the spinal cord, which controls the lower part of the body, and become larger over time. myelin, the protective coating around nerve fibers, is slowly destroyed. As more and more fibers die, the brain's signals are short-circuited, thereby blocking communication with the lower body. Myelopathy can occur at any time in HIV disease and up to 55 percent of HIV-positive people at autopsy show some degree of myelopathy.
Also connected is hiv neuropathy, which also affects up to a third of HIV-positive people. patients initially report a numb or tingling feeling in their feet that may later spread to other extremities. others report painful sensations when they stand or apply pressure on the feet. A decrease in foot and ankle reflexes accompanies this problem. This can be caused both by the progress of the disease and by some of the medicines that HIV-positive people take; ddl, ddC, and d4T have been linked to these problems.
About 3 percent of all people with HIV have an opportunistic infection called progressive multifocal leukoencephalopathy. The jc virus is reactivated in immune dysfunction and leads to walking problems, visual difficulties, cognitive problems, and eventually death. The brain shows many lesions when MRI is performed.
Primary central nervous system (CNS) lymphoma occurs in about 2 percent of HIV disease patients. CNS lymphoma is a tumor of a form of white blood cells called lymphocytes. Lymphomas can occur anywhere in the lymph system and often spread to the nervous system. Primary CNS lymphoma refers to a form of lymphoma that is confined to the brain, spinal cord, their lining, and/or the inside of the eye. Irradiation is sometimes successful as treatment. It has been shown to increase in effectiveness when combined with the drug methotrexate.
toxoplasmosis is a disease caused by a parasite called Toxoplasma gondii. It is found in many animals and humans. It generally is kept under control but in immune suppressed people can cause a range of neurological problems. It can be spread in the feces of animals, particularly cats. Once exposed, however, cats generally only are infectious for one or two weeks. The combination of two drugs, pyrimethamine and sulfadiazine, is used to treat the disease. Diagnosis is through tests for the parasite in the blood and CT or MRI. Typi cally the parasite can cause a form of encephalitis that is very dangerous. Symptoms include fever, confusion, headache, disorientation, personality changes, tremor, and seizures.
cytomegalovirus causes another infection that a majority of people in the United States already have in their body but that a healthy immune system can keep in check. The most common illness caused by CMV is retinitis. This is the death of cells in the retinas, leading to blindness. Advanced cases can spread to many parts of the body and cause problems. This does not occur until late-stage HIV disease. HAART has brought most cases of CMV under control, and CMV infection has dropped in occurrence.
neurologic dysfunction Abnormal, disturbed, or impaired functioning of the nervous system.
neurology The branch of medical science dealing with the study of the nervous system and its disorders.
neurolytic block The injection of ethyl alcohol or another chemical around a group of nerves to provide long-lasting relief from pain that has not been controlled successfully with medication. Alcohol or phenol damages the nerves, which will therefore give longer pain-relieving ability than topical or injection medications. After the nerves have been damaged, they try to repair themselves over the next several years; greater pain than was originally experienced may result. Therefore, these blocks are usually only performed for the treatment of pain as terminal illnesses such as cancer. Neurolytic blocks can often have unintended side effects of damaging nerves not intended to be blocked.
neuromuscular therapy Physical therapy that emphasizes the role of the brain, spine, and nerves in muscular pain. one goal of the therapy is to relieve tender congested spots in muscle tissue and compress nerves that may radiate pain to other areas of the body.
neuron Major cell of nervous tissue; the structural and functional unit of the nervous system, specialized for transmission of information in the form of
Was this article helpful?