chapter  12
Hot-Water Epilepsy: A Geographically Specific Epilepsy Syndrome
Pages 8

Clinical Features In HWE, seizures are precipitated by hot water bath or immersion in hot water.

Though it is customary practice to bathe everyday among south Indians, head bath is done generally once in 3-15 days. Temperature of the hot water used for bathing ranges between 40-50°C (ambient room temperature - 25-30°C). Usually water is poured over the body or head using a Jig. A proportion of patients, 5-10% may have seizures even when hot water is not poured on the head and only on the body. Isolated cases of HWE have been reported in people taking showers or tub baths.7 HWE epilepsy is more commonly reported in children. It has also been reported in adults from south India.2,4,6*9 In almost all the series there is a male preponderance (2-2.5:1). Seizure frequency is more related to the frequency of head bathing. Mosdy the seizure type is complex partial seizure with or without secondary generalization. Seizure semiology includes dazed look, sense of fear, irrelevant speech, visual and

auditory hallucinations with complex automatisms. Primary generalized tonic clonic seizure is the seizure type in about one-third of the patients. Seizures usually last for 1-3 minutes. Video recording of seizures have been done in the laboratory in a few cases.5,7,15,17 About 10% of patients express intense desire/pleasure and continue to pour hot water over the head until they lose consciousness and could be considered as ‘Self induced HWE’.7 In patients with HWE neurologic examination is essen­ tially normal. Positive family history of epilepsy has been reported in 7-22.6% of probands. Nonreflex epilepsy occurs in 16% - 38% of patients with HWE.5*4’7

Electroencephalography Interictal scalp electroencephalography (EEG) is usually normal, but diffuse ab­

normalities may be seen in about 15-20% of the records.3'4,6'7 Lateralized or local­ ized spike discharges in the anterior temporal regions have been reported in a few cases.2,3,5*18 Ictal EEG recording has technical limitations and are often difficult to obtain. There are seven published reports of ictal EEG recordings during seizure provocation. The observed ictal EEG abnormalities include: rhythmic delta in tem­ poral leads,16 sharp and slow waves in the unilateral hemispherical leads,17 bilateral spikes,20 and temporal activity.11'12 Video-EEG recording in one patient o f‘bathing epilepsy* had demonstrated delta activity starting in the right hemisphere with rapid spread to the other hemisphere.24