Cardiac innervation and clinical correlates in idiopathic Parkinson's disease.

We evaluated the cardiac innervation status of patients with idiopathic Parkinson's disease (IPD), in order to recognize cardiac dysautonomia at an early clinical stage, using I- -iodobenzylguanidine ( I-MIBG) scintigraphy and its relation to other clinical and laboratory parameters. Fourteen patients with IPD at Hoehn-Yahr stage I and 11 age-matched controls were studied. Patients were scored according to the Unified Parkinson's Disease Rating Scale (UPDRS) in aspects of daily life activities, cognitive and emotional status and motor examination. All patients underwent 5 min electrocardiographic recordings in order to assess the heart rate variability. Planar I-MIBG studies at 15 min and 3 h after intravenous injection of 185 MBq were performed. Heart-to-mediastinum (H/M) ratios were calculated. Plasma catecholamine levels were also evaluated. The mean H/M ratios in patients and controls were 1.84+/-0.40 and 2.35+/-0.29, respectively (P <0.05). Although the mean plasma adrenaline and noradrenaline levels were in the normal range, a weak inverse correlation existed between the noradrenaline levels and late I-MIBG H/M ratios (r =-0.442), which was not statistically significant. There were no correlations between the other parameters. Eight patients had normal electrocardiography, whereas four had findings of autonomic imbalance. In conclusion, cardiac dysautonomia is common and seems to occur independent of the clinical stage and symptoms in patients with IPD. I-MIBG scintigraphy is a powerful tool in its assessment.

Pulmonary involvement in Behçet's disease: evaluation of 123 I-MIBG retention.

Pulmonary involvement in Behçet's disease (BD) is reported to indicate poor prognosis and high mortality. Our aim was to evaluate the pulmonary vascular status in BD. As 123I-meta-iodobenzylguanidine (123I-MIBG) shares the same uptake, storage and release mechanisms as norepinephrine, associated with the functional state of pulmonary endothelium, it may reflect endothelial injury. Twenty-five patients (13 males, 12 females; mean age, 36.44 years) and 12 age-matched controls were included. After intravenous injection of 123I-MIBG, thorax images were taken at 15 min and 4 h. Appropriate regions of interest were drawn, and heart to mediastinum (H/M) ratios and lung retention indices (LRI) were calculated. The difference between the LRI of controls (75.6+/-4%) and patients (87.7+/-10%) was found to be extremely significant (P<0.005). The LRIs of active (92.85+/-12%) and inactive (83.65+/-5%) states of BD were significantly different (P<0.05) from each other. There was no significant difference between the H/M ratios of controls (2.4+/-0.27) and patients (2.39+/-0.31) or between patients in active and inactive disease states. Our study revealed prolonged lung retention of 123I-MIBG in BD, probably reflecting the severity of the disease. In conclusion, 123I-MIBG lung retention is a valuable finding in the evaluation of pulmonary vascular status and may be a potential marker of prognosis in BD.