Neurological manifestations of AIDS

Introduction
In 1981, physicians became aware of the frequent occurrences of otherwise rare opportunistic infections and neoplasms-notably Pneumocystis carinii pneumonia and Kaposi sarcoma- in otherwise healthy homosexual men. The study of these patients led to the recognition of the new viral disease - AIDS (Acquired immune deficiency syndrome). Human immune deficiency virus infection is characterized by an acquired and usually profound decrease in the immunity of our body (there is reduction in CD4 cell count). It is the failure of the immune system that explains the development of wide variety of opportunistic infections and unusual neoplasms.

In a span of 20 years, HIV and AIDS have spread worldwide. World health organization estimated that approximately 34,000,000 adults were infected with AIDS and that about 850,000 adults in the United States were sero-positive for the virus. In the United States, AIDS affects mainly homosexual and bisexual cases and male and female drug users.

Forty to sixty percent of all patients with acquired immune deficiency syndrome (AIDS) will develop neurological symptoms One third of these patients present to the doctor initially with neurological complaints. Only approximately 5% of the patients who die with AIDS have a normal brain on autopsy.

Neurological complications in patients infected with Human immunodeficiency virus

Brain:

• AIDS dementia complex
• Acute HIV related encephalitis
• Cytomegalovirus encephalitis
• Varicella-zoster encephalitis
• Metabolic encephalopathies
• Cerbral toxoplasmosis (parasitic infection)
• Primary CNS lymphoma
• Cryptoccoma (fungal infection)
• Brain abscess/Tuberculoma
• Neurosyphilis

Spinal cord:

• Vacuolar myelopathy
• Herpes simplex or zoster myelitis

Meninges:

• Aseptic meningitis
• Cryptococccal meningitis
• Tuberculous meningitis
• Syphylitic meningitis
• Metastatic lymphomatous meningitis

Peripheral nerve and root:

• Infectious
• Herpes zoster
• Cytomegalovirus lumbar poly radiculopathy

Virus or immune related:

• Acute and chronic inflammatory HIV polyneuritis
• Mononeuritis multiplex
• Sensorimotor demyelinating polyneuropathy
• Distal painful sensory polyneuritis

Muscle:

• Polymyosittis and other myopathies

Out of all the conditions mentioned above, the following are the most common conditions producing disease in the brain of AIDS patients are the following:

• Toxoplasmosis
• Primary CNS lymphoma
• Progressive multifocal leukoencephalopathy
• Cryptococcal abscess (fungal abscess).

Manifestations of CNS (Central nervous system) toxoplasmosis:
Toxoplasmosis abscess is the most common lesion causing mass effect in the AIDS patient. Is constitutes 70-80% of the cerebral mass lesions in AIDS. It also produces meningo encephalitis and encephalopathy. CNS toxoplasmosis occurs late in the course of HIV infection, usually when the CD4 counts are less than 200 cells per cubic millimeter. Diagnosis is made by examination of spinal fluid, MRI and CT scans. Treatment is by pyrimethamine and sulfadiazine.

Primary CNS lymphoma:
It occurs in approximately 10% of the AIDS patient. It is a type of cancer usually associated with a virus known as Epstein - Barr virus. The patient has mental status changes like confusion and drowsiness, blindness, speaking difficulty, weakness or numbness of limbs. The disease is usually progressive and the patient may die within a few months, occasionally surviving longer with treatment with drugs like methotrexate and corticosteroids.

Diagnostic tests for HIV infection:
Many screening tests are now available to the detection of antibodies to HIV. All of them are based on enzyme-linked immunoassay, which is highly sensitive. The Western blot test is more specific and it is a confirmatory test.

Treatment for HIV infection:
The treatment of HIV infection/AIDS is very difficult. Patient and their family require counseling and education, and frequently, psychiatric support in addition to complex drug regimens. Drug therapy for HIV infection continues to change rapidly. A combination of three drugs AZT, Lamivudine and Indinavir, prolongs the survival of AIDS patient.

Did you know?
Forty to sixty percent of all patients with acquired immune deficiency syndrome (AIDS) will develop neurological symptoms One third of these patients present to the doctor initially with neurological complaints. Only approximately 5% of the patients who die with AIDS have a normal brain on autopsy.