Locations Main Campus: Chesterfield, MO 63017   |   Locations
314-434-1500 314-434-1500   |   Contact Us

Multimedia Encyclopedia

E-mail Form
Email Results


Neurocognitive disorder

Organic mental disorder (OMS); Organic brain syndrome


Neurocognitive disorder is a general term that describes decreased mental function due to a medical disease other than a psychiatric illness. It is often used synonymously (but incorrectly) with dementia .



Listed below are conditions associated with neurocognitive disorder.


  • Bleeding into the brain (intracerebral hemorrhage)
  • Bleeding into the space around the brain ( subarachnoid hemorrhage )
  • Blood clot inside the skull causing pressure on brain ( subdural hematoma )
  • Concussion


  • Low oxygen in the body (hypoxia)
  • High carbon dioxide level in the body (hypercapnia)


  • Dementia due to many strokes ( multi-infarct dementia )
  • Heart infections ( endocarditis , myocarditis )
  • Stroke
  • Transient ischemic attack ( TIA )


  • Alzheimer disease (also called senile dementia, Alzheimer type)
  • Creutzfeldt-Jacob disease
  • Diffuse Lewy Body disease
  • Huntington disease
  • Multiple sclerosis
  • Normal pressure hydrocephalus
  • Parkinson disease
  • Pick disease


  • Kidney disease
  • Liver disease
  • Thyroid disease ( hyperthyroidism or hypothyroidism )
  • Vitamin deficiency (B1, B12, or folate)


  • Alcohol withdrawal state
  • Intoxication from drug or alcohol use
  • Wernicke-Korsakoff syndrome (a long-term effect of excessive alcohol consumption or malnutrition )
  • Withdrawal from drugs (especially sedative-hypnotics and corticosteroids)


  • Any sudden onset (acute) or long-term (chronic) infection
  • Blood poisoning ( septicemia )
  • Brain infection ( encephalitis )
  • Meningitis (infection of the lining of the brain and spinal cord)
  • Prion infections, such as mad cow disease
  • Late-stage syphilis

Complications of cancer can also lead to neurocognitive disorder.

Other conditions that may mimic organic brain syndrome include:

  • Depression
  • Neurosis
  • Psychosis




Symptoms can differ based on the disease. In general, organic brain syndromes cause:

  • Agitation
  • Confusion
  • Long-term loss of brain function ( dementia )
  • Severe, short-term loss of brain function ( delirium )


Exams and Tests


Tests depend on the disorder, but may include:

  • Blood tests
  • Electroencephalogram (EEG)
  • Head CT scan
  • Head MRI
  • Lumbar puncture (spinal tap)




Treatment depends on the underlying condition. Many conditions are treated mainly with rehabilitation and supportive care to help the person with activities lost due to areas where brain function is affected.

Medicines may be needed to reduce aggressive behaviors that can occur with some of the conditions.


Outlook (Prognosis)


Some disorders are short-term and treatable. But many are long-term or get worse over time.


Possible Complications


People with neurocognitive disorder often lose the ability to interact with others or function on their own.


When to Contact a Medical Professional


Call your health care provider if:

  • You have been diagnosed with organic brain syndrome and you are uncertain about the exact disorder.
  • You have symptoms of this condition.
  • You have been diagnosed with neurocognitive disorder and your symptoms become worse.




Beck BJ, Tompkins KJ. Mental disorders due to another medical condition. In: Stern TA, Fava M, Wilens TE, Rosenbaum JF, eds. Massachusetts General Hospital Comprehensive Clinical Psychiatry . 2nd ed. Philadelphia, PA: Elsevier; 2016:chap 21.

Douglas VC, Josephson SA. Dementia and systemic disease. In: Aminoff MJ, ed. Aminoff's Neurology and General Medicine . 5th ed. Philadelphia, PA: Elsevier; 2014:chap 61.

  • Brain - illustration

    The major areas of the brain have one or more specific functions.



    • Brain - illustration

      The major areas of the brain have one or more specific functions.



    A Closer Look


      Self Care


        Tests for Neurocognitive disorder



          Review Date: 2/27/2016

          Reviewed By: Amit M. Shelat, DO, FACP, Attending Neurologist and Assistant Professor of Clinical Neurology, SUNY Stony Brook, School of Medicine, Stony Brook, NY. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.

          The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed medical professional should be consulted for diagnosis and treatment of any and all medical conditions. Links to other sites are provided for information only -- they do not constitute endorsements of those other sites. © 1997- A.D.A.M., Inc. Any duplication or distribution of the information contained herein is strictly prohibited.




          A.D.A.M. content is best viewed in IE9 or above, Firefox and Google Chrome browser.

          Content is best viewed in IE9 or above, Firefox and Google Chrome browser.