Sudden unexplained death syndrome

Sudden unexplained death syndrome was first noted in 1977 among Hmong refugees in the US. The disease was again noted in Singapore, when a retrospective survey of records showed that 230 otherwise healthy Thai men died suddenly of unexplained causes between 1982 and 1990: publication of this data provoked a diplomatic incident.

Features
The condition appears to affect primarily young Hmong men from Laos (median age 33) and northeastern Thailand (where the population are mainly of Laotian descent). There is a strong hereditary component and the victims tend to die in their sleep.

Survivors describe a feeling of intense fear and paralysis. There is a sensation of pressure in the chest, the presence of an alien being in the room and altered sensation.

Pathology
The cause of this syndrome is currently believed to be a form of Brugada Syndrome.

It was noted very early on that the disease had the characteristics of a familial cardiac conduction defect (i.e., a problem with the electrical pathways of the heart). and one study has shown evidence for a long-QT syndrome in populations at risk. Thiamine deficiency is common in the risk population because of diet, and is also a cause of a prolonged QT-interval; but proof that inducible ventricular arrhythmia is the cause of this disease came only with the publication of the DEBUT trial in 2003.

Treatment
The only proven way to prevent death is by implantation of a cardiovertor defibrillator. Oral antiarrhythmics such as propranolol are ineffective.

Folk beliefs
This phenomenon is well known among the Hmong people of Laos, who ascribe these deaths to a malign spirit, dab tsog (pronounced "da cho"), said to take the form of a jealous woman. Hmong men may even go to sleep dressed as women so as to avoid the attentions of this spirit.

Synonyms

 * Sudden Unexpected Nocturnal Death Syndrome (SUNDS)
 * Bangungut (Phillipines)
 * Dab tsog (Laos)
 * Laitai (Thailand)
 * Pokkuri disease (Japan)