Tectal plate gliomas: a review.

INTRODUCTION: Tectal plate gliomas are generally benign neoplastic lesions arising in the brainstem which can, with local extension, obstruct the aqueduct of Sylvius and lead to hydrocephalus. ANATOMY: Diagnosis is based on initial suspicion fostered by the presentation of an obstructive hydrocephalus followed by physical exam which may potentially reveal indications of pyramidal tract dysfunction or cranial nerve palsies. DISCUSSION: MRI studies reveal a characteristic well-circumscribed, isodense or hypodense mass on T1-weighted images, with hyperdensity on T2 imaging. Yet current radiological methods insufficiently distinguish tectal plate gliomas from brainstem tumors or gliomas in the neighboring structures, and a definitive diagnosis requires biopsy and histopathological analysis. Management is planned according to the degree of associated signs and symptoms, and may range from diligent observation and periodic screening for advancing tumor development, to cerebrospinal fluid shunting in an effort to resolve obstructive hydrocephalus, to radio- and chemotherapy. A wide range of minimally invasive approaches using endoscopy is available for the neurosurgeon, including endoscopic third ventriculostomy and endoscopic aqueductoplasty.

Testing awareness in focal seizures: Clinical practice and interpretation of current guidelines.

The International League Against Epilepsy (ILAE) classification of focal seizures uses recall of experiences post-ictally to assess for awareness and not ictal responsiveness to external stimuli, stating that responsiveness is often not tested. We investigated how clinicians assess for seizure awareness by administering an online survey. We found that most respondents use both responsiveness and recall to assess for awareness in the clinic (78%) and in the epilepsy monitoring unit (72%). Furthermore, 60% of respondents believe that the ILAE recommends using both measures. Given our results, we believe that using both responsiveness and recall would provide a more practical classification of impaired consciousness in focal seizures.

Nonepileptic Myoclonus in COVID-19: Case Report.

In late 2019, the novel coronavirus, SARS-CoV-2, and the disease it causes, COVID-19, was identified. Since then many different neurological manifestations of COVID-19 have been well reported. Movement abnormalities have been rarely described. We report here a critically ill patient with COVID-19 who developed generalized myoclonus during the recovery phase of the infection. Myoclonus was associated with cyclical fevers and decreased alertness. Movements were refractory to conventional anti-epileptic therapies. There was concern that myoclonus could be part of a post-infectious immune-mediated syndrome. The patient improved fully with a 4-day course of high-dose steroids. Our experience highlights a rare, generalized myoclonus syndrome associated with COVID-19 that may be immune-mediated and is responsive to treatment.

Reactive Thrombocytosis Related Cerebral Venous Thrombosis: A Rare Complication of Untreated Iron Deficiency Anemia.

Thrombocytosis can be either primary or secondary, and it can cause venous pro-thrombotic states like cerebral venous thrombosis. Untreated iron deficiency anemia is postulated to cause reactive (secondary) thrombocytosis due to the proliferation of common progenitor cells. Here we present a case of a middle-aged woman with polycystic ovary syndrome and episodes of menorrhagia. She presented with headache and focal sensory deficits, and her neuroimaging showed evidence of cerebral venous sinus thrombosis (CVST). Laboratory tests showed microcytic hypochromic anemia, low ferritin, high total iron-binding capacity (TIBC), and thrombocytosis with a platelet count of 1,523,000/mm³. A comprehensive workup for hypercoagulable states and primary causes of thrombocytosis was negative. It was concluded that the etiology of her CVST was a reactive thrombocytosis from chronic untreated iron deficiency anemia. Anticoagulation with apixaban and corrective treatment for iron deficiency anemia was initiated. A repeated neuroimaging after four months showed significantly less clot burden in the cerebral venous sinuses, and then apixaban was stopped after six months. Laboratory tests after one year of iron replacement therapy showed improvement in the hemoglobin and hematocrit as well as normalization of platelet count. This case highlights a rare yet potentially dangerous complication of a common untreated condition, i.e., iron deficiency anemia.

Pharmacotherapy for Nonconvulsive Seizures and Nonconvulsive Status Epilepticus.

Most seizures in critically ill patients are nonconvulsive. A significant number of neurological and medical conditions can be complicated by nonconvulsive seizures (NCSs) and nonconvulsive status epilepticus (NCSE), with brain infections, hemorrhages, global hypoxia, sepsis, and recent neurosurgery being the most prominent etiologies. Prolonged NCSs and NCSE can lead to adverse neurological outcomes. Early recognition requires a high degree of suspicion and rapid and appropriate duration of continuous electroencephalogram (cEEG) monitoring. Although high quality research evaluating treatment with antiseizure medications and long-term outcome is still lacking, it is probable that expeditious pharmacological management of NCSs and NCSE may prevent refractoriness and further neurological injury. There is limited evidence on pharmacotherapy for NCSs and NCSE, although a few clinical trials encompassing both convulsive and NCSE have demonstrated similar efficacy of different intravenous (IV) antiseizure medications (ASMs), including levetiracetam, valproate, lacosamide and fosphenytoin. The choice of specific ASMs lies on tolerability and safety since critically ill patients frequently have impaired renal and/or hepatic function as well as hematological/hemodynamic lability. Treatment frequently requires more than one ASM and occasionally escalation to IV anesthetic drugs. When multiple ASMs are required, combining different mechanisms of action should be considered. There are several enteral ASMs that could be used when IV ASM options have been exhausted. Refractory NCSE is not uncommon, and its treatment requires a very judicious selection of ASMs aiming at reducing seizure burden along with management of the underlying condition.

The Evolution of Corpus Callosotomy for Epilepsy Management.

Corpus callosotomy, first used in the management of epilepsy by William P. van Wagenen in 1940, was for years a contentious procedure. Two decades later, Nobel Laureate Roger W. Sperry's split-brain studies inspired surgeons to reexamine the role of corpus callosotomy in the control of epileptic seizures. In 1962, Joseph Bogen and Philip Vogel performed complete corpus callosotomies in patients with a history of generalized seizures. The identification of a set of postsurgical disconnection symptoms and other neurologic deficits begged the improvement of the surgical technique. Modifications to the operation, including anterior callosotomy, posterior callosotomy, partial callosotomy, staged callosotomy, microsurgical techniques, and radiosurgical techniques, continue to refine the procedure.