REM sleep behavior disorder is related to striatal monoaminergic deficit in MSA.
OBJECTIVE
To explore the neurochemical basis of REM sleep behavior disorder (RBD) in multiple-system atrophy (MSA).


METHODS
In 13 patients with probable MSA, nocturnal, laboratory-based polysomnography was used to rate the severity of REM atonia loss by the percentage of REM sleep with tonically increased electromyographic (EMG) activity and the percentage of REM sleep with phasic EMG bursts. PET with (+)-[11C]dihydrotetrabenazine ([11C]DTBZ) was employed to measure the density of striatal monoaminergic terminals and SPECT with (-)-5-[123I]iodobenzovesamicol ([123I]IBVM) to measure the density of 123I]IBVM.


RESULTS
Age and gender distributions were similar in patient and normal control groups. The MSA subjects showed decreased mean [11C]DTBZ binding in the striatum (p < 0.0001) and decreased [123I]IBVM binding in the thalamus (p < 0.001). Moreover, in the MSA group, striatal [11C]DTBZ binding was inversely correlated with the severity of REM atonia loss (p = 0.003). Thalamic [123I]IBVM binding, however, was not correlated to the severity of REM atonia loss.


CONCLUSIONS
Decreased nigrostriatal dopaminergic projections may contribute to RBD in MSA.
Gilman
S
S
Department of Neurology, University of Michigan, Ann Arbor, USA. sgilman@umich.edu
Koeppe
R A
RA
Chervin
R D
RD
Consens
F B
FB
Little
R
R
An
H
H
Junck
L
L
Heumann
M
M
D000328:Adult; D017677:Age Distribution; D000368:Aged; D001667:Binding, Competitive; D015306:Biogenic Monoamines / Q000378:metabolism*; D002250:Carbon Radioisotopes; D003342:Corpus Striatum / Q000000981:diagnostic imaging / Q000378:metabolism*; D004576:Electromyography; D005260:Female; D006801:Humans; D007457:Iodine Radioisotopes; D008297:Male; D008875:Middle Aged; D019578:Multiple System Atrophy / Q000150:complications / Q000378:metabolism / Q000503:physiopathology*; D010880:Piperidines; D017286:Polysomnography; D011237:Predictive Value of Tests; D020187:REM Sleep Behavior Disorder / Q000175:diagnosis* / Q000209:etiology / Q000378:metabolism*; D012016:Reference Values; D017678:Sex Distribution; D013747:Tetrabenazine / Q000031:analogs & derivatives*; D013764:Tetrahydronaphthalenes; D013788:Thalamus / Q000000981:diagnostic imaging / Q000378:metabolism; D014055:Tomography, Emission-Computed; D015899:Tomography, Emission-Computed, Single-Photon
D015306:Biogenic Monoamines; D002250:Carbon Radioisotopes; D007457:Iodine Radioisotopes; D010880:Piperidines; D013764:Tetrahydronaphthalenes; C065043:5-iodobenzovesamicol; C032811:dihydrotetrabenazine; D013747:Tetrabenazine