Organic brain syndrome - Overview

OBS; Organic mental disorder (OMS); Chronic organic brain syndrome

Organic brain syndrome (OBS) is a general term that refers to diseases (usually not psychiatric disorders) that cause decreased mental function.

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)
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, or alcohol 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:

Reviewed last on: 2/13/2008
Luc Jasmin, MD, PhD, Departments of Anatomy & Neurological Surgery, University of California, San Francisco, CA. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.