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Eur J Nucl Med Mol Imaging (2008) 35:681685 DOI 10.1007/s00259-007-0673-1
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Cardiac sympathetic denervation imaging in movement disorders and dementias
Giovanni Lucignani
Published online: 8 January 2008 # Springer-Verlag 2007
The sympathetic nervous system greatly influences cardiovascular physiology, and the importance of cardiac innervation abnormalities in the physiopathology of various cardiac diseases has been emphasised. Cardiac neurotransmission imaging with single-photon-emission computed tomography (SPECT) allows in vivo assessment of the myocardial nervous system. At present, the most commonly used SPECT tracer to assess cardiac neurotransmission is metaiodobenzylguanidine labelled with iodine-123 (123I-MIBG). Cardiac 123I-MIBG scintigraphy allows autonomic neuropathy to be detected in the early stages of diabetes mellitus. In patients with heart failure, the assessment of cardiac sympathetic activity has important prognostic implications. Targeting neuronal dysfunction with
123I-MIBG scintigraphy in patients with heart transplantation, ischaemic heart disease, hypertension, diabetes mellitus, heart failure, drug-induced cardiotoxicity and dysautonomias can contribute to early diagnosis, prognostic stratification and appropriate treatment [1]. However, this is not all of the uses for 123I-MIBG, as an emerging application of this tracer is being pursued for studies in movement disorders.
MIBG uptake in Parkinsons disease
About 10 years ago, Satoh et al. [2], from the Division of Neurology, Nagasaki Kita Hospital, Japan, reported the results of a study carried out to evaluate cardiac sympathetic function
in patients with Parkinsonsdisease (PD).To thisend,they used 123I-MIBG in patients with PD. Early and delayed images of the anterior view were obtained 15 min and 4 h, respectively, after the injection of 123I-MIBG. 123I-MIBG uptake was quantified by calculating a heart-to-mediastinum (H/M) count ratio. They found that the H/M ratio was markedly reduced in the patients with PD stages 25onthe Hoehn and Yahr (H&Y) scale compared with the control subjects. None of the subjects with neurodegenerative diseases showed a marked decrease in myocardial MIBG uptake. This study marked the beginning of a new research field.
As remarked upon by Goldstein [3], from the Clinical Neurocardiology Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, USA, more than 40 neuroimaging studies have reported evidence for the loss of sympathetic noradrenergic nerves in PD. Cardiac sympathetic denervation is virtually universal in patients with PD and neurogenic orthostatic hypotension. About one half of patients with PD who...