Sleep-wake habits and disorders in a series of 100 adult epilepsy patients--a prospective study

Comorbidity between epilepsy and sleep disorders

Despite being relatively common and potentially able to have clinical and pathophysiological consequences, the comorbidity between epilepsy and sleep disorders is poorly investigated in the literature and rarely taken into consideration by clinicians in general practice. There is increasing evidence that obstructive sleep apnoea (OSA) coexists in epilepsy (in 10% of unselected adult epilepsy patients, 20% of children with epilepsy and up to 30% of drug-resistant epilepsy patients). A few lines of evidence suggest that continuous positive airway pressure treatment of OSA in epilepsy patients improves seizure control, cognitive performance and quality of life. Parasomnias and epileptic seizures can coexist in the same subject making the differential diagnosis of these conditions particularly challenging. In childhood, a frequent association between epilepsy and NREM arousal parasomnias, enuresis and rhythmic movement disorder has been documented. A particular pattern of association has been found between nocturnal frontal lobe epilepsy (NFLE) and NREM arousal parasomnias, the latter being found in the personal or family history of up to one third of NFLE patients. As far as REM parasomnias are concerned, REM sleep behaviour disorder, unrecognised or misdiagnosed, has been found to co-occur in 12% of elderly epilepsy patients. Patients with epilepsy often complain of poor, non-restorative sleep; however, insomnia in epilepsy is poorly investigated, with the literature giving conflicting prevalence data and no information on the impact of this disorder on seizure control, or on the best therapeutic approach to insomnia in this particular group of patients. A greater awareness, among clinicians, of the comorbidities between sleep disorders and epilepsy may help to prevent misdiagnosis and mistreatment. Sleep hygiene measures in epilepsy need to be more comprehensive, taking into account the various pathologies that may underlie disordered sleep in epilepsy patients.

Genetic evidence for a role for protein kinase A in the maintenance of sleep and thalamocortical oscillations

STUDY OBJECTIVES

Genetic manipulation of cAMP-dependent protein kinase A (PKA) in Drosophila has implicated an important role for PKA in sleeplwake state regulation. Here, we characterize the role of this signaling pathway in the regulation of sleep using electroencephalographic (EEG) and electromyographic (EMG) recordings in R(AB) transgenic mice that express a dominant negative form of the regulatory subunit of PKA in neurons within cortex and hippocampus. Previous studies have revealed that these mutant mice have reduced PKA activity that results in the impairment of hippocampus-dependent long-term memory and long-lasting forms of hippocampal synaptic plasticity.

DESIGN

PKA assays, in situ hybridization, immunoblots, and sleep studies were performed in R(AB) transgenic mice and wild-type control mice.

MEASUREMENTS AND RESULTS

We have found that R(AB) transgenic mice have reduced PKA activity within cortex and reduced Ser845 phosphorylation of the glutamate receptor subunit GluR1. R(AB) transgenic mice exhibit non-rapid eye movement (NREM) sleep fragmentation and increased amounts of rapid eye movement (REM) sleep relative to wild-type mice. Further, R(AB) transgenic mice have more delta power but less sigma power during NREM sleep relative to wild-type mice. After sleep deprivation, the amounts of NREM and REM sleep were comparable between wild-type and R(AB) transgenic mice. However, the homeostatic rebound of sigma power in R(AB) transgenic mice was reduced.

CONCLUSIONS

Alterations in cortical synaptic receptors, impairments in sleep continuity, and alterations in sleep oscillations in R(AB) mice imply that PKA is involved not only in synaptic plasticity and memory storage but also in the regulation of sleep/wake states.

Nocturnal seizures and the effects of anticonvulsants on sleep

Epilepsy is a common condition that affects up to 1% of the population. Patients with epilepsy are particularly sensitive to the adverse effects of sleep disruption. Failure to recognize and treat sleep disturbances can lead to worsening of attention, cognitive functioning, and quality of life, and can increase seizures. Anticonvulsant agents have the potential to either improve or worsen sleep and sleep disorders in patients with epilepsy. Therefore, awareness of the implications of sleep disorders and anticonvulsants is critical for the optimal care of patients with epilepsy.

Influence of sleep disturbance on quality of life of patients with epilepsy

The frequency of sleep disturbances in patients with epilepsy and their impact on quality of life (QoL) have been documented in a few reports, and the results are conflicting. We identified 124 consecutive epilepsy out-patients who visited the epilepsy out-patient clinics at the University Hospital of Alexandroupolis, the AHEPA Hospital in Thessaloniki and the Aeginitio Hospital in Athens. We measured excessive daytime sleepiness (EDS) with the Epworth Sleepiness Scale (ESS), obstructive sleep apnea (OSA) with the Sleep Apnea scale of the Sleep Disorders Questionnaire (SA-SDQ), and insomnia with the Athens Insomnia Scale (AIS). We evaluated quality of life by the Quality of Life in Epilepsy Inventory (QOLIE-31). EDS was found in 16.9% (21/124) of epileptic patients, OSA in 28.2% (35/124), and insomnia in 24.6% (30/122). In multivariate analysis, we found that insomnia was an independent negative factor for Total score (p<0.001), Overall QoL (p=0.002), Emotional well-being (p<0.001), Energy/fatigue (p<0.001), Cognitive functioning (p=0.04) and Social functioning (p=0.03), and OSA only for Cognitive functioning (p=0.01). According to our findings, EDS, OSA, and insomnia are frequent in epileptic patients. Epileptic patients with sleep disturbance, mainly insomnia, have significant QoL impairment.

Subjective somnolence relates mainly to depression among patients in a tertiary care epilepsy center

Many patients with epilepsy complain of decreased energy and somnolence. There is increased awareness that comorbidity, especially depression, plays an important role in determining the quality of life for patients with epilepsy. We set out to determine how subjective somnolence is affected by depression, age, hours of sleep, sleep apnea, seizure frequency, and numbers of antiepileptic drugs and central nervous system drugs. A questionnaire and chart review were used to investigate patients in a tertiary referral center. We found that subjective somnolence was prominent and that it relates mainly to depression, less to obstructive sleep apnea, and not to the other variables. Further investigation is needed into the relationship between depression and subjective somnolence in patients with epilepsy.