Reflex seizures triggered by cutaneous stimuli

Among the different precipitating stimuli for reflex seizures, Touch-Induced Seizures (TIS) and Hot Water Seizures (HWS) are consistently described in different reports. The aim of this study was to analyze the clinical, EEG and image data of patients with TIS and HWS.

We retrospectively analyzed patients who were followed up in our Epilepsy Unit and had seizures triggered by these stimuli. All patients were studied with electroencephalography (EEG) and magnetic resonance (MR).

We recruited six patients, including five men, with an age range of 30-64 years-old. Four patients had TIS; all them had focal motor seizures after the stimuli, with epileptic foci in the fronto-central regions associated with peri-central gyri lesions on MR. One patient had HWS related to a septo-optic dysplasia with periopercular polymicrogyria, and one patient had focal seizures that evolved into bilateral convulsions triggered by washing the mouth with cold water. We considered this last patient to have water contact-induced seizures (WCIS).

Seizures in TIS are most likely focal, without impairment of awareness, and refractory to medical treatment. Antiepileptic drugs can prevent the progression to bilateral convulsion. The origins of such seizures seem to be related to small lesions or epileptogenic zones in the perirolandic areas. Lesional HWS and WCIS are focal seizures that involve impairment of consciousness or focal seizures that evolve to bilateral convulsion, are not such location specific and involve larger ictogenic areas. In both epilepsies, stimulus avoidance is the most effective treatment.