Effects of Levodopa Therapy on Cerebral Arteries and Perfusion in Parkinson's Disease Patients

J Magn Reson Imaging. 2022 Mar;55(3):943-953. doi: 10.1002/jmri.27903. Epub 2021 Sep 3.

Abstract

Background: Levodopa is the most-commonly used therapy for Parkinson's Disease (PD). Imaging findings show increased cerebral blood flow (CBF) response to levodopa, but the artery morphological change is less studied.

Purpose: To investigate the effect of levodopa on cerebral arteries and CBF.

Study type: Prospective.

Population: 57 PD patients (56 ± 10 years, 26 males) and 17 age-matched healthy controls (AMC, 57 ± 9 years, 9 males) were scanned at baseline (OFF). Patients were rescanned 50 minutes after taking levodopa (ON).

Field strength and sequence: 3 T; Simultaneous noncontrast angiography intraplaque imaging (SNAP) based on turbo field echo; Pseudo-continuous arterial spin labeling (PCASL) based on echo-planner imaging.

Assessment: The Unified Parkinson's Disease Rating Scale (UPDRS-III) was used to assess the disease severity. Length and radius of arteries were measured from SNAP images. CBF was calculated from PCASL images globally and regionally.

Statistical tests: Mann Whitney U tests were conducted in comparing PD vs. AMC. Wilcoxon matched-pairs signed rank tests were used in comparing OFF vs. ON, and the more-affected vs. the less-affected hemisphere in PD. Linear regressions were performed to test the correlations of neuroimaging findings with behavioral changes. Significance threshold was P < 0.05 with Bonferroni correction.

Results: PD patients were identified with significantly lower CBF (PD OFF Mean = 40.15 ± 5.99, AMC Mean = 43.48 ± 6.21 mL/100 g/min) and shortened total artery length (PD OFF Mean = 5851.07 ± 1393.45, AMC Mean = 7479.16 ± 1335.93 mm). Levodopa elevated CBF of PD brains (PD ON Mean = 41.48 ± 6.32 mL/100 g/min) and expanded radius of proximal arteries. Artery radius change significantly correlated with CBF change in corresponding territories (r = 0.559 for Internal Carotid Arteries, r = 0.448 for Basilar Artery, and r = 0.464 for Middle Cerebral Artery M1). Global CBF significantly related to UPDRS-III (r = -0.391) post-levodopa.

Data conclusion: Levodopa can increase CBF by dilating proximal arteries.

Level of evidence: 1 TECHNICAL EFFICACY STAGE: 4.

Keywords: Levodopa; Parkinson's disease; cerebral arteries; cerebral blood flow; perfusion; simultaneous noncontrast angiography and intraplaque imaging.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Cerebral Arteries
  • Cerebrovascular Circulation / physiology
  • Female
  • Humans
  • Levodopa* / therapeutic use
  • Male
  • Middle Aged
  • Parkinson Disease* / diagnostic imaging
  • Parkinson Disease* / drug therapy
  • Perfusion
  • Prospective Studies
  • Spin Labels

Substances

  • Spin Labels
  • Levodopa