technetium-tc-99m-exametazime and Acquired-Immunodeficiency-Syndrome

Periodic lateralised epileptiform discharges (PLEDs) can be seen associated to nonconvulsive status epilepticus (NCSE), although their pathophysiological meaning remains questionable. Functional neuroimaging has suggested that, in this setting, PLEDs may indeed be an ictal pattern. In this report we describe perfusional changes in a patient with AIDS, PLEDs and NCSE.. A 37-year-old man with AIDS, cryptococcosis and recurrent epileptic seizures was admitted. After initial treatment, he remained comatose, and had MRI and serial EEG recordings performed. Technetium-99m-ethyl cysteinate dimer (99mTc-ECD) SPECT scans were also obtained, before and after continuous benzodiazepine infusion.. EEG disclosed PLEDs over the right fronto-polar region while MRI revealed meningeal thickening and scattered unspecific findings. SPECT revealed marked focal hyperperfusion overlapping the areas with PLEDs, both resolved after continuous midazolam infusion and clinical improvement.. This report demonstrates association of PLEDs, NCSE, and focal hyperperfusion on SPECT, additionally supporting the concept of PLEDs as an ictal pattern. Considering that status epilepticus may eventually not be detected by conventional approaches alone, we advocate the use of functional neuroimaging to assess suspected patients with impaired consciousness.

Topics: Acquired Immunodeficiency Syndrome; Adult; Electroencephalography; Functional Laterality; Humans; Hyperemia; Male; Periodicity; Radiopharmaceuticals; Status Epilepticus; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

The pathogenesis of neurologic and neuropsychologic dysfunction in HIV-1 infection is unclear. The purpose of the study was to determine an association between cerebral perfusion and HIV-1-related ocular microangiopathic syndrome.. We studied 28 HIV-1-infected patients, seven of whom presented with asymptomatic HIV infection, nine with lymphadenopathy syndrome or AIDS-related complex, and 12 with AIDS. Cerebral perfusion was semi-quantitatively measured by single photon emission computed tomography of the brain using technetium-99 hexamethyl-propylenamine oxime (HMPAO-SPECT). The conjunctival manifestation of HIV-1-related microangiopathic syndrome was measured by a rating scale determining blood-flow sludging and, retinal cotton-wool spots were counted. CD4 count, neopterin, beta 2-microglobulin (beta 2M), haemoglobin, and age were determined as putative confounding variables.. Mean conjunctival sludge in patients with normal HMPAO-SPECT findings was 1.3 +/- 0.5 (mean +/- s.e.m.); no cotton-wool spots were present. In patients with slightly impaired HMPAO-SPECT, it was 2.1 +/- 0.6 and mean cotton-wool spot count was 1.1 +/- 0.4. In patients with severely impaired HMPAO-SPECT, mean conjunctival sludge was 4.5 +/- 0.3 and mean cotton-wool spot count was 4.9 +/- 1.1 HMPAO-SPECT findings were closely associated with conjunctival sludge (r = 0.72; P < 0.001) and number of cotton-wool spots (r = 0.78; P < 0.001), whereas only a slight association with staging of HIV disease was found (P = 0.052). Analysis of covariance controlling for CD4 count neopterin, beta 2M, age, and haemoglobin demonstrated a significant difference between the three HMPAO-SPECT groups for both the number of cotton-wool spots (P < 0.001) and the conjunctival sludge rating (P < 0.001).. There was a close association between severity of HIV-1-related ocular microangiopathic syndrome and severity of cerebral hypoperfusion. Microvascular alterations might contribute to the pathogenesis of neurological and neuropsychological symptoms in patients with HIV-1 disease. Furthermore, the conjunctival sludge rating and the number of cotton-wool spots might be appropriate indicators for severity of microvascular changes of the central nervous system [corrected].

Topics: Acquired Immunodeficiency Syndrome; Adult; Aged; AIDS-Related Complex; beta 2-Microglobulin; Biopterins; Brain; CD4-Positive T-Lymphocytes; Conjunctiva; Conjunctival Diseases; Hemoglobins; HIV Infections; HIV-1; Humans; Leukocyte Count; Male; Microcirculation; Middle Aged; Neopterin; Organotechnetium Compounds; Oximes; Syndrome; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

Cerebral blood flow (CBF) was evaluated by gamma camera 99mTc-HMPAO SPECT in 11 patients with AIDS-related neurotoxoplasmosis and correlated with neurological findings and the results of CT and MRI. Evident CBF abnormalities were observed in all patients with involvement of at least two cerebral lobes. In 10 patients the abnormalities were bilateral and in 8 patients basal ganglia were involved; no specific hypoperfusion pattern was however evident. Focal lesions were found in 7 patients by CT (sensitivity: 63.6%) and in 10 patients by MRI (sensitivity: 90.9%). It may be concluded that neurotoxoplasmosis in AIDS patients is associated with a high prevalence of focal cortical and subcortical hypoperfusion but that the scintigraphic findings are not specific; that HMPAO SPECT may show focal hypoperfusion in patients with normal CT studies and/or non-focal MRI abnormalities; that the hypoperfusion may be more extensive than the corresponding MRI lesion(s) and that it may be present even in areas with normal MRI signals; and that more experience and longitudinal studies are needed to assess the possible impact of HMPAO SPECT on follow-up and therapy monitoring.

Topics: Acquired Immunodeficiency Syndrome; Adult; Brain Diseases; Cerebrovascular Circulation; Female; Humans; Male; Organotechnetium Compounds; Oximes; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon; Toxoplasmosis

Four patients with the acquired immunodeficiency syndrome (AIDS) and fever were investigated using donor leucocyte scans. The lung/liver and lung/spleen uptake ratios in these patients were compared with the uptake ratios in donor leucocyte scans in seven neutropenic (non-AIDS) patients and five patients who had autologous leucocyte scans performed over the same time period. For all scans indium-111-oxime-labelled leucocytes were used, except for one AIDS patient in whom technetium-99m hexamethyl-propylene amine oxide (HMPAD)-labelled donor leucocytes were used. There were no adverse reactions to the donor cell infusions. Two patients had repeat studies 8 weeks apart (from different donors) without ill effect. There were no differences in the 111In uptake ratios between the three groups. There were three positive studies in the patients with AIDS, and these elucidated the cause of the pyrexia in all three. The negative case is more difficult to confirm, but the clinical course and the absence of focal disease on post-mortem have been taken to support the scan findings. There was no difference in the acceptability of the technique or the distribution of the labelled leucocytes between the AIDS and non-AIDS patients. Donor leucocyte imaging of patients with AIDS is probably more effective and considerably less hazardous for technical staff than autologous leucocyte methods. This study demonstrates that the technique can be applied successfully to patients with AIDS.

Topics: Acquired Immunodeficiency Syndrome; Adult; Aged; Bacterial Infections; Blood Donors; Fever of Unknown Origin; Humans; Indium Radioisotopes; Isotope Labeling; Leukocytes; Middle Aged; Opportunistic Infections; Organometallic Compounds; Organotechnetium Compounds; Oximes; Oxyquinoline; Radionuclide Imaging; Technetium Tc 99m Exametazime

In order to determine if brain perfusion abnormalities, which are known in patients with acquiredimmunodeficiency syndrome dementia, occur in early stages of human immunodeficiency virus infection, technetium 99m hexamethyl-propyleneamine oxime-single-photon emission computed tomography studies were performed in 20 patients infected with human immunodeficiency virus who belonged to Walter Reed stages I through IV. None of these patients demonstrated signs of dementia or severe neurological dysfunction. Pathological patterns of hexamethyl-propyleneamine oxime uptake were seen in 14 patients, seven of whom had normal results during neurological examination. Only four patients had signs of cerebral atrophy on cranial computed tomographic scan. These data suggest that subtle changes in cerebral perfusion seem to arise early in the course of human immunodeficiency virus infection and may indicate human immunodeficiency virus encephalopathy before neurological symptoms or noticeable structural damage occurs.

Topics: Acquired Immunodeficiency Syndrome; Adult; Aged; Cerebrovascular Circulation; Female; Humans; Male; Middle Aged; Organotechnetium Compounds; Oximes; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

The purpose of the presented study was to determine the diagnostic value of correlated EEG and SPECT findings in patients with CNS-manifestations of AIDS. Ten HIV 1 infected patients had been examined. Diagnoses: meningitis (2 x), lymphoma (2 x), necrotizing encephalitis (1 x), toxoplasmosis (7 x) (Some patients had more than one diagnosis). Unenhanced and Gd-DTPA enhanced MR, 99mTc-HM-PAO SPECT and clinical EEG were compared. In 9/10 patients MR demonstrated intracranial lesions. In one patient with necrotizing encephalitis (not detected by MR), SPECT revealed an inhomogeneous cerebral perfusion. Only lymphoma was hyperperfused. Toxoplasmic lesions-when detectable by SPECT-were hypoperfused. Reduced rCBF was also seen in brain regions not affected directly, but functionally associated to altered areas. EEG revealed diffuse signs such as slowing in patients with brain atrophy, but also in those patients with lesions of basal ganglia and thalamus. Focal signs in the EEG were in concordance with imaging findings in only 2/10 patients. In 4/10 patients foci even adjacent to the cortex - as shown by MR - remained undetected by EEG. One patient with an active toxoplasmosis had sharp waves over the affected region. The parallel application of the three methods as suggested in this paper appears useful not only for scientific purposes. In most cases, this procedure provides relevant diagnostic information. It is recommended for AIDS-patients with CNS manifestations of unknown etiology.

Topics: Acquired Immunodeficiency Syndrome; Adult; Brain; Brain Diseases; Brain Neoplasms; Electroencephalography; Encephalitis; HIV-1; Humans; Lymphoma; Magnetic Resonance Imaging; Male; Meningitis; Middle Aged; Organotechnetium Compounds; Oximes; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon; Tomography, X-Ray Computed; Toxoplasmosis

Topics: Acquired Immunodeficiency Syndrome; Gallium Radioisotopes; Humans; Organotechnetium Compounds; Oximes; Radionuclide Imaging; Technetium Tc 99m Exametazime

Single photon emission computed tomography (SPECT) studies were performed in AIDS dementia complex using IMP in 12 patients (and HM-PAO in four of these same patients). In all patients, SPECT revealed either multiple or focal uptake defects, the latter corresponding with focal signs or symptoms in all but one case. Computerized tomography showed a diffuse cerebral atrophy in eight of 12 patients, magnetic resonance imaging exhibited changes like atrophy and/or leukoencephalopathy in two of five cases. Our data indicate that both disturbance of cerebral amine metabolism and alteration of local perfusion share in the pathogenesis of AIDS dementia complex. SPECT is an important aid in the diagnosis of AIDS dementia complex and contributes to the understanding of the pathophysiological mechanisms of this disorder.

Topics: Acquired Immunodeficiency Syndrome; Adult; Amphetamine; Brain; Dementia; Diagnosis, Differential; Electroencephalography; Female; Humans; Iodine Radioisotopes; Magnetic Resonance Imaging; Male; Middle Aged; Neurologic Examination; Organometallic Compounds; Oximes; Technetium; Technetium Tc 99m Exametazime; Tomography, Emission-Computed

We present preliminary data on the utility of functional brain imaging with [99mTc]-d,l-HM-PAO and single photon emission computed tomography (SPECT) in the study of patients with dementia of the Alzheimer type (DAT), HIV-related dementia syndrome, and the "on-off" syndrome of Parkinson's disease. In comparison with a group of age-matched controls, the DAT patients revealed distinctive bilateral temporal and posterior parietal deficits, which correlate with detailed psychometric evaluation. Patients with amnesia as the main symptom (group A) showed bilateral mesial temporal lobe perfusion deficits (p less than 0.02). More severely affected patients (group B) with significant apraxia, aphasia, or agnosia exhibited patterns compatible with bilateral reduced perfusion in the posterior parietal cortex, as well as reduced perfusion to both temporal lobes, different from the patients of the control group (p less than 0.05). SPECT studies of HIV patients with no evidence of intracraneal space occupying pathology showed marked perfusion deficits. Patients with Parkinson's disease and the "on-off" syndrome studied during an "on" phase (under levodopa therapy) and on another occasion after withdrawal of levodopa ("off") demonstrated a significant change in the uptake of [99mTc]-d,l-HM-PAO in the caudate nucleus (lower on "off") and thalamus (higher on "off"). These findings justify the present interest in the functional evaluation of the brain of patients with dementia. [99mTc]-d,l-HM-PAO and regional cerebral blood flow (rCBF)/SPECT appear useful and highlight individual disorders of flow in a variety of neuropsychiatric conditions.

Topics: Acquired Immunodeficiency Syndrome; Adult; Aged; Alzheimer Disease; Brain; Cerebrovascular Circulation; Dementia; Female; Humans; Male; Middle Aged; Organometallic Compounds; Oximes; Parkinson Disease; Technetium; Technetium Tc 99m Exametazime; Tomography, Emission-Computed