Teaching Video NeuroImage: Monocular Rotational Nystagmus Caused by Superior Oblique Myokymia.

A 61-year-old man presented with 2 days of "flickering" vision. The symptom resolved with closure of the left eye. Examination demonstrated involuntary high-frequency, low-amplitude intorting movements of the left eye, consistent with superior oblique myokymia (Video 1). Ocular ductions were full, and there were no abnormal movements of the right eye.

Evaluating consciousness and awareness during focal seizures: responsiveness testing versus recall testing

Objective: The current International League Against Epilepsy (ILAE) guidelines classify focal seizures based on awareness, defined as successful postictal recall of ictal experiences, and exclude the use of responsiveness during seizures for classification. One reason for this exclusion is that responsiveness was thought to not be commonly tested during seizures. Our goal was to determine whether, in at least some settings, responsiveness testing during seizures is relatively common. Methods: We assessed how often responsiveness and recall were each evaluated in patients with focal epilepsy undergoing surface and intracranial EEG-video monitoring. We performed this evaluation by retrospectively reviewing video recordings from 121 seizures from 48 patients during their stay in the epilepsy monitoring unit between September 2012 and November 2019. Results: We found that responsiveness during seizures was tested more frequently than recall of ictal events after seizures. Of 121 seizures in 48 patients, responsiveness was tested in 101 seizures, whereas recall was tested in only 38. Significance: Evaluating if consciousness is impaired during seizures is of critical importance for guiding recommendations for people with epilepsy, such as whether it is safe for them to drive or operate machinery. The ILAE classification guidelines are intended to be broadly useful, but our findings demonstrate that at least in one important clinical setting, responsiveness was used more commonly than recall to evaluate patients during focal seizures. Although our preliminary findings should be replicated in a larger sample and in other patient groups, they suggest that responsiveness testing during focal seizures might be relatively common in at least some clinical practice settings. With further study, this may lead to a re-evaluation of criteria for classifying focal seizures to include both responsiveness and recall of experiences during seizures, as both may provide important information to guide clinical care.

Migration characteristics as a prognostic factor in cerebral sparganosis.

OBJECTIVE: To differentiate diagnostic and prognostic factors from the clinical material of patients with cerebral sparganosis in central South China. METHODS: Consecutive patients with cerebral sparganosis from our hospital between 2010 and 2018 were retrospectively enrolled. The clinical manifestations, radiographic features, treatment, and outcomes of these patients were analyzed. RESULTS: Thirty patients with cerebral sparganosis were included, and foci migration on magnetic resonance imaging was detected in 22 patients, from whom we observed 4 migration modes: interlobar migration (50.0%, 11/22); transmidline migration (27.3%, 6/22); transventricular migration (13.6%, 3/22); and cerebellum-brainstem migration (9.1%, 2/22). The percentage of good outcomes was higher in patients with live worm capture than in those without live worm capture (75.0%, 12/16 vs 33.3%, 2/6). Exposure to preoperative antiparasitic medication was associated with worm migration toward the cortical surface, which led to a higher probability of live worm capture. CONCLUSIONS: We propose 4 modes of sparganosis migration that are correlated with worm capture and neurologic prognosis. We found that exposure to antiparasitic medication was associated with worm migration toward the cortical surface, leading to a higher probability of live worm capture. These observations suggest a novel significance for preoperative medication of cerebral sparganosis.

Reliability of patient self-report of cognition, awareness, and consciousness during seizures.

OBJECTIVE: Clinicians rely on patient self-report of impairment during seizures for decisions including driving eligibility. However, the reliability of patient reports on cognitive and behavioral functions during seizures remains unknown. METHODS: We administered a daily questionnaire to epilepsy patients undergoing continuous video-EEG monitoring, asking about responsiveness, speech, memory, awareness, and consciousness during seizures in the preceding 24 hours. We also administered a questionnaire upon admission about responsiveness, speech, and awareness during seizures. Subjective questionnaire answers were compared with objective behavioral ratings on video review. Criteria for agreement were Cohen's kappa >0.60 and proportions of positive and negative agreement both >0.75. RESULTS: We analyzed 86 epileptic seizures in 39 patients. Memory report on the daily questionnaire met criteria for agreement with video review (κ = 0.674 for early, 0.743 for late recall). Subjective report of awareness also met agreement criteria with video ratings of memory (κ = 0.673 early, 0.774 late). Concordance for speech was relatively good (κ = 0.679) but did not meet agreement criteria, nor did responsiveness or consciousness. On the admission questionnaire, agreement criteria were met for subjective report of awareness versus video ratings of memory (κ = 0.814 early, 0.806 late), but not for other comparisons. INTERPRETATION: Patient self-report of memory or awareness showed the best concordance with objective memory impairment during seizures. Self-report of impairment in other categories was less reliable. These findings suggest that patient reports about impaired memory during seizures may be most reliable, and otherwise determining functional impairments should be based on objective observations.

End-of-Life Care Decision-Making in Stroke.

Stroke is one of the leading causes of death and long-term disability in the United States. Though advances in interventions have improved patient survival after stroke, prognostication of long-term functional outcomes remains challenging, thereby complicating discussions of treatment goals. Stroke patients who require intensive care unit care often do not have the capacity themselves to participate in decision making processes, a fact that further complicates potential end-of-life care discussions after the immediate post-stroke period. Establishing clear, consistent communication with surrogates through shared decision-making represents best practice, as these surrogates face decisions regarding artificial nutrition, tracheostomy, code status changes, and withdrawal or withholding of life-sustaining therapies. Throughout decision-making, clinicians must be aware of a myriad of factors affecting both provider recommendations and surrogate concerns, such as cognitive biases. While decision aids have the potential to better frame these conversations within intensive care units, aids specific to goals-of-care decisions for stroke patients are currently lacking. This mini review highlights the difficulties in decision-making for critically ill ischemic stroke and intracerebral hemorrhage patients, beginning with limitations in current validated clinical scales and clinician subjectivity in prognostication. We outline processes for identifying patient preferences when possible and make recommendations for collaborating closely with surrogate decision-makers on end-of-life care decisions.

Parallel pathways to decreased subcortical arousal in focal limbic seizures.

Focal limbic seizures can cause loss of consciousness. Previous work suggests that hippocampal seizures can increase activity in the lateral septum (LS) and decrease cholinergic output from the basal forebrain (BF), leading to deficits in conscious arousal. The mechanism by which LS and BF interact is unclear. In this study, we used anterograde and retrograde tracing to investigate anatomical pathways connecting LS and BF. We found that LS projects directly to BF and indirectly to BF via the thalamic paratenial nucleus (PT). Acute electrophysiology experiments during electrically induced focal limbic seizures showed that multiunit activity decreased in PT during the ictal period and was associated with increased cortical slow wave activity. These results suggest that LS could functionally inhibit BF during a seizure directly, or could indirectly decrease excitatory output to BF through PT. Further work investigating such parallel inhibitory and excitatory pathways to subcortical arousal may ultimately lead to new treatment targets for consciousness-impairing limbic seizures.

Thalamic Stimulation Improves Postictal Cortical Arousal and Behavior.

The postictal state following seizures is characterized by impaired consciousness and has a major negative impact on individuals with epilepsy. Previous work in disorders of consciousness including the postictal state suggests that bilateral deep brain stimulation (DBS) of the thalamic intralaminar central lateral nucleus (CL) may improve level of arousal. We tested the effects of postictal thalamic CL DBS in a rat model of secondarily generalized seizures elicited by electrical hippocampal stimulation. Thalamic CL DBS was delivered at 100 Hz during the postictal period in 21 female rats while measuring cortical electrophysiology and behavior. The postictal period was characterized by frontal cortical slow waves, like other states of depressed consciousness. In addition, rats exhibited severely impaired responses on two different behavioral tasks in the postictal state. Thalamic CL stimulation prevented postictal cortical slow wave activity but produced only modest behavioral improvement on a spontaneous licking sucrose reward task. We therefore also tested responses using a lever-press shock escape/avoidance (E/A) task. Rats achieved high success rates responding to the sound warning on the E/A task even during natural slow wave sleep but were severely impaired in the postictal state. Unlike the spontaneous licking task, thalamic CL DBS during the E/A task produced a marked improvement in behavior, with significant increases in lever-press shock avoidance with DBS compared with sham controls. These findings support the idea that DBS of subcortical arousal structures may be a novel therapeutic strategy benefitting patients with medically and surgically refractory epilepsy.SIGNIFICANCE STATEMENT The postictal state following seizures is characterized by impaired consciousness and has a major negative impact on individuals with epilepsy. For the first time, we developed two behavioral tasks and demonstrate that bilateral deep brain stimulation (DBS) of the thalamic intralaminar central lateral nucleus (CL) decreased cortical slow wave activity and improved task performance in the postictal period. Because preclinical task performance studies are crucial to explore the effectiveness and safety of DBS treatment, our work is clinically relevant as it could support and help set the foundations for a human neurostimulation trial to improve postictal responsiveness in patients with medically and surgically refractory epilepsy.

Application of the APE2-CHN and RITE2-CHN scores for autoimmune seizures and epilepsy in Chinese patients: A retrospective study.

PURPOSE: To assess the performance of the Antibody Prevalence in Chinese Patients with Epilepsy and Encephalopathy (APE2-CHN) and Response to Immunotherapy in Chinese Patients with Epilepsy and Encephalopathy (RITE2-CHN) scores in Chinese patients with epilepsy of unknown etiology. METHODS: We conducted a retrospective study of selected patients from Xiangya Hospital, Central South University (01/01/2017-02/28/2019) whose serum and/or cerebrospinal fluid (CSF) samples were examined for autoimmune encephalitis antibodies. Of these, patients with diagnostic code of seizure or epilepsy were selected in our study. An APE2-CHN score was assigned to each patient and a RITE2-CHN score was calculated for each patient who received immunotherapy. Receiver-operating characteristic (ROC) curve was used to assess each score. RESULTS: 191 patients were enrolled in our study. 36 were identified with specific etiologies. The remaining 155 patients had unknown etiology. Central nervous system-specific antibodies were detected in 76 (49.0 %) patients, after excluding patients with only anti-thyroid peroxidase or glutamic acid decarboxylase antibodies. N-methyl-d-aspartate receptor (NMDAR) antibody (48.7 %, 37/76) was the most common subtype of our sample, followed by γ-aminobutyric acid type B receptor (GABAR) (14.5 %, 11/76). Clinical features including new-onset epilepsy, neuropsychiatric changes, speech disorder, movement disorder and inflammatory CSF profile correlated with positive antibody results. The sensitivity and specificity of APE2-CHN ≥ 5 in predicting the presence of neural-specific autoantibodies in our study were 85.5 % and 58.9 % respectively. In the subset of patients who received immunotherapy (n = 112), sensitivity and specificity of a RITE2 -CHN ≥ 8 in predicting favorable seizure outcome were 98.6 % and 63.2 % respectively. The area under the curve (AUC) of RITE2-CHN was greater than that of RITE2 (Z = 3.196, p < 0.05) while there was no significant difference in AUC between APE2 and APE2-CHN (Z = 1.058, p = 0.290). CONCLUSION: The APE2-CHN and RITE2-CHN scores may be useful screening tools in predicting positive antibody findings and prognosis of suspected autoimmune seizures or associated epilepsy in the Chinese population.

Neural network models of the tactile system develop first-order units with spatially complex receptive fields.

First-order tactile neurons have spatially complex receptive fields. Here we use machine-learning tools to show that such complexity arises for a wide range of training sets and network architectures. Moreover, we demonstrate that this complexity benefits network performance, especially on more difficult tasks and in the presence of noise. Our work suggests that spatially complex receptive fields are normatively good given the biological constraints of the tactile periphery.

Anatomy Based Networks and Topology Alteration in Seizure-Related Cognitive Outcomes.

Epilepsy is a paroxysmal neurological disorder characterized by recurrent and unprovoked seizures affecting approximately 50 million people worldwide. Cognitive dysfunction induced by seizures is a severe comorbidity of epilepsy and epilepsy syndromes and reduces patients' quality of life. Seizures, along with accompanying histopathological and pathophysiological changes, are associated with cognitive comorbidities. Advances in imaging technology and computing allow anatomical and topological changes in neural networks to be visualized. Anatomical components including the hippocampus, amygdala, cortex, corpus callosum (CC), cerebellum and white matter (WM) are the fundamental components of seizure- and cognition-related topological networks. Damage to these structures and their substructures results in worsening of epilepsy symptoms and cognitive dysfunction. In this review article, we survey structural, network changes and topological alteration in different regions of the brain and in different epilepsy and epileptic syndromes, and discuss what these changes may mean for cognitive outcomes related to these disease states.

Dynamic functional disturbances of brain network in seizure-related cognitive outcomes.

Epilepsy is a prevalent neurologic disorder affecting approximately 50 million people worldwide. Cognitive dysfunction induced by seizures is one of the severe comorbidities of epilepsy and epileptic syndrome, which has a negative impact on epileptic patients' quality of life. Several mechanisms may be associated with cognitive impairment in patients with epilepsy. Here, we review how the dynamic functional alterations of brain network influence seizure-related cognitive outcomes.