to devise a staged algorithm for managing BI. METHODS: We conducted a retrospective cohort study in 2 neurosurgical centers and included patients with a BI, as defined by a position of the dens tip at least 5 mm above the Chamberlain line. Other craniovertebral junction anomalies, such as atlas assimilation, platybasia, and Chiari malformations, were documented. C1-C2 stability was assessed with a dynamic computed tomography scan. RESULTS: We included 30 patients with BI with a mean follow-up of 56 months (min = 12, max = 166). Posterior decompression and fusion (n = 8) was only performed in cases of obvious atlanto-axial instability (eg, increased atlanto-dental interval or hypermobility on flexion/extension), while anterior decompression (transoral or transnasal) was reserved to patients with lower cranial nerves deficits (eg, swallowing dysfunction) and irreducible anterior compression (n = 9). Patients with posterior signs (eg, Valsalva headaches) or myelopathy but without C1-C2 instability nor anterior signs were managed with an isolated foramen magnum decompression, with or without duraplasty (n = 13). Complications were more frequent for combined procedures, including neurological deterioriation (n = 4) and tracheostomy (n = 2), but reinterventions were more likely in patients undergoing posterior decompression alone (n = 3). CONCLUSION: Patient selection is key to determine the appropriate surgical strategy for BI: In our experience, combined approaches are only needed for patients with irreducible and symptomatic anterior compression, while fusion should be restricted to patient with obvious signs of atlanto-axial instability. Other BI patients can be managed by foramen magnum decompression alone to minimize surgical morbidity.

Spinal Anterior Dural Dissection: Moving From Differential to Unifying Diagnosis.

BACKGROUND AND OBJECTIVES: Cerebrospinal fluid (CSF) collections extending longitudinally at the anterior aspect of the spinal dura have been reported in association with various conditions and under multiple names. The aim of this study was to report cases associated with brachial amyotrophy (BA) and examine its relationship with other clinical variants. METHODS: We conducted a retrospective cohort study including patients who presented with a motor deficit of the upper limbs and an anterior interdural CSF collection on spinal MRI. We performed a systematic review of the literature to include cases revealed by BA. RESULTS: Seven patients presenting with BA and a confirmed dural dissection on spinal MRI were included. All patients were male with a slowly progressing history of asymmetrical and proximal motor deficit of the upper limbs. Chronic denervation affecting mostly C5 and C6 roots was found on electroneuromyography. Spinal MRI demonstrated an anterior CSF collection dissecting the interdural space and exerting a traction on cervical motor roots. Dynamic computed tomography myelogram localized the dural defect every time it was performed (4/7 cases), and surgical closure was possible for 3 patients, leading to resolution of the collection. Literature review yielded 18 other published cases of spinal dural dissections revealed by BA, including 4 in association with spontaneous intracranial hypotension and 4 others in association with superficial siderosis. CONCLUSION: We propose a unifying diagnosis termed "spinal anterior dural dissection" (SADD) to encompass spinal dural CSF collections revealed by BA (SADD-BA), spontaneous intracranial hypotension (SADD-SIH), or superficial siderosis (SADD-SS).

Laminoplasty with tented duraplasty for Hirayama disease.

BACKGROUND: Hirayama disease (HD) is a characterized by progressive amyotrophy of the upper limbs due to a forward displacement of the cervical dura during neck flexion. METHODS: Unlike other treatment options aiming at preventing cervical flexion (e.g., collar or arthrodesis), laminoplasty with tented duraplasty addresses dural dysplasia. Technically, the procedure consists in enlarging the dural sac by performing an expansile duraplasty that is secured to the yellow ligaments, in association with an open-book laminoplasty. CONCLUSION: Laminoplasty with tented duraplasty is a surgical option addressing the cause of HD to prevent further neurological deterioration while preserving cervical motion.

Deep retroinsular and parieto-opercular origin of vestibular symptoms: A stereoelectrocenphalography (SEEG) study.

Several studies have shown that the retroinsular and posterior parietal operculum regions play a central role in vestibular processing. Electrical stimulations performed during stereoelectroencephalography (SEEG) in patients with focal drug-resistant epilepsy could contribute to the analysis of this area. Among the 264 SEEGs performed in both an adult and a paediatric epilepsy surgery centre, we retrospectively identified 24 patients (9%) reporting vertigo during electrical stimulations (ES). In seven of them (29% of patients experiencing vertigo during ES), it was evoked by stimulating the retroinsular region. The reported responses were mostly not rotatory sensations but actually illusions of body, limb or limb segment movement. The involved area is limited. Moreover, two patients reported having the same symptoms at the beginning of their seizures starting in the same region. Our case study confirms the pivotal role of the retroinsular and posterior parietal operculum areas in vestibular responses, and we therefore advise the exploration of this region when patients report an illusion of body movement at the beginning of their seizures.

Long-Term Outcomes after Incomplete Resection of Intramedullary Grade II Ependymomas: Is Adjuvant Radiotherapy Justified?

Ependymomas are the most common intramedullary tumors in adults. While gross total resection is the aim of surgery, tumor infiltration might limit resection. In cases of subtotal removal, the necessary adjuvant management remains unclear. The aim of our study was to assess the need for adjuvant radiotherapy after an incomplete resection of grade II intramedullary ependymomas (IME-II). We retrospectively reviewed all cases of IME-II operated upon at a single tertiary neurosurgical center from 2009 to 2018. Patients with anaplastic or myxopapillary ependymomas, and patients with a follow-up of less than three years, were excluded. We included 46 patients: 19 (41.3%) had a gross total resection; 21 (45.7%) had a subtotal resection; and 6 (13%) had a partial resection. None of the patients underwent adjuvant radiotherapy. Over a median follow-up of 79 months (range = 36-186), seven patients presented a radiological tumor progression with a mean delay of 50.9 months (range = 18-85), of which two were symptomatic (4.3%). Progression-free survival (PFS) was 90.1% at 5 years and 76.8% at 10 years. The extent of the resection was the only significant risk factor for secondary tumor progression (p = 0.012). Four of the seven patients with recurring IME-II were treated: three patients had a second surgery, leading to two GTR and one STR, followed by radiotherapy in one case, and one patient underwent radiotherapy alone. In this study, the rate of symptomatic progression and retreatment after incomplete resection of IME-II without adjuvant radiotherapy was low, suggesting a conservative approach in such cases.

Long-term outcome of surgical treatment for idiopathic spinal arachnoid web: A case series.

OBJECTIVE: Spinal arachnoid web (SAW) is a rare condition of the spine with limited long-term follow-up data in the literature. The longest reported follow-up period was an average 3.2 years. The objective of this study is to report our long-term results of patients who underwent surgical treatment for symptomatic idiopathic SAW. METHODS: We conducted a retrospective review of cases of idiopathic SAW that were operated between 2005-2020. We collected preoperative and last follow-up (LFU) data on motor force, sensory loss, pain, upper motor neuron (UMN) sign, gait disorder, sphincter dysfunction, syringomyelia, hyperintensity on T2-MRI, appearance of newer symptoms and number of reoperations. RESULTS: Our study included 9 patients with a mean follow-up period of 3.6years (range 2-9.1years). The surgical intervention involved a standard centered laminectomy, durotomy and arachnoid lysis. At presentation, motor weakness was present in 77.8% of patients, sensory loss in 66.7%, pain in 88.9%, sphincter dysfunction in 33.3%, UMN sign in 22%, gait disorder 55.6%, syringomyelia in 55.6% and MRI T2 hyperintensity in 55.6% of patients. At LFU, there was an improvement in all symptoms and signs to varying degrees. No new neurological symptoms appeared postoperatively, and there was no recurrence during the follow-up period. CONCLUSION: Our results demonstrate that the reported immediate and short-term favorable outcomes following arachnoid lysis for symptomatic SAW persist over a long-term period and the risk of readhesion-correlated neurological deterioration following conventional surgical intervention is low.

Surgical management of pituicytomas: a single-center case series.

OBJECTIVE: Pituicytomas (PT) are rare benign sellar and/or supra sellar tumors which surgical treatment might be challenging, owing to the hypervascularity of the tumor. Here, we report our experience with PTs, describe their clinical and radiological features, and propose an optimal therapeutic strategy. METHODS: This is a retrospective single-center study, reporting the clinical manifestations, radiological characteristics, histopathological features, treatment strategies and long-term outcomes of four patients who have been treated for a PT at Bicêtre University Hospital in Paris, France, over the past 7 years. RESULTS: Four patients were operated mean age at presentation was 60.25 years. Main symptoms, which tended to be progressive, included visual field defects and pituitary-hypothalamic dysfunction. Radiologically, all our cases resented with sellar and suprasellar localization with cavernous invasion in 75% of cases. Endoscopic transphenoidal approach was performed as first surgery for all cases. Transcranial route was done in one case. During surgery, important bleeding was observed in all cases. Gross total resection was obtained with a single surgery in two cases and a second surgery was necessary in the two remaining cases. Pathological diagnosis was confirmed in all cases. No recurrences were noted after an average follow-up of 3.6 years. CONCLUSIONS: PT is a rare differential diagnosis of sellar and/or parasellar tumors, whose hemorrhagic nature can become a challenge during surgery. We added four more cases to the literature to make physicians establish Piticytomas at suspicion diagnosis for sellar and/or suprasellar masses. Knowing the diagnosis, a preparation should be made preoperatively to avoid possible complications peroperatively.

Validity of algorithms for identifying mild traumatic brain injury in the French national emergency department database OSCOUR: a retrospective multicentre validation study protocol.

INTRODUCTION: The French emergency department (ED) surveillance network OSCOUR transmits data on ED visits to Santé publique France (the national public health agency). As these data are collected daily and are almost exhaustive at a national level, it would seem relevant to use them for national epidemiological surveillance of mild traumatic brain injury (mTBI). This article presents the protocol of a planned study to validate algorithms for identifying mTBI in the OSCOUR database. Algorithms to be tested will be based on International Classification of Diseases (ICD)-10 codes. METHODS AND ANALYSIS: We will perform a multicentre validation study of algorithms for identifying mTBI in OSCOUR. Different combinations of ICD-10 codes will be used to identify cases of mTBI in the OSCOUR database. A random sample of mTBI cases and non-cases will be selected from four EDs. Medical charts will serve as the reference standard to validate the algorithms. The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of the different algorithms, as well as their 95% CIs, will be calculated and compared. ETHICS AND DISSEMINATION: The ethics committee of the French National Data Protection Authority (CNIL) approved this study (n° 921152, 1 August 2021). Results will be submitted to national and international peer-reviewed journals and presented at conferences dedicated to trauma and to methodologies for the construction and validation of algorithms.

Surgical Management after Chiari Decompression Failure: Craniovertebral Junction Revision versus Shunting Strategies.

Revision surgery after posterior fossa decompression for Chiari malformation is not uncommon and poses both strategic and technical challenges. We conducted a single-center retrospective cohort study including all adult patients who underwent revision surgery after posterior fossa decompression for Chiari type I malformation between 2010 and 2019. Among 311 consecutive patients operated on for Chiari malformation at our institution, 35 patients had a least one revision surgery with a mean follow-up of 70.2 months. Mean delay for revision was 28.8 months. First revision surgery was performed at the level of the foramen magnum in 25/35 cases and consisted in duraplasty revision in all cases, arachnolysis (51.4%), additional bone decompression (37.1%), tonsillar coagulation or resection (25.7%), 4th ventricle to cervical subarachnoid spaces shunt (5.7%). Most repeat revisions consisted in CSF diversion procedures, with either ventriculo-peritoneal or syringo-peritoneal shunts. Mean number of interventions per patient was 3.2, with 22.9% of patients undergoing 4 or more surgeries. Based on our experience, we propose that revision at the level of the foramen magnum should be considered as a first-line strategy for Chiari decompression failure. Shunting procedures can be performed in case of extensive arachnoiditis or repeated failures.

Somatomotor or somatosensory facial manifestations in patients with temporobasal epilepsies.

OBJECTIVE: The semiology of temporo-basal epilepsy has rarely been analysed in the literature. In this paper, we report three patients with proven basal temporal epilepsy with somatomotor or somatosensory facial ictal semiology, highly suggestive of insulo-opercular onset. METHODS: The three patients had a temporobasal lesion and their drugresistant epilepsy was cured with resection of the lesion (follow-up duration: 7-17 years). We reviewed the medical charts, non-invasive EEG data as well as the stereoelectroencephalography (SEEG) performed in two patients. Quantitative analysis of ictal fast gamma activity was performed for one patient. RESULTS: Early ictal features were orofacial, either somatomotor in two patients or ipsilateral somatosensory in one. The three patients had prior sensations compatible with a temporal lobe onset. Interictal and ictal EEG pointed to the temporal lobe. The propagation of the discharge to the insula and operculum before the occurrence of facial features was seen on SEEG. Facial features occurred 7-20 seconds after electrical onset. Quantitative analysis of six seizures in one patient confirmed the visual analysis, showing statistically significant fast gamma activity originating from basal areas and then propagating to insuloopercular regions after a few seconds. SIGNIFICANCE: We report three cases of lesional temporo-basal epilepsy responsible for orofacial semiology related to propagation of insulo-opercular ictal discharge. In MRI-negative patients with facial manifestations, this origin should be suspected when EEG is suggestive. These observations may contribute to our understanding of brain networks.

Relationship between mild traumatic brain injury and the gut microbiome: A scoping review.

There is increasing evidence for the important role of gut microbiota (GMB) in the development and progression of neurologic pathologies. Some studies have shown that modifying the microbiome profile can confer benefits to patients. Mild traumatic brain injury (mTBI) is a common occurrence in the general population. Although most patients recover, in a minority, disabling symptoms can persist for several months. We carried out a review of the literature to assess the effect of mTBI on GMB and to determine whether alleviating dysbiosis can improve clinical outcomes in mTBI patients. We performed searches in Medline/PubMed and Embase using the keywords "MTBI" AND "microbiome" OR "microbiota". Additional articles were identified by manual searches and using the Google search engine. In animal models, a clear perturbation of GMB was reported following TBI and probiotic supplementation (Lactobacillus acidophilus or Clostridium butyricum) improved neurologic function. There were no studies on changes in GMB after mTBI in humans; however, pre- or probiotic supplementation reduced the infection rate in patients with severe TBI and shortened the time spent in the intensive care unit without conferring any neurologic benefits. Thus, although the findings from animal models are promising, clinical studies are needed to determine whether therapeutic strategies that restore gut microbiome profile can improve long-term outcomes of patients with mTBI.

Reintervention rate of arachnolysis versus shunting for nonforaminal syringomyelia.

OBJECTIVE: Surgical treatment for nonforaminal syringomyelia related to spinal arachnoiditis is still controversial. The authors sought to assess respective outcomes and rates of reintervention for shunting and spinal cord untethering (arachnolysis) in spinal arachnoiditis with syringomyelia. METHODS: This retrospective cohort study was conducted at a single reference center for syringomyelia. Patients undergoing arachnolysis and/or shunting interventions for nonforaminal syringomyelia were screened. RESULTS: The study included 75 patients undergoing 130 interventions. Arachnolysis without shunting was performed in 48 patients, while 27 patients underwent shunting. The mean follow-up between the first surgery and the last outpatient visit was 65.0 months (range 12-379 months, median 53 months). At the last follow-up, the modified McCormick score was improved or stabilized in 83.4% of patients after arachnolysis versus 66.7% after shunting. Thirty-one (41.3%) patients underwent reintervention during follow-up, with a mean delay of 33.2 months. The rate of reintervention was 29.2% in the arachnolysis group versus 63.0% in the shunting group (chi-square = 8.1, p = 0.007). However, this difference was largely driven by the extension of the arachnoiditis: in patients with focal arachnoiditis (≤ 2 spinal segments), the reintervention rate was 21.6% for arachnolysis versus 57.1% for shunting; in patients with extensive arachnoiditis, it was 54.5% versus 65.0%, respectively. Survival analysis assessing the time to the first reintervention demonstrated a better outcome in both the arachnolysis (p = 0.03) and the focal arachnoiditis (p = 0.04) groups. CONCLUSIONS: Arachnolysis led to fewer reinterventions than shunting in patients with nonforaminal syringomyelia. There was a high risk of reintervention for patients with extensive arachnopathies, irrespective of the surgical technique.

18 F-FDG-PET hypometabolic pattern reveals multifocal epileptic foci despite limited unique stereotyped seizures.

PURPOSE: Interictal positron emission tomography (PET) with 18F-FDG has largely proved its utility in presurgical evaluation of drug-resistant epilepsies (DRE) and in the surgical outcomes. Interictal hypometabolism topography is related to the neuronal networks involved in the seizure onset zone (SOZ) and spread pathways. 18F-FDG PET has a good prognostic value for post-surgical outcome, especially in cases with unique focal ictal semiology and a limited extent of hypometabolism. Surprisingly few patients have similar limited ictal features but extended hypometabolism. The objective of this study is to show that stereoelectro encephalography (SEEG) provides an explanation for this large hypometabolism, which impacts the surgical strategy. METHODS: A cohort of 248 patients underwent 18F-FDG PET and SEEG to explore for refractory epilepsy in two close tertiary epilepsy centers between January 2009 and December 2017. From this cohort, a subset of patients was selected with extended PET metabolism despite showing unique and limited ictal features in scalp EEG. The surgical outcome of this subset of patients has been analysed with respect to their FDG-PET and SEEG to understand the relationship between PET/SEEG/ presentation and surgical outcome. RESULTS: We report a series of seven patients with DRE and unique stereotyped ictal semiology but extensive 18F-FDG-PET hypometabolism revealing unexpected multifocal SOZ using SEEG. All SOZ were encompassed by the hypometabolic area. CONCLUSION: Our results demonstrate the necessity of accounting for the discrepancy between limited symptoms and widespread hypometabolism which can reveal multifocal SOZ. In those patients, surgical possibilities should be considered carefully.

Management of Chiari malformation type I and syringomyelia during pregnancy and delivery.

OBJECTIVE: Although a recurrent question in clinical practice, the management of Chiari malformation type I (CMI) and/or syringomyelia during pregnancy and delivery is still debated. The aim of this study was to investigate the modalities of delivery and anesthesia in women presenting with CMI and/or syringomyelia at a national reference center, and to question their potential role in the natural history of these conditions. STUDY DESIGN: We conducted a retrospective cohort study using a standardized questionnaire, a customized clinical severity score and data from medical records. RESULTS: 83 patients were included in the final analysis: 32 had CMI without syringomyelia, 27 had CMI with syringomyelia and 24 had non-foraminal syringomyelia. Most patients (55/83) were not diagnosed at the time of their pregnancy, 12 had surgery before being pregnant and 16 were diagnosed but not operated. Most women underwent vaginal delivery (62 %) and neuraxial (i.e. epidural or spinal) anesthesia (69 %). However, the proportion of cesarean procedures increased to 53.6 % and even 83.3 % when considering only patients already diagnosed or operated on, respectively. Nonetheless, neither vaginal compared to cesarean delivery (change in clinically severity score: -1.5 ± 0.4 versus -0.9 ± 0.4, p = 0.4) nor neuraxial compared to general anesthesia (-1.2 ± 0.3 versus -1.5 ± 0.6, p = 0.7) were associated with increased clinical deterioration. CONCLUSION: Although individual evaluation is mandatory, this study supports that neither delivery nor anesthesia modalities affect the natural history for the vast majority of patients with CMI and/or syringomyelia.

Clinical Image of a Spinal Ependymoma Discovered 8 Years after Initial Misdiagnosis as an Idiopathic Syringomyelia.

With the increasing frequency of neuroimaging, incidental intramedullary cavities are diagnosed more frequently. We present a case of asymptomatic incidental intramedullary cervical cavity diagnosed as an idiopathic syringomyelia as initial magnetic resonance imaging (MRI) showed an isolated cystic image without contrasted component. The patient had no subsequent MRI follow-up, but eventually showed symptoms 8 years later. By this stage of the disease, the MRI appearance had changed, showing a solid and enhanced component. The patient underwent surgical resection and histopathology concluded a papillary ependymoma (grade 2). This case illustrates how asymptomatic intramedullary cavities may hide an underlying tumoral process and why these cavities should not be considered as idiopathic syringomyelia by default, except after prolonged MRI follow-up.

Prospective Follow-up of Intramedullary Slitlike Cavities: A Consecutive Series of 48 Patients.

Object: Predicting whether intramedullary slitlike cavity (SC) will worsen over time or remain stable is an outstanding clinical challenge. The aim of this study was to identify early features of SC (clinical and magnetic resonance imaging [MRI] findings). Methods: We prospectively included all patients referred to our institution following the discovery of a SC and divided them in two groups: typical SC (defined as a cavity spanning fewer than three vertebrae, not enlarging the spinal cord, and located at the midline between the anterior third and posterior two-thirds of the spinal cord) or atypical SC (all others). Clinical evolution and changes in MRI features were evaluated during follow-up. In some patients, diffusion tensor imaging was performed and cervical cord cross-sectional area was analyzed. Results: A total of 48 consecutive patients were included in the study. The mean follow-up was 58 months. Of the seven patients presenting with deficits at first consultation, two worsened and five remained stable. Of the 41 patients without deficits, seven worsened and 34 remained stable. None of the patients developed severe motor deficits or experienced enlargement of the cavity; 7% of patients who presented with typical SC worsened compared with 35% with atypical SC. The negative predictive value was 0.93 (P = 0.02). Conclusion: Most patients remained stable and a subset of patients developed minor motor deficits. For clinical management, we propose surveillance of patients with a typical SC and close follow-up of those with an atypical SC and/or presenting with deficits.