Azedine Medhkour

Complete heart block with ventricular asystole during left vagus nerve stimulation for epilepsy

Vagus nerve stimulation (VNS) is an important therapeutic option for individuals with refractory epilepsy who have failed multiple antiepileptic drugs (AEDs). The intricate relationship of the vagus nerve to cardiac function raises concern that vagal stimulation may affect cardiac rhythm and function. Previous pre- and postmarketing studies have not shown this to be a significant problem, with the incidence of bradyarrhythmias reported to be about 0.1%. We review three cases of ventricular asystole with complete heart block that occurred during intraoperative lead tests. The purpose of these case reports is to identify the specific type of cardiac abnormality associated with vagus nerve stimulation and to identify individuals at risk.

Surgical outcomes after posterior fossa decompression with and without duraplasty in Chiari malformation-I.

INTRODUCTION Chiari malformation-I (CM) is one of the most controversial entities in the contemporary neurosurgical literature. Posterior fossa decompression (PFD) is the preferred treatment for CM with and without syringomyelia. A variety of surgical techniques for PFD have been advocated in the literature. The aim of this study was to evaluate our results of surgically treated patients for CM-I with and without syringomyelia; using extradural dura-splitting and intradural intraarachnoid techniques. METHODS A retrospective review of the medical records of all the patients undergoing PFD was conducted. Symptomatic patients with tonsillar herniation≥3-mm below the foramen magnum on neuroimaging, and CSF flow void study demonstrating restricted or no CSF flow at the craniocervical junction, were offered surgical treatment. In patients without syringomyelia, extradural decompression with thinning of the sclerotic tissue at the cervicomedullary junction and splitting of outer dural layer was performed. In patients with syringomyelia, the dura was opened and an expansile duraplasty was performed. RESULTS The mean age of 8 males and 34 females was 33.8 years (range, 16-58 years). Headache (39/41; 95%), and/or tingling and numbness (17/41; 42%) were the most common presenting symptoms. The syrinx was associated with CM-I in 5/41 (12%) patients. PFD without durotomy was performed in 29/41 (73%) patients. The mean duration of preoperative symptoms was significantly longer in duraplasty group (4.6 versus 1.7 years, P=0.005, OR=0.48, CI=0.29-0.8). The use of duraplasty was significantly associated with presence of complications (P=0.004, OR=0.5, CI=0.3-0.8) and longer duration of hospital stay (P=0.03, OR=2.7, CI=1.1-6.8). The overall complication rate was 6/41(15%) patients. The overall improvement rate was evident in 84% (36/41); 12% (5/41) were stable; and 5% (2/41) had worsening of symptoms. The history of prior CM decompression was associated with unfavorable outcomes (P=0.04, OR=14, CI=1.06-184). One patient experienced recurrence one year after the PFD with duraplasty. CONCLUSION The present study reports favorable surgical outcomes with extra-dural decompression of the posterior fossa in patients CM-I without syringomyelia. For patients with syringomyelia and history of prior PFD, intradural intra-arachnoid decompression is required. The prior history of decompression was associated with unfavorable outcomes. The use of duraplasty was associated with longer duration of hospital stay and higher complication rate. Further large cohort prospective study is needed to provide any recommendation on the indication of intra or extradural decompression for a given CM-I patient.

External lumbar drain: A pragmatic test for prediction of shunt outcomes in idiopathic normal pressure hydrocephalus

Background: The consensus on most reliable supplemental test to predict the shunt responsiveness in patients with idiopathic normal pressure hydrocephalus (iNPH) is lacking. The aim of this study is to discuss the utility of external lumbar drain (ELD) in evaluation of shunt responsiveness for iNPH patients. Methods: A retrospective review of 66 patients with iNPH was conducted. All patients underwent 4-day ELD trial. ELD-positive patients were offered ventriculoperitoneal shunt (VPS) surgery. The primary outcome evaluation parameters were gait and mini mental status examination (MMSE) assessment. The family and patient perception of improvement was accounted for in the outcome evaluation. Results: There were 38 male and 28 female with mean age of 74 years (range 45-88 years). ELD trial was positive in 86% (57/66) of patients. No major complications were encountered with the ELD trial. A total of 60 patients (57 ELD-positive, 3 ELD-negative) underwent VPS insertion. The negative ELD trial (P = 0.006) was associated with poor outcomes following shunt insertion. The positive ELD trial predicted shunt responsiveness in 96% patients (P < 0.0001, OR = 96.2, CI = 11.6-795.3). A receiver operating characteristic (ROC) curve analysis revealed that the ELD trial is reasonably accurate in differentiating shunt responder from non-responder in iNPH patients (area under curve = 0.8 ± 0.14, P = 0.02, CI = 0.52-1.0). The mean follow-up period was 12-months (range 0.3-3 years). The significant overall improvement after VPS was seen in 92% (55/60). The improvement was sustained in 76% of patients at mean 3-year follow-up. The number of comorbid conditions (P = 0.034, OR = 4.15, CI = 1.2-9.04), and a history of cerebrovascular accident (CVA) (P = 0.035, OR = 4.4, CI = 1.9-14.6) were the predictors of poor outcome following shunt surgery. Conclusion: The positive ELD test predicted shunt responsiveness in 96% of patients. With adequate technique, maximal results with minimal complications can be anticipated. The number of comorbidities, history of CVA and negative ELD test were significantly associated with poor shunt outcomes.

Ossification in an extra-intradural spinal meningioma—pathologic and surgical vistas

BACKGROUND CONTEXT Intradural and intratumorous ossification in spinal meningiomas are rare compared to their cranial counterparts. Extradural extension of the spinal meningioma is not uncommon. To the best of our knowledge, the ossification in an extra-intradural spinal meningioma is not yet reported in the literature. PURPOSE The authors report a rare case of an extra-intradural spinal meningioma with ossification and calcification. The review of literature including the surgical challenges and the histologic variations as well as histogenesis of the ossified spinal meningioma is discussed. STUDY DESIGN Case report and review of the literature. METHODS A 61-year-old woman presented with complaints of numbness and weakness for 3 years, and gait disturbances for 6 months. Magnetic resonance imaging revealed a mass compressing the spinal cord at the T4 level. RESULTS Complete resection of the tumor was achieved with coagulation and partial resection of the dura. Histopathological examination demonstrated a psammomatous spinal meningioma with intratumorous and intradural mature lamellar bone formation, complete with marrow and hematopoietic cells. The patient is asymptomatic at 3-year postoperative follow-up. CONCLUSIONS Despite adherence of the ossified mass to the dura, arachnoid, and spinal cord, complete atraumatic resection of the mass was possible with favorable surgical outcome. In addition to calcification as a likely forerunner of ossification in the psammomatous subtype of meningioma, metaplastic differentiation of neoplastic cells to osseous and hematopoietic component might play a crucial role.

Acute Left-sided Foot Drop Attributed to Recurrent Synovial Chondromatosis of the Lumbar Spine

Objective: To discuss an uncommon case of nerve root compression caused by synovial chondromatosis of the lumbar spine. Summary of background: Synovial chondromatosis is an uncommon, benign monoarthritic condition of the synovial lining of large joints of the body. It is considered a metaplastic process rather than a neoplastic one, in which nodules are formed from aggregates of chondrocytes in the synovium. The nodules cause non-specific symptoms such as pain and decreased range of motion in the affected joint. In rare instances, synovial chondromatosis has been known to involve the spine, with associated radiculopathy. We report a case of synovial chondromatosis of the lumbar spine, which to our knowledge is the first case with foot drop. Case presentation: A 58-year-old woman presented with symptoms of lower back pain with unilateral radiation, numbness, and tingling. After primary resection of an extradural cartilaginous mass in the region of L4-L5, her symptoms remitted. One year post-operatively, she experienced a progressive recurrence of her symptoms and the acute onset of foot drop. Re-excision provided partial symptomatic relief. Histopathology showed nodular aggregates of benign cartilage, consistent with synovial chondromatosis. Conclusion: Synovial chondromatosis of the spine is a rare but potentially challenging problem for both patients and clinicians. Due to the broad clinical presentation and vague imaging profile, preoperative diagnosis is difficult. The histopathologic findings must be correlated clinically to arrive at the correct diagnosis. Surgical removal may resolve the symptoms, though recurrence requiring re-excision is not uncommon. This is the fourth reported case of synovial chondromatosis involving the lumbar spine, and the first with recurrence resulting in an exacerbation of prior symptoms including foot drop.

The Art of Mimicry: Anterior Clinoid Dural-Based Cavernous Hemangioma Mistaken for a Meningioma

BACKGROUND Cavernous hemangiomas account for 5%-13% of central nervous system vascular lesions. They are usually found intra-axially but rarely involve extra-axial structures, most commonly the middle cranial fossa. A cavernous hemangioma manifesting as a clinoid meningioma is extremely rare. CASE DESCRIPTION A 36-year-old man presented with an asymptomatic intracranial mass found incidentally after a motor vehicle accident. Preoperative magnetic resonance imaging revealed a well-defined dural-based lesion arising from the right anterior clinoid process that was nearly homogeneously enhancing. The radiologic diagnosis was meningioma. The mass was resected via a right pterional craniotomy with microsurgical technique. Complete resection of the mass was performed with no complications and no significant bleeding. Contrasting with the radiologic and gross tumor appearance, histopathologic examination revealed dilated vascular spaces, sclerotic vessels without intervening neural tissue, and intravascular thrombi suggesting slow blood flow-all consistent with cavernous hemangioma. CONCLUSIONS Anterior clinoid dural-based cavernous hemangiomas are extremely rare. Although preoperative diagnosis is difficult using imaging, this etiology should be considered for any dural-based middle fossa lesion, owing to the tendency for these lesions to bleed heavily during resection in some instances.

A Unique Case of Carotid Splaying by a Cervical Vagal Neurofibroma and the Role of Neuroradiology in Surgical Management

Carotid splaying, also known as the Lyre sign, is a widening of the carotid bifurcation due to the displacement of the internal carotid artery and the external carotid artery just distal to the point of divergence. This phenomenon is classically exhibited by highly vascularized carotid body tumors and, in rare cases, by cervical sympathetic chain schwannomas. Demonstration of the Lyre sign by a cervical vagal neurofibroma, however, is a unique occurrence that has not been previously documented in the literature. Neurofibromas are slow growing, poorly vascularized soft tissue masses and are a hallmark of the autosomal dominant genetic disorder, neurofibromatosis type 1 (NF-1). While targeted genetic therapies are evolving, management is currently dependent on a case-by-case resection of tumors with specific indications for chemo and radiation therapy. These resections rely on magnetic resonance imaging (MRI) to visualize tumor location and infiltration, but even in the setting of an established NF-1 diagnosis, additional imaging can be beneficial in ruling out more precarious tumors and optimizing surgical outcomes. In this case, a 25-year-old female with known NF-1 presented with an enlarging cervical mass that demonstrated splaying of the left internal and external carotid arteries on MRI. Due to the typical association of the Lyre sign with carotid body tumors, magnetic resonance angiography (MRA) was crucial in guiding surgical decision making. Carotid body tumors are highly vascularized, may compress carotid branches, and carry a high risk of intraoperative bleeding. They are best visualized with MRA, which assesses carotid splaying and patency, and demonstrates vascular blushing within the tumor. This patients MRA demonstrated the Lyre sign, patency of all carotid vessels, and a lack of vascularity within the mass, thus lowering suspicion for a carotid body tumor. Intraoperative use of imaging results facilitated a successful resection of a soft tissue tumor with minimal blood loss and no complications. Postoperative histologic examination confirmed a neurofibroma and definitively ruled out a carotid body tumor. This case highlights the importance of utilizing MRA whenever carotid splaying is seen on MRI and supports the consideration of neurofibromas in the differential for this finding.

Is There a Genetic Correlation between Multiple Sclerosis and Cerebral Aneurysms

BACKGROUND Multiple sclerosis (MS) is a common autoimmune and neurodegenerative disease of the central nervous system characterized by inflammatory demyelination, axonal degeneration, and neuronal loss. The exact pathogenesis of MS remains uncertain; however, studies have shown that the development of MS is influenced by genetic and environmental factors. Cerebral aneurysms (CAs) are life-threatening lesions of cerebral vessels characterized by a bulge in the intracranial arterial wall that spontaneously ruptures. It has been hypothesized that patients with MS are at increased risk of developing cerebral aneurysms. This hypothesis can be supported by analyzing the pathogenesis and genetics of the development of MS and CA. To our knowledge, no previous studies have shown an association between MS and CA. CASE DESCRIPTION In this report, we performed middle cerebral artery aneurysm clipping for two patients with MS who were referred to our clinic for CA in the bifurcation of middle cerebral artery that was found incidentally on magnetic resonance imaging. We aim to identify any genetic correlation between MS and CA pathogenesis. CONCLUSION This report suggests a possible genetic association between MS and CAs. The strongest evidence of association was found for the TNFRSF1A gene, a proinflammatory gene that is involved in mitogen-activated protein kinase (MAPK) and NF-Kappa B signaling pathways, and has been identified as a candidate gene in the development of MS. MAPKs were also found to be elevated in CAs.