Organic brain syndrome

Alternative names:

chronic organic brain syndrome; OBS; organic mental disorder

Definition:

A general term that refers to physical disorders that cause a decrease in mental function, usually not including psychiatric disorders.

Causes, incidence, and risk factors:

Organic brain syndrome (OBS) is a common "diagnosis" of the elderly. It is not an inevitable part of aging, however. OBS is not a separate disease entity, but is a general term used to categorize physical conditions that can cause mental changes.

Disorders associated with OBS include, but are not limited to:

• degenerative disorders:
  • Creutzfeldt-Jacob disease
  • Huntington disease
  • multiple sclerosis
  • normal pressure hydrocephalus
  • Pick's disease
  • senile dementia/Alzheimer's type

• cardiovascular disorders:
  • arrhythmias - may cause some types of OBS
  • cardiac infections (endocarditis, myocarditis, etc.)--may sometimes cause OBS
  • hypertensive brain injury
  • multi-infarct dementia
  • stroke
  • TIA

• trauma-induced brain injury:
  • chronic subdural hematoma
  • concussion
  • intracerebral hemorrhage
  • subarachnoid hemorrhage

• dementia due to metabolic causes
• respiratory conditions--may cause or aggravate OBS
  • hypoxia (decreased oxygen in the body)
  • hypercapnia (increased carbon dioxide levels in the body)

• infections
  • any acute or chronic infection
  • septicemia (presence in the bloodstream of toxic by-products caused by infection)
  • meningitis
  • encephalitis

• drug and alcohol related conditions
  • intoxication, drug abuse or alcohol use
  • long-term effects of alcohol, Wernicke-Korsakoff syndrome
  • alcohol withdrawal state
  • withdrawal from drugs (especially sedative-hypnotics and corticosteroids)

• Parkinson's disease

Other conditions that may be related to organic brain syndrome include depression, neuroses, and psychoses of various types, which may occur simultaneously with the OBS.