engleski

Importance of myocardial MIBG scintigraphy in differentiating idiopatic Parkinson's disease from other neurodegenerative diseases

Aim: The aim of this study was to explore and evalute the usefulness of I-131 MIBG myocardial scintigraphy in patients with idiopathic Parkinson’s disease and other neurological conditions with similar symptoms. Because of common overlapping in signs and symptoms of these neurodegenerative syndromes, especially in the early stages, the differential diagnosis can be troublesome. Materials and Methods: Sixty-one patients (age from 35 to 86, mean 59) with rigidity, tremor, hypokinesia and other related symptoms, with diverse neurological working diagnoses, underwent MIBG scintigraphy. Planar chest MIBG imaging was performed 15 min, 2, 3, 4 and 24 hours after tracer injection. Myocardial MIBG activity was quantified by calculating heart to mediastinum ratio (H/M ratio). H/M value over 1.8 was considered normal, between 1.31 -1.79 decreased, and less than 1.3 severely decreased. None of the patients in this study had heart disease or any other medical condition which can influence MIBG uptake. Results: In total, H/M ratio from early and delayed MIBG scintigraphy was pathologically decreased in 42 (69%) patients. In 77% of cases of IPD suspected patients we have confirmed the main working diagnosis, thus establishing a high degree of diagnostic certainty. H/Mratios in IPD patients was not significantly correlated with disease duration and theHYscale. In 8 patients with MSAwe changed initial diagnosis to IPD (73%). Three patients confirmed as MSA had normal HM ratios. In 16 patients with extrapyramidal symptoms we had 10 normal findings, and because of pathological HM ratio we changed final diagnosis to IPD in 6 patients. Of 4 other patients, 3 had pathological HM ratios, thus changing their final diagnosis to IPD. Conclusions: According to our findings, cardiac autonomic nervous system dysfunction is common in IPD, but not in other neurological conditions, especially not in MSA. We report that myocardial MIBG scintigraphy can be a powerful, yet very simple and affordable method in differential diagnosis of IPD, thus greatly assisting in diagnosing impaired peripheral adrenergic activity. Also, myocardial MIBG imaging can be of great help in establishing final diagnosis in patients with extrapyramidal symptoms, especially when nigrostriatal dopamine transporter imaging is not available. Longitudinal follow-up studies are needed in order to evaluate the effects of myocardial MIBG imaging as an indispensable method of prognostic value in routine clinical practice and management of patients with various neurological conditions.

MIBG ; IPD ; Neurodegenerative diseases ; Imaging

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