Interictal head-turning sign in patients with idiopathic generalized epilepsy during initial medical interview: A matched multicenter study.

Background: Utilizing interictal manifestations for the diagnosis of epilepsy is challenging. We investigated whether an interictal "head-turning sign," typically indicative of dependence on others observed in Alzheimer's disease, can act as a behavioral marker of idiopathic generalized epilepsy.

Methods: This multicenter study examined 579 consecutive patients, with a mean age of 36.8 ± 20.4 years, who did not have an intellectual disability and had their first outpatient visit for epilepsy evaluation between 2019 and 2023. Patients were categorized into IGE, non-IGE epilepsy, non-epileptic, and psychiatric conditions based on their ultimate diagnostic outcomes to identify difference of the occurrence of the head-turning sign among them. Additionally, we extracted data from patients under the age of 40, specifically adolescents and young adults (AYA). Then we used propensity score matching to confirm the reproducibility of observed differences and to identify associated factors within the AYA age group.

Results: The occurrence of the head-turning sign was significantly more prevalent in the IGE group compared to the non-IGE group (20.4 % vs. 2.2 %; P<0.0001) and non-epileptic group (20.4 % vs. 8.3 %; P=0.033). Following the matching, the head-turning sign was still evident in IGE relative to non-IGE patients (14.6 % vs. 4.5; P=0.004), yielding a 94 % specificity for IGE. IGE diagnosis (P<0.0001), myoclonic seizure (P<0.0001), being visited by a parent (P=0.017), and comorbidity with headache (P=0.021) were significantly associated with the head-turning sign. Multivariate analysis revealed that IGE (odds ratio: OR=2.80, P=0.028), attending with a parent (OR=2.92, P=0.029), and comorbidity with headache (OR=4.06, P=0.016) were independently associated with the head-turning sign.

Conclusions: We confirmed a substantial association between the interictal "head-turning sign" and IGE. This unique sign may reflect a tendency towards dependence on others in IGE, and may serve as a promising diagnostic auxiliary marker for identifying IGE in the AYA age group.