Amnesia

A pathological impairment of human memory. Specify the affected time period, task and process rather than assuming loss of all forms of learning or all prior knowledge.

Diencephalic amnesia is impaired human memory associated with damage to diencephalic structures and their connections, including thalamic or mammillary pathways. It differs anatomically from damage confined to the hippocampus, although the relevant structures participate in connected systems. A comparative postmortem study linked anterior thalamic degeneration with amnesia in an alcohol-related clinical sample; associated pathology and case differences still limit assigning every deficit to one isolated structure. ^[ref]

A severe amnesic syndrome associated with thiamine deficiency, often but not exclusively in the context of alcohol misuse. Its eponym refers to Sergei Korsakoff. Co-occurring damage varies across patients, making comparison with non-amnesic pathological controls valuable.

Loss or impaired retrieval of information acquired before onset of the condition. Its temporal extent and detail can differ from deficits in new learning.

Impaired formation or retention of new human memory after onset of the condition, distinct from a general loss of sensory perception or intelligence.