Clinical picture involving amnesia without the presence of dementia, caused by damage to certain deep brain areas through vitamin B deficiency (inadequate nutrition) in alcoholism, for example, or Wernicke’s disease. The condition can also occur whenever large numbers of brain cells are destroyed. Characteristic features are memory problems in which recent and less recent events cannot be retained (e.g. the way to the toilet, appointments or yesterday’s meals). Disorientation and loss of a sense of time and one’s surroundings follow. Memory gaps can unconsciously be filled in by confabulation. The course of the disorder depends on the underlying condition. If damage is irreversible it is often permanent. In the case of the commonest cause, alcoholism, vitamin B treatment can often improve the picture, although often only partially.