Sauna for hot water epilepsy (bathing-induced reflex epilepsy)
Evidence review
Overview
Hot water epilepsy is a reflex epilepsy in which seizures are triggered by bathing in hot water or pouring hot water over the head, mostly starting in childhood and more common in males. In case series from Turkey, the mean triggering water temperature was 106.5 F (41.4 C), many patients also had spontaneous seizures, and the first-line measure was lowering the water temperature or shortening the bath. In a 15-year follow-up of 50 patients, about three-quarters had a good prognosis with preventive measures alone, but one-quarter developed chronic epilepsy that responded poorly to antiseizure drugs. Heat exposure is a trigger, not a therapy, in this condition; whether dry sauna triggers seizures has not been studied.
Key findings
- 15-year follow-up, 50 patients: 76% good prognosis (36% complete remission, 40% controlled with preventive measures only); 24% poor prognosis with continuing seizures, of whom only 1 of 12 was controlled by antiseizure drugs (Balgetir 2022)
- Frequent hot-water seizures (p=0.019) and spontaneous seizures outside bathing were associated with poor prognosis (Balgetir 2022)
- 21 patients: seizures triggered by hot-water bathing or pouring water over the head; 62% also had spontaneous seizures; 6 self-induced seizures (Bebek 2001)
- 8 patients: mean triggering water temperature 106.5 F (41.4 C); lowering water temperature was the first step, with antiseizure drugs needed in 3 (Zeki 2010)
Every study we reviewed
3 found harm
Each study was checked on PubMed. The colored edge shows the direction of the result. The research library lists 31 studies on epilepsy, across all heat and cold therapies, including case reports and older work not graded here.
Long-term clinical course and prognosis of hot water epilepsy: 15-Year follow-up.
Balgetir F et al. Epilepsy Behav. 2022. PubMed 35180572 · DOI
- Who
- Patients with hot water epilepsy (31 male, 19 female), mean age at onset 14.5 years (Turkey)
- What
- Exposure: hot-water bathing as a seizure trigger; management by preventive measures (cooler or shorter baths) with or without antiseizure drugs
- Measured
- Long-term seizure control and prognosis
- Result
- 38 of 50 (76%) had a good prognosis: 18 (36%) complete remission without preventive measures and 20 (40%) controlled with preventive measures only; 12 (24%) had continuing seizures despite prevention, and antiseizure treatment controlled seizures in only 1 of them. Frequent hot-water seizures (p=0.019) and spontaneous seizures outside bathing were associated with poor prognosis.
- Limitations
- Single-centre clinical series; diagnosis based on history and witness accounts; no comparison group.
Hot water epilepsy: clinical and electrophysiologic findings based on 21 cases.
Bebek N et al. Epilepsia. 2001. PubMed 11580768 · DOI
- Who
- Patients with hot water epilepsy seen until 1999, male to female 3:1, onset age 19 months to 27 years (Istanbul, Turkey)
- What
- Exposure: bathing with hot water and/or pouring water over the head
- Measured
- Seizure triggers, seizure types, EEG and imaging findings, control
- Result
- Seizures were triggered mainly by hot-water bathing or pouring water over the head; 6 patients self-induced seizures and 9 reported pleasure during seizures; 20 had partial seizures (8 with secondary generalization); 62% also had spontaneous seizures. Control was achieved by lowering the temperature or shortening the bath, with medication needed in several patients.
- Limitations
- Clinic case series; follow-up incomplete.
Hot water epilepsy: seizure type, water temperature, EEG findings and treatment.
Zeki G et al. Neurologist. 2010. PubMed 20220445 · DOI
- Who
- Patients with hot water epilepsy, mean onset age 10.5 years (Turkey)
- What
- Exposure: hot-water bathing
- Protocol
- 106.5 °F
- Measured
- Seizure type, triggering water temperature, EEG, response to management
- Result
- Mean triggering water temperature 106.5 F (41.4 C); 7 of 8 had generalized tonic-clonic seizures during hot bathing; 6 had seizures only with hot bathing. Over a mean 23 months, 5 became seizure-free and 3 needed antiseizure drugs, after which they also became seizure-free.
- Limitations
- 8 patients; short follow-up.
Protocols used in the studies
No treatment protocol: the studies describe hot-water bathing (mean triggering water temperature 106.5 F (41.4 C)) as a seizure trigger and its avoidance by cooler, shorter baths.
What is still unknown
Whether dry sauna or other forms of whole-body heating trigger seizures in hot water epilepsy; genetic basis; why antiseizure drugs work poorly in the chronic form.
Safety
Cautions for sauna in this condition
- In hot water epilepsy, hot baths and pouring hot water over the head trigger seizures; lowering the water temperature and shortening the bath are first-line measures (PMIDs 11580768, 20220445).
- About a quarter of patients develop chronic epilepsy with poor response to antiseizure drugs, especially those with frequent bathing seizures or spontaneous seizures (PMID 35180572).
- A seizure during hot-water immersion carries a drowning risk; people with any seizure disorder should not bathe or use heat therapy alone.
- See general-safety.
For clinicians
Suggested rationale
Case series of hot water epilepsy (Bebek 2001; Zeki 2010; Balgetir 2022) show that hot-water bathing triggers seizures in this reflex epilepsy and that avoiding hot baths is part of management; heat therapy is not indicated, and dry sauna has not been studied in these patients.
Suggested wording only. The treating clinician decides whether it reflects their clinical judgment for this patient.
Typical ICD-10 codes: G40.5, G40.8. Examples only; the clinician assigns the code.
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