Few studies have systematically investigated insomnia in adults with epilepsy.
Researchers have performed a prospective cross-sectional investigation of the prevalence, severity, and comorbidities of insomnia in 90 adults with epilepsy using a battery of self-reported instruments and polysomnography.
Insomnia severity was quantified using the Insomnia Severity Index ( ISI ).
Fifty-nine of 90 ( 65.5% ) adults with epilepsy reported insomnia ( ISI greater than or equal to 8 ), moderate or severe ( ISI greater than or equal to 15 ) in 28.9%.
Good agreement between standard clinical diagnostic criteria and ISI was found for patients with ISI scores less than 8 and greater than or equal to 15.
Scores on the modified Beck Depression Inventory ( mBDI ) ( r=0.25, p=0.021 ), the original BDI ( r=0.32, p=0.002 ), and self-reported total sleep duration ( TSD ) ( r=-0.3, p=0.006 ) were significantly related to ISI score.
A multiple regression model found that decreased total sleep duration ( beta=-0.93, p=0.007 ), head trauma ( beta=4.37, p=0.003 ), sedative-hypnotic use ( beta=4.86, p=0.002 ), antiepileptic polytherapy ( beta=3.52, p=0.005 ), and asthma/COPD ( beta=3.75, p=0.014 ) were predictors of a higher ISI score.
For 63 patients with focal epilepsy, an increased mBDI ( beta=0.24, p=0.015 ), decreased total sleep duration ( beta=-1.11, p=0.008 ), asthma / COPD ( beta=4.19, p=0.02 ), and epilepsy surgery ( beta=5.33, p=0.006 ) were significant predictors of an increased ISI score.
Patients with temporal lobe epilepsy ( TLE ) showed a trend for greater severity compared with those with extra-TLE ( beta=-2.92, p=0.054 ).
In conclusion, these findings indicate that severity of insomnia in adults with epilepsy is more likely to be associated with comorbid medical and depressive symptoms and less likely to be directly related to epilepsy.
Good agreement between standard clinical diagnostic criteria for insomnia and the ISI for subjects without insomnia symptoms and for those with moderate-to-severe symptoms supports the use of this instrument in epilepsy research. ( Xagena )
Yang KI et al, Epilepsy Behav 2016;60:27-32