Organic brain syndrome (OBS) is a general term that refers to diseases (usually not psychiatric disorders) that cause decreased mental function.
Alternative Names
OBS; Organic mental disorder (OMS); Chronic organic brain syndrome
Causes, incidence, and risk factors
OBS is common in the elderly. It is not a part of the normal aging process, however.
OBS is not a separate disease, but is a general term used to describe physical conditions that can cause mental changes.
Disorders associated with OBS include:
- Brain injury caused by trauma
- Bleeding into the brain (intracerebral hemorrhage)
- Bleeding into the space around the brain (
subarachnoid hemorrhage ) - Blood clot causing pressure on brain (
chronic subdural hematoma )
-
Concussion
- Breathing conditions
- Low oxygen in the body (hypoxia)
- High carbon dioxide levels in the body (hypercapnia)
-
Cardiovascular disorders - Abnormal heart rhythm (
arrhythmias ) - Brain injury due to high blood pressure (hypertensive brain injury)
- Dementia due to many strokes (
multi-infarct dementia ) - Heart infections (
endocarditis ,myocarditis ) -
Stroke - Transient ischemic attack (
TIA )
- Abnormal heart rhythm (
- Degenerative disorders
-
Creutzfeldt-Jacob disease - Diffuse Lewy Body disease
-
Huntington's disease -
Multiple sclerosis -
Normal pressure hydrocephalus -
Parkinson's disease -
Pick's disease -
Senile dementia, Alzheimer's type
-
-
Dementia due to metabolic causes - Drug and alcohol-related conditions
-
Alcohol withdrawal state - Intoxication,
drug abuse , oralcohol use - Long-term effects of alcohol,
Wernicke-Korsakoff syndrome - Withdrawal from drugs (especially sedative-hypnotics and corticosteroids)
-
- Infections
- Any sudden onset (acute) or long-term (chronic) infection
- Blood poisoning (
septicemia ) - Swelling of the brain (
encephalitis ) - Swelling of the lining of the brain and spinal cord (
meningitis )
- Other medical disorders
- Cancer
- Kidney disease
- Liver disease
- Thyroid disease (high or low)
- Vitamin deficiency (B12 and others)
Other conditions that may be related to organic brain syndrome include:
-
Depression - Neurosis
-
Psychosis









