Absence epilepsy beyond adolescence: an outcome analysis after 45 years of follow-up

Genetic generalized epilepsies in adults - challenging assumptions and dogmas

Genetic generalized epilepsy (GGE) syndromes start during childhood or adolescence, and four commonly persist into adulthood, making up 15-20% of all cases of epilepsy in adults. These four GGE syndromes are childhood absence epilepsy, juvenile absence epilepsy, juvenile myoclonic epilepsy and epilepsy with generalized tonic-clonic seizures alone. However, in ~20% of patients with GGE, characteristics of more than one syndrome are present. Novel insights into the genetic aetiology, comorbidities and prognosis of the GGE syndromes have emerged and challenge traditional concepts about these conditions. Evidence has shown that the mode of inheritance in GGE is mostly polygenic. Neuropsychological and imaging studies indicate similar abnormalities in unaffected relatives of patients with GGE, supporting the concept that underlying alterations in bilateral frontothalamocortical networks are genetically determined. Contrary to popular belief, first-line anti-seizure medication often fails to provide seizure freedom in combination with good tolerability. Nevertheless, long-term follow-up studies have shown that with advancing age, many patients can discontinue their anti-seizure medication without seizure relapses. Several outcome predictors have been identified, but prognosis across the syndromes is more homogeneous than previously assumed. Overall, overlap in pathophysiology, seizure types, treatment responses and outcomes support the idea that GGEs are not separate nosological entities but represent a neurobiological continuum.

Accurate detection of typical absence seizures in adults and children using a two-channel electroencephalographic wearable behind the ears

OBJECTIVE

Patients with absence epilepsy sensitivity <10% of their absences. The clinical gold standard to assess absence epilepsy is a 24-h electroencephalographic (EEG) recording, which is expensive, obtrusive, and time-consuming to review. We aimed to (1) investigate the performance of an unobtrusive, two-channel behind-the-ear EEG-based wearable, the Sensor Dot (SD), to detect typical absences in adults and children; and (2) develop a sensitive patient-specific absence seizure detection algorithm to reduce the review time of the recordings.

METHODS

We recruited 12 patients (median age = 21 years, range = 8-50; seven female) who were admitted to the epilepsy monitoring units of University Hospitals Leuven for a 24-h 25-channel video-EEG recording to assess their refractory typical absences. Four additional behind-the-ear electrodes were attached for concomitant recording with the SD. Typical absences were defined as 3-Hz spike-and-wave discharges on EEG, lasting 3 s or longer. Seizures on SD were blindly annotated on the full recording and on the algorithm-labeled file and consequently compared to 25-channel EEG annotations. Patients or caregivers were asked to keep a seizure diary. Performance of the SD and seizure diary were measured using the F1 score.

RESULTS

We concomitantly recorded 284 absences on video-EEG and SD. Our absence detection algorithm had a sensitivity of .983 and false positives per hour rate of .9138. Blind reading of full SD data resulted in sensitivity of .81, precision of .89, and F1 score of .73, whereas review of the algorithm-labeled files resulted in scores of .83, .89, and .87, respectively. Patient self-reporting gave sensitivity of .08, precision of 1.00, and F1 score of .15.

SIGNIFICANCE

Using the wearable SD, epileptologists were able to reliably detect typical absence seizures. Our automated absence detection algorithm reduced the review time of a 24-h recording from 1-2 h to around 5-10 min.

Social outcome and psychiatric comorbidity of generalized epilepsies - A case-control study

OBJECTIVE

To investigate social outcome and psychiatric comorbidity of patients with idiopathic/genetic generalized epilepsies (IGEs) and its subtypes (epilepsy with generalized tonic-clonic seizures alone [EGTCS], juvenile absence epilepsy [JAE], and juvenile myoclonic epilepsy [JME]).

METHODS

A cohort of 402 adult patients with IGE from the Danish island Funen was matched with 4020 randomly selected geography-, age-, and sex-matched controls via the Danish Civil Registration System. Based on register data, we compared social status measured by cohabitant status, educational attainment, income, affiliation to labor market, and psychiatric comorbidity.

RESULTS

As compared to controls, patients with IGE had similar cohabitant status but fewer children (no children: 59.0% vs 50.9%), and lower educational level (primary school only: 46.0% vs 37.3%), employment rate (outside of workforce: 56.7% vs 46.5%), and income (low income: 32.6% vs 24.9%) (P < 0.001 for all comparisons). Having IGE was associated with higher a proportion of psychiatric comorbidity (IGE, 22.6%; controls, 13.0%) (P < 0.001). Seizure-free patients did not differ from controls; patients with persistent seizures had lower incomes and employment rates. In the IGE subgroup analyses, JME was associated with worse social status in all parameters studied (eg, 65.9% of JME patients were outside the workforce vs 44.5% of matched controls; P < 0.001), whereas no adverse social status was identified in patients with EGTCS and JAE.

SIGNIFICANCE

Patients with IGE in general and JME in particular have poorer social status and more psychiatric comorbidity than matched population controls without epilepsy. Poor seizure control was associated with social status and may contribute to negative socioeconomic consequences associated with IGE.