Heart rate and autonomic biomarkers distinguish convulsive epileptic vs. functional or dissociative seizures.

OBJECTIVE: 20-40% of individuals whose seizures are not controlled by anti-seizure medications exhibit manifestations comparable to epileptic seizures (ES), but there are no EEG correlates. These events are called functional or dissociative seizures (FDS). Due to limited access to EEG-monitoring and inconclusive results, we aimed to develop an alternative diagnostic tool that distinguishes ES vs. FDS. We evaluated the temporal evolution of ECG-based measures of autonomic function (heart rate variability, HRV) to determine whether they distinguish ES vs. FDS. METHODS: The prospective study includes patients admitted to the University of Rochester Epilepsy Monitoring Unit. Participants are 18-65 years old, without therapies or co-morbidities associated with altered autonomics. A habitual ES or FDS is recorded during admission. HRV analysis is performed to evaluate the temporal changes in autonomic function during the peri­ictal period (150-minutes each pre-/post-ictal). We determined if autonomic measures distinguish ES vs. FDS. RESULTS: The study includes 53 ES and 46 FDS. Temporal evolution of HR and autonomics significantly differ surrounding ES vs. FDS. The pre-to-post-ictal change (delta) in HR differs surrounding ES vs. FDS, stratified for convulsive and non-convulsive events. Post-ictal HR, total autonomic (SDNN & Total Power), vagal (RMSSD & HF), and baroreflex (LF) function differ for convulsive ES vs. convulsive FDS. HR distinguishes non-convulsive ES vs. non-convulsive FDS with ROC>0.7, sensitivity>70%, but specificity<50%. HR-delta and post-ictal HR, SDNN, RMSSD, LF, HF, and Total Power each distinguish convulsive ES vs. convulsive FDS (ROC, 0.83-0.98). Models with HR-delta and post-ictal HR provide the highest diagnostic accuracy for convulsive ES vs. convulsive FDS: 92% sensitivity, 94% specificity, ROC 0.99). SIGNIFICANCE: HR and HRV measures accurately distinguish convulsive, but not non-convulsive, events (ES vs. FDS). Results establish the framework for future studies to apply this diagnostic tool to more heterogeneous populations, and on out-of-hospital recordings, particularly for populations without access to epilepsy monitoring units.

Primary Central Nervous System Lymphoma Presenting as Parkinsonism with Atypical MRI Findings and Elevated 14-3-3 Protein.

Primary central nervous system lymphoma (PCNSL) is a rare neoplasm with an incidence of 2 to 3% of all CNS malignancies. The diagnosis can be challenging, especially with atypical presentations. Movement disorders can be one of the rare presentations of PCNSL. Here, we present an unusual case of gradually progressing Parkinsonism with an elevation of cerebrospinal fluid (CSF) 14-3-3 protein and atypical imaging findings found to have PCNSL. A 76-year-old female patient presented with gait and intermittent speech difficulty. Initial workup revealed a contrast-enhancing lesion in the bilateral putamen and head of caudate without any mass effect. Her symptoms were rapidly progressed over 6 months and presented with mild dysarthria, bradykinesia, mild rigidity, and reduced left arm swinging. These features were consistent with Parkinsonism. The repeat imaging showed the progression of hyperintensities in the bilateral putamen. The patient underwent a stereotypic biopsy of the right caudate nucleus, which revealed PCNSL. She was treated with high-dose methotrexate and is currently in remission. Diagnosis of movement disorders remains clinical and rapid progression of symptoms, and atypical presentation must warrant further imaging and workup.

Lateralized Periodic Discharges are Predictive of Seizures in Patients with Intracerebral Hemorrhage.

BACKGROUND: Patients with intracerebral hemorrhages (ICHs) have higher incidence of seizures. Previous studies have suggested that location and size of hemorrhage may increase epileptogenicity. We aim to evaluate seizure development risk factors from clinical examination, imaging, and continuous electroencephalography (cEEG) in critically ill patients with ICH. METHODS: We reviewed 57 consecutive patients with ICH admitted to a neurocritical intensive care unit over a 24-month period who were monitored on cEEG. Their demographic and examination data, ICH score, Glasgow Coma Scale (GCS), location of bleed, cEEG patterns, and discharge status were analyzed. RESULTS: Sixteen (28%) patients from our study cohort had seizures at a mean duration of 7.46 h from cEEG hookup. Fifteen (93%) of those patients had only electrographic seizures. The finding of lateralized periodic discharges (LPDs) was significantly (P = 0.019) associated with seizures. Other variables, such as ICH score, size and location of hemorrhage, GCS, mental status, and other cEEG patterns, were not significantly associated with seizures. CONCLUSION: We found that LPDs were predictive of seizures in ICH patients. cEEG for longer than 24 h is preferred for detection of seizures as they occurred at a mean later than 7 h and most were without clinical signs.

Seizure prophylaxis in the neuroscience intensive care unit.

BACKGROUND: Seizures are a considerable complication in critically ill patients. Their incidence is significantly high in neurosciences intensive care unit patients. Seizure prophylaxis with anti-epileptic drugs is a common practice in neurosciences intensive care unit. However, its utility in patients without clinical seizure, with an underlying neurological injury, is somewhat controversial. BODY: In this article, we have reviewed the evidence for seizure prophylaxis in commonly encountered neurological conditions in neurosciences intensive care unit and discussed the possible prognostic role of continuous electroencephalography monitoring in detecting early seizures in critically ill patients. CONCLUSION: Based on the current evidence and guidelines, we have proposed a presumptive protocol for seizure prophylaxis in neurosciences intensive care unit. Patients with severe traumatic brain injury and possible subarachnoid hemorrhage seem to benefit with a short course of anti-epileptic drug. In patients with other neurological illnesses, the use of continuous electroencephalography would make sense rather than indiscriminately administering anti-epileptic drug.

The Benefit of Neuromuscular Blockade in Patients with Postanoxic Myoclonus Otherwise Obscuring Continuous Electroencephalography (CEEG).

Introduction. Myoclonus status epilepticus is independently associated with poor outcome in coma patients after cardiac arrest. Determining if myoclonus is of cortical origin on continuous electroencephalography (CEEG) can be difficult secondary to the muscle artifact obscuring the underlying CEEG. The use of a neuromuscular blocker can be useful in these cases. Methods. Retrospective review of CEEG in patients with postanoxic myoclonus who received cisatracurium while being monitored. Results. Twelve patients (mean age: 53.3 years; 58.3% male) met inclusion criteria of clinical postanoxic myoclonus. The initial CEEG patterns immediately prior to neuromuscular blockade showed myoclonic artifact with continuous slowing (50%), burst suppression with myoclonic artifact (41.7%), and continuous myogenic artifact obscuring CEEG (8.3%). After intravenous administration of cisatracurium (0.1 mg-2 mg), reduction in artifact improved quality of CEEG recordings in 9/12 (75%), revealing previously unrecognized patterns: continuous EEG seizures (33.3%), lateralizing slowing (16.7%), burst suppression (16.7%), generalized periodic discharges (8.3%), and, in the patient who had an initially uninterpretable CEEG from myogenic artifact, continuous slowing. Conclusion. Short-acting neuromuscular blockade is useful in determining background cerebral activity on CEEG otherwise partially or completely obscured by muscle artifact in patients with postanoxic myoclonus. Fully understanding background cerebral activity is important in prognostication and treatment, particularly when there are underlying EEG seizures.

Fovea and foveation in Parkinson's disease.

Nondemented Parkinson's disease (PD) patients report problems on nonmotor tasks that depend on visual or visuospatial abilities. In PD, foveal vision is impaired. Experimental studies in humans and monkeys established that foveal processing and visuospatial attention may be linked through saccadic eye movements. Saccadic eye movements "bring" eccentric targets to the direct sight line for closer scrutiny by foveal processing. This is called foveation. This review musters the arguments for impaired foveal vision and impaired cortical control of voluntary saccades in PD. Retinal impairment of spatial contrast vision is selective in PD. Thus, the reviewed literature includes a brief survey of the physiology of foveal pathways. This is necessary to understand the specificity of the retinopathy of PD, documented by clinical evidence, relying on psychophysical, electrophysiological, and imaging techniques. These have recently been supplanted by the results of retinal imaging using Optical Coherence Tomography (OCT). Studies of cortical mechanisms in PD reviewed here relied on neuropsychological, electrophysiological (EEG), and imaging techniques. Impaired functional anatomy and electrophysiology in PD are reviewed. The exact relationship of retinal foveal deficits and visuospatial attention and postural control impairment in PD remain challenging research questions. This review will hopefully will provide useful material for future studies.