organic brain syndrome
Noun: A mental disorder or abnormality caused by a physical impairment of the brain's structure or function. It is a general term for decreased mental function due to a physical, or "organic," medical disease, rather than a psychiatric (psychological) illness.
This term is used in medical and clinical contexts to describe a set of symptoms—such as confusion, memory loss, or personality changes—that have a identifiable physical cause in the brain. - The patient's sudden confusion and disorientation were diagnosed as an organic brain syndrome resulting from a severe infection. - Dementia of the Alzheimer's type is a classic example of a chronic organic brain syndrome.
- The term is often used broadly to distinguish conditions with a known physiological origin (e.g., from injury, toxin, or disease) from those considered primarily functional psychiatric disorders.
- In modern diagnostic classifications, the specific cause (e.g., traumatic brain injury, substance intoxication, neurodegenerative disease) is usually identified instead of using this general term.
- Organic mental disorder: A closely related synonym, often used interchangeably.
- Delirium: An acute, often reversible organic brain syndrome characterized by confusion.
- Dementia: A chronic, usually progressive organic brain syndrome marked by memory loss and cognitive decline.
- Organic mental disorder
- Cognitive disorder due to a general medical condition (a more modern descriptive phrase)
Note: As a specific medical term, it is not typically used in idiomatic expressions. Its usage is primarily clinical. - "Rule out organic causes": A common medical phrase meaning to investigate and exclude physical brain diseases as the source of psychiatric symptoms. - Before treating the depression, the doctor needed to rule out organic causes for the patient's fatigue.
- mental abnormality resulting from disturbance of the structure or function of the brain