Amnesia typically occurs in
High-Yield Explanation
A variety of brain pathologies can give rise to severe memory impairment, the most common being the following: degenerative disorders (paicularly Alzheimer' disease and Huntington' disease); chronic alcohol abuse giving rise to Korsakoff' syndrome; traumatic head injury; temporal lobe surgery; encephalitis; cerebral vascular disorders (including subarachnoid haemorrhage resulting from ruptured aneurysms); anoxic brain damage (following, for example, myocardial infarction, carbon monoxide poisoning, or respiratory arrest); cerebral tumours. Reference: Shoer Oxford textbook of Psychiatry seventh edition, page no. 354.