Effects of dopaminergic depletion and brain atrophy on neuropsychiatric symptoms in de novo Parkinson's disease

J Neurol Neurosurg Psychiatry. 2018 Feb;89(2):197-204. doi: 10.1136/jnnp-2017-316075. Epub 2017 Sep 26.

Abstract

Background: Neuropsychiatric symptoms impact the patients' quality of life and caregivers' burdens in Parkinson's disease (PD). We aimed to investigate the effects of striatal dopaminergic depletion and brain atrophy on the neuropsychiatric symptoms of patients with PD.

Methods: Two hundred and seven patients with de novo drug-naïve PD underwent dopamine transporter (DAT) positron emission tomography and brain MRI scanning. In addition, the patients were assessed with caregiver-administered neuropsychiatric inventory (NPI) questionnaires. To evaluate the effects of DAT uptake, subcortical volume and cortical thinning on the patients' neuropsychiatric symptoms, we performed logistic regression and negative binomial regression analyses on the NPI data after controlling for possible confounders.

Results: Frontal cortical thinning was associated with the presence of nighttime behaviour and irritability, and the thinning correlated with the severity of the nighttime behaviour. Temporal cortical thinning was associated with the presence of aggression/agitation, and it correlated with the severity of the aggression/agitation. Subcortical atrophy in the accumbens was associated with the presence of disinhibition and correlated with the severity of the disinhibition. Putamen atrophy and insular thinning were independently associated with the presence of apathy, but only insular thinning correlated with the severity of the apathy. Of the predictors, only frontal cortical thinning correlated with the total NPI score.

Conclusions: The results of this study suggested that accumbens atrophy and frontotemporal cortical thinning, especially frontal cortical thinning, independently contributed to neuropsychiatric symptoms in patients with PD, while DAT uptake did not affect the neuropsychiatric symptoms.

Keywords: cortical thickness; dopamine transporter imaging; neuropsychiatric symptom; parkinson’s disease; subcortical atrophy.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Aggression / psychology*
  • Anxiety / psychology
  • Apathy*
  • Appetite
  • Atrophy
  • Brain / diagnostic imaging*
  • Brain / metabolism
  • Brain / pathology
  • Cerebral Cortex / diagnostic imaging
  • Cerebral Cortex / metabolism
  • Cerebral Cortex / pathology
  • Depression / psychology*
  • Dopamine Plasma Membrane Transport Proteins / metabolism
  • Female
  • Fluorine Radioisotopes
  • Humans
  • Inhibition, Psychological*
  • Irritable Mood*
  • Logistic Models
  • Magnetic Resonance Imaging
  • Male
  • Middle Aged
  • Nucleus Accumbens / diagnostic imaging
  • Nucleus Accumbens / metabolism
  • Nucleus Accumbens / pathology
  • Organ Size
  • Parkinson Disease / diagnostic imaging
  • Parkinson Disease / metabolism
  • Parkinson Disease / pathology
  • Parkinson Disease / psychology*
  • Positron-Emission Tomography
  • Tropanes

Substances

  • Dopamine Plasma Membrane Transport Proteins
  • Fluorine Radioisotopes
  • Tropanes
  • 2-carbomethoxy-8-(3-fluoropropyl)-3-(4-iodophenyl)tropane