Narcolepsy- O&E explantions

Para 1;Sleep disorder involving irresistible episodes of sleep which it thought to affect 1 in 2000 and can be triggered by intense emotion. Symptoms include cataplexy whereby an individual loses muscle tone and may collapse, sleep paralysis which is an inability to move and hypnagogic hallucinations these being, vivid, often frightening dreamlike experiences. Narcolepsy usually develops in adolescence or early adulthood.
Par 2; Von Economo suggested that patients with encephalitis lethargica, which has similar symptoms to narcolepsy, had damage to the hypothalamus and midbrain. There is little evidence that narcolepsy is caused by brain damage, however a case study reported by Scammell et al 2001 showed as a result of stroke that damage to the hypothalamus led to a 23 year old developing narcolepsy. Clearly it would be unwise to generalise from a single case study that all narcoleptic sufferers have damaged hypothalamuses however it does suggest that narcolepsy seems to have a biological basis thus supporting the nature side of the nature V nurture debate. In addition a relationship between neurology and narcolepsy was also supported by Arill et l 2001 who reported a case of narcolepsy as a result of a tumour in the hypothalamus
Para 3; Para 3; Hypocretin is believed to be involved in narcolepsy. This is a chemical that is made by the hypothalamus and is involved in regulating arousal levels. The hypothalamus stops making hypocretin at night, which is why people sleep during this time. This is supported by Scammell et al's case study, which involved testing the patients cerebrospinal fluid and was found to show reduced levels of hypocretin. Post mortem studies of the brains of Parkinson's sufferers, who display similar symptoms to narcoleptics, revealed a significant reduction of cells that contain hypocretin, However, a causal relationship cannot be deduced from such studies as It could be that the narcolepsy or Parkinson's diseased caused the reduced levels of hypocretin rather than the other way round, this argument could also be applied to Arii et al's case study.
Para 4; Animal studies appear to support the role of the hypothalamus and hypocretin as demonstrated by Geraschenko et al 2003 who used a neurotoxin to destroy the lateral hypothalamus of rats and measured the decline in hypocretin produced. It is interesting to note that these rats also suffered sleep abnormalities. Genes clearly have a role to play in narcolepsy as breeders have developed dogs that show narcoleptic tendencies. Nishino & Mignot 1997 discovered a genetic mutation in narcoleptic Dobermans that affected the hypocretin but this mutation did not apply to humans. Application of such research and findings to humans. Applicaton of suc research and findings to humans can perhaps be considered reductionist in ignoring the complexity of human existence and reducing a complicated disorder soley to the actions of cells within the hypothalamus, it could be suggested t overlook external or social environmental factors that may have a role in sleep disorders suh as narcolepsy.
Para 5; A twin study carried out by ingot et al 1998 indicates that only 4/16 pairs of MZ showed narcolepsy in both, this suggests that whilst there appears to be a genetic link or susceptibility, other factors may well trigger the onset of the disorder.
Para 6; It has been suggested by Thannickal 2009 that the body's immune system, Human leuckocyte antigens might attack the cells that produce hypocretin, thus reducing the ability to regulate sleep however, this remains unsupported. Perhaps a more holistic and multidisciplinary approach would uncover non biological as well as biological triggers therefore providing a balance to the nature nurture debate over narcolepsy
Extra research
1. IDA; The fact that low hypocretin levels are implicated as a cause of narcolepsy suggests that a cure os obvious- give sufferers a dose of hypocretin. However it is not that simple because the hypocretin molecule is relatively unstable. If given my mouth or injection it is broken down before it reaches the brain. Therefore, researchers are currently trying to create an artificial drug to replace the missing hypocretin in the brains of neuroleptics. But even this wont result in a cure because the condition is merely controlled by continuously taking the drug; the condition has not ended. It is possible that in the future that transplanting hypocretin-producing cells may result in a cure.

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Narcolepsy- O&E explantions

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	Created by chloehathaway about 10 years ago