Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0019693 (HIV)
 170,526 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The human immunodeficiency virus infected persons frequently have manifestations of central nervous system disfunction. These can be primary involvement or secondary processes such as infections or tumors. The present paper presents a short review of radiologic CNS findings in patients with AIDS as seen on CT and or MRI. The radiologic findings of HIV-1 encephalitis, toxoplasmosis, primary CNS lymphoma, PMLE, cryptococcosis, histoplasmosis, CMV encephalitis, HVS and varicella are presented. We expect this will ultimately help in the management of the AIDS patient.
 ...
PMID:CNS involvement in AIDS patients as seen with CT and MR: a review. 181 9

Fifteen male homosexual subjects (mean age 31.6 +/- 7.2 yr) who were asymptomatic, but HIV-1 seropositive (HIV+) were compared to 15 male age-matched HIV-1 seronegative (HIV-) subjects using resting PET/FDG studies and MR scans. Mean cerebral metabolic rates for glucose (mg/100 g/min) in the HIV+ and HIV- subjects were 7.7 +/- 1.7 and 7.0 +/- 2.1, (p = 0.44), respectively. An index of regional metabolic asymmetry for the whole brain was 5.8% +/- 3.2% in the HIV+ and 2.7% +/- 2.3% in the HIV- (p = 0.002), and the difference was most prominent in the prefrontal area. Significant asymmetries were found in 10/15 HIV+ subjects, primarily in prefrontal (7/15) and premotor (4/15) regions. MRI scans showed no abnormalities on clinical or quantitative evaluation in HIV+ subjects. Upon follow-up of HIV+ subjects over 18-40 mo, seven became symptomatic, of which two died. There was no relationship between the presence of PET scan abnormalities and earlier onset of symptomatic disease.
 ...
PMID:Metabolic asymmetries in asymptomatic HIV-1 seropositive subjects: relationship to disease onset and MRI findings. 188 May 74

Brain MRI and/or CT were performed on 72 HIV-infected patients at various stages of the disease, and on 34 controls. The neuroradiological findings were related to duration of the infection, neurological symptoms, and cognitive abnormalities as well as to immunological findings in the CSF and blood. All types of brain atrophy were more severe and more frequent in HIV-infected subjects than in controls. Patients with neurological symptoms, those with advanced HIV infection, and patients with a duration of HIV infection of more than 4 years showed the most severe and most frequent neuroradiological abnormalities, including central and cortical atrophy, brain stem atrophy, and cerebellar atrophy. Subjects with cognitive defects exhibited more severe central atrophy than cognitively intact patients. However, slight brain atrophy and/or parenchymal lesions were found in 57% of cognitively intact HIV-seropositive individuals. Patients with brain atrophy and those with radiologically normal brain, both showed increased intrathecal synthesis of total IgG, and intrathecal HIV-antibody synthesis. However, a declined general immune response and a lowered CSF leukocyte count were seen predominantly in patients with brain atrophy. The results suggest that subcortical, neurologically "silent" areas of brain white matter are an early target of HIV infection.
 ...
PMID:Mild brain atrophy in early HIV infection: the lack of association with cognitive deficits and HIV-specific intrathecal immune response. 198 93

Leakage of Gd-DTPA through a defective blood-brain barrier is measured quantitatively using dynamic MRI scanning, in which repeated scans are made after a bolus injection. Image registration artifacts are minimized; a dose of 0.1 mM/kg and an IR sequence enable enhancement to be measured quantitatively. The triexponential enhancement curve is fitted to a theoretical model based on compartmental analysis. The transfer constant, or permeability surface area product per unit volume of tissue (k), and leakage space per unit volume of tissue (v1) are measured. Estimates for a quickly enhancing multiple sclerosis lesion are k = 0.050 min-1, v1 = 21%; for a slow one k = 0.013 min-1, v1 = 49%. This implies permeability in the range 4-17 x 10(-6) cm s-1, in broad agreement with other physiological methods. The method is noninvasive and can be used to make serial measurements in patients and in experimental animal models. The time course of pathological aspects of diseases with blood-brain barrier breakdown, such as multiple sclerosis, tumors, and infections (e.g., HIV) can be studied, along with their response to therapy. The measurements are of physiological variables and are therefore independent of imaging equipment and field.
 ...
PMID:Measurement of the blood-brain barrier permeability and leakage space using dynamic MR imaging. 1. Fundamental concepts. 206 10

In forty patients at early and advanced stages of HIV infection (Walter Reed stages I-IV) regional cerebral blood flow was determined by 99mTc-HMPAO SPECT, comparing the results with CT and MRI findings. All patients with HIV encephalopathy (AIDS dementia complex) had pathologic SPECT results (multilocular, patchy uptake defects), but also in earlier and even earliest stages of HIV infection positive SPECT findings were observed. Compared to functional SPECT imaging, morphologically orientated methods (CT, MRI) were insensitive in detecting HIV-induced foci: more than 50% of the patients with pathologic SPECT findings had negative CT or MRI scans. Most patients in advanced Walter Reed stages had neurological abnormalities accompanied by positive SPECT. Subtle alterations of HMPAO uptake were observed even in a few cases of early HIV infection without neurological CNS symptoms. The data presented suggest that HMPAO SPECT is highly sensitive in the detection of altered brain perfusion not only in advanced but also early stages of HIV infection. Changes in regional cerebral blood flow are present before noticeable structural defects may be observed. Thus, it is suggested to use HMPAO SPECT in the evaluation and monitoring of patients with, and particularly at risk for, HIV encephalopathy.
 ...
PMID:Functional and morphological findings in early and advanced stages of HIV infection: a comparison of 99mTc-HMPAO SPECT with CT and MRI studies. 207 86

Two human retroviruses, HIV-1 and HTLV-I, have been associated with myelopathies in addition to other neurologic disorders. We report an American dually infected with HIV-1 and HTLV-I who developed steroid-responsive myeloneuropathy. This 28-year-old bisexual man developed interstitial pneumonitis and a transient midthoracic sensory level followed by the evolution of a slowly progressive spastic paraparesis and sensorimotor neuropathy. Serologic studies demonstrated coinfection with both HIV-1 and HTLV-I. Peripheral blood absolute CD4 count was persistently within the normal range. Cranial MRI was normal and spinal MRI showed T3-T10 atrophy. Serial CSF analyses demonstrated marked intrathecal synthesis of anti-HTLV-I IgG, lymphocytic pleocytosis, elevated protein and immunoglobulin G, and oligoclonal bands. HIV-1 was isolated from CSF but not from peripheral nerve. Lymphoproliferative studies confirmed spontaneous proliferation in both blood and CSF. Soluble interleukin 2 receptor and soluble CD8 were greatly elevated in blood and CSF when compared with patients with HIV-related vacuolar myelopathy and seronegative patients with other causes of myelopathy. Nerve biopsy showed epi- and endoneurial CD8+ lymphocytic infiltration without vasculitis; muscle biopsy showed features of acute and chronic denervation. A 6-week course of prednisone produced sustained improvement in leg strength and walking times. We speculate that the myeloneuropathy was caused by HTLV-I in the setting of coinfection with HIV-1.
 ...
PMID:Steroid-responsive myeloneuropathy in a man dually infected with HIV-1 and HTLV-I. 216 Oct 92

We have studied 95 HIV seropositive patients (77 males and 18 females; mean age: 31 years): 67 had no neurological symptoms or signs, 28 had various neurological symptoms and signs. This study included a full multimodal evoked potentials (MEP) assessment: visual evoked potentials by flash and reversal checkerboard; brainstem auditory evoked potentials; somatosensory evoked potentials obtained by stimulation of the median nerve. Patient evaluation further included: electroencephalography, electromyography with measurement of conduction velocities and neuroimaging (brain CT scan and/or MRI). We found abnormal MEP for all modalities. The prevalence of abnormal results was high in neurological symptomatic patients; in non neurological ones, the changes tended to be more frequent with the progression of the HIV infection. Whatever the stage of the disease, the various modes were equally affected. MEP were abnormal in 54.7 p. 100 of the cases: in 41.8 p. 100 (28/67) of patient without neurological signs (in 4/12 of fully asymptomatic subjects, 11/34 ARC patients and 13/21 AIDS patients) vs 85.7 p. 100 of neurological symptomatic patients. In neurological asymptomatic patients, a similar proportion of abnormal MEP was found in asymptomatic and ARC patients, while the evolution into AIDS was associated with a higher prevalence of abnormal MEP. In the latter group, MEP changes were nearly as frequent as in neurological symptomatic patients. Comparison between MEP and other electrophysiological procedures (EEG, EMG) and with neuroimaging techniques (CT Scan, MRI) showed the high sensitivity of the MEP technique at all stages of the disease. EMG was a sensitive method and complementary to MEP. The EEG and neuroimaging techniques showed abnormalities principally at the neurological symptomatic stage. Previous studies could not be properly compared.(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:[Multimodal evoked potentials in human immunodeficiency virus infection]. 218 85

Motor tests were performed in 50 HIV-infected patients in all stages according to the current CDC classification, but without any clinically evident central nervous system deficit, and the results compared with an age-matched control group. Patients were excluded from the study if there was alcohol or drug abuse, fever and/or opportunistic cerebral infection. The parameters tested were postural tremor of the outstretched hands, most rapid voluntary alternating index finger movements (MRAM) and rise time of most rapid index finger extensions (MRC). Whereas tremor peak frequencies did not differ significantly in the patients and controls, MRAM and rise times of MRCs showed significant slowing in the patient group. Morphologically, the motor test performance of the HIV-infected patients was similar to that of patients with manifest basal ganglia disease (Parkinson's, Huntington's and Wilson's diseases). MRI scans of all patients were normal. It is concluded that in HIV-infected patients there is a very early subclinical central nervous system affection, especially of the basal ganglia, which is detectable with appropriate, quantitative motor function tests. These functional abnormalities precede the structural alterations in the MRI scans.
 ...
PMID:Motor dysfunction in HIV-infected patients without clinically detectable central-nervous deficit. 227 70

We studied 126 HIV seropositive patients (106 men, 20 women; mean age: 32 years): 45 had neurological signs, 81 had none. Multimodal evoked potential (MEP) assessment included: visual EPs by flash and reversal checkerboard; brain-stem auditory EPs; somatosensory EPs by stimulation of the median nerve. Evaluation also included: electroencephalography, electromyography with measurement of conduction velocities, neuroimaging (CT scan and MRI). We found abnormal MEPs for all modalities. The prevalence of abnormal results was high in neurologically symptomatic patients; in non-neurological subjects, the changes were more dramatic as HIV infection progressed. Whatever the stage of the disease, the modalities were equally affected. MEPs were abnormal in 54.7% of patients: in 41.8% of those without neurological signs vs. 85.7% of those with these signs. Comparison of MEPs and other electrophysiological procedures and neuroimaging techniques showed the high sensitivity of MEPs at all stages of the disease. EMG was sensitive and complementary to MEPs. EEG and neuroimaging showed abnormalities principally at the neurological symptomatic stage. Our results agree with those found in the literature. Abnormal MEPs may: (1) indicate latent neurological involvement of the visual, auditory and somatosensory pathways, (2) help diagnose an encephalitis suspected on neuropsychological, non-quantifiable testing.
 ...
PMID:Multimodal evoked potentials in HIV infected patients. 228 52

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)
 ...
PMID:Central nervous system disorders in AIDS. 248 19


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>