Sudden Unexplained Nocturnal Death Syndrome: The Hundred Years’ Enigma

Sudden arrhythmic death syndrome is rare in most areas around the world. This syndrome occurs in populations that are culturally and genetically distinct and people who leave the population carry with them the vulnerability to die suddenly during sleep. Sudden unexplained death syndrome was first noted in 1977 among southeast Asian Hmong refugees in the United States and Canada.^[4][5]

Laotian Hmongs were chosen for the study because they had one of the highest sudden death rates while sleeping in the United States. They were originally from Southern China and the highlands of North Vietnam, Laos, and Thailand. The location that was picked for this study was in Ban Vinai in the Loei Province, which is approximately 15 kilometers from the Lao border. This study took place between October 1982 and June 1983 as this syndrome became more of a relevant pressing issue. Ban Vinai was the location chosen because it had 33,000 refugees in 1982, which was the largest population of victims.^[11] Because this syndrome was occurring most commonly in those particular men, researchers found it most beneficial and effective to study the population in which they migrated from instead of studying victims and populations in the U.S. Because of religious limitations the Hmong men in Ban Vinai were not allowed to receive autopsies. Therefore, the only results and research obtained were victims outside of their religion or geographical area. An interview was arranged with the next of kin who lived with the victim, witnessed the death, or found the body. The interviews were open ended and allowed the person who was next of kin to describe what they witnessed and what preceding events they thought were relevant to the victim’s death. The interviewers also collected information such as illness history, the circumstances of the death, demographic background, and history of any sleep disturbances. A genealogy was then created which included all the relatives and their vital status and circumstances of death.^[11]

Society and culture

In a medical journal, the author suggested that the Hmong who died were killed by their own beliefs in the spiritual world, otherwise known as Nocturnal pressing spirit attacks. In Indonesia it is called digeuton, which translates to “pressed on” in English.^[12] In China it is called bèi guǐ yā (traditional Chinese: 被鬼壓; simplified Chinese: 被鬼压) which translates to “crushed by a ghost” in English.^[12] The Dutch call the presence a nachtmerrie, the night-mare.^[12] The “merrie” comes from the Middle Dutch mare, an incubus who “lies on people’s chests, suffocating them”. This phenomenon is known among the Hmong people of Laos,^[16] who ascribe these deaths to a malign spirit, dab tsuam (pronounced “dah chua”), said to take the form of a jealous woman.

During the 1970s and 1980s, when an outbreak of this syndrome began, many of the Southeast Asians were not able to worship properly due to the guerrilla war against the government of Laos with the United States. Hmong people believe that when they do not worship properly, do not perform religious ritual properly or forget to sacrifice, the ancestor spirits or the village spirits do not protect them, thus allowing the evil spirit to reach them. These attacks induce a nightmare that leads to sleep paralysis when the victim is conscious and experiencing pressure on the chest.^[12] It is also common to have a REM state that is out of sequence where there is a mix of brain states that are normally held separate.^[12] After the war, the United States government scattered the Hmong across the country to 53 different cities.^[12] Once these nightmare visitations began, a shaman was recommended for psychic protection from the spirits of their sleep.^[12] However, scattered across 53 different cities, these victims had no access to any or the right shaman to protect them from this syndrome.

Hmong people believed that rejecting the role of becoming a shaman, they are taken into the spirit world.

Bangungot is depicted in the Philippines as a mythological creature called batibat or bangungot. This hag-like creature sits on the victim’s face or chest so as to immobilize and suffocate him. When this occurs, the victim usually experiences paralysis.

English names

Name	Acronym	Notes
sudden unexpected death syndrome	SUDS
sudden unexplained death syndrome	SUDS
sudden unexpected nocturnal death syndrome	SUNDS
sudden unexplained nocturnal death syndrome	SUNDS
sudden adult death syndrome	SADS	(parallel in form with SIDS)
sudden arrhythmia death syndrome	SADS
sudden arrhythmic death syndrome	SADS
sudden arrhythmic cardiac death syndrome	—
bed death	—

Names in other languages

Term	Language	Notes
bangungot or urom	Filipino[17]	The term originated from the Tagalog word meaning “to rise and moan in sleep”.[18] It is also the Tagalog word for nightmare.
dab tsog	Hmong[16]	dab tsog means ‘ghost“
lai tai	Thai	(Thai: ใหลตาย; meaning “sleep and die”)[14][19]
dolyeonsa	Korean
pokkuri disease	Japanese[20]
ya thoom[citation needed]	Arabic
albarsty (Kyrgyz: албарсты)	Kyrgyz