Clinical evolution of seizures: distribution across time of day and sleep/wakefulness cycle

Abstract

Seizures can evolve sequentially into different clinical phases. For example, a seizure may start as an aura (first phase), then evolve into a tonic seizure (second phase), and evolve further into a generalized tonic-clonic semiology (third phase). It is currently unknown whether specific seizure evolutions cluster at particular times of the day and/or during sleep/wakefulness. We aimed to describe the distribution of the clinical evolution of seizures across time of day and sleep/wake state. We included all patients with at least two seizure phases admitted for long-term electroencephalogram monitoring during a 5 year period. Two-hundred-and-fifteen patients (866 seizures) presented with two different phases and 87 patients (324 seizures) evolved into a third clinical phase. During phase two, evolution into clonic seizures differed across time (p = 0.047) with peaks at 0-3 h and 6-9 h and during sleep (p < 0.001), evolution into automotor seizures peaked during wakefulness (p = 0.015), evolution into tonic seizures differed across time (p = 0.005) with peaks at 21-12 h and during sleep (p = 0.0119), and generalized tonic-clonic seizures peaked during sleep (p = 0.0067). Findings remained statistically significant after multivariable analysis adjusting, separately, for potential confounders (semiology of the first phase, age, gender, days in the long-term electroencephalographic monitoring unit, abnormal neuroimaging, number of antiepileptic medications, and seizure localization). During phase three, seizure evolutions followed the same pattern of distribution as during phase two but differences did not reach statistical significance. Our data demonstrate that the evolution of seizures into different phases cluster at specific times of day and at specific phases of the sleep/wakefulness cycle.

Seizure occurrence and the circadian rhythm of cortisol: a systematic review

“…All studies that provided separate data for adults focused on focal seizures. For two of the studies, only data for specific generalized seizure types could be included in our analysis, because of possible overlap in patient populations with other studies of the same research group [32,33]. Epileptic seizures were monitored by scalp EEG in 12 studies and intracranial ECoG in two.…”

“…Also, the exact number of patients in which seizures of specific localizations or seizure types were recorded was not reported in the majority of articles. Minimal overlap in seizure data between different studies cannot be completely excluded but was mitigated as much as possible by excluding data from studies describing the same patient population [32,33]. Furthermore, none of the selected studies measured cortisol during seizure registration.…”

“…Most of the original studies described an increased seizure occurrence in the (early) morning compared to the rest of the day, both in epilepsy populations of all ages [31,34,35] and in cohorts including children [32,33,[36][37][38][39] or adults separately [40]. Many also reported a peak at varying times in the afternoon or the evening [32-37,39-45].…”

BMAL1 controls the diurnal rhythm and set point for electrical seizure threshold in mice

“…In patients with lesional epilepsy characterized by seizures originating from the frontal lobe, nearly three quarters of their seizures occur during sleep (Kaleyias et al, 2011). Furthermore, sleep not only increases the frequency of epileptiform abnormalities, but also alters electrographic seizure morphology and distribution (Sanchez Fernandez et al, 2013). Seizures can also influence changes in sleep.…”

An update in sleep neurology: the latest bedtime stories

“…Patients on a telemetry unit were more likely to have progression of automotor seizure semiology during the day but more likely to progress to tonic-clonic seizures during sleep [23]. Chronotherapeutics is still an emerging area in neurology but one with significant potential and proven benefit in cancer medicine [24].…”