The role of stand-alone videos in the diagnosis of seizures.

The diagnosis of seizures and seizure mimics relies primarily on the history, but history has well-known limitations. Video recordings of events are a powerful extension of the history because they allow neurologists to view the events in question. In addition, they are readily available in situation, whereas the gold standard of EEG-video is not. That includes underserved or rural areas, and events that are too infrequent to be captured during a few days of EEG-video monitoring. Brief cellphone videos have been shown to be valuable to suggest or guide the correct diagnosis.

The Yield of Ambulatory Video-EEG: Predictors of Successful Event Capture.

Background and Objectives: The purpose of this study was to assess the likelihood of capturing a patient's typical event in question on ambulatory video-EEG monitoring (AVEM) based on certain baseline patient or event characteristics. Methods: We retrospectively reviewed 300 studies that resulted between June 2021 and August 2022 ordered by adult epileptologists. Patients were included in event analysis if the study was ordered for the purpose of capturing an event (and excluded for all other purposes). Results: A total of 149 studies were included in event analysis. Sixty-eight patients (46%) had their typical events captured on AVEM. Diagnosis was an epileptic seizure in 17 patients (25%), psychogenic nonepileptic seizure in 7 (10%), and other nonepileptic events in 44 (65%). Regarding event frequency, for patients who on average had daily events, 84% had events captured, which corresponds to a significantly increased odds ratio (OR 17.90, 95% CI 7.55-42.44, p < 0.001). For those who had events <1 per week to ≥1 per month, only 9% had events captured (OR 0.06, 95% CI 0.02-0.19, p < 0.001). No patients who had events less frequently than once per month had a diagnostic AVEM. Regarding the number of antiseizure medications (ASMs), the odds ratio was increased for those not on ASMs (OR 2.65, 95% CI 1.17 -6.03, p = 0.02) and decreased for those on 1 ASM (OR 0.28, 95% CI 0.13 -0.60, p = 0.001). There was no statistical significance based on event type (motor vs nonmotor), prior seizure diagnosis, history of psychiatric comorbidity, or presence of a focal brain lesion. Discussion: Certain baseline characteristics can increase or decrease the pretest probability of capturing a typical event on AVEM, particularly the frequency of events and number of ASMs. This can be useful information for clinicians before ordering a study so that resources can be properly allocated.

Normal variants and artifacts: Importance in EEG interpretation.

Overinterpretation of EEG is an important contributor to the misdiagnosis of epilepsy. For the EEG to have a high diagnostic value and high specificity, it is critical to recognize waveforms that can be mistaken for abnormal patterns. This article describes artifacts, normal rhythms, and normal patterns that are prone to being misinterpreted as abnormal. Artifacts are potentials generated outside the brain. They are divided into physiologic and extraphysiologic. Physiologic artifacts arise from the body and include EMG, eyes, various movements, EKG, pulse, and sweat. Some physiologic artifacts can be useful for interpretation such as EMG and eye movements. Extraphysiologic artifacts arise from outside the body, and in turn can be divided into the environments (electrodes, equipment, and cellphones) and devices within the body (pacemakers and neurostimulators). Normal rhythms can be divided into awake patterns (alpha rhythm and its variants, mu rhythm, lambda waves, posterior slow waves of youth, HV-induced slowing, photic driving, and photomyogenic response) and sleep patterns (POSTS, vertex waves, spindles, K complexes, sleep-related hypersynchrony, and frontal arousal rhythm). Breach can affect both awake and sleep rhythms. Normal variants or variants of uncertain clinical significance include variants that may have been considered abnormal in the early days of EEG but are now considered normal. These include wicket spikes and wicket rhythms (the most common normal pattern overread as epileptiform), small sharp spikes (aka benign epileptiform transients of sleep), rhythmic midtemporal theta of drowsiness (aka psychomotor variant), Cigánek rhythm (aka midline theta), 6 Hz phantom spike-wave, 14 and 6 Hz positive spikes, subclinical rhythmic epileptiform discharges of adults (SREDA), slow-fused transients, occipital spikes of blindness, and temporal slowing of the elderly. Correctly identifying artifacts and normal patterns can help avoid overinterpretation and misdiagnosis. This is an educational review paper addressing a learning objective of the International League Against Epilepsy (ILAE) curriculum.

Value of smartphone videos for diagnosis of seizures: Everyone owns half an epilepsy monitoring unit.

The diagnosis of epilepsy is primarily based on the history and the verbal description of the events in question. Smartphone videos are increasingly used to assist in the diagnosis. The purpose of this study is to evaluate their value for the diagnosis of seizures. We prospectively collected smartphone videos from patients who presented to our epilepsy center over two years. The video-based diagnosis was then compared to the eventual diagnosis based on video-electroencephalographic (EEG) monitoring with recorded episodes. Video-EEG studies and smartphone videos were reviewed by two separate physicians, each blinded to the other's interpretation. Fifty-four patients were included in the final analysis (mean age = 34.7 years, SD = 17 years). Data (either smartphone video or video-EEG monitoring) were inconclusive in 18 patients. Of the 36 patients with conclusive data, 34 (94%) were in agreement. Smartphone video interpretation can be a useful adjunctive tool in the diagnosis of seizure-like events.

Intracranial recordings for non-lesional mesiotemporal epilepsy? Almost always, but not quite always.

•The majority of patients with non-lesional mesial TLE needs intracranial recordings.•This rule should not be rigid and there are some exceptions. Decisions should be individualized.•For bilateral mesial temporal lobe epilepsy, chronic ECoG with RNS may be preferable over "traditional" short-term intracranial recording.

Avoiding complacency when treating uncontrolled seizures: why and how?

Introduction: Despite the advances in the diagnosis and treatment of epilepsy, approximately 30% of the patients remain intractable. Uncontrolled seizures have deleterious consequences, including brain damage, cognitive decline, decreased quality of life, and increased mortality.Areas covered: In this article, the authors discuss the treatment gap in patients with intractable epilepsy and the possible mechanisms of drug resistance. The authors provide a treatment algorithm for patients with intractable epilepsy, including non-pharmacological treatment options, such as diet, neurostimulation (vagus nerve stimulation, responsive neurostimulation, and deep brain stimulation), curative surgeries, and palliative surgeries.Expert opinion: There are currently several gaps in the management of seizures. Thirty percent of the 1% of the population with epilepsy is drug resistant. Non-pharmacologic treatments have improved in the last 30 years and continue to do so, but epilepsy surgery in general is still vastly under-utilized. Resective surgery is the only potentially curative procedure. Neurostimulation is generally palliative and is also improving, with smarter types of neurostimulation and paradigms.

Outcome of prolonged video-EEG monitoring in a new VA monitoring unit.

BACKGROUND AND OBJECTIVE: For patients with refractory seizures or seizure-like activity, prolonged inpatient video-electroencephalography (EEG) (v-EEG) is standard of care to guide diagnosis and management. The purpose of this study was to describe the outcome of v-EEG in a new Veterans' Administration (VA) hospital epilepsy monitoring unit (EMU). METHODS: We reviewed all prolonged (>24 h) inpatient v-EEGs performed in our EMU (2 beds) at the James A Haley VA in Tampa, FL over a five-and-a-half-year period (11/2013-07/2019). A total of 216 prolonged v-EEGs were performed. The patient population consisted of adult veterans (185 males, 31 females) ranging from 21 years to 89 years old (mean 52.5). The duration of monitoring ranged from 24 h to 9 days (mean 3.6 days). RESULTS: Of the 216 studies, 39 (18%) exclusively had epileptic seizures (ES). Of these, 37 (95%) had focal seizures, and 2 (5%) had generalized seizures. Of the 37 cases with focal seizures, all but 2 had clear ictal changes on EEG. Eighteen (8.5%) EEG studies revealed interictal epileptiform abnormalities without a clinical event. Sixty-eight (31.5%) of the v-EEGs had exclusively nonepileptic events (NEE). Of these, 27 (12.5%) were psychogenic nonepileptic seizures (PNES), and 41 (19%) were other NEE. Ninety-one (42%) of the studies were inconclusive, either because of lack of events captured (63) or because the events recorded were not the patient's typical episodes (27). SIGNIFICANCE: Compared to non-VA series, we found a lower proportion of PNES, and a higher proportion of inconclusive studies.

The Role of EEG in the Erroneous Diagnosis of Epilepsy.

Errors in diagnosis are relatively common in medicine and occur in all specialties. The consequences can be serious for both patients and physicians. Errors in neurology are often because of the overemphasis on 'tests' over the clinical picture. The diagnosis of epilepsy in general is a clinical one and is typically based on history. Epilepsy is more commonly overdiagnosed than underdiagnosed. An erroneous diagnosis of epilepsy is often the result of weak history and an 'abnormal' EEG. Twenty-five to 30% of patients previously diagnosed with epilepsy who did not respond to initial antiepileptic drug treatment do not have epilepsy. Most patients misdiagnosed with epilepsy turn out to have either psychogenic nonepileptic attacks or syncope. Reasons for reading a normal EEG as an abnormal one include over-reading normal variants or simple fluctuations of background rhythms. Reversing the diagnosis of epilepsy is challenging and requires reviewing the 'abnormal' EEG, which can be difficult. The lack of mandatory training in neurology residency programs is one of the main reasons for normal EEGs being over-read as abnormal. Tests (including EEG) should not be overemphasized over clinical judgment. The diagnosis of epilepsy can be challenging, and some seizure types may be underdiagnosed. Frontal lobe hypermotor seizures may be misdiagnosed as psychogenic events. Focal unaware cognitive seizures in elderly maybe be blamed on dementia, and ictal or interictal psychosis in frontal and temporal lobe epilepsies may be mistaken for a primary psychiatric disorder.

EEG Findings in Posterior Reversible Encephalopathy Syndrome.

Introduction. Posterior reversible encephalopathy syndrome (PRES) is a relatively common cause of encephalopathy in the hospital setting, and the EEG findings have not been well described. The purpose of this study was to review the EEG findings in a series of patients with PRES. Methods. We retrospectively reviewed our electronic medical record database to identify patients who received a diagnosis of PRES at Tampa General Hospital from January 2016 to October 2017. The diagnosis of PRES was suspected on clinical presentation and confirmed by magnetic resonance imaging. We selected patients with PRES who had received at least 1 EEG. EEGs were interpreted by 2 board-certified electroencephalographers. Results. From January 2016 to October 2017, 19 patients were diagnosed with PRES at Tampa General Hospital. Of those, 10 received at least 1 EEG. Four patients were male, 6 were female. The ages ranged from 21 to 87 (mean was 47). The patients had the following clinical presentations: 5 with encephalopathy, 8 with seizures, 2 with vision changes, and 3 with headache (some patients had more than 1 symptom). EEGs findings were as follows: 3 were normal; 3 showed intermittent generalized slowing; 2 showed continuous generalized slowing; 3 showed background slowing; 1 showed background suppression; 1 showed generalized rhythmic delta activity (GRDA); 1 showed GRDA, plus spike/sharp-wave discharges; 1 showed generalized periodic discharges. The etiologies were as follows: 9 from hypertension, 1 secondary to eclampsia, 3 due to posttransplant immunosuppression, and 1 patient was undergoing chemotherapy (some were multifactorial). Conclusion. EEG findings in PRES are diverse, with no specific or even predominant pattern, based on this small sample size.

Association Between Positive Occipital Sharp Transients of Sleep and Lambda Waves.

Positive occipital sharp transients of sleep (POSTS) and lambda waves have similar morphology and location. We studied a possible association between these 2 normal EEG patterns. We reviewed a series of consecutive unselected ambulatory EEGs during a 3-month period (October 16, 2017 to January 19, 2018) and identified records with POSTS and records with lambda waves. Statistical analysis was performed using a chi-square test. A total of 140 ambulatory EEGs were reviewed. Duration of EEGs ranged from 24 to 168 hours (mean 76 hours). The population was 34% males, with ages ranging from 3 to 93 years (mean 48 years). Of the 140 records, 30 were abnormal, including 20 with epileptiform abnormalities. A chi-square test for independence (with Yates continuity correction) indicated a significant association between POSTS and lambda waves, χ2(1, n = 140) = 69.208, p < .001, φ = 0.72. In addition, 100% of records with lambda waves had POSTS, and 72% of records with POSTS had lambda waves. There is a high association between lambda waves and POSTS. This suggests a strong similarity between the 2 waveforms, and possibly a common occipital generator.