The clinical and electroencephalographic findings for 25 patients with seizures precipitated by hot water bathing (HWE) were analyzed by researchers at Sisle Etfal Education Hospital, Istanbul, Turkey. In a retrospective review of records of the epilepsy outpatient clinic since 1995, the age at onset of HWE patients ranged from 6 months to 37 years (mean age, 13 years), 52% having their first seizure in the first decade. Male-female ratio was 3:1. Three (12%) had a history of febrile seizures, and 11 (44%) a family history of epilepsy, none of the family members having HWE. HWE patterns were complex partial (CPS) in 20 (80%), secondary generalized in 10 (40%), and primarily generalized tonic-clonic in 5 (20%). Seventeen (68%) had seizures only precipitated by bathing; 8 (32%) had spontaneous seizures also. CPSs were manifested by staring, confused speech, déjà vu, faint feeling, taste of soap, nausea, vomiting, pleasurable feeling including orgasm, and visual and auditory hallucinations. Nine (36%) patients self-induced the seizures by either increasing the temperature of the water, or by increasing the amount of water poured on the head. Pouring the water over the head (11 patients), the temperature of the water (9 patients), and termination of the bath (8 patients) were the most common triggers. Interictal EEGs obtained in 22 patients showed epileptiform abnormalities over temporal regions in 9 (41%). Brain MRIs in 15 patients and CTs in 2 were normal except for cortical atrophy in 1 and mesial temporal sclerosis in 1. Treatment with AEDs, mainly carbamazepine, in 16 patients prevented seizure recurrence; avoidance of the precipitating factor prevented seizures in the remainder. [1]

COMMENT. Hot water epilepsy is a benign form of reflex epilepsy, typically complex partial with temporal lobe localization, and occurring most frequently in children and young adults, males predominantly. Reports of HWE are most prevalent in India and Turkey, where sitting to bathe and pouring hot water over the head from a bowl are common customs.

Seizures precipitated by very hot water-head baths (40-50°C), a regional religious custom, were reported in 279 patients between 1980-83 in Bangalore, Southern India [2]. Clinical features were similar to those reported in the Turkish clinic patients: ages ranged from 8 months to 58 years, 28% below 6 years; males predominated 2.65:1; only 7% had a history of febrile seizures; 67% had HW-induced complex partial seizures; and 30% had spontaneous non-reflex epilepsy also. A family history of epilepsy was positive in 22%, but HWE in only 7%. In treatment, the avoidance of the hot water stimulus to the head was supplemented with AEDs. The mechanism was unclear. A hot-air stimulus to the scalp failed to induce attacks. In infants, a febrile seizure induced by the hot water might explain some attacks, but was not confirmed by body temperature recordings. A specific tactile reflex seizure may occur in response to combing the hair in children with absence epilepsy (Millichap; personal observation of a case of repeated eye fluttering and seizure induction by tapping the scalp). Two cases of HWE with CPS, in association with focal cortical dysplasia, and localized to the left parietal region in 1, are reported by Grosso S et al. (Ped Neur Briefs 2004; 18:70). [3]

Lennox WG (in Epilepsy and Related Disorders, Boston; Little, Brown; 1960;357-370) prefers the term “sensory precipitation“ to reflex epilepsy, for seizures induced by touch, smell, taste, hearing, and sight. He cites a case recounted by Hughlings Jackson (1886) of a boy who had falling (astatic or myoclonic) seizures if his head or face was unexpectedly touched. Lennox records failure of seizure induction “by non-painful hot or cold skin applications.”