Neuropsychological Outcome in Perinatal Stroke Associated With Epileptiform Discharges in Sleep

BACKGROUND

Patients with arterial perinatal stroke often suffer long-term motor sequelae, difficulties in language, social development, and behaviour as well as epilepsy. Despite homogeneous lesions, long-term behavioural and cognitive outcomes are variable and unpredictable. Sleep-related epileptic encephalopathies can occur after early brain injury and are associated with global developmental delays. We hypothesized that sleep-potentiated epileptiform abnormalities are associated with worse developmental outcomes after perinatal stroke.

METHODS

Participants were identified from a population-based cohort (Alberta Perinatal Stroke Project). Inclusion criteria were magnetic resonance imaging-confirmed arterial perinatal stroke, age 4 to 18 years, electroencephalogram (EEG) including sleep, and comprehensive neuropsychological evaluation. Sleep-related EEG abnormalities were categorized by an epileptologist blinded to the cognitive outcome. Associations between EEG classification and neuropsychological outcomes were explored (t tests, Bonferroni correction for multiple comparisons).

RESULTS

Of 128 potentially eligible participants, 34 (53% female) had complete EEG (mean age, 8.1 years; range, 0.2-16.4) and neuropsychology testing (mean age, 9.8 years; range 4.4-16.7). Twelve (35%) were classified as having electrical status epilepticus in sleep. Patients with abnormal EEGs were more likely to have statistically worse scores when corrected for multiple comparisons, in receptive language (median, 1st percentile; IQR 1-7th percentile; p<0.05), and externalizing behaviours (median, 82nd percentile; IQR, 79-97th percentile; p<0.05).

CONCLUSIONS

Developmental outcome in language and behaviour in children with arterial perinatal stroke is associated with electrical status epilepticus in sleep. Increased screening with sleep EEG is suggested, whereas further studies are necessary to determine if treatment of EEG abnormalities can improve outcome.

Subclinical epileptiform activity in children with electrical status epilepticus during sleep: effects on cognition and behavior before and after treatment with levetiracetam

We performed a double-blind placebo-controlled crossover study of the effects of spike activity during sleep and when awake on learning, long-term memory, vigilance and behavior before and after treatment with levetiracetam in children with electrical status epilepticus during sleep. At baseline, verbal learning declined with increasing spike activity, but there were no relations between spike activity and memory, vigilance or behavior. Levetiracetam was effective in reducing sleep-related spike activity, but on a group level, this had no clear effects on behavior, vigilance or learning and memory. Our results do not allow firm conclusions whether to treat nocturnal epileptiform activity or not; larger samples and longer follow-up may be needed.

Epileptic encephalopathy with continuous spike-waves during slow-wave sleep including Landau-Kleffner syndrome

Epileptic encephalopathy with continuous spike-waves during slow-wave sleep (CSWS) is a spectrum of epileptic conditions best defined by the association of cognitive or behavioral impairment acquired during childhood and not related to another factor other than the presence of abundant interictal epileptiform discharges (IED) during sleep, which tend to diffuse over the whole scalp. It is part of the childhood focal epileptic syndromes, some cases being idiopathic and overlapping with benign rolandic epilepsy, and others being symptomatic of a structural brain lesion. Landau-Kleffner syndrome (LKS) is a particular presentation where acquired aphasia is the core symptom. Clinical, neurophysiological, and cerebral glucose metabolism data support the hypothesis that IED play a prominent role in the cognitive deficits by interfering with the neuronal networks at the site of the epileptic foci but also at distant connected areas. Therefore, the treatment should aim to suppress IED. This may be achieved using conventional antiepileptic drugs, but corticosteroids seem to have more pronounced and sustained efficacy. Outcome for epilepsy is usually good, CSWS being an age-dependent EEG pattern, whereas outcome for cognition, language, and behavior is variable. Rehabilitation represents an important part of the treatment and visual forms of language should be encouraged in children with LKS.