Reliability of MIBG myocardial scintigraphy in the diagnosis of Parkinson's disease

Abstract

Aim: To evaluate the reliability of [123 I]meta-iodobenzylguanidine (MIBG) myocardial scintigraphy for diagnosing Parkinson's disease (PD). Patients/Methods: A series of 391 outpatients showing one or more parkinsonian-like symptoms was longitudinally followed up for accurate clinical diagnosis. MIBG scintigraphy was performed in the patients and 10 normal controls of similar age. The heart to mediastinum uptake ratio was calculated in each person, and the values were considered abnormal if they were greater than two standard deviations below the control mean. Results: MIBG uptake was decreased in most patients with PD (87.7%), and was seen in all advanced cases with HohenYahr stage III or more; the sensitivity and specificity of scintigraphy for detecting PD were 87.7% and 37.4%, respectively. Surprisingly, over half of the patients without PD (66.5%) also exhibited low uptake, resulting in considerable overlap in the ratios between PD and the other disorders. Conclusion: MIBG scintigraphy is a sensitive, but not specific, test for PD. Low MIBG uptake does not necessarily indicate PD, but is essential for diagnosing advanced PD.

Role of 123I-Metaiodobenzylguanidine Myocardial Scintigraphy in Parkinsonian Disorders

“…These findings suggested that degeneration of the cardiac sympathetic nerve begins even in the presymptomatic stage of PD, when neuronal loss in the dorsal vagal nucleus is not yet evident. The present study also revealed relatively preserved cardiac 123 I-MIBG uptake in MSA, consistent with previous studies (Yoshita et al, 1998;Nagayama et al, 2005 (Yoshita et al, 1998;Braune et al, 1999;Orimo et al, 1999;Druschky et al, 2000;Takatsu et al;2000a, 2000b. Postmortem studies demonstrated that postganglionic cardiac sympathetic nerve fibers are markedly decreased in all PD patients, but not necessarily in those with MSA, providing substantial evidence of discrepant 123 I-MIBG uptake between PD and MSA (Orimo et al, 2001(Orimo et al, , 2002.…”

“…Decreased cardiac uptake of 123 I-IMIBG has been reported in LBD (Yoshita et al, 2001;Watanabe et al, 2001;Nagayama et al, 2005;Suzuki et al, 2006;Suzuki et al, 2007), and a role for postganglionic cardiac sympathetic nerves in PD was demonstrated (Orimo et al, 2001). Thus, reduced uptake of 123 I-MIBG is considered to reflect lesions in postganglionic cardiac sympathetic neurons in PD.…”

Imaging of genetic and degenerative disorders primarily causing Parkinsonism

“…Mediastinal 123 I-MIBG signal is reduced in the majority of PD cases, even if no clinical evidence of autonomic failure is present (Fig 6). However, 50% of stage 1 PD cases still show normal cardiac MIBG uptake so this approach is not as sensitive a marker as DAT imaging for discriminating early PD from healthy subjects (Nagayama et al, 2005). 123 I-MIBG SPECT is normal in most cases of MSA as here the autonomic dysfunction results from loss of pre-rather than post-synaptic innervation (Druschky et al, 2000).…”

Neurological applications for myocardial MIBG scintigraphy

“…However, a reduction of cardiac mIBG uptake was found in some patients with MSA [46,47]. Indeed, although the number of tyrosine hydroxylase-immunoreactive (TH-ir) axons of the heart is markedly decreased in PD and basically preserved in MSA [47,48], 6 out of 15 subjects with longer duration of illness and with pathologically confirmed MSA exhibited a slightly decreased number of TH-ir axons [49]. This result suggests that a reduction of cardiac mIBG uptake can occur in MSA.…”