Amnesia or amnaesia (see spelling differences) is a condition in which memory is disturbed. The causes of amnesia are organic or functional. Organic causes include damage to the brain, through trauma or disease, or use of certain (generally sedative) drugs. Functional causes are psychological factors, such as defense mechanisms. Hysterical post-traumatic amnesia is an example of this. Amnesia may also be spontaneous, in the case of transient global amnesia. This global type of amnesia is more common in middle-aged to elderly people, particularly males, and usually lasts less than 24 hours.
Neurologic Manifestations :: Neurological Disorders

Amnesia Support Group - Designed to help amnesia patients and relatives, in coping with all forms of Amnesia and the problem that occur in daily life. Site is in German and English.
Meta Description: [ Selbsthilfegruppe Amnesie-Patienten und Angehörige, self help for amnesia patients and dependants ]
Neuroland - Information about transient global amnesia including diagnostic criteria, clinical features, precipitating factors, incidence, differential diagnosis and further reading.
Philip Schatz, Ph.D.: TGA - Transient global amnesia: The causes, epidemiology, diagnoses, symptoms, the course of the illness and prognosis.