Correlations Between Working Memory Impairment and Neurometabolites of the Prefrontal Cortex in Drug-Naive Obsessive-Compulsive Disorder

Abstract

Purpose This study aimed to investigate the mechanism of working memory (WM) impairment in drug-naive obsessive-compulsive disorder (OCD) by using neuropsychological tests and proton magnetic resonance spectroscopy ( 1 H-MRS). Patients and Methods A total of 55 patients with drug-naive OCD and 55 healthy controls (HCs) were recruited for this study. The working memory (WM) was evaluated using the digit span test (DST), visual space memory test (VSMT), and the 2-back task and stroop color word test (SCWT). The bilateral metabolite levels of the prefrontal cortex (PFC) were evaluated by 1H-MRS, then determined the ratios of N-acetyl aspartate (NAA), choline-containing compounds (Cho), and myo-inositol (MI) to creatine (Cr). The independent sample t -test was used to analyse the differences in WM performance and neurometabolite ratios. Multivariate linear regression analysis was performed to screen the influential factors of WM, with an introduction level of 0.05 and a rejection level of 0.10. Results 1) Patients with OCD performed significantly worse on DST (score), VSMT (score), 2-back task (accuracy rate), SCWT (execution time) when compared with HCs. 2) NAA/Cr and Cho/Cr in the left PFC (lPFC) and MI/Cr ratios in the bilateral PFC of OCD patients were significantly lower when compared to HCs. 3) For OCD patients, the NAA/Cr ratio in the lPFC was negatively correlated with the score of DST (forwards), the Cho/Cr ratio in the lPFC was positively correlated with the accuracy rate of 2-back task, and the MI/Cr ratio in the right PFC (rPFC) was positively correlated with the score of DST (forwards) and the accuracy rate of VSMT. We also found that the compulsive symptoms showed a positive correlation with MI/Cr ratio of the rPFC. Conclusion Drug-naive OCD patients have demonstrated WM impairments, including phonological loop, visual-spatial sketchpad and central executive system, and the WM impairments might be associated with hypometabolism in the PFC, especially the lPFC.

Inflammation in obsessive–compulsive disorder: A literature review and hypothesis‐based potential of transcranial photobiomodulation

“…We postulate that targeting the PFC may be effective in treating OCD. t‐PBM has been shown to modulate the PFC (Holmes et al., 2019; Shahdadian et al., 2022), and studies have found reduced functional connectivity (Li, Hu, et al., 2020) and hypometabolism (Yue et al., 2021) in the PFC of patients with OCD. Other neurostimulation techniques, including TMS (Carmi et al., 2018; Liang et al., 2021; Tzirini et al., 2022), tDCS (Adams et al., 2022; Brunelin et al., 2018), and DBS (Hartmann et al., 2015; Senova et al., 2019), have targeted the PFC in OCD treatment.…”

“…The cortico‐striato‐thalamo‐cortical loops, comprising the fronto‐limbic, sensorimotor, ventral cognitive, ventral affective, and dorsal cognitive circuits, play important roles (Shephard et al., 2021). These circuits, involving regions like the PFC, pre‐supplementary motor area (pre‐SMA), orbitofrontal cortex, and nucleus accumbens, are implicated in a range of OCD symptoms from emotional responses and habit formation to reward processing and executive functions (Li, Hu, et al., 2020; Shephard et al., 2021; Yue et al., 2021).…”

“…These circuits, involving regions like the PFC, pre-supplementary motor area (pre-SMA), orbitofrontal cortex, and nucleus accumbens, are implicated in a range of OCD symptoms from emotional responses and habit formation to reward processing and executive functionsShephard et al, 2021;Yue et al, 2021).We postulate that targeting the PFC may be effective in treating OCD. t-PBM has been shown to modulate the PFC(Holmes et al, 2019;Shahdadian et al, 2022), and studies have found reduced functional connectivity and hypometabolism(Yue et al, 2021) in the PFC of patients with OCD. Other neurostimulation techniques, including TMS(Carmi et al, 2018;Liang et al, 2021;Tzirini et al, 2022), tDCS(Adams et al, 2022;Brunelin et al, 2018), and DBS(Hartmann et al, 2015;Senova et al, 2019), have targeted the PFC in OCD treatment.In addition to the PFC, we postulate that t-PBM could also target the pre-SMA.…”

“…The cortico-striatothalamo-cortical loops, comprising the fronto-limbic, sensorimotor, ventral cognitive, ventral affective, and dorsal cognitive circuits, play important roles(Shephard et al, 2021). These circuits, involving regions like the PFC, pre-supplementary motor area (pre-SMA), orbitofrontal cortex, and nucleus accumbens, are implicated in a range of OCD symptoms from emotional responses and habit formation to reward processing and executive functionsShephard et al, 2021;Yue et al, 2021).We postulate that targeting the PFC may be effective in treating OCD. t-PBM has been shown to modulate the PFC(Holmes et al, 2019;Shahdadian et al, 2022), and studies have found reduced functional connectivity and hypometabolism(Yue et al, 2021) in the PFC of patients with OCD.…”