Cardiac 123I-MIBG scintigraphy can assess the disease severity and phenotype of PD.
OBJECTIVE
Cardiac (123)I-metaiodobenzylguanidine (MIBG) scintigraphy studies of patients with idiopathic Parkinson's disease (PD) found decreased uptake. Whether this decrease is associated with clinical severity as assessed by the Unified Parkinson's Disease Rating Scale (UPDRS) and the phenotypes of PD has not been determined.


METHODS
Cardiac MIBG scintigraphy was performed on 34 patients with PD, 7 with multiple system atrophy (MSA), 4 with dementia with Lewy bodies (DLB), and 11 normal controls (NCs). Early and delayed MIBG heart/mediastinum (H/M) ratios were evaluated. PD severity was assessed by the Hoehn and Yahr (H-Y) stage and UPDRS. Patients were grouped in two phenotypes, tremor and postural instability gait difficulty (PIGD)-dominant groups based on UPDRS components. Associations between MIBG uptake and age at onset, UPDRS, and disease phenotype were analyzed in each group.


RESULTS
The early H/M ratio was significantly lower in patients with PD (1.45+/-0.207) than in the NCs (2.08+/-0.231), and in those with MSA (1.99+/-0.284), but not in those with DLB (1.29+/-0.0435). The delayed H/M ratio for PD (1.33+/-0.276) also was significantly decreased as compared to the ratios for NCs (2.17+/-0.286) and MSA (2.16+/-0.414) but not DLB (1.16+/-0.0949). The early H/M ratio was significantly correlated with both UPDRS score and age at onset, whereas the delayed H/M ratio only was significantly correlated with age at onset. The PIGD-dominant group had significantly higher UPDRS scores and lower H/M ratios than the tremor-dominant group.


CONCLUSIONS
Cardiac MIBG scintigraphy can be used to differentiate PD from MSA and NC, and to determine the disease severity and phenotypes of PD.
Saiki
Shinji
S
Department of Neurology, Kanazawa Medical University, 1-1 Daigaku, Uchinada, Kahoku, Ishikawa 920-0923, Japan. saibon@kanazawa-med.ac.jp
Hirose
Genjiro
G
Sakai
Koichiro
K
Kataoka
Satoshi
S
Hori
Ariyuki
A
Saiki
Misuzu
M
Kaito
Muichi
M
Higashi
Kotaro
K
Taki
Suzuka
S
Kakeshita
Kazuo
K
Fujino
Susumu
S
Miaki
Miho
M
D019797:3-Iodobenzylguanidine / Q000493:pharmacokinetics; D000328:Adult; D017668:Age of Onset; D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D016022:Case-Control Studies; D004791:Enzyme Inhibitors / Q000493:pharmacokinetics; D005260:Female; D020234:Gait Ataxia / Q000175:diagnosis / Q000503:physiopathology; D006321:Heart / Q000187:drug effects*; D006801:Humans; D007457:Iodine Radioisotopes / Q000493:pharmacokinetics; D020961:Lewy Body Disease / Q000175:diagnosis / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D019578:Multiple System Atrophy / Q000175:diagnosis / Q000503:physiopathology; D009460:Neurologic Examination; D010300:Parkinson Disease / Q000175:diagnosis* / Q000503:physiopathology; D010641:Phenotype; D011877:Radionuclide Imaging / Q000379:methods; D012044:Regression Analysis; D012720:Severity of Illness Index; D018709:Statistics, Nonparametric; D014202:Tremor / Q000175:diagnosis / Q000503:physiopathology
D004791:Enzyme Inhibitors; D007457:Iodine Radioisotopes; D019797:3-Iodobenzylguanidine