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The implication of nigrostriatal dopaminergic degeneration in the pathogenesis of REM sleep behavior disorder
Author(s) -
Kim Y. K.,
Yoon IY.,
Kim JM.,
Jeong SH.,
Kim K. W.,
Shin YK.,
Kim B. S.,
Kim S. E.
Publication year - 2010
Publication title -
european journal of neurology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.881
H-Index - 124
eISSN - 1468-1331
pISSN - 1351-5101
DOI - 10.1111/j.1468-1331.2009.02854.x
Subject(s) - dopaminergic , rem sleep behavior disorder , putamen , medicine , rapid eye movement sleep , synucleinopathies , parkinson's disease , polysomnography , chin , neuroscience , striatum , dopamine transporter , pathogenesis , psychology , dopamine , eye movement , alpha synuclein , ophthalmology , disease , anatomy , apnea
Background and purpose: The pathogenesis of rapid eye movement (REM) sleep behavior disorder (RBD) is not clear despite its frequent association with Parkinson’s disease (PD). We investigated whether the nigrostriatal dopaminergic system is involved in the development of idiopathic RBD. Methods: Fourteen patients with RBD, 14 patients with PD and 12 normal controls were included in the study. The diagnosis of RBD was confirmed on polysomnography. All the participants performed single‐photon emission computed tomography imaging 3 h after injection of [ 123 I]FP‐CIT. During REM sleep of the RBD patients, each 30‐s epoch was rated as ‘tonic’ when there was at least 50% of tonically maintained chin electromyography (EMG) activity in the epoch. Phasic EMG activities were calculated as the percentage of 3‐s mini‐epoch containing phasic EMG events (leg and chin, separately). Results: The RBD patients showed a trend of lower binding in the striatum than the normal controls ( P = 0.07), and the significance was revealed in the putamen ( P = 0.02). However, in 11 individual cases of the 14 RBD patients, the dopamine transporter (DAT) densities in the putamen still remained within the normal range. In the RBD patients, there was no correlation between EMG activities and DAT densities. Conclusions: Nigrostriatal dopaminergic degeneration could be a part of the pathogenesis of RBD, but not essential for the development of RBD. The lack of correlation between RBD severity and DAT densities suggests that another pathogenic process not related to nigrostriatal dopaminergic transmission may be implicated in RBD.