Semiological value of rhythmic ictal non-clonic hand (RINCH) motions in epileptic seizures

To study the semiological significance of rhythmic ictal non-clonic hand (RINCH) motions in epileptic seizures, as observed in prolonged video-EEG monitoring (VEM).

Retrospective observational study of patients with epilepsy admitted for prolonged VEM between 2020 and 2024, who exhibited RINCH motions during recorded seizures. Electroclinical data were collected and analysed, focusing on the duration and associated semiology of RINCH motions.

Among 379 patients admitted for VEM, RINCH motions were observed in 12 (66.6% male, mean age [standard deviation], 44.7 [11.3] years). All patients were right-handed. Seizure onset occurred in the temporal lobe in 10 cases (83.3%) and left hemisphere in 11 (91.6%). Aetiology was structural in 9 patients (75%), unknown in 2 (6,7%), and autoimmune in 1 (8.3%). All seizures were associated with impaired awareness and automatisms. Ictal or postictal language impairment were observed in 9 patients (75%). Only one case progressed to bilateral tonic-clonic seizure. RINCH motions involved the right hand in all seizures, and in one case spread to the contralateral hand. These movements appeared within a median of 25 seconds (Q₁-Q₃, 12-90) after clinical onset, with a median duration of 19 seconds (Q₁-Q₃, 11-48). EEG onset occurred after clinical onset in 7 cases (58.3%), and was consistently observed over the left anterior temporal region, except for one case with a parietal origin.

RINCH motions represent an uncommon but distinctive manifestation of epileptic seizures, often accompanied by impaired awareness, automatisms and aphasia. These movements typically occur in the hand contralateral to the seizure onset zone. The most frequent seizure onset localisation is the left temporal lobe (dominant) in right-handed patients.