Sudden arrhythmic death syndrome (SADS) is a sudden unexpected death of adolescents and adults, mainly during sleep. One relatively common type is known as Brugada syndrome.The syndrome is rare in most areas around the world but occurs in populations that are culturally and genetically distinct. It was first noted in 1977 among southeast Asian Hmong refugees in the United States and Canada. The syndrome was again noted in Singapore when a retrospective survey of records showed that 230 otherwise healthy Thai foreign workers living in Singapore died suddenly of unexplained causes between 1982 and 1990. Causes
A sudden death in a young person can be caused by heart disease (including cardiomyopathy, congenital heart disease, myocarditis, genetic connective tissue disorders) or conduction disease (WPW syndrome, etc. ), medication-related causes or other causes. Rare diseases called ion channelopathies may play a role such as long QT syndrome (LQTS), Brugada syndrome (BrS), CPVT (catecholaminergic polymorphic ventricular tachycardia), PCCD (progressive cardiac conduction defect), early repolarization syndrome, mixed sodium channel disease, and short QT syndrome. In 20% of cases, no cause of death can be found, even after extensive examination.In young people with type 1 diabetes, unexplained deaths could be attributed to night time hypoglycemia triggering abnormal heart rhythms or cardiac autonomic neuropathy, a damage to nerves that control the function of the heart.Medical examiners have taken into account various factors, such as nutrition, toxicology, heart disease, metabolism, and genetics.
A brainstem stroke syndrome falls under the broader category of stroke syndromes, or specific symptoms caused by vascular injury to an area of brain (for example, the lacunar syndromes). As the brainstem contains numerous cranial nuclei and white matter tracts, a stroke in this area can have a number of unique symptoms depending on the particular blood vessel that was injured and the group of cranial nerves and tracts that are no longer perfused. Symptoms of a brainstem stroke frequently include sudden vertigo and ataxia, with or without weakness. Brainstem stroke can also cause diplopia, slurred speech and decreased level of consciousness. A more serious outcome is locked-in syndrome. Syndromes
The midbrain syndromes (Significant overlap between these three syndromes)
Superior alternating hemiplegia or Webers syndrome
Paramedian midbrain syndrome or Benedikts syndrome
Claudes syndrome
Medial pontine syndrome or Middle alternating hemiplegia or Fovilles syndrome
Lateral pontine syndrome or Marie-Foix syndrome
Medial medullary syndrome or Inferior alternating hemiplegia
Lateral medullary syndrome or Wallenberg syndrome

History
A history of locked in syndromes. Jean-Dominique Bauby
Parisian journalist Jean-Dominique Bauby had a stroke in December 1995, and, when he awoke 20 days later, he found his body was almost completely paralyzed; he could control only his left eyelid. By blinking this eye, he slowly dictated one alphabetic character at a time and, in so doing, was able over a great deal of time to write his memoir, The Diving Bell and the Butterfly. Three days after it was published in March 1997, Bauby died of pneumonia.