Neurological manifestations of acquired immunodeficiency syndrome
Introduction
Introduction to the nervous system manifestations of acquired immunodeficiency syndrome Acquired immunodeficiency syndrome (AIDS), or AIDS, is a unique immunodeficiency disease caused by human immunodeficiency virus (HIV). Since its first report in 1981, AIDS has spread widely around the world and has achieved high rates of infection, posing a serious threat to human health and survival. According to WHO estimates, 2.3 million people died in 1997 alone. AIDS. At present, about 30 million people worldwide are infected. HIV is a neurotropic virus that can be highly selectively invaded and localized in the nervous system. Neurological complications often worsen AIDS and accelerate its death. basic knowledge The proportion of illness: 0.0005% Susceptible people: no specific population Mode of transmission: sexual transmission, blood transmission, mother-to-child transmission Complications: Toxoplasmosis, cytomegalovirus infection, cryptococcosis, herpes simplex, herpes zoster, syphilis
Cause
Neurological manifestations of acquired immunodeficiency syndrome
(1) Causes of the disease
In 1983, Montagnier and colleagues isolated a retrovirus from a homosexual patient with lymph node disease and named the virus a lymphadenopathy-associated virus (LAV), and soon Callo and his assistants described a The retrovirus, which is present in the blood of AIDS patients, is called human T-lymphocyte virus (HTLV-III). It was later confirmed that LAV and HTLV-III are the same virus. In 1986, the International Virus Committee unified it as human. Immunodeficiency virus (HIV).
HIV is a retrovirus, a type C RNA virus. Because it contains reverse transcriptase, it can synthesize DNA using viral RNA as a template. The virus has two subtypes, and HIV-1 can cause immunodeficiency and AIDS. Worldwide distribution; HIV-2 causes immunodeficiency only for African immigrants in western Africa and Europe.
When the immune function of people living with HIV is severely damaged by the virus, and the ability to maintain the lowest disease resistance is not achieved, the infected person develops into an AIDS patient. As the human immunity decreases, people become more and more infected. Pathogenic microorganisms, and the degree of infection will become more and more serious, and eventually will die due to various complex infections.
(two) pathogenesis
The human immunodeficiency virus selectively binds to the cell surface CD4+ receptor, infects and destroys the host's CD4+ lymphocytes (ie, T helper lymphocytes), causing severe cellular immunodeficiency in the body, leading to many opportunistic infections, such as the Karst lung sac. Insect pneumonia, toxoplasmosis, viruses, fungi and bacterial infections; at the same time, the susceptibility of certain tumors, such as Kaposi sarcoma, lymphoma, is increased, infected lymphocytes can enter the central nervous system, and half of the surface of nerve cells Lactose ceramide molecules bind, cause direct infection, and cause a variety of damage in long-term survival. In addition, they can also be mediated by immune, infected monocytes and macrophages release cytokines, HIV gene products, etc. Sexual inflammatory damage.
High-risk groups of the disease include homosexual or bisexual men, intravenous drug addicts, heterosexual contact, hemophilia or other diseases. Blood or blood products and offspring of HIV-infected persons, through close contact with the blood of patients with this disease, semen Infected by excrement, mucus and tissue.
Prevention
Prevention of neurological manifestations in acquired immunodeficiency syndrome
China's "Regulations on AIDS Prevention and Control" was adopted and announced at the 122nd executive meeting of the State Council on January 18, 2006, and will be implemented as of March 1, 2006.
AIDS is transmitted through sexual contact, blood and mother-to-child transmission; it is not infected with the daily life and work of HIV-infected patients or patients.
1. Self-love and self-love are the fundamental measures to prevent sexual contact with HIV. Correct use of quality condoms and early treatment and cure of sexually transmitted diseases can greatly reduce the risk of infection and spread of AIDS and sexually transmitted diseases.
2. Sharing syringes Intravenous drug use is a high-risk behavior of infecting and transmitting AIDS. It is necessary to refuse drugs and cherish life.
3. Avoid unnecessary injections, blood transfusions, and use of blood products; if necessary, use blood or blood products that have been tested for HIV antibodies and use disposable syringes or strictly sterilized instruments.
4. Promptly adopt antiviral drug intervention for pregnant women infected with HIV, reduce the time-consuming injury operation, avoid breastfeeding and other preventive measures, and greatly reduce the possibility of fetal infection.
5. AIDS voluntary counseling and testing is an important prevention and treatment measure for early detection of infected people and patients.
6. Caring for, helping, not discriminating against HIV-infected patients and patients, and encouraging them to participate in AIDS prevention and treatment are important measures to control the spread of AIDS.
7. AIDS threatens everyone and every family, affects the development and stability of society, and prevention of AIDS is the responsibility of the whole society.
Complication
Neurological manifestations of acquired immunodeficiency syndrome Complications Toxoplasmosis cytomegalovirus infection cryptococcal disease herpes simplex herpes zoster syphilis
In addition to the effects on the nervous system, HIV infection also has a direct effect on various organ systems (prone to the lungs, gastrointestinal tract, eyes, skin); many other opportunistic lesions, including focal and diffuse changes and tumors It can also occur in AIDS patients.
Opportunistic infections appear to favor certain diseases such as toxoplasmosis, cytomegalovirus infection, cryptococcosis, herpes simplex and herpes zoster, and uncommon type of tuberculosis infection, and in some cases concurrent syphilis infection.
Symptom
Acquired immunodeficiency syndrome, neurological symptoms, common symptoms, nausea and vomiting, HIV infection, immunodeficiency, diarrhea, fatigue, dementia, loss of appetite, dysphagia, sore throat, sensory disturbance
1. Clinical stage of HIV infection
From infection to morbidity, HIV generally goes through two periods.
(1) prodromal symptoms: Most patients will show non-specific prodromal symptoms such as fever, fatigue, night sweats, sore throat, difficulty swallowing, loss of appetite, diarrhea, weight loss, and generalized lymph nodes and hepatosplenomegaly. For the AIDS-ralated complex, some people call it pre-AIDS or clinically inevident seroconversion, in which the virus invading the central nervous system is Growth in cerebrospinal fluid can occur with self-limiting aseptic meningitis, and encephalitis is less common.
(2) Full-blown AIDS: The clinical manifestations of this period are various. Except for the direct effect of HIV on various organ systems (the lungs, gastrointestinal tract, eyes, skin and nervous system) There are also a range of opportunistic infections and tumors.
2. Clinical types of HIV infection
According to the etiology and pathogenesis, the performance of HIV infection in the nervous system is divided into two categories: primary and secondary.
(1) Primary HIV infection in the nervous system: 40% to 50% of AIDS patients in the clinic have neurological manifestations, and 10% to 27% are first symptoms. At autopsy, more than 80% of AIDS patients have pathological changes in the nervous system.
1 nervous system acute acute infection of HIV: mostly acute aseptic meningitis, manifested as fever, headache, general malaise, vomiting and meningeal irritation, cerebrospinal fluid only mild lymphocytosis and protein moderate increase, this and other Viral meningitis is similar, a small number of acute meningoencephalitis, acute mental symptoms, disturbance of consciousness, transient coma and convulsions, brain parenchymal damage, EEG diffuse abnormalities and epileptic discharge, CT scans are normal, There may also be single encephalitis, acute ascending or transverse myelitis, inflammatory peripheral neuropathy, which may be the first symptom of HIV infection, or may occur at the same time or later in the AIDS-related complex. The acute symptoms of most patients can disappear within a few weeks, but nervous system infections continue to exist and can develop into subacute or chronic infections.
2 nervous system chronic primary infection of HIV
A. AIDS dementia complex (ADC): is the most common neurological manifestation during the AIDS epidemic. It is found in about 20% of AIDS patients. About 1/3 of the patients have intrinsic signs in the early stage, and about 2/3 patients in the late stage. Intrinsic, formerly known as subacute or chronic HIV encephalitis, also known as AIDS encephalopathy or encephalitis, this change may be the main or only manifestation of the disease, a subarachnoid dementia progressing in early stage, early performance Slow thinking, memory loss, distraction, emotional apathy and language barriers, etc., may also have motor dysfunction, limb movement disorder, ataxia gait and two-eyed saccade dysfunction, late stage may appear severe dementia, no movement Sexual silence, exercise inability and paraplegia with bladder rectal dysfunction, silence is a prominent manifestation of advanced disease, in children mainly manifested as cognitive dysfunction and spasm weakness, which in turn impairs brain growth and development, the pathological basis of intrinsic is diffuse Multifocal leukoaraiosis, accompanied by a small amount of lymphocytes around the blood vessels, clusters of foamy macrophages and multinucleated cells infiltrating, cerebrospinal fluid can be normal or protein content Lymphocytes are slightly elevated, HIV antibodies are present, HIV virus culture can be positive, EEG shows diffuse slow waves, brain CT and MRI show cortical atrophy and ventricle enlargement, and flaky or diffuse white matter lesions can be diagnosed. Play a role.
B. Vacuolar myelopathy: a common disease in AIDS autopsy. The myelopathy of the white matter vacuolar degeneration is similar to subacute degeneration. It often exists in combination with AIDS dementia syndrome. As the main symptom of this disease alone, the clinical manifestations of progressive paralysis, often accompanied by deep sensory disturbances and sensory ataxia, the vast majority of patients in a few weeks to several months rely on wheelchairs, a few within a few years Painless progression, individual patients may have spinal myoclonus, the pathological changes are similar to subacute combined degeneration, mainly for vacuolization of the white matter of the white matter, with the most obvious posterior cord and lateral cord, often accompanied by Spinal cord swelling or loss of myelin, in situ hybridization or isolation and culture of HIV positive.
C. Peripheral neuropathy: About 15% of AIDS patients have peripheral nerve damage, and the abnormalities of peripheral nerves in autopsy can reach 35%. Clinical manifestations are various forms of peripheral neuropathy, the most common distal symmetric polyneuropathy. For the obvious abnormality and sensation, the HIV virus has been isolated from the peripheral nerves. This result proves for the first time that the lesion is viral polyneuritis, and there are multiple mononeuropathy, chronic inflammatory demyelinating polyneuropathy. Sensory ataxia neuropathy and progressive painful radiculopathy.
D. Myopathy: Muscle damage in the form of inflammatory myopathy has been reported in AIDS, can occur at any stage of AIDS, clinically less common, manifested as subacute onset of proximal weakness and muscle atrophy, Serum muscle enzymes are elevated, and muscle biopsy shows inflammatory cell infiltration around the blood vessels, muscle membrane or interstitium.
(2) Secondary neurological manifestations of AIDS: In addition to the direct effects of HIV infection on the nervous system, many other opportunistic lesions, including focal and diffuse changes, can also occur in AIDS patients, opportunistic infections seem to prefer Certain diseases, such as toxoplasmosis, cytomegalovirus infection, cryptococcosis, herpes simplex and herpes zoster, and uncommon type of tuberculosis infection, in some cases concurrent with syphilis infection, in general, Pneumocystis carinii infection and Kaposi sarcoma does not involve the nervous system, focal lesions are most common with toxoplasmosis, followed by lymphoma; diffuse lesions are most commonly cytomegalovirus and cryptococcal infection.
1 Central nervous system opportunistic infections:
A. Toxoplasmosis: Before the widespread use of anti-protozoal drugs, Toxoplasma gondii was the most common opportunistic infection pathogen of AIDS. In the autopsy pathology report of AIDS, about 13% of cases were found to have inflammatory necrotic lesions caused by Toxoplasma gondii. Toxoplasmosis is the most common focal complication, with subacute onset, chronic progressive development, hemiplegia, aphasia seizures, brain stem, cerebellum or basal ganglia symptoms and signs, cerebrospinal fluid usually The protein content is increased to 50-200mg/dl, and 1/3 of the cases have cell-growth changes. PCR can detect Toxoplasma DNA, strengthen brain CT and MRI to see single or multiple massive lesions, and have circular enhancement. The diagnosis depends on brain biopsy. If the anti-toxoplasma treatment is applied for a few weeks, the brain lesions of AIDS patients cannot be reduced. Other causes, mainly lymphoma, should be considered.
B. Fungal infections: Cryptococcus meningitis and individual cryptococcal granulomatous lesions are the most common fungal complications of HIV infection, meningitis or meningoencephalitis symptoms do not appear to be obvious, and cerebrospinal fluid cytology protein and sugar are rarely abnormal For these reasons, evidence of Cerebrospinal Fluid Cryptococcus infection must be stained with Indian ink, antigen testing and fungal culture.
C. Viral infection: cytomegalovirus, herpes simplex virus, herpes zoster virus can cause meningitis, encephalitis and myelitis. In autopsy cases, about 1/3 of AIDS patients have cytomegalovirus infection, encephalitis Patients with seizures, unconsciousness and obvious lumbar radiculitis may be caused by cytomegalovirus infection. The diagnosis of cytomegalovirus infection in the deceased is difficult to establish, because cerebrospinal fluid culture is usually negative, antibody titer is non-specifically elevated, and brain biopsy And virus isolation is helpful for diagnosis. Herpes zoster virus infection is a relatively rare complication of AIDS. However, once it occurs, the condition is quite serious, manifested as multifocal damage of white matter, similar to progressive multifocal leukoencephalopathy. It is manifested as cerebral vasculitis with hemiplegic or rare form of myelitis. Herpes simplex virus type I and type II are also present in the brain of AIDS patients, but the clinical relationship between them is unclear, and the papilloma virus is caused by papillomavirus. Sexual multifocal leukoencephalopathy.
D. Bacterial infection: Mycobacteria, Listeria, Staphylococcus aureus, etc. can cause various meningitis, in which M. tuberculosis and intracellular non-chromobacteriosis are slightly more common.
E. Syphilis infection: syphilitic meningitis and meningeal vascular syphilis have a high incidence in AIDS patients. It is unreliable to judge the activity of syphilis by cerebrospinal fluid cell count. The diagnosis relies entirely on serological examination.
(3) Secondary tumors of the central nervous system:
1 primary lymphoma: about 5% of AIDS patients with primary central nervous system lymphoma, clinical and imaging difficult to identify with toxoplasmosis, the diagnosis requires a brain biopsy, the disease has a poor prognosis, most The patient died within 6 months.
2Kopasi sarcoma: very rare, most of the central nervous system involved with other visceral involvement and extensive lung metastasis, clinical focal symptoms, CT with focal damage, often combined with central nervous system opportunistic infections, such as the brain Toxoplasmosis, cryptococcal meningitis, etc.
Examine
Examination of the nervous system manifestations of acquired immunodeficiency syndrome
At present, there are various methods for detecting HIV antibodies, which are based on the principle of highly specific enzyme-linked immunosorbent assay, in which ELISA is most commonly used, and the determination of p24 core antigen by ELISA is more practical, however, there is a small Some false positive reactions, especially when used to detect low-risk populations of HIV infection, so ELISA positive results need to be re-examined.
The Western blot test method uses a specific viral protein recognition antibody to test the pathogen. It is more specific than the ELISA test and can be used for the judgment of positive results. A new method for detecting HIV infection using the purified antigen method is being developed, which is more than the current application method. More specificity.
On the basis of a detailed medical history and a comprehensive and focused examination, the necessary selective auxiliary examinations are performed, including: CT and MRI examinations, chest radiographs, skull base radiographs, cerebrospinal fluid, blood routine, urine routine, blood electrolytes, Blood sugar, urea nitrogen, electrocardiogram, ultrasound, etc.
Diagnosis
Diagnosis and identification of nervous system manifestations of acquired immunodeficiency syndrome
The incidence of AIDS is increasing all over the world, and the increase in Asia is faster. Therefore, the possibility of AIDS should be considered in the diagnosis of unexplained nervous system diseases. The diagnosis of AIDS neurological syndrome needs to be based on epidemiological data, clinical manifestations of patients. Comprehensive judgments in immunology, virology and imaging examinations rely mainly on nerve biopsy, HIV antigen and antibody determination.
HIV infection has a direct effect on all organs of the body; the predilection is lung, gastrointestinal, eye, skin and nervous system, so it should respond to highly suspected patients, showing non-specific precursors in pre-AIDS. Symptoms such as fever, fatigue, night sweats, sore throat, difficulty swallowing, loss of appetite, diarrhea, weight loss, and systemic lymph nodes and hepatosplenomegaly should be measured for HIV antigens and antibodies.
The identification of clinical manifestations is not described here.
