Jared S. Fridley

Bariatric surgery for the treatment of idiopathic intracranial hypertension

OBJECT The purpose of this study was to review the literature on the effectiveness of bariatric surgery for obese patients with idiopathic intracranial hypertension (IIH) with regard to both symptom resolution and resolution of visual deficits. METHODS The published literature was reviewed using manual and electronic search techniques. Data from each relevant manuscript were gathered, analyzed, and compared. These included demographic data, pre- and postoperative symptoms, pre- and postoperative visual field deficits, bariatric procedure type, absolute weight loss, changes in body mass index, and changes in CSF opening pressure. RESULTS Eleven relevant publications (including 6 individual case reports) were found, reporting on a total of 62 patients. The Roux-en-Y gastric bypass was the most common bariatric procedure performed. Fifty-six (92%) of 61 patients with recorded postoperative clinical history had resolution of their presenting IIH symptoms following bariatric surgery. Thirty-four (97%) of 35 patients who had undergone pre- and postoperative funduscopy were found to have resolution of papilledema postoperatively. Eleven (92%) of 12 patients who had undergone pre- and postoperative formal visual field testing had complete or nearly complete resolution of visual field deficits, and the remaining patient had stabilization of previously progressive vision loss. In 13 patients both pre- and postoperative CSF pressures were recorded, with an average postoperative pressure decrease of 254 mm H(2)O. Changes in weight loss and body mass index varied depending on the reported postoperative follow-up interval. CONCLUSIONS The published Class IV evidence suggests that bariatric surgery may be an effective treatment for IIH in obese patients, both in terms of symptom resolution and visual outcome. Prospective, controlled studies are necessary for better elucidation of its role.

Brain stimulation for the treatment of epilepsy.

The treatment of patients with refractory epilepsy has always been challenging. Despite the availability of multiple antiepileptic medications and surgical procedures with which to resect seizure foci, there is a subset of epilepsy patients for whom little can be done. Currently available treatment options for these unfortunate patients include vagus nerve stimulation, the ketogenic diet, and electric stimulation, both direct and indirect, of brain nuclei thought to be involved in epileptogenesis. Studies of electrical stimulation of the brain in epilepsy treatment date back to the early 20th century, beginning with research on cerebellar stimulation. The number of potential targets has increased over the years to include the hippocampus, subthalamic nucleus, caudate nucleus, centromedian nucleus, and anterior nucleus of the thalamus (ANT). Recently the results of a large randomized controlled trial, the electrical Stimulation of the Anterior Nucleus of Thalamus for Epilepsy (SANTE) trial, were published, demonstrating a significant reduction in mean seizure frequency with ANT stimulation. Soon after, in 2011, the results of a second randomized, controlled trial-the NeuroPace RNS trial-were published. The RNS trial examined closed-loop, responsive cortical stimulation of seizure foci in patients with refractory partial epilepsy, again finding significant reduction in seizure frequency. In the present review, the authors examine the modern history of electrical stimulation of the brain for the treatment of epilepsy and discuss the results of 2 important, recently published trials, the SANTE and RNS trials.

The safety and efficacy of use of low-molecular-weight heparin in pediatric neurosurgical patients

OBJECT Low-molecular-weight heparins (LMWHs), mainly enoxaparin, offer several advantages over standard anticoagulation therapies such as unfractionated heparin and warfarin, including predictable pharmacokinetics, minimal monitoring, and subcutaneous administration. The purpose of this study was to determine the safety and efficacy of LMWHs in pediatric neurosurgical patients. METHODS A retrospective study was performed with patients 18 years old or younger who were admitted to the Pediatric Neurosurgery Service at Texas Childrens Hospital and treated with LMWH for either therapeutic or prophylactic purposes between March 1, 2011, and December 30, 2013. Demographic and clinical features and outcomes were recorded. RESULTS LMWH was administered for treatment of venous thromboembolic events (VTEs) in 17 children and for prophylaxis in 24 children. Clinical resolution of VTEs occurred in 100% (17 of 17) of patients receiving therapeutic doses of LMWH. No patient receiving prophylactic doses of LMWH developed a new VTE. Major or minor bleeding complications occurred in 18% (3 of 17 children) and 4% (1 of 24 children) of those receiving therapeutic and prophylactic doses, respectively. All 4 patients who experienced hemorrhagic complications had other bleeding risk factors-i.e., coagulopathies and antiplatelet medications. CONCLUSIONS LMWH seems to be safe and efficacious for both management and prophylaxis of VTEs in pediatric neurosurgery. However, pediatric practitioners should be aware of higher risk for bleeding complications with increasing doses of LMWH, especially in patients with preexisting bleeding disorders or concurrent use of antiplatelet agents.

Immediate development of a contralateral acute subdural hematoma following acute subdural hematoma evacuation

Contralateral hematoma formation following acute subdural hematoma (ASDH) evacuation is a well-described complication. The most common type of contralateral hematoma is an epidural hematoma. Rarely, ASDH develops on the contralateral side. We report an elderly woman who presented with a post-traumatic ASDH and underwent ipsilateral hematoma evacuation by craniotomy and subsequently developed a contralateral ASDH. Because of the potential consequences of a delayed ASDH, there should be a low threshold for early post-operative imaging following ASDH evacuation, especially in elderly patients and those with additional associated intracranial injuries.

Currarino syndrome and spinal dysraphism.

Currarino syndrome is a rare constellation of congenital anomalies characterized by the triad of sacral dysgenesis, presacral mass, and anorectal malformation. It is frequently associated with other congenital anomalies, often including occult spinal dysraphism. Mutations in the MNX1 gene are identified in the majority of cases. The authors report a rare case of Currarino syndrome in an infant with tethered cord syndrome and a dorsal lipomyelomeningocele continuous with a presacral intradural spinal lipoma, in addition to an imperforate anus and a scimitar sacrum. They review the literature to highlight patterns of occult spinal dysraphism in patients with Currarino syndrome and their relationship to tethered cord syndrome. Approximately 60% of the patients with Currarino syndrome reported in the literature have an occult spinal dysraphism. Published studies suggest that the risk of tethered cord syndrome may be higher among patients with a lipoma and lower among those with a teratoma or anterior meningocele.

Biocompatibility of reduced graphene oxide nanoscaffolds following acute spinal cord injury in rats.

Background: Graphene has unique electrical, physical, and chemical properties that may have great potential as a bioscaffold for neuronal regeneration after spinal cord injury. These nanoscaffolds have previously been shown to be biocompatible in vitro; in the present study, we wished to evaluate its biocompatibility in an in vivo spinal cord injury model. Methods: Graphene nanoscaffolds were prepared by the mild chemical reduction of graphene oxide. Twenty Wistar rats (19 male and 1 female) underwent hemispinal cord transection at approximately the T2 level. To bridge the lesion, graphene nanoscaffolds with a hydrogel were implanted immediately after spinal cord transection. Control animals were treated with hydrogel matrix alone. Histologic evaluation was performed 3 months after the spinal cord transection to assess in vivo biocompatibility of graphene and to measure the ingrowth of tissue elements adjacent to the graphene nanoscaffold. Results: The graphene nanoscaffolds adhered well to the spinal cord tissue. There was no area of pseudocyst around the scaffolds suggestive of cytotoxicity. Instead, histological evaluation showed an ingrowth of connective tissue elements, blood vessels, neurofilaments, and Schwann cells around the graphene nanoscaffolds. Conclusions: Graphene is a nanomaterial that is biocompatible with neurons and may have significant biomedical application. It may provide a scaffold for the ingrowth of regenerating axons after spinal cord injury.

Small cell lung cancer metastasis in the pituitary gland presenting with seizures and headache

We report an adult female with a small cell lung cancer (SCLC) pituitary metastasis who presented with seizures and headache. While headache is a common presentation of pituitary metastases, seizures have been very rarely reported. The patient was found on MRI to have a suprasellar tumor with pituitary infundibulum involvement. She underwent endoscopic transsphenoidal resection of the tumor which was shown to be metastatic SCLC. Subsequent imaging revealed widespread systemic metastases. The patient subsequently underwent chemotherapy.

Malignant Rhabdoid Tumor of the Spine in an Infant: Case Report and Review of the Literature

Malignant rhabdoid tumors of the spine are rare pediatric neoplasms that have a poor prognosis. The histological, ultrastructural, and immunohistochemical features are essential elements used in their diagnosis. We report the case of a malignant rhabdoid tumor of the cervical spine in a 13-month-old infant. Tumor cells were vimentin positive with prominent nucleoli indented by eosinophilic cytoplasmic inclusions containing intermediate filaments. INI1 immunostaining was negative. This patient was operated on twice for symptomatic spinal cord compression. Despite chemotherapy, she developed worsening leptomeningeal dissemination, lower cranial nerve dysfunction, and hydrocephalus that did not respond to CSF diversion. She died 4 months after initial diagnosis. We review the literature on spinal malignant rhabdoid tumor and discuss the nomenclature, pathology, radiology, treatment, and outcomes of this rare entity.

Nuances in Localization and Surgical Treatment of Syringomyelia Associated with Fenestrated and Webbed Intradural Spinal Arachnoid Cyst: A Retrospective Analysis.

INTRODUCTION Intradural spinal arachnoid cysts (SACs) are among many etiologies for syringomyelia. Consequentially, neurologic symptoms arise such as pain, gait disturbance, and bladder dysfunction. Identification of SAC on magnetic resonance imaging (MRI) can be challenging, as SACs can be fenestrated or in the form of fine webs. METHODS Imaging and clinical data for 7 patients who underwent surgical treatment for SAC associated with syringomyelia were reviewed. All previous publications of this pathology were reviewed via MEDLINE search. RESULTS Seven patients with a mean age 59 years were found to have a SAC causing syringomyelia. Intraoperative exploration confirmed SAC appearances of fine webs or a fluid-filled loculation impinging on the spinal cord. Common presentations were back pain, gait disturbance, and bladder incontinence. Diagnosis was made by MRI, although in 3 cases, the SAC was not identified on the initial review. Computed tomography myelogram was performed in one case due to the enlarged syringomyelia and lack of obvious spinal cord compression. Thoracic laminectomy/laminoplasty was performed for all patients, centered at the level of a subtle indentation of the cord; the syringomyelia proper was not directly addressed. Postoperatively, all patients had complete resolution of their symptoms with MRI demonstrating resolution of the syringomyelia. CONCLUSIONS Careful evaluation of the MRI can demonstrate subtle indentation of the cord at the caudal or cephalad end of the syringomyelia and may obviate the need for additional imaging. Meticulous arachnoid dissection and establishment of good CSF flow is sufficient for resolution of the syringomyelia, averting the need for more aggressive procedures.

Neuromonitoring for Intramedullary Spinal Cord Tumor Surgery

BACKGROUND Intramedullary spinal cord tumors (IMSCT) account for about 2%-4% of tumors of the central nervous system. Surgical resection continues to be the most effective treatment modality for most intramedullary tumors, with gross total resection leading to preserved neurologic function and improved survival. However, surgical treatment is often difficult and carries significant risk of postoperative neurologic complications. Intraoperative neuromonitoring has been shown to be of clinical importance in the surgical resection of IMSCT. The main monitoring modalities include somatosensory evoked potentials, transcranial motor evoked potentials via limb muscles or spinal epidural space (D-waves), and dorsal column mapping. These monitoring modalities have been shown to inform surgeons intraoperatively and in many cases, have led to alterations in operative decision. METHODS We reviewed the literature on the usefulness of intraoperative neuromonitoring for intramedullary spinal tumor resection and its role in predicting postoperative neurologic deficits. A MEDLINE search was performed (2000-2015) and 13 studies were reviewed. Detailed information and data from the selected articles were assessed and compiled. Data were extracted showing the role of monitoring in outcomes of surgery. CONCLUSIONS By using intraoperative somatosensory evoked potentials, transcranial motor evoked potentials, D-waves, and dorsal column mapping, spinal injury could be prevented in most cases, thereby improving postoperative neurologic functioning and outcome in patients undergoing surgery for IMSCT.