Impaired cardiac uptake of meta-[123I]iodobenzylguanidine in Parkinson's disease with autonomic failure.
OBJECTIVE
To selectively investigate postganglionic sympathetic cardiac neurons in patients with Parkinson's disease and autonomic failure.


METHODS
Metaiodobenzylguanidine (MIBG) is a pharmacologically inactive analogue of noradrenaline, which is similarly metabolized in noradrenergic neurons. Therefore the uptake of radiolabelled MIBG represents not only the localization of postganglionic sympathetic neurons but also their functional integrity. Ten patients with Parkinson's disease and autonomic failure underwent standardized autonomic testing, assessment of catecholamine plasma levels and scintigraphy with [123I]MIBG.


RESULTS
The cardiac uptake of MIBG, as demonstrated by the heart/mediastinum ratio, was significantly lower in patients in comparison with controls. Scintigraphy with MIBG allowed the selective in-vivo investigation of postganglionic sympathetic cardiac efferents in patients with autonomic failure, a procedure which was previously confined to post-mortem examination.


CONCLUSIONS
These findings point to a relevant postganglionic pattern of involvement of the autonomic nervous system (ANS) in Parkinson's disease and autonomic failure.
Braune
S
S
Neurologische Universitätsklinik Freiburg, Germany.
Reinhardt
M
M
Bathmann
J
J
Krause
T
T
Lehmann
M
M
Lücking
C H
CH
D019797:3-Iodobenzylguanidine / Q000493:pharmacokinetics*; D000368:Aged; D000369:Aged, 80 and over; D001342:Autonomic Nervous System Diseases / Q000150:complications / Q000000981:diagnostic imaging / Q000378:metabolism*; D016022:Case-Control Studies; D005260:Female; D006321:Heart / Q000000981:diagnostic imaging / Q000294:innervation; D006801:Humans; D007457:Iodine Radioisotopes / Q000493:pharmacokinetics; D008297:Male; D009206:Myocardium / Q000378:metabolism*; D009638:Norepinephrine / Q000097:blood; D010300:Parkinson Disease / Q000150:complications / Q000000981:diagnostic imaging / Q000378:metabolism*; D013564:Sympathetic Nervous System / Q000000981:diagnostic imaging / Q000503:physiopathology*; D013565:Sympatholytics / Q000493:pharmacokinetics*; D015899:Tomography, Emission-Computed, Single-Photon
D007457:Iodine Radioisotopes; D013565:Sympatholytics; D019797:3-Iodobenzylguanidine; D009638:Norepinephrine