A term that is used to characterize multiple cognitive deficits, including memory impairment. In order to be labeled dementia, at least one of the following mental disabilities must be present:

• Apraxia inability to perform motor tasks despite having an intact motor system.

• Aphasia loss of language function.

• Agnosia failure to recognize objects, and disturbances in abstract thinking, planning, initiating, sequencing, and stopping complex behavior.

This dementia is due to the physiologic consequence of the underlying infectious disease (e.g., HIV-1 virus, or syphilitic spirochete Treponema pallidum). Dementia in association with HIV infection may also result from accompanying central nervous system (CNS) tumors and from opportunistic infections.

The rate that dementia progresses varies widely.

• Syphilitic dementia shows up with symptoms in approximately 5 to 15 years. It is usually seen between the ages of 30 to 50. The most common signs include: tremors of the hands, tongue and lips; dysarthria; and dysgraphia. Clinically, dementia mimics any organic brain syndrome.

• AIDS dementia complex begins with: Stage 0 (normal) during which normal mental and physical activity moves to difficulty in concentration and memory. In Stage 1 (mild), the disease advances, and patients are slower and less agile. With the advance of the disease to Stage 2 (moderate), the patient performs poorly on mental tests, is unable to work, and may require a cane. In Stage 3 (severe), the patient has major intellectual incapacitates. Stage 4 (end stage) progresses all the way to a vegetative state.

Differentiating delirium from dementia is necessary. Diagnostic criteria have been developed, and the diagnosis is made almost solely on clinical grounds. Laboratory tests are performed to search for medical causes of the delirium.

• Syphilitic dementia - Cerebrospinal fluid (CSF) contains syphilitic antibodies.

• AIDS dementia - CSF may show normal or slightly increased protein, and a mild lymphocytosis. HIV can usually be isolated directly from the CSF. Computed tomography (CT) and magnetic resonance imaging (MRI) help in the diagnosis to reveal any localized brain lesions, cerebral atrophy, strokes or tumors. The levels of CD4+T-lymphocyte cell counts influence dementia progress and the development of opportunistic infections. (See Diagnostic Code: 6351 HIV-Related illness)

Treating the cause of dementia may slow the progress of the disease; however, it will not eliminate it. Supportive actions such as frequent orientation to time, place and person; maintenance of the same surroundings; institution of activities that are repeated and non-stressful; and use of rooms that contain sensory stimuli are helpful. Moderate exercise may be recommended to reduce restlessness and to improve balance. Medications to control undesirable behaviors should be limited and minimal doses should be used.

Due to the progressive nature of dementia, a referral to a social agency may be indicated to assist in care-giving. It is suggested that a living will be made before the patient is mentally incapacitated.