Effects of Anticonvulsant Medication on EEG Sleep Architecture

Slow wave sleep is associated with forgetting in patients with temporal lobe epilepsy

While time spent in slow wave sleep (SWS) after learning promotes memory consolidation in the healthy brain, it is unclear if the same benefit is obtained in patients with temporal lobe epilepsy (TLE). Interictal epileptiform discharges (IEDs) are potentiated during SWS and thus may disrupt memory consolidation processes thought to depend on hippocampal-neocortical interactions. Here, we explored the relationship between SWS, IEDs, and overnight forgetting in patients with TLE. Nineteen patients with TLE studied object-scene pairs and memory was tested across a day of wakefulness (6 hrs) and across a night of sleep (16 hrs) while undergoing continuous scalp EEG monitoring. We found that time spent in SWS after learning was related to greater forgetting overnight. Longer duration in SWS and number of IEDs were each associated with greater forgetting, although the number of IEDs did not mediate the relationship between SWS and memory. Further research, particularly with intracranial recordings, is required to identify the mechanisms by which SWS and IEDs can be pathological to sleep-dependent memory consolidation in patients with TLE.

Neuropsychological consequences of sleep disturbance in children with epilepsy

A growing body of research reveals strong relationships between sleep disturbance, sleep architecture, and neuropsychological functioning in children. Children with epilepsy experience numerous neuropsychological comorbidities, including cognitive deficiencies and emotional/behavioral difficulties; thus, it is reasonable to consider the moderating role of sleep in this population. This review summarizes findings involving the prevalence and characteristics of sleep problems often experienced by children with epilepsy. The complex and bidirectional relationship between sleep and seizure frequency is discussed. Research pertaining to the relationship between sleep disturbance and daytime cognition as well as behavior reveals a substantial association between these variables. Clinically relevant practices related to the assessment and treatment of sleep-related complications are reviewed, and directions for further research involving intervention and assessment are also reviewed.

Sleep architecture as correlate and predictor of symptoms and impairment in inter-episode bipolar disorder: taking on the challenge of medication effects

This study was designed to clarify the association between inter-episode bipolar disorder (BD) and sleep architecture. Participants completed a baseline symptom and sleep assessment and, 3 months later, an assessment of symptoms and impairment. The effects of psychiatric medications on sleep architecture were also considered. Participants included 22 adults with BD I or II (inter-episode) and 22 non-psychiatric controls. The sleep assessment was conducted at the Sleep and Psychological Disorders Laboratory at the University of California, Berkeley. Follow-up assessments 3 months later were conducted over the phone. Results indicate that, at the sleep assessment, BD participants exhibited greater rapid eye movement sleep (REM) density than control participants with no other group differences in sleep architecture. Sleep architecture was not correlated with concurrent mood symptoms in either group. In the BD group, duration of the first REM period and slow-wave sleep (SWS) amount were positively correlated with manic symptoms and impairment at 3 months, while REM density was positively correlated with depressive symptoms and impairment at 3 months. The amount of Stage 2 sleep was negatively correlated with manic symptoms and impairment at 3 months. In contrast, for the control group, REM density was negatively correlated with impairment at 3 months. SWS and Stage 2 sleep were not correlated with symptoms or impairment. Study findings suggest that inter-episode REM sleep, SWS and Stage 2 sleep are correlated with future manic and depressive symptoms and impairment in BD. This is consistent with the proposition that sleep architecture may be a mechanism of illness maintenance in BD.

Sleep and circadian rhythms in children and adolescents with bipolar disorder

The aim of this paper is to highlight the importance of the sleep-wake cycle in children and adolescents with bipolar disorder. After presenting an overview of the measurement and function of human sleep, we describe changes in sleep and circadian functioning across the life cycle. We then review evidence that, in adults, sleep and/or circadian rhythms are of considerable influence in the multifactorial causal chain implicated in relapse in bipolar disorder, discussing relevant mechanisms. The latter include abnormalities in the amount and timing of sleep, the role of social zeitgebers, and the importance of sleep in regulating emotional responses and mood. We next present preliminary data indicating considerable sleep disturbance among children and adolescents with bipolar disorder. Given the considerable sleep disturbance evident among children and adolescents with bipolar disorder along with a key role for sleep in emotion regulation and learning, we conclude that sleep among children and adolescents with bipolar disorder is a critical domain for future research. An agenda for future research is presented that includes descriptive studies, investigations of causality, and treatment development research.

Treatment of sleep disorders in epilepsy

The interrelationship of sleep and epilepsy is described. Seizures and their treatment, including antiepileptic medications, may affect sleep. In turn, sleep disorders may influence seizure control and contribute to daytime sleepiness in epilepsy patients. Parasomnias and other sleep-related disorders may mimic epileptic seizures, although the history and video-EEG polysomnography are often useful in distinguishing these events. The treatment of epilepsy patients with sleep disorders or sleep complaints, such as sleepiness or insomnia, is discussed. Diagnosis and treatment of coexisting sleep disorders may improve not only daytime sleepiness, but also seizure control. Sedating AEDs may benefit epilepsy patients with insomnia, and stimulating AEDs may benefit epilepsy patients with daytime sleepiness.