Acute epileptiform abnormalities are the primary predictors of post-stroke epilepsy: a matched, case-control study.

Stroke patients who underwent continuous EEG (cEEG) monitoring within 7 days of presentation and developed post-stroke epilepsy (PSE; cases, n = 36) were matched (1:2 ratio) by age and follow-up duration with ones who did not (controls, n = 72). Variables significant on univariable analysis [hypertension, smoking, hemorrhagic conversion, pre-cEEG convulsive seizures, and epileptiform abnormalities (EAs)] were included in the multivariable logistic model and only the presence of EAs on EEG remained significant PSE predictor [OR = 11.9 (1.75-491.6)]. With acute EAs independently predicting PSE development, accounting for their presence may help to tailor post-acute symptomatic seizure management and aid anti-epileptogenesis therapy trials.

Fatal Brain Injury Following Carbon Dioxide Angiography.

INTRODUCTION: Carbon dioxide (CO2) as a contrast agent has been in use as early as the 1920s for visualization of retroperitoneal structures. Digital subtraction angiography (DSA) using CO2 as a contrast agent for vascular imaging was developed in the 1980s. Currently, CO2  angiography is an alternative agent in patients with chronic kidney disease (CKD) and those who are at risk of developing contrast-induced nephropathy. However, CO2 causes neurotoxicity if the gas inadvertently enters the cerebrovascular circulation leading to fatal brain injury. CASE PRESENTATION: A 71-year-old female with h/o sickle cell trait, hypertension, obesity, metastatic renal cell cancer status post nephrectomy, bone metastasis, chronic kidney disease was admitted for elective embolization of the humerus bone metastasis. Given the high probability of contrast-induced nephropathy, CO2 angiography was chosen for embolization of the metastasis. During the procedure, the patient became unresponsive. Emergent medical management with hyperventilation, 100% fraction oxygen inhalation was performed. Her neuroimaging showed global cerebral edema. An intracranial pressure monitor was placed which confirmed intracranial hypertension. Hyperosmolar therapy was administered with no improvement in clinical examination. She progressed to brain stem herniation. Given poor prognosis, the family opted for comfort measures and the patient expired. DISCUSSION AND CONCLUSIONS: Inadvertent carbon dioxide entry into cerebrovascular circulation during angiography can cause fatal brain injury. Caution must be exercised while performing CO2  angiography in blood vessels above the diaphragm.

Central Nervous System Fungal Infection-Related Stroke: A Descriptive Study of Mold and Yeast-Associated Ischemic Stroke.

OBJECTIVE: Central nervous system (CNS) ischemic events caused by fungal infections are rare, and clinical characteristics of these ischemic events are largely unknown. The objective of this manuscript is to highlight characteristics of fungal-related strokes and describe possible mechanistic differences between CNS mold and yeast infection-related strokes. METHODS: We report a single-center retrospective case series of all adult patients who presented with concurrent CNS fungal infection and stroke between 2010 and 2018. Patients believed to have a stroke etiology due to cardioembolic, atheroembolic, or strokes nontemporally associated with a CNS fungal infection and those with incomplete stroke workups were excluded from analysis. RESULTS: Fourteen patients were identified with ischemic stroke and concurrent CNS fungal infection without other known ischemic stroke etiology. Eight patients had a CNS yeast infection, and 6 had a CNS mold infection. All patients presented with recurrent or progressive stroke symptoms. Six patients were immune-compromised. Four patients admitted to intravenous drug use. All yeast infections were identified by cerebrospinal fluid culture or immunologic studies while all but one of the mold infections required identification by tissue biopsy. Leptomeningeal enhancement was only associated with CNS yeast infections, while basal ganglia stroke was only associated with CNS mold infections. CONCLUSION: Ischemic stroke secondary to CNS fungal infections should be considered in patients with recurrent or progressive cryptogenic stroke, regardless of immune status and cerebrospinal fluid profile. CNS yeast and mold infections have slightly different stroke and laboratory characteristics and should have a distinct diagnostic method. Depending on clinical suspicion, a thorough diagnostic approach including spinal fluid analysis and biopsy should be considered.

Anti-N-methyl-D-aspartate Encephalitis Concomitantly with Tall-cell Variant Papillary Thyroid Carcinoma.

Anti-N-methyl-D-aspartate (NMDA) encephalitis is an autoimmune-mediated process characterized by psychosis, seizures, dyskinetic movements, and autonomic instability. At least half of the reported cases are paraneoplastic, particularly associated with an ovarian teratoma. None have been reported to be associated with thyroid tumor. We present a case of anti-NMDA encephalitis concomitantly occurring in setting of papillary thyroid carcinoma in a woman who presented with headaches, myalgia and somnolence mimicking meningoencephalitis. A 29-year-old African female presented with fever, headache, myalgia, somnolence and behavioral changes. Initial evaluation was significant for lymphocytic pleocytosis with normal glucose and protein. She was started on broad spectrum empiric antibiotics. Despite antibiotics, she continued to have worsening encephalopathy, hallucinations, epileptic seizures, and multifocal dyskinesias involving the face and extremities with no electroencephalogram correlate. Extensive infectious workup was unremarkable. Whole-body CT with contrast and ovarian ultrasound were unremarkable for malignancy. Serum auto-antibodies to the NMDA receptor and thyroid peroxidase were detected. She was treated with high-dose intravenous steroids, plasmapheresis, intravenous immunoglobulin, and rituximab with no clinical or serological response. Fluorodeoxyglucose positron emission tomography (FDG-PET) showed a hypermetabolic thyroid nodule. Fine needle aspiration of the nodule revealed papillary thyroid carcinoma. She underwent total thyroidectomy and pathology showed two foci of tall-cell variant papillary thyroid carcinoma. Serological and clinical response followed shortly after tumor resection. The NMDA receptor stain of the papillary thyroid carcinoma was nonreactive. We describe the coincidentally co-occurrence of NMDA encephalitis in a patient with papillary thyroid carcinoma. This case highlights the importance of presumed cases of non-paraneoplastic NMDA encephalitis, FDG-PET may help in detecting occult malignancies.

Thromboelastography With Platelet Mapping is Not an Effective Measure of Platelet Inhibition in Patients With Spontaneous Intracerebral Hemorrhage on Antiplatelet Therapy.

Thromboelastography with platelet mapping (TEG-PM) is a modality to measure platelet function, especially in patients taking antiplatelet medications. It consists of two components: arachidonic acid (AA), which is sensitive to aspirin, and adenosine diphosphate (ADP), which is sensitive to clopidogrel. In patients with spontaneous intracerebral hemorrhages (sICH), the clinical interpretation of platelet mapping is unclear. The objective of this study was to evaluate TEG-PM in patients with sICH on aspirin and/or clopidogrel who receive platelet transfusions. This study was an IRB-approved, retrospective case-control study over three years at an academic medical center. Adult patients with sICH were included if they had an admission computed tomography head (CTH) and platelet mapping followed by a repeat platelet mapping and CTH post platelet transfusion. A threshold of 50% inhibition was used as the benchmark for both ADP and AA inhibition. Around 248 subjects with sICH were identified, and 107 were excluded for incomplete documentation, leaving 141 for analysis. Of these, nine met our inclusion criteria. No statistical significance was found on the antithrombotic effects of aspirin or clopidogrel on TEG-PM (p=1.00 for both). Sensitivity and specificity of TEG-PM for clopidogrel was 100% and 42.9%, respectively, and 80% and 0%, respectively, for aspirin. Platelet transfusion did not significantly change AA or ADP inhibition (p=1.00). Hemorrhagic expansion on CTH was not associated with a decrease AA or ADP inhibition (p=1.00). TEG-PM is not an effective measure of platelet inhibition in sICH patients who were on antiplatelet medications and is not a reliable measurement following platelet transfusion.

Somatosensory Evoked Potentials as a Tool to Evaluate Brainstem Herniation in the Neuroscience Intensive Care Unit.

Somatosensory evoked potentials (SSEPs) are a sensitive, minimally invasive technique used to localize dysfunction of myelinated peripheral and central axons in the nervous system. The utility of SSEPs in acutely assessing central nervous system function in brainstem herniation in the neuroscience intensive care unit (NICU) has not been well established. We discuss a case of an 18-year-old, postpartum female who presented with intermittent headache, diplopia, nausea/vomiting and cachexia following delivery two months prior. Shortly after arrival to the emergency department, she developed flaccid quadriparesis and complete ophthalmoplegia. Computed tomography (CT) of the head showed effacement of the basal cisterns along with 2 cm cerebellar tonsillar herniation into the foramen magnum concerning for intracranial hypotension. Raising the head of bed caused hemodynamic instability necessitating prolonged Trendelenburg positioning. The patient was evaluated with serial SSEPs which initially showed a bilateral low amplitude N20 response and normal N13 response. Subsequent SSEP testing showed increased N20 amplitude which correlated with clinical improvement in the patient. SSEP is a minimally invasive and sensitive method used to assess the integrity of the somatosensory nervous system pathway; SSEPs may be a useful monitoring adjunct to assess the evolution of posterior fossa lesions leading to brainstem compression.

Delayed Post-hypoxic Leukoencephalopathy: A Case Series and Review of the Literature.

Delayed post-hypoxic leukoencephalopathy (DPHL) is a unique clinical entity that presents with cognitive impairment days to weeks after an episode of acute hypoxic brain injury. Frequently hypoxia is unrecognized as a mechanism for clinical decline and extensive workup ensues. We present two cases of DPHL highlighting the neuroimaging findings. In both patients, a cerebral hypoxic event was followed by a recovery phase with subsequent delayed clinical decline. Patient 1 suffered hypoxia from drug-induced respiratory depression and lack of post-operative positive airway pressure (PAP) support. Her neurological exam on follow-up revealed progressive cognitive decline. Magnetic resonance imaging (MRI) brain showed bilateral white matter changes involving the centrum semiovale. Patient 2 developed a generalized tonic-clonic seizure during an endobronchial biopsy procedure and was found to have multiple air emboli on computed tomography (CT) head scan. She was initially in a drug-induced coma for her seizures. Electroencephalography (EEG) on day 14 of admission showed changes consistent with diffuse encephalopathy. MRI brain showed bilateral white matter changes particularly at the watershed zones and in the centrum semiovale. DPHL is a rare and under-recognized clinical entity that requires clinical suspicion and detailed evaluation for diagnosis. Neuroimaging studies can provide prognostic information regarding the extent of neurological injury.

Continuous Electroencephalography in the Critically Ill: Clinical and Continuous Electroencephalography Markers for Targeted Monitoring.

PURPOSE: Electrographic seizures detected by continuous electroencephalography (CEEG) in critically ill patients with altered mental status is becoming increasingly recognized. Data guiding the appropriate selection of patients to be monitored on CEEG are lacking. The aims of this article were to study the incidence of seizures in the critical care setting and to evaluate for clinical predictors to improve the efficiency of CEEG monitoring. METHODS: Retrospective review of the CEEG and clinical data on 1,123 consecutive patients who had continuous video EEG over a 24-month period. RESULTS: Seizures were recorded in 215 patients on CEEG monitoring (19.1%). In total, 89.3% of these seizures occurred without clinical signs. Patients who were in a coma were more likely to have EEG seizures (odds ratio, 3.64; 95% confidence interval, 2.23-5.95) compared with those awake. The incidence of seizures was overrepresented in patients with extra-axial tumors (41.9%), multiple sclerosis (35.7%), and intra-axial tumors (33.0%). Lateralized periodic discharges were predictive (odds ratio, 8.27; 95% confidence interval, 5.52-12.46) of seizure occurrence compared with those with no epileptiform patterns. Only generalized periodic discharges with triphasic morphology had no increased odds of seizure (odds ratio, 1.02; 95% confidence interval, 0.24-3.03). When present, electroencephalography seizures were detected within 24 hours in 92% of monitored patients. CONCLUSIONS: Continuous electroencephalography monitoring in the critical care setting demonstrates a linear increase in seizure incidence with declining mental status. Recognizing clinical conditions and electroencephalography markings may help in the appropriate selection of critically ill patients for CEEG monitoring.

Optimizing SPECT SISCOM analysis to localize seizure-onset zone by using varying z scores.

PURPOSE: Subtraction ictal single photon emission computed tomography (SPECT) co-registered to magnetic resonance imaging (MRI) (SISCOM) is a useful modality to identify epileptogenic focus. Using this technique, several studies have generally considered the area of highest ictal hyperperfusion, as outlined by thresholding the difference images with a standard z score of 2, to be highly concordant to the epileptogenic focus. In clinical practice, several factors influence ictal hyperperfusion and using different SISCOM thresholds can be helpful. We aimed to systematically evaluate the localizing value of various z scores (1, 1.5, 2, and 2.5) in a seizure-free cohort following resective epilepsy surgery, and to examine the localizing information of perfusion patterns observed at each z score. METHODS: Twenty-six patients were identified as having ictal-interictal SPECT images, preoperative and postoperative MRI studies, and having remained seizure free for at least 6 months after temporal or extratemporal surgical resection. SISCOM analysis was performed using preoperative MRI studies, and then blindly reviewed for localization of hyperperfused regions. With the added information from postoperative, coregistered MRI, perfusion patterns were determined. KEY FINDINGS: Using pair-wise comparisons, we found that the optimal z score for SPECT-SISCOM localization of the epileptogenic zone was 1.5, not the commonly used z score of 2. The z score of 1.5 was 84.8% sensitive and 93.8% specific. The z score of 1.5 had a moderate interrater agreement (0.70). When an hourglass configuration hyperperfusion pattern was present, a trend toward correctly localizing the seizure onset region was suggested (100% of the 11 observed occurrences). Nonetheless this trend was not statistically significant, possibly reflecting the small number of occurrences in our study. SIGNIFICANCE: SISCOM is a useful modality in evaluating patients for epilepsy surgery. This study shows that the z score of 1.5 represents a highly sensitive and specific SISCOM threshold that should be examined in conjunction with the traditionally used z score of 2 to enhance the chances of correct localization. Further prospective investigations are needed to confirm this finding in large patient series.

Radiological correlate of ocular flutter in a case with paraneoplastic encephalitis.

We present an interesting [18F]fluoro-2-deoxyglucose positron emission tomography (FDG-PET) imaging finding in a patient with ocular flutter and cerebellar ataxia as part of anti-Ma 1/2 antibody-mediated paraneoplastic syndrome associated with a testicular seminoma. He had a typical anterior mesial temporal hyperintensity on magnetic resonance imaging (MRI) without gadolinium enhancement. In addition, his FDG-PET images showed increased deep cerebellar and inferior rectus and superior oblique ocular muscles FDG uptake. This case is the first to visualize in vivo the possible underlying neuropathological mechanism of ocular flutter associated with cerebellar nuclei on functional imaging.