Hot-water epilepsy: From bench to bedside

Hot water epilepsy with alone and spontaneous seizures in childhood

OBJECTIVES

Hot water epilepsy (HWE) is a type of epilepsy that primarily affects children. This study was aimed to evaluate the clinical, electroencephalogram (EEG), neuroimaging findings, and treatment options in children with HWE.

METHODS

The medical records of 24 patients who had HWE were evaluated retrospectively.

RESULTS

There were 2767 patients diagnosed with epilepsy during the seven-year period, and 0.86 % of the patients had HWE. The median age of the patients was three (range 1.2-7 years), with a male predominance (male/female ratio: 7.1). Six patients (25 %) had HWE with spontaneous seizures (HWESS) and 18 patients (75 %) had HWE alone (HWEA). 11 patients had focal onset seizures, 13 patients had generalized onset seizures. EEG abnormalities were found in 7 patients (29.2 %). Three patients (12.5 %) had nonspecific MRI findings. Developmental abnormalities (autism spectrum disorder, learning disability and speech disturbance.) were detected in 8 patients (33.3 %). Only one patient's (4.2 %) seizure could be controlled by changing bathroom habits. Twenty-three patients (95.8 %) were given antiepileptic drugs. 18 of 24 patients had come for follow-up visits for two years, nine of them used monotherapy and seizures did not recur. The treatment response was 55.5 %. Oxcarbazepine (8 patients, 33.3 %) and valproic acid (7 patients, 29.2 %) were the most chosen two drugs for HWE. The genetic tests performed were not accepted relevant to the patients' clinical conditions and epilepsy.

CONCLUSION

The frequency of the HWE was not as high in the literature. Male predominance, EEG abnormalities may be seen. Changing bath room habits did not improve the treatment as a first line management, all the patients except one used antiepileptic drug treatment. Until now, there has been no study in Turkey showing the frequency of HWE exclusively in children.

Long-term clinical course and prognosis of hot water epilepsy: 15-Year follow-up

OBJECTIVE

Hot water epilepsy (HWE) is a type of reflex epilepsy triggered by bathing with hot water. Hot water epilepsy is generally considered as a self-limiting benign disease although its long-term course and prognosis remains unknown. In this study, we aimed to determine the long-term clinical course and prognosis of hot water epilepsy and possible factors affecting them.

METHODS

The diagnosis of HWE was made based on the clinical history obtained from patients and their first degree relatives witnessing to the seizures and video recordings of seizures if available; then, the type of seizure was identified. Good prognosis was defined as patients whose seizures were controlled with or without preventive measures and who did not require antiepileptic treatment. The poor prognosis was defined as patients whose seizures continued despite preventive measures and required antiepileptic treatment.

RESULTS

The study included 50 (31 male and 19 female) patients with a mean follow-up of 17.63 ± 10.46 (median, 15.0) years. The age at onset of seizure was 14.52 ± 12.71 (median: 10.0) years. There were 38 (76%) patients in the good prognosis group. 18 (36%) of them achieved complete remission, who did not require preventive measures. In the remaining 20 (40%) patients, seizures could be controlled with only preventive measures. Seizures could be controlled with antiepileptic treatment in only 1 (2%) of 12 (24%) patients in the poor prognosis group. A significant relationship was found between the frequency of hot water seizures (HWSs) and poor prognosis (p = 0.019), as well as the presence of spontaneous seizures outside of bathing and poor prognosis (p = 0.000).

SIGNIFICANCE

Hot water epilepsy, as previously known, is not a self-limiting benign disease. Approximately ¾ of the cases have a good prognosis, but the rest are in the case of chronic epilepsy. The low response rate to antiepileptics' treatment suggests that the pathogenesis of the HWE may differ from other epilepsies.

Reflex Epilepsy

Reflex seizures (RS) are epileptic events that are objectively and consistently elicited in response to a specific afferent stimulus or by an activity of the patient. The specific stimulus can be a variety of heterogenous intrinsic or extrinsic factors, ranging from the simple to the complex, such as flashing lights or reading a book. These seizures can take a variety of forms, comprising either general or focal onset, with or without secondary generalization. Reflex epilepsies (RE) are classified as a specific syndrome in which all epileptic seizures are precipitated by sensory stimuli. The few designated RE include idiopathic photosensitive occipital lobe epilepsy, other visual sensitive epilepsies, primary reading epilepsy, and startle epilepsy. RS that occurs within other focal or generalized epilepsy syndromes that are associated with distinct spontaneous seizures are classified by the overarching seizure type. Most patients experience spontaneous seizures along with their provoked events. RS originate from stimulation of functional anatomic networks normally functioning for physiological activities, that overlap or coincide with regions of cortical hyperexcitability. Generalized RS typically occur within the setting of IGEs and should be considered as focal seizures with quick secondary generalization via cortico-cortical or cortico-reticular pathways. In aggregate, activation of a critical neuronal mass, supported and sustained by cortico-subcortical and thalamocortical pathways eventually result in a seizure. Treatment includes antiseizure medication, commonly valproate or levetiracetam, along with lifestyle modifications, and when amenable, surgical intervention. High clinical suspicion and careful history taking must be employed in all epilepsy patients to identify reflex triggers.

Clinical and Genetic Features in Patients With Reflex Bathing Epilepsy

Objective

To describe the clinical and genetic findings in a cohort of individuals with bathing epilepsy, a rare form of reflex epilepsy.

Methods

We investigated by Sanger and targeted resequencing the SYN1 gene in 12 individuals from 10 different families presenting with seizures triggered primarily by bathing or showering. An additional 12 individuals with hot-water epilepsy were also screened.

Results

In all families with bathing epilepsy, we identified 8 distinct pathogenic or likely pathogenic variants and 2 variants of unknown significance in SYN1, 9 of which are novel. Conversely, none of the individuals with hot-water epilepsy displayed SYN1 variants. In mutated individuals, seizures were typically triggered by showering or bathing regardless of the water temperature. Additional triggers included fingernail clipping, haircutting, or watching someone take a shower. Unprovoked seizures and a variable degree of developmental delay were also common.

Conclusion

Bathing epilepsy is genetically distinct reflex epilepsy caused mainly by SYN1 mutations.

A case report of sudden epileptic death linked to thermal water after mud therapy

We present the case of a 60-year-old male, with a long history of epilepsy, who was discovered submerged and unconscious in a small thermal whirlpool bath. The circumstances were forensically reviewed to include examination of clinical data and an autopsy with toxicological analysis. The conclusion was that “warm” hydro-therapy had contributed more than “hot” mud-therapy to the onset of epilepsy which led to accidental drowning, notwithstanding the deceased’s treatment with the long-lasting, poly-drug antiepileptic therapy. Further, we analysed the Italian medical indications of wellness centres for patients with epilepsy or other diseases.

Cortical-Subcortical morphometric signature of hot water epilepsy patients

BACKGROUND

Cortical and subcortical grey matter (GM) morphometric changes have been demonstrated Temporal Lobe Epilepsy (TLE) or Idiopathic Generalized Epilepsies (IGE). Hot Water Epilepsy (HWE) has not hitherto been studied in these perspectives.

PURPOSE

To investigate the cortical and subcortical grey matter in subjects with HWE in terms of thickness, volume, and surface area using Surface-Based Morphometry (SBM). To assess relationships of SBM-derived metrics with clinical variables.

MATERIALS AND METHODS

Ninety-nine people with HWE and 50 age-matched healthy controls underwent high resolution volumetric MRI brain. These were processed with FreeSurfer to obtain SBM parameters i:e cortical thickness, cortical volume, and Cortical surface area. Volumes of seven subcortical GM structures (hippocampus, globus pallidus, nucleus ambiguous(NA), caudate nucleus, putamen, thalamus, and amygdala) were computed. Intergroup morphometric differences and their correlation with epilepsy-specific clinical variables were calculated.

RESULTS

SBM revealed a global reduction in bihemispheric cortical thickness and left hemispheric cortical volume. Besides, a regional difference in the morphometric measures was noted in temporo-limbic, parietal, pre-cuneus, and the cingulate region. Reduced volume of thalami and left caudate alongside an increased volume of the bilateral amygdala, bilateral nucleus ambiguous (NA), right caudate, and putamen was the other cardinal observation.

CONCLUSION

HWE subjects show alterations in the morphometry of the cortical ribbon and the subcortical grey matter. The temporal semiology, 'reflex nature' pathophysiology correlates involvement of temporo-limbic structures/somatosensory cortex, while the involvement of structures like pre-cuneus, posterior cingulate, and frontal regions are in agreement with functional networks related loss of awareness. That bilateral amygdala swelling occurs in HWE is a novel observation and may signal that it could be a distinct variant of Mesial TLE.

Repetitive Arm and Hand Movements (Complex Motor Stereotypy) in a Six-Year Boy

Abnormal movements are not uncommon in children. Most of these abnormal movements can be defined by the available criteria. Abnormal movements are easily diagnosed in adults. Most of these abnormal movements are well categorized and diagnosed by the defined characteristics. Sometimes it is difficult to diagnose an unusual movement disorder in children, particularly if it is rare and there are no investigations to prove the diagnosis. Repetitive arm and hand movements (complex motor stereotypy) is one such disorder which is rare and difficult to diagnose unless seen before. In this case report, we described a 6-year-old boy with this disorder, in whom it took 6 years to diagnose.

Eating Epilepsy in North India: Case Series and Its Management

Eating epilepsy is a rare form of reflex epilepsy where seizures are triggered by eating. We describe a case series of 12 such patients presenting to our epilepsy clinic based in North India. Eating epilepsy was noted to have male predominance with focal seizures with impaired awareness. Most of these patients had either temporal or perisylvian localization. Clobazam taken half an hour before meal was found to be an effective add-on therapy in its management.

Reflex epileptic mechanisms in ictogenesis and therapeutic consequences

Recent studies of reflex epileptic mechanisms in human epilepsy using advanced methods of neurophysiology and functional neuroimaging have contributed much to elucidate pathophysiological processes of seizure generation. Whereas in lesional focal epilepsies reflex mechanisms usually relate directly to the anatomical focus, in system epilepsies they have helped to define which functional anatomical systems serving physiological function are recruited by the ictogenic mechanisms. Reflex epileptic seizures can often be prevented by avoidance or modification of triggers or by prophylactic benzodiazepine administration. Surgical options apply to focal cases. According to restricted experiences with pharmacotherapy, without controlled studies and little information on new AEDs, reflex seizures in system epilepsies appear to respond best to valproic acid and in focal epilepsies, to carbamazepine.