Association between white matter microstructure and cognitive function in patients with methamphetamine use disorder

Abstract

Methamphetamine use disorder (MUD) has been associated with broad neurocognitive impairments. While the cognitive impairments of MUD have been demonstrated, the neuropathological underpinnings remain inadequately understood. To date, the published human diffusion tensor imaging (DTI) studies involving the correlation between diffusion parameters and neurocognitive function in MUD are limited. Hence, the present study aimed to examine the association between cognitive performance and white matter microstructure in patients with MUD. Forty-five patients with MUD and 43 healthy controls (HCs) completed their demographic information collection, cognitive assessments, and DTI imaging. DTI images were preprocessed to extract fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity (AD), and radial diffusivity (RD) of various fiber tracts. Univariate tests were used to examine group differences in cognitive assessments and DTI metrics. Linear regression was used to examine the relationship between these two metrics. The results revealed that patients with MUD had lower subset scores of the MATRICS Consensus Cognitive Battery (MCCB), which reflects five cognitive domains: processing speed, attention, verbal learning, visual learning, problem-solving. Patients with MUD also had significantly higher AD, MD, and RD values of the left superior longitudinal fasciculus than HCs. Furthermore, the RD value of the left superior longitudinal fasciculus was a significant predictor of processing speed and problem-solving ability, as shown by the digit-symbol coding test and NAB-Mazes scores, respectively. Findings extended our understanding of white matter microstructure that is related to neurocognitive deficits in MUD and provided potential targets for the prevention and treatment of this chronic disorder.

Keywords: diffusion tensor imaging; methamphetamine use disorder; neurocognition; problem solving; processing speed; superior longitudinal fasciculus; white matter.

FIGURE 1

The figure displays the lsmean and standard error of the AD, MD, and RD values of the left SLF for the two groups. For all diffusivity values, the MUD group has higher AD, MD, and RD values of the left SLF than the HC group after controlling for age, level of education, drinking status, smoking status, and betel use, and after Bonferroni correction for multiple testing. The bottom right panel shows the left SLF. AD, axial diffusivity; HC, healthy control; MD, mean diffusivity; MUD, methamphetamine use disorder; RD, radial diffusivity; SLF, superior longitudinal fasciculus

FIGURE 2

The figure shows the association between cognitive domains of the significant MCCB and the AD and RD values of the left SLF. Only RD value of the left SLF was predictive of DCST and MAB‐mazes scores. AD, axial diffusivity; CPT‐IP, continuous performance test‐identical pairs; DSCT, digit‐symbol coding task; HC, healthy control; HVLT‐R, Hopkins verbal learning test‐revised; MCCB, MATRICS consensus cognitive battery; MUD, methamphetamine use disorder; NAB‐mazes, neuropsychological assessment battery‐mazes; RD, radial diffusivity; SLF, superior longitudinal fasciculus