Cardiovascular dysautonomia in Parkinson's disease and multiple system atrophy.
OBJECTIVE
To determine whether Parkinson's disease (PD) can be distinguished from multiple system atrophy (MSA) on the basis of the assessment of iodine-123 meta-iodobenzylguanidine (123I-MIBG) radioactivity in heart and cardiovascular autonomic function.


METHODS
Seventeen patients with MSA, 39 with PD, and 25 healthy volunteers underwent 123I-MIBG scintigraphy and hemodynamic autonomic function tests using Valsalva maneuver (VM). Baroreceptor reflex sensitivity (BRS) was measured using the slope of the relation between RR interval and blood pressure during the fourth phase.


RESULTS
123I-MIBG radioactivity in heart of patients with PD was lower than that of control subjects and patients with MSA, but there was some overlap between PD and MSA. BRS in patients with PD who had a 123I-MIBG radioactivity similar to that in MSA was larger than that in patients with MSA, with no overlap in any patient.


CONCLUSIONS
Assessment of BRS may be useful for differentiating between MSA and PD that had a 123I-MIBG radioactivity similar to MSA.
Department of Neurology, Aoto Hospital, Tokyo, Japan. h.oka@jikei.ac.jp
H
H
Oka
S
S
Mochio
M
M
Yoshioka
M
M
Morita
K
K
Onouchi
K
K
Inoue
D019797:3-Iodobenzylguanidine; D000368:Aged; D001341:Autonomic Nervous System / Q000000981:diagnostic imaging / Q000503:physiopathology*; D017704:Baroreflex / Q000502:physiology; D002319:Cardiovascular System / Q000000981:diagnostic imaging / Q000294:innervation* / Q000503:physiopathology; D016022:Case-Control Studies; D006801:Humans; D007457:Iodine Radioisotopes; D008875:Middle Aged; D019578:Multiple System Atrophy / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D010300:Parkinson Disease / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D011877:Radionuclide Imaging; D019275:Radiopharmaceuticals; D014636:Valsalva Maneuver
D007457:Iodine Radioisotopes; D019275:Radiopharmaceuticals; D019797:3-Iodobenzylguanidine