Howan Leung

Association of subjective anxiety, depression, and sleep disturbance with quality-of-life ratings in adults with epilepsy

Purpose:  To determine the relative contributions of subjective anxiety, depression, sleep disturbance, and seizure‐related variables to quality‐of‐life scores in adults with epilepsy, and the interrelationships among these factors.

Finding the missing link between ictal bradyarrhythmia, ictal asystole, and sudden unexpected death in epilepsy.

Basic science studies of the human brain have supported the cortical representation of cardiovascular responses, including heart rate variability. Clinical observations of ictal bradyarrhythmia may be mechanistically explained by the influence of the central autonomic network, although the localization and lateralization issues need to be considered in the light of patterns of seizure spread, hand dominance, and presence of lesions. Ictal bradyarrhythmia also offers a mechanistic explanation of sudden unexpected death in epilepsy (SUDEP), though it may explain only some but not all cases of SUDEP. The missing links are (1) clinical evidence of common factors shared by patients with ictal bradyarrhythmia and patients who die from SUDEP, (2) evidence of arrhythmia as a risk factor for SUDEP from epidemiological studies, and, (3) determination of the importance of ictal bradyarrhythmia in SUDEP with respect to other proposed mechanisms including apnea and intrinsic cardiac abnormalities. There remains a need to review the seizure mechanisms in cases of SUDEP and to step up the amount of concurrent ECG/intracranial EEG analysis in both ictal bradyarrhythmia and SUDEP cases.

How generalised are secondarily “generalised” tonic–clonic seizures?

In clinical practice, epileptic seizures with focal onset and subsequent generalised motor involvement are referred to as secondarily generalised seizures. The purpose of this study was to investigate the degree of electrophysiological generalisation in seizures that are clinically secondarily generalised. Intracranial EEG recordings of secondarily generalised tonic–clonic seizures were visually and quantitatively analysed for the presence of epileptiform activity. In 24 (26%) of 93 seizures recorded from 17 (27%) of 64 patients, intracranial EEG channels were found that never recorded epileptiform activity during secondarily generalised tonic–clonic seizures. Our results demonstrate that seizures that are secondarily generalised clinically are not always generalised electrophysiologically. This may have therapeutic implications.

Headache in patients with epilepsy: A prospective incidence study

High prevalence of headache has been reported in patients with refractory epilepsy in cross‐sectional surveys based on retrospective recall. We conducted a prospective study to document the incidence of headache over a 3‐month observation period in a cohort of 227 adult patients with less refractory epilepsy. The mean seizure frequency was 2.46 per month. Fifty (22%) patients reported to have had at least one headache episode, 45 (19.8%) had interictal headache, 11 (4.8%) had periictal headache, and 5 (2.2%) had both interictal and periictal headache. Forty‐nine percent of the patients with headache took over‐the‐counter analgesics as acute treatment. The headache was rated to have made very severe or substantial impact on their lives by 34% of patients. A formal headache diagnosis was not made in any of the patients prior to the survey. Although the incidence of headache in epilepsy patients appeared to be low, it was underdiagnosed and associated with substantial negative impact.

Autonomic dysfunction in different subtypes of post-acute ischemic stroke.

OBJECTIVES Central autonomic impairment is frequent in ischemic stroke at acute or chronic stages. The mechanism by which these symptoms occur in patients with ischemic stroke has not been elucidated. This study sought to investigate cardiovascular autonomic function in patients with different subtypes of post-acute ischemic stroke. METHODS 77 ischemic stroke patients [50 patients with large-artery atherosclerosis (LAA) and 27 patients with small-vessel occlusion (SVO), average 6 months after stroke onset] and 37 elderly controls were recruited. All performed Ewings battery autonomic function tests and power spectral analysis of heart rate variability (HRV). RESULTS Stroke patients with both LAA and SVO had significantly lower low frequency power spectral density than controls. The prevalence of autonomic dysfunction in both groups (82.0% patients with LAA and 63.0% with SVO) was higher than that in controls (21.6%). Patients with LAA showed impairment of all parasympathetic tests (all P<0.05) and one of the sympathetic tests (mean fall in systolic blood pressure on standing: P = 0.058) and those with SVO only showed impairment in two parasympathetic tests (heart rate response to deep breathing: P = 0.010; heart rate response to standing: P = 0.004) in comparison with controls. Patients with LAA had significantly more impairment than those with SVO in some autonomic parameters (Valsalva ratio: P = 0.039; mean fall in systolic blood pressure on standing: P = 0.015). CONCLUSIONS Irrespective of the subtype of the ischemia, post-acute stroke patients showed a parasympathetic cardiac deficit. Additionally, parasympathetic and sympathetic cardiovascular modulations were more severely impaired in patients with LAA.

Mesial frontal epilepsy and ictal body turning along the horizontal body axis.

OBJECTIVE To evaluate the clinical utility of mesial frontal semiology. DESIGN Retrospective case series. SETTING Tertiary epilepsy referral center. PATIENTS Part 1 of the study involved 152 patients who underwent frontal lobe surgery. Part 2 involved 253 patients who underwent non-frontal lobe surgery. MAIN OUTCOME MEASURES Inclusion criteria for both parts of the study were seizure localization by analysis of resection margins (mesial frontal, lateral frontal, orbitofrontal, nonfrontal) or intracranial exploration and an Engel class I outcome. In part 1, 84 patients had their habitual seizures analyzed by video encephalography using a semiology checklist of 47 items during the early phase (electrographic onset to 10 seconds) and late phase (rest of episode). Localization semiology was analyzed by chi(2) test with Bonferroni correction and cluster analysis when occurrence exceeded 10% in at least 1 region. In part 2, 144 patients had their habitual seizures screened with mesial frontal semiology from the first part of study during the early phase only. RESULTS In part 1 of the study, the statistically significant localizing semiology for the mesial frontal region in the early phase was ictal body turning along the horizontal axis (57% of patients), crawling (57% of patients), restlessness (64.3% of patients), facial expressions of anxiety (42.9% of patients) and fear (35.7% of patients), grimacing produced by bilateral facial contraction (42.9% of patients), barking (32.1% of patients), head shaking (25% of patients), and pelvic raising (25% of patients) (all P< .001). In the late phase, recurrent utterance (21.4% of patients) was the additional statistically significant item (P< .002). In part 2 of the study, ictal body turning along the horizontal axis gave a 55.2% positive predictive value, which improved to 85.7% when clustered with restlessness, facial expressions of anxiety and fear, and barking. CONCLUSIONS Ictal body turning along the horizontal body axis and semiology with physiological movement are not only prevalent semiology items of mesial frontal lobe epilepsy but they distinguish mesial frontal from lateral frontal and orbitofrontal seizures.

Long‐term prognosis of Chinese patients with a lacunar infarct associated with small vessel disease: a five‐year longitudinal study

Rationale Lacunar infarct associated with small vessel disease is a common stroke subtype in China and has a favorable short-term prognosis. Data on its long-term prognosis among Chinese patients are lacking. Aims We aimed to study its long-term prognosis and predictors for poor outcomes. Design We followed up to 75 consecutive Chinese stroke patients who had a lacunar infarct for a period of 5 years. Clinical outcomes with respect to mortality and recurrent stroke were noted. We evaluated baseline clinical and imaging predictors for such outcomes using the Cox regression analysis. Study Outcomes Sixteen (21·3%) patients died and 12 (16%) patients had recurrent stroke during follow-up. Twenty-one (28%) patients had combined events of either death and/or recurrent stroke. Univariate Cox regression analysis showed that age, literacy, National Institute of Health Stroke Scale, incident stroke/transient ischemic attack, and white matter lesion volume predicted survival, while, age, National Institute of Health Stroke Scale, systolic blood pressure, hyperhomocysteinemia, silent lacunes, microbleeds, and white matter lesion volume predicted recurrent stroke. Multivariate Cox regression analysis showed that National Institute of Health Stroke Scale (HR 1·25, 95% CI 1·05–1·48) and white matter lesion volume (HR 1·46, 95% CI 1·11–1·92) predicted combined events of mortality and/or recurrent stroke after age adjustment. Conclusion Approximately one in four patients either died and/or had recurrent stroke within 5 years after a lacunar infarct. Age, stroke severity, and volume of white matter lesion predict a poor long-term prognosis.

Evolution of intracranial atherosclerotic disease under modern medical therapy.

Understanding how symptomatic intracranial atherosclerotic disease (ICAD) evolves with current medical therapy may inform secondary stroke prevention.

Wavelet-denoising of electroencephalogram and the absolute slope method: A new tool to improve electroencephalographic localization and lateralization

OBJECTIVE In ictal scalp electroencephalogram (EEG) the presence of artefacts and the wide ranging patterns of discharges are hurdles to good diagnostic accuracy. Quantitative EEG aids the lateralization and/or localization process of epileptiform activity. METHODS Twelve patients achieving Engel Class I/IIa outcome following temporal lobe surgery (1 year) were selected with approximately 1-3 ictal EEGs analyzed/patient. The EEG signals were denoised with discrete wavelet transform (DWT), followed by computing the normalized absolute slopes and spatial interpolation of scalp topography associated to detection of local maxima. For localization, the region with the highest normalized absolute slopes at the time when epileptiform activities were registered (>2.5 times standard deviation) was designated as the region of onset. For lateralization, the cerebral hemisphere registering the first appearance of normalized absolute slopes >2.5 times the standard deviation was designated as the side of onset. As comparison, all the EEG episodes were reviewed by two neurologists blinded to clinical information to determine the localization and lateralization of seizure onset by visual analysis. RESULTS 16/25 seizures (64%) were correctly localized by the visual method and 21/25 seizures (84%) by the quantitative EEG method. 12/25 seizures (48%) were correctly lateralized by the visual method and 23/25 seizures (92%) by the quantitative EEG method. The McNemar test showed p=0.15 for localization and p=0.0026 for lateralization when comparing the two methods. CONCLUSIONS The quantitative EEG method yielded significantly more seizure episodes that were correctly lateralized and there was a trend towards more correctly localized seizures. SIGNIFICANCE Coupling DWT with the absolute slope method helps clinicians achieve a better EEG diagnostic accuracy.

Prognosticating acute symptomatic seizures using two different seizure outcomes

Purpose:  This study examined the profiles and prognosis of first acute symptomatic seizure (ASS). Because seizure recurrences may occur in the setting of a persisting or reemerging acute symptomatic cause or in the setting of an unprovoked seizure, we documented the prognosis of ASS in terms of acute symptomatic seizure (AS) or unprovoked seizure (US) recurrence.