Reduced dopamine transporter binding predates impulse control disorders in Parkinson's disease.
Impulse control disorders (ICD) are relatively common in Parkinson's disease (PD) and generally are regarded as adverse effects of dopamine replacement therapy, although certain demographic and clinical risk factors are also involved. Previous single-photon emission computed tomography (SPECT) studies showed reduced ventral striatal dopamine transporter binding in Parkinson patients with ICD compared with patients without. Nevertheless, these studies were performed in patients with preexisting impulse control impairments, which impedes clear-cut interpretation of these findings. We retrospectively procured follow-up data from 31 medication-naïve PD patients who underwent dopamine transporter SPECT imaging at baseline and were subsequently treated with dopamine replacement therapy. We used questionnaires and a telephone interview to assess medication status and ICD symptom development during the follow-up period (31.5 ± 12.0 months). Eleven patients developed ICD symptoms during the follow-up period, eight of which were taking dopamine agonists. The PD patients with ICD symptoms at follow-up had higher baseline depressive scores and lower baseline dopamine transporter availability in the right ventral striatum, anterior-dorsal striatum, and posterior putamen compared with PD patients without ICD symptoms. No baseline between-group differences in age and disease stage or duration were found. The ICD symptom severity correlated negatively with baseline dopamine transporter availability in the right ventral and anterior-dorsal striatum. The results of this preliminary study show that reduced striatal dopamine transporter availability predates the development of ICD symptoms after dopamine replacement therapy and may constitute a neurobiological risk factor related to a lower premorbid dopamine transporter availability or a more pronounced dopamine denervation in PD patients susceptible to ICD.
Department of Psychiatry, VU University Medical Center, Amsterdam, The Netherlands; Department of Anatomy & Neurosciences, VU University Medical Center, Amsterdam, The Netherlands; Neuroscience Campus Amsterdam, VU/VUmc, Amsterdam, The Netherlands.
Chris
C
Vriend
Anna H
AH
Nordbeck
Jan
J
Booij
Ysbrand D
YD
van der Werf
Tommy
T
Pattij
Pieter
P
Voorn
Pieter
P
Raijmakers
Elisabeth M J
EM
Foncke
Elsmarieke
E
van de Giessen
Henk W
HW
Berendse
Odile A
OA
van den Heuvel
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D007174:Disruptive, Impulse Control, and Conduct Disorders / Q000150:complications / Q000175:diagnosis / Q000378:metabolism*; D004298:Dopamine / Q000378:metabolism; D050483:Dopamine Plasma Membrane Transport Proteins / Q000378:metabolism*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010300:Parkinson Disease / Q000150:complications / Q000378:metabolism*; D012189:Retrospective Studies; D015899:Tomography, Emission-Computed, Single-Photon
D050483:Dopamine Plasma Membrane Transport Proteins; D004298:Dopamine
Parkinson's disease; dopamine replacement therapy; dopamine transporter; impulse control; neuropsychiatry