The Centers for Disease Control and Prevention estimated that by the end of 2006, 1,106,400 people were living with human immunodeficiency virus, or HIV.
The virus can be transmitted through unprotected sex, sharing needles, or from mother to child during the pregnancy, while giving birth, or when breastfeeding.
Some people infected with the virus have flu-like symptoms, though others live symptom-free with the virus for years. Even if a patient is not experiencing symptoms, the virus is still affecting his/her immune system. Patients in the late stage of HIV — acquired immune deficiency syndrome or AIDS — have a severely damaged immune system and are susceptible to opportunistic infections.
HIV/AIDS can affect the normal functioning of nerve cells, which can result in neurological symptoms. The National Institute of Neurological Disorders and Stroke noted that more than 50 percent of adults with AIDS in the United States suffer from some type of neurological problem. The neurological complications may involve the central nervous system or the peripheral nervous system. Examples of neurological issues that HIV patients may face include confusion, sensation changes in the limbs and weakness. Some patients may experience neurological issues as a complication of the medications they use.
Several neurological conditions may occur in patients with HIV/AIDS. For example, some patients with an advanced HIV infection may develop HIV-associated dementia, or AIDS dementia complex, in which they have cognitive dysfunction and behavioral changes. Patients may also have encephalitis — an inflammation of the brain.
About 10 percent of patients with untreated AIDS may develop toxoplasma encephalitis, which is caused by Toxoplasma gondii, a parasite, according to the National Institute of Neurological Disorders and Stroke. Other neurological conditions associated with a weakened immune system include cryptococcal meningitis and progressive multifocal leukoencephalopathy. Some HIV patients may have central nervous system lymphomas, which can cause symptoms such as seizures, paralysis, visual problems and speech problems.