Electro-clinical correlation of rinch and peri-ictal vegetative symptoms

Abstract

Rhythmic ictal non-clonic hand (RINCH) movements and peri-ictal vegetative symptoms (PIVS) are rare semiological signs in temporal lobe epilepsy (TLE). RINCH refers to rhythmic, low-amplitude, complex hand movements that typically lateralize to the contralateral hemisphere, while PIVS includes manifestations such as ictal spitting and post-ictal coughing, more frequently associated with non-dominant TLE. We report a unique case of a 40-year-old woman with drug-resistant dominant TLE who exhibited both RINCH and PIVS as part of her habitual seizures. Non-invasive EEG and imaging localized the seizure onset to the left anterior temporal region. Stereoelectroencephalography (SEEG) confirmed seizure onset in the left mesial temporal pole with rapid propagation to the hippocampus, amygdala, and other limbic structures. Notably, RINCH was observed only in seizures that showed ictal spread to the superior temporal gyrus (STG) and superior temporal sulcus (STS), suggesting their role in mediating semi-automatic motor behaviors. Ictal spitting and other PIVS were linked to the spread to the entorhinal and parahippocampal regions. The patient underwent left anterior temporal lobectomy with histopathological confirmation of hippocampal sclerosis and has remained seizure-free at one-year follow-up. This case provides a rare anatomo-electro-clinical correlation of RINCH and PIVS using SEEG and emphasizes that while RINCH retains lateralizing value, PIVS may not. Our findings underscore the importance of invasive EEG in characterizing complex semiology and refining the epileptogenic zone in dominant TLE.