Bidirectional Correlations Between Dopaminergic Function and Motivation in Parkinson’s Disease
Year: 2021
Type: article
Abstract: OBJECTIVE: To test the hypothesis that striatal dopamine function influences motivational alterations in Parkinson disease (PD), we compared vesicular monoamine transporter 2 (VMAT2) and dopamine transporter (DaT) imaging data in PD patients with impulse control disorders (ICDs), apathy, or neither. METHODS: F-AV133) and DaTscans from the Parkinson's Progression Markers Initiative (PPMI) multicenter observational study. Apathy and ICDs were assessed using the Movement Disorders Society-revised Unified Parkinson's Disease Rating Scale (MDS-UPDRS) and the Questionnaire for Impulsive-Compulsive Disorders in Parkinson's Disease (QUIP), respectively. We used analysis of variance (ANOVA) and log-linear mixed-effects (LME) regression to model SBRs with neurobehavioral metrics. RESULTS: Among 23 participants (mean age 62.7 years, mean disease duration 1.8 years) with VMAT2 imaging data, 5 had apathy, 5 had an ICD, and 13 had neither. ANOVA indicated strong groupwise differences in VMAT2 binding in right anterior putamen [F(2,20) = 16.2, p < 0.0001), right posterior putamen [F(2,20) = 16.9, p < 0.0001), and right caudate [F(2,20) = 6.8, p = 0.006)]. Post-hoc tests and repeated-measures analysis with LME regression also supported right striatal VMAT2 elevation in the ICD group and reduction in the apathy group relative to the group with neither ICD nor apathy. DaT did not exhibit similar correlations, but normalizing VMAT2 with DaT SBR strengthened bidirectional correlations with ICD (high VMAT2/DaT) and apathy (low VMAT2/DaT) in all striatal regions bilaterally. CONCLUSIONS: Our findings constitute preliminary evidence that striatal presynaptic dopaminergic function helps describe the neurobiological basis of motivational dysregulation in PD, from high in ICDs to low in apathy.
Institutions: Johns Hopkins University, Johns Hopkins Medicine
Language: English
Subfield: Neurology
Field: Medicine
Domain: Health Sciences
Open Access status: green
Awards: Astrocyte NLRP3 inflammasome activation in Parkinson's disease, Medical Scientist Training Program, Anxiety in Parkinson's: Use of quantitative methods to guide rational treatment, Molecular Imaging of the Nicotinic Cholinergic Receptor in Parkinson's disease (PD): Implication of for understanding the neurobiology of cognitive impairment, Medical Scientist Training Program
OpenAlex ID: W3131084139