AIDS dementia complex

January 2007     View PDF     En español

Diagnosing ADC

Three tests are required to diagnose ADC accurately: a mental status exam, one of the standard scans (CT and/or MRI) and a spinal tap. These may also help tell ADC apart from other brain disorders like toxoplasmosis, PML (progressive multifocal leukoencephalopathy) or lymphoma. Care should be taken, however, as ADC may occur along with the symptoms of other brain disorders. Diagnosing both conditions at the same time can be more difficult.

The main way to detect and evaluate ADC is through a mental status exam. The examination is designed to reveal problems like short- or long-term memory loss, problems with orientation, concentration and abstract thinking as well as swings in mood. Imaging of the brain with scans (like an x-ray) is also used. Certain lab tests can also be useful like examining cerebrospinal fund (CSF), obtained by a spinal tap (also called lumbar puncture).

CT and MRI scans are routinely used in the detection of ADC. CT scans are x-rays that use special beams to produce detailed images of organs and structures within the body. In people with ADC these scans usually show signs of destroyed brain tissue. MRI, or Magnetic Resonance Imaging, is a sensitive brain scan that is used when CT findings are not conclusive. Results from both of these tests are helpful in ruling out other causes for the symptoms.

Tests of CSF may help determine if someone has ADC, but they are not conclusive. Mostly they’re used to rule out other causes of the symptoms of ADC, and that’s why they’re important. Many people with ADC have higher levels of certain proteins or white blood cells in their CSF. However, not everyone with these levels turn out to have ADC. Also, people with advanced ADC are generally more likely to have higher HIV levels in their CSF, although people with no symptoms of brain disorders sometimes have high HIV levels in their CSF.