Central nervous system disorders in AIDS.

AIDS is no longer a rare disease affecting only a small segment of our population. It has now been observed throughout the United States and most other countries in the world. As the current data demonstrate, the effect of AIDS on the nervous system is profound and widespread. About 10% of all AIDS patients will first present with a neurological complaint. Evaluation of this complaint will then lead to the diagnosis of AIDS. Nearly 40% of all AIDS patients will develop major neurological symptoms during their lifetime; these symptoms may be related to primary HIV infection or secondarily to any of a number of opportunistic processes. At autopsy, 75% of AIDS patients will have neuropathological abnormalities. The AIDS-related central neurological syndromes are many and varied, as are their associated signs and symptoms. As with radiologic and serologic examination, the findings resulting from clinical examination of the AIDS patient with neurological illness are nonspecific. While there are clinical findings that are suggestive of one or another class of AIDS-related neurological illness, there is such overlap in their presentations as to make specific CNS diagnosis on the basis of clinical examination virtually impossible. The differential diagnosis of AIDS-related neurological illness is made even more difficult by the frequent observation of multiple CNS pathological processes in the same AIDS patient. Nearly one-third of all histologically examined AIDS cases had multiple intracranial pathologies. Multiple treatable pathological abnormalities have been identified both within the same intracranial lesion and within different lesions, and both simultaneously and sequentially. Thus, the evaluation and treatment of the AIDS patient with central neurological illness is a difficult challenge. Close attention must be paid to subtle neurological complaints, and careful neurological examination is warranted in all AIDS patients. Once the patient complains of neurological dysfunction or a neurological abnormality is identified on clinical examination, a careful workup including MRI or CT brain scanning and cerebrospinal fluid examination is indicated. Specific diagnosis must then be made on the basis of CSF findings, response to empiric therapy or biopsy. Therapy for AIDS-related CNS diseases in not unlike that for the same disease in other patient populations. (see Chapters 18 and 19). There is no cure for HIV encephalitis; azidothymidine (AZT) appears to cross the blood-brain barrier, and trials of AZT for the treatment of HIV encephalitis show early promise.(ABSTRACT TRUNCATED AT 400 WORDS)