Retinal microvasculopathy and reduced cerebral blood flow in patients with acquired immunodeficiency syndrome.
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Acquired Immunodeficiency Syndrome↗
Biomedical subjects
K Tatsch
Publications and source records attributed to K Tatsch.
Decrease of D2 receptors indicated by 123I-iodobenzamide single-photon emission computed tomography relates to neurological deficit in treated Wilson's disease.
Single-photon emission computed tomography with 123I-iodobenzamide, a dopamine D2 receptor antagonist, was employed to study dopamine D2 receptor densities in 17 patients with biochemically proved Wilson's disease and stable neurological status with therapy and in 5 age-matched control subjects. Of the 17 patients with Wilson's disease, 5 were neurologically asymptomatic, 3 had cerebellar signs, 1 exhibited a mild parkinsonian syndrome, 7 showed a parkinsonian syndrome and cerebellar signs, and 1 had generalized dystonia and a parkinsonian syndrome. In 5 age-matched control subjects specific isotope binding as calculated by the basal ganglia to frontal cortex ratio was 1.57 +/- 0.04 (mean +/- standard deviation). The ratio in patients with Wilson's disease ranged from 1.56 +/- 0.05 (n = 5, asymptomatic patients) to 1.17 +/- 0.02 (n = 4, marked neurological impairment). We observed an almost linear correlation between the reduction of 123I-iodobenzamide (IBZM) binding and the severity of neurological signs at the time of IBZM-SPECT (correlation coefficient, -0.84; p < 0.01). We suggest that the reduction of postsynaptic striatal dopamine D2 receptors as detected by IBZM-SPECT reflects striatal neuronal damage in Wilson's disease.
Adolescent↗
Marked reduction of striatal dopamine D2 receptors as detected by 123IBZM-SPECT in a Wilson's disease patient with generalized dystonia.
[123I]iodobenzamide-single photon emission computed tomography (IBZM-SPECT) was employed to study the distribution of dopamine D2 receptors in a patient with biochemically proven Wilson's disease presenting with generalized dystonia. IBZM is a dopamine D2 receptor antagonist with high affinity and specific binding to basal ganglia detectable by SPECT. IBZM-SPECT in this patient (age, 20 years) displayed a striatum to frontal cortex ratio of 1.2 compared to 1.55 +/- 0.05 (mean +/- SD) in normal controls (n = 7; mean age, 53.3 years). In parallel with this finding, MRI with heavily T2-weighted sequences showed atrophy and low signal intensity changes of the basal ganglia. There was no improvement of dystonia after a subcutaneous injection of apomorphine. In contrast, IBZM-SPECT of a neurologically asymptomatic Wilson's disease patient (age, 21 years) displayed a striatum to frontal cortex ratio of 1.6. The MRI scan of this patient was normal. It is suggested that the observed apomorphine-unresponsive generalized dystonia in this Wilson's disease patient is related to striatal lesions proven by IBZM-SPECT and MRI.
Adult↗
Abnormalities of cerebral blood flow in the acute phase of bacterial meningitis in adults.
The frequency, course and clinical significance of changes in regional cerebral blood flow (rCBF) during bacterial meningitis were investigated in 14 adult patients. The results of 99mTc-hexamethylpropylene amine oxime (HMPAO) single photon emission computed tomography (SPECT) were compared with the clinical signs and findings using cerebral angiography and conventional CT. HMPAO SPECT was performed 2-15 days (median 4.5 days) after the onset of neurological disease. Decreased HMPAO accumulation was detected in 13 patients. SPECT studies revealed focal hypoperfusion corresponding to the clinical symptoms in 6 patients suffering from hemiparesis or hemiataxia. Conventional cranial CT disclosed brain infarction in only 1 patient. Focal hypoperfusion was also found in 7 of 8 patients without clinical evidence of focal neurological deficits. In 6 patients, HMPAO SPECT findings were abnormal although cerebral angiography was normal. At follow-up examinations 3-45 weeks after the acute disease, abnormalities revealed by HMPAO SPECT had improved or had even disappeared in all patients studied. Our results indicate that reduced rCBF is a frequent finding in bacterial meningitis in the adult. In most patients it probably represents a functional and reversible disorder without structural lesion detectable on CT.
Acute Disease↗
123I-iodobenzamide-SPECT predicts dopaminergic responsiveness in patients with de novo parkinsonism.
We used 123I-iodobenzamide-single photon emission computed tomography (IBZM-SPECT) in a prospective study to investigate 38 patients with parkinsonism (Hoehn and Yahr stage I to III) not previously treated with dopamimetic drugs. Thirty-four patients only showed symptoms of Parkinson's disease, and four patients showed, in addition, subtle clinical signs of progressive supranuclear palsy or multisystem atrophy. IBZM is a dopamine D2 receptor antagonist detectable by SPECT. We compared IBZM-SPECT results with clinical response to subcutaneous injections of the D1/D2 dopamine receptor agonist apomorphine (38 patients) and long-term dopamimetic therapy (31 patients). IBZM-SPECT results predicted a positive or negative response to apomorphine in 30 of 34 patients (apomorphine response in four patients was equivocal) and response to dopamimetic therapy in 27 of 31 patients. Thus, imaging of dopamine D2 receptors using readily available IBZM-SPECT seems to distinguish between L-dopa-responsive (most likely Parkinson's disease of Lewy body type) and L-dopa-unresponsive parkinsonism in patients not previously treated with dopamimetic drugs.
Adult↗
Simultaneous assessment of bolus transport and contraction parameters in multiple-swallow investigations.
A better understanding of scintigraphic findings may lead to a wider acceptance of esophageal transit studies. The purpose of this study, therefore, was to correlate standard manometric parameters with the quantitative and qualitative characteristics of liquid and semi-solid bolus transport. Twenty-nine patients were simultaneously investigated with esophageal scintigraphy and manometry. Single-swallow and sum-image data of six consecutive swallows were analyzed. No significant relationship between transit time and the velocity of the peristaltic wave could be identified, which suggests that factors other than peristaltic velocity (e.g., pharyngeal pump) essentially modulate esophageal transit. There was also no linear correlation between esophageal emptying and peristaltic amplitudes. Emptying was normal in patients with amplitudes greater than 30 mmHg and reduced in those with amplitudes less than 30 mmHg. This suggests that a threshold pressure greater than 30 mmHg is necessary to propel a test bolus adequately. Patterns in condensed images have been shown to specifically reflect the events in corresponding manometric recordings. Normal and different pathologic types of peristalsis presented analogous findings in both modalities. Thus, an analysis of the relationship between bolus transport and contraction parameters in simultaneous studies increases understanding of quantitative and qualitative scintigraphic results.
Adult↗
SPECT imaging of dopamine D2 receptors with 123I-IBZM: initial experience in controls and patients with Parkinson's syndrome and Wilson's disease.
123I-(S-)-2-hydroxy-3-iodo-6-methoxy-N[(1-ethyl-2-pyrrolidinyl) methyl]-benzamide (123I-IBZM) is a highly selective CNS D2 dopamine receptor ligand suitable for SPECT. This study reports on IBZM-SPECT findings in 60 patients including eight controls and 52 patients presenting with disorders of the dopaminergic system, including idiopathic Parkinson's syndrome (IPS) (n = 18), Parkinson's syndromes of other aetiology (PS) (n = 24) and Wilson's disease (n = 10). SPECT was performed 2 h p.i. of 185 MBq 123I-IBZM. For semiquantitative evaluation basal ganglia to frontal cortex ratios (BG/FC ratios) were calculated. In controls BG/FC ratios of 1.55 +/- 0.05 S.D. were observed. Findings in IPS patients (BG/FC ratio: 1.51 +/- 0.05) were not different from controls. In PS patients striatal IBZM binding (BG/FC ratio: 1.35 +/- 0.11) was significantly (P less than 0.001) lower compared to the control and IPS groups. Asymptomatic patients with Wilson's disease presented normal IBZM binding. In those with neurologic symptoms IBZM fixation was markedly reduced. IBZM-SPECT has shown to be a suitable means for in vivo imaging of striatal dopamine D2 receptors in controls and various disorders of the dopaminergic system. Our preliminary data suggest that IBZM-SPECT is potentially useful for discriminating between IPS and PS (sensitivity: 100%; specificity: 83%). In patients with Wilson's disease IBZM accumulation seems to correlate with the presence of neurologic symptoms.
Adolescent↗
Multiple swallow test for the quantitative and qualitative evaluation of esophageal motility disorders.
Esophageal motility was evaluated from the analysis of six consecutive swallows. A sum image was generated comprising the representative information of an entire study. Calculation of emptying rates and characterization of the bolus behavior was performed from the sum image and the single swallow data. In 86 patients investigated, liquid and solid-phase studies showed a remarkable variation of single swallow data in normals (relative variation coefficient for liquid: 10%, solid: 14%), which were even higher (p less than 0.001) in patients with disorders (liquid: 31%, solid: 25%). As sum images compensate for this intra-individual variation, false-positive (liquid: 16%, solid: 25%) or negative single swallow findings (liquid: 36%, solid: 27%) are reduced. Qualitative analysis of condensed sum images provided characteristic image patterns representing different pathophysiologic aspects. Since the method introduced better discriminates between normal and pathologic function, it may enhance diagnostic accuracy.
Deglutition↗
Condensed images for evaluating gastric motility patterns.
A condensed imaging technique was applied to gastric emptying studies to investigate (a) whether different types of motility disorders may be distinguished by characteristic image patterns and (b) whether the findings obtained provide additional information compared to standard quantitative measurements. Condensed images and quantitative data of gastric emptying were evaluated in 75 consecutive patients with normal function (n = 16) and various disorders (n = 59) such as peptic ulcer, postvagotomy, pyloric obstruction, dumping syndrome, gastroparesis etc. Condensed images were generated from a gastric region of interest. They display the distribution and behaviour of a radioactive test meal in a space-time matrix, whose horizontal and vertical dimensions are temporal and spatial, respectively. As shown in a series of representative examples condensed images disclose a variety of well-defined image patterns reflecting different pathophysiological mechanisms. This qualitative characterization of gastric emptying patterns provided in 34 of the 75 patients (45%) important new information compared to quantitative data. The application of condensed imaging techniques to gastric emptying studies (complementary to quantitative measurements) may, therefore, enhance the diagnostic value of scintigraphic techniques.
Gastric Emptying↗
Reduced cerebral blood flow in early stages of human immunodeficiency virus infection.
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.
Acquired Immunodeficiency Syndrome↗
Value of 67gallium scintigraphy in primary diagnosis and follow-up of opportunistic pneumonia in patients with AIDS.
Opportunistic pneumonias are a life-threatening complication in patients with AIDS. Early diagnosis and therapy is necessary to improve the prognosis. This study was designed to assess the value of 67gallium scintigraphy in the primary detection and follow-up of these special pneumonias. 67Gallium scintigraphy was performed in 40 patients: 10 normal controls and 30 HIV-positive patients with AIDS or AIDS-related complex (ARC). 67Gallium scan results were compared with current chest x-rays and the results of pathogen detection. The evaluation of positive scans was based on a quantification of the pulmonary uptake, expressed as a pulmonary/soft tissue uptake ratio. Only 8 of 30 patients had a normal scan, while 22 of 30 showed diffuse (13/22) or focal (9/22) increases of pulmonary uptake. In seven of eight patients with normal scans the chest radiograph was negative as well. The one patient with negative scan but positive chest radiograph had pulmonary Kaposi's sarcoma. In 11 of 22 patients, the 67gallium scan and chest x-ray were positive simultaneously. In the other 11 of 22 patients with positive scans, chest radiographs were initially negative but showed pathology in five cases within 1-2 weeks. The reason for positive scans in most cases was an opportunistic lung infection; other forms of pneumonia were observed only in two cases. The defined uptake ratio was demonstrated to be a highly sensitive parameter for monitoring pneumonia and the effects of therapy in follow-up studies. In conclusion, quantitative 67gallium scintigraphy proved to be a reliable and highly sensitive method for primary detection and follow-up of opportunistic pneumonias in patients with AIDS.
AIDS-Related Complex↗
67Ga-scintigraphy for evaluation of AIDS-related intestinal infections.
This study was designed to evaluate the role of 67Ga-scintigraphy in AIDS-related intestinal infections. Seventeen out of twenty-five HIV-positive patients (68%) primarily investigated with 67Ga-scans to screen for opportunistic pneumonia presented pathologic abdominal 67Ga-uptake which was, in most cases, due to proven opportunistic intestinal infection (cytomegalovirus, atypical mycobacteria, cryptosporidiosis etc.). The correlation of abdominal with pulmonary findings has shown that AIDS-related intestinal infections and opportunistic pneumonia may occur concomitantly in the majority cases (11/17). In 6/17 patients positive abdominal findings were observed without opportunistic pneumonia at the same time. Gallium imaging of the abdomen has shown to identify successfully the most common extrapulmonary sites of HIV-related infections. Thus, abdominal imaging or whole body scintigraphy should be a mandatory part of each 67Ga-scan in patients with HIV infection, even if it was primarily performed to screen for opportunistic pneumonia only. Knowledge of multilocular opportunistic infections, usually caused by different pathogens, is clinically important for further diagnostic and therapeutic management.
AIDS-Related Complex↗
Functional and morphological findings in early and advanced stages of HIV infection: a comparison of 99mTc-HMPAO SPECT with CT and MRI studies.
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.
AIDS Dementia Complex↗
[Parametric esophageal scintigrams of transit studies using the multiple swallow technique: a comparison of a new method with a standard esophageal transit test].
Established single-swallow techniques for the assessment of oesophageal motility disorders encompass a high potential of falsely positive/negative findings caused by the considerable variability between single swallows. In this study, therefore, a new form of parametric oesophageal scintigraphy (POeS) is introduced which allows simultaneous assessment of 15-20 consecutive swallows. To assess the value of this combined qualitative/semiquantitative method 166 patients with various oesophageal motility disorders were tested in an intraindividual comparison with a standard oesophageal transit test (OeTT). In contrast to OeTT, POeS yields specific image patterns which permit a differentiation between various forms of peristaltic disorder. By the use of POeS the bolus behaviour during its oesophageal passage is well characterized, the main location of the functional disorder can be identified and a correct classification of the severity can be achieved as well. In contrast to OeTT, diagnosis in POeS is based on a series of consecutive swallows. Misinterpretation due to possible variations between single swallows is often observed in OeTT, providing up to 30% false-positive and 52% false-negative findings which are almost eliminated using POeS.
Deglutition↗
[The place of 67Ga scintigraphy in the primary diagnosis and follow-up evaluation of opportunistic pneumonia in patients with AIDS].
Opportunistic pneumonias are a life-threatening complication in patients with AIDS. Early diagnosis and therapy is necessary to improve prognosis. This study was designed to assess the value of 67Ga scintigraphy in the primary detection and follow-up of these special pneumonias. 67Ga scintigraphy was performed in 40 patients: 10 normal controls and 30 HIV-positive patients with AIDS or AIDS-related complex (ARC). 67Ga scan results were compared with current chest radiographs and the results of pathogen detection. The evaluation of positive scans was based on a quantification of the pulmonary uptake, expressed as a pulmonary/soft-tissue uptake ratio. Only 8/30 patients had a normal scan, 22/30 showed diffuse (13/22) or focal (9/22) increases of pulmonary uptake. In 7/8 patients with normal scans the chest radiograph was negative as well. The one patient with negative scan but positive chest radiograph had pulmonary Kaposi's sarcoma. In 11/22 patients the 67Ga scan and chest radiograph were positive simultaneously. In the other 11/22 patients with positive scans chest radiographs were initially negative but showed pathology in 5 cases within 1-2 weeks. The reason for positive scans in most cases was an opportunistic lung infection; other forms of pneumonia were only observed in two cases. The defined uptake ratio demonstrated to be a highly sensitive parameter for monitoring pneumonia and the effects of therapy in follow-up studies. In conclusion, quantitative 67Ga scintigraphy proved to be a reliable and highly sensitive method for primary detection and follow-up of opportunistic pneumonias in patients with AIDS.
Acquired Immunodeficiency Syndrome↗