Amnesia and the Amnestic Syndrome

Abstract

A close relationship seems to exist both clinically and psychopathologically between impairment of consciousness and its consequence in memory function-circumscribed amnesia-and the amnestic or Korsakow syndrome. In many cases an amnestic syndrome develops out of conditions of loss or impairment of consciousness or it initiates a clinical course which leads to impairment or loss of consciousness and eventually even to death. Although in such cases the amnestic syndrome is usually of short duration, numerically they seem to be more frequent than the chronic symptomatologically unchanging cases which one sees in alcoholics and seniles. Psychopathologically amnesia represents an unselective loss of memory for a limited period of time, due to lack or impairment of perceptual awareness. The amnestic syndrome on the other hand represents a selective type of memory dysfunction whereby recent personal memories cannot be recalled. It seems to be due to impairment of an integrative function other than perceptual awareness namely awareness of the personal meaning of events which is necessary for the registration of events as personal experiences available for future recall. Intact perceptual awareness is an essential pre-requisite for awareness of personal meaning but the latter is also dependent on the emotional charge of the situation. Consequently lesions and processes involving those structures of the brain functionally responsible for perceptual awareness and/or for emotional functions may be expected to lead to an amnestic syndrome. This is born out by neuropathological findings which demonstrate pathological changes in the hypothalamus in cases with impairment of consciousness and in the mammillary bodies with Korsakow's syndrome. The mammillary bodies form part of the activating system responsible for conscious perceptual awareness as well as of Papez' harmonious mechanism of the emotions.

Some Functional Relationships in Geriatric Psychiatry*

“…It is, however, likely that they are important for drive regulation (21). Thus it is of interest to consider that they are situated at the crossroads of two important cerebral systems: the reticular activating system and the limbic system (22). The excitatory state of the reticular formation presumably influences memory storage function at this point.…”