Reverse perfusion pattern in myocardial spect with 99mTc-sestaMIBI.

RATIONALE: The aim of our study was to investigate the myocardial perfusion deficit in rest images as compared to stress images in myocardial scintigraphy (MS). OBJECTIVES: The aim of this study is to investigate the reverse perfusion (RP) pattern in MS. METHODS AND RESULTS: 263 patients were enrolled in the study (72 females and 191 males; mean age 65.7 ± 9.5 years old). Mean body mass index (BMI) was of 27.6 ± 3.8 Kg/m2. 115 patients were positive for a previous history of myocardial infarction (MI). 142 patients reported a revascularization treatment (percutaneous transluminal coronary angioplasty, PTCA, cardiac stent placement, coronary artery bypass grafting, CABG). All the patients underwent MS following standard single day Stress/Rest protocol. In our series, 27 patients presented a RP pattern. We did not find statistically significant differences when considering age (p = 0.7988), sex (p = 0.0657), BMI (p = 0.8611), diabetes (p = 0.8259), dyslipidemia (p = 0.1464) or smoking status (p = 0.6829) in RP patients vs. non-RP patients. A history of MI is related to a RP pattern (p < 0.0001). A history of previous revascularization was not related with RP (p = 0.6868). DISCUSSION: The result of our study suggested that RP is probably related to artifacts of various origins. Further studies are necessary especially in microvascular dysfunction or a long history of disease.

Different patterns of cardiac sympathetic denervation in tremor-type compared to akinetic-rigid-type Parkinson's disease: molecular imaging with ¹²³I-MIBG.

The aim of this study was to evaluate the correlation between the clinical motor phenotypes of Parkinson's disease (PD) and ¹²³I-MIBG myocardial uptake. In total, 53 patients with PD [31 males and 22 females, mean age 62±10 years; 19 Hoehn & Yahr (H&Y) stage 1, 9 stage 1.5, 15 stage 2 and 10 at stage 3] were examined and subdivided into different clinical forms on the basis of dominance of resting tremor (n=19, TDT) and bradykinesia plus rigidity (n=34, ART). This status was correlated with the semi-quantitative analysis of ¹²³I-MIBG myocardial uptake. An age-matched control group of 18 patients was recruited (8 males and 10 females, mean age 62.4±16.3 years). ¹²³I-MIBG myocardial uptake significantly correlated with disease duration in early (r²=0.1894; P=0.0028) and delayed images (r²=0.1795; P=0.0037) in PD patients, while no correlation was found when considering age at examination, UPDRS III motor examination section score and H&Y score. PD patients showed a reduced ¹²³I-MIBG myocardial uptake compared to the control group in early (P=0.0026) and delayed images (P=0.0040), and ¹²³I-MIBG myocardial uptake was significantly lower in delayed images in TDT patients compared with ART patients (P=0.0167). A decrease was detected in the heart-to-mediastinum (H/M) ratio in delayed images compared to that of the early images in TDT patients (P=0.0040) and in the whole PD population (P=0.0012), while no differences were found in ART patients (P=0.1043). The results of the present study revealed that the cardiac sympathetic system is more severely impaired in TDT than in ART patients and ¹²³I-MIBG molecular imaging has the potential help in improving therapeutic planning in these patients.

Cognitive impairment in asymptomatic stages of HIV infection. A longitudinal study.

Seventy-eight asymptomatic HIV-seropositive (aHIV) subjects were examined by means of an extensive neuropsychological test battery in comparison with 32 HIV-seronegative controls. They were also tested with regard to CD4+ and serum p24 antigen. Fifty-six of them completed a clinical follow-up of 12 up to 36 months and 35 also underwent a second session of neuropsychological, CD4+ and p24 antigen assessments at a 12- to 18-month interval from the first session. Results obtained lead to the following conclusions: (a) even among aHIV subjects there is a significant prevalence (28.2%) of cognitive abnormalities for which no cause other than HIV can be found, and therefore this suggests the possible development of HIV-related brain damage since the earliest stages of infection; (b) most sensitive to early HIV-related cognitive impairment are timed psychomotor tasks and memory tasks which require attention, learning and 'active' monitoring or retrieval of information; (c) during the early asymptomatic stages of HIV infection, there is no clear-cut evidence of a cross-sectional relationship between cognition and immunological/ virological markers (at least in the high ranges of CD4+ cell counts considered here); only in relatively more advanced stages does this relationship become evident in the subgroup of aHIV subjects with cognitive abnormalities; (d) the presence of cognitive abnormalities in early HIV infection is predictive of a further decrease in cognitive functioning and faster progression to AIDS-this latter reflected by a faster rate of decline in the number of CD4+ cells and by an increase in positivity of serum p24 antigen.

Neuropsychological tests and [99mTc]-HM PAO SPECT in the diagnosis of Alzheimer's dementia.

Twenty-three patients with Alzheimer's dementia (AD) in relatively early stages and 40 patients with other cognitive disorders of vascular or degenerative aetiology underwent neuropsychological examination and [99mTc]-HM PAO single photon emission computed tomography (SPECT). In contrast to the commonly accepted notion of a posterior temporoparietal reduction of tracer uptake as the typical SPECT pattern of AD, the most consistent feature found in the SPECT images of our AD patients was a hippocampal uptake deficit, associated with a variable degree of temporal, parietal and frontal deficit (extending from the posterior to the anterior regions), according to the severity of the disease. These results support the theory of AD as a "hippocampal dementia", at least in the early stages. Neuropsychological tests were found to be somewhat more specific and more accurate than SPECT in distinguishing AD from non-AD cases.