Seizures precipitated by very hot water-head baths (40-50° C), a regional religious custom, or showers were seen in 279 patients between 1980-83 in Bangalore, Southern India, and are reported from the Depts of Neurology and Biostatistics, National Institute of Mental Health and Neurosciences, Bangalore, India, and the Neuroepidemiology Branch, National Institute of Neurological Disorders, NIH, Bethesda, MD, USA. The ages ranged from 8 mos to 58 yrs with a childhood preponderance and 28% below 6 years. The male:female ratio was 2.65:1. Only 7% had a history of febrile convulsions. Complex partial seizures were the most frequent manifestation of HWE (67%) and generalized tonic-clonic seizures occurred in 33%. Spontaneous non-reflex epilepsy followed or preceded the onset of HWE in 30%. A positive family history of epilepsy was obtained in 22% and for HWE in only 7%. The avoidance of the hot water stimulus should be supplemented with anticonvulsant medication in therapy. [1]

COMMENT. The mechanism of HWE is unclear. A hot-air stimulus to the heads of patients failed to induce attacks. A kindling effect has been induced in rats by repeated exposure of the head to hot water [2]. Hot water applied to the abdomen induces fever and changes in cortical electrical activity of cats and kittens [3]. The body temperature of patients in the present study is not documented and fever induced by the hot water stimulus may explain some cases, especially in younger children.

Absence epilepsy evoked by thinking or talking about driving an automobile is an unusual example of reflex epilepsy also reported in the current issue of Epilepsia (Bencze KS et al. of the Dept of Neurology, University of South Florida, Tampa, FL).