Wolf Robert Christian, Werler Florian, Schmitgen Mike M, Wolf Nadine D, Wittemann Miriam, Reith Wolfgang, Hirjak Dusan
Department of General Psychiatry at the Center for Psychosocial Medicine, Heidelberg University, Heidelberg, Germany.
Department of Psychiatry and Psychotherapy, Saarland University, Saarbrücken, Germany.
Addict Biol. 2023 Mar;28(3):e13270. doi: 10.1111/adb.13270.
Sensorimotor dysfunction has been previously reported in persons with cannabis dependence. Such individuals can exhibit increased levels of neurological soft signs (NSS), particularly involving motor coordination, sensorimotor integration and complex motor task performance. Abnormal NSS levels can also be detected in non-dependent individuals with heavy cannabis use (HCU), yet very little is known about the functional correlates underlying such deficits. Here, we used resting-state functional magnetic resonance imaging (MRI) to investigate associations between NSS and intrinsic neural activity (INA) in HCU (n = 21) and controls (n = 26). Compared with controls, individuals with HCU showed significantly higher NSS across all investigated subdomains. Three of these subdomains, that is, motor coordination, sensorimotor integration and complex motor task behaviour, were associated with specific use-dependent variables, particularly age of onset of cannabis use and current cannabis use. Between-group comparisons of INA revealed lower regional homogeneity (ReHo) in left precentral gyrus, left inferior occipital gyrus, right triangular pat of the inferior frontal gyrus and right precentral gyrus in HCU compared with controls. In addition, HCU showed also higher ReHo in right cerebellum and left postcentral gyrus compared with controls. Complex motor task behaviour in HCU was significantly related to INA in postcentral, inferior frontal and occipital cortices. Our findings indicate abnormal ReHo in HCU in regions associated with sensorimotor, executive control and visuomotor-integration processes. Importantly, we show associations between ReHo, cannabis-use behaviour and execution of complex motor tasks. Given convergent findings in manifest psychotic disorders, this study suggests an HCU endophenotype that may present with a cumulative risk for psychosis.
先前已有报道称，大麻依赖者存在感觉运动功能障碍。这类个体的神经学软体征（NSS）水平会升高，尤其涉及运动协调、感觉运动整合和复杂运动任务表现。在大量使用大麻的非依赖个体中也能检测到异常的NSS水平，但对于这些缺陷背后的功能相关性却知之甚少。在此，我们使用静息态功能磁共振成像（MRI）来研究大量使用大麻者（n = 21）和对照组（n = 26）中NSS与内在神经活动（INA）之间的关联。与对照组相比，大量使用大麻者在所有研究的子领域中NSS均显著更高。其中三个子领域，即运动协调、感觉运动整合和复杂运动任务行为，与特定的使用相关变量有关，特别是大麻使用的起始年龄和当前大麻使用情况。INA的组间比较显示，与对照组相比，大量使用大麻者左侧中央前回、左侧枕下回、右侧额下回三角部和右侧中央前回的局部一致性（ReHo）较低。此外，与对照组相比，大量使用大麻者右侧小脑和左侧中央后回的ReHo也更高。大量使用大麻者的复杂运动任务行为与中央后回、额下回和枕叶皮质的INA显著相关。我们的研究结果表明，大量使用大麻者在与感觉运动、执行控制和视觉运动整合过程相关的区域存在异常的ReHo。重要的是，我们显示了ReHo、大麻使用行为和复杂运动任务执行之间的关联。鉴于在明显的精神障碍中也有类似的发现，本研究提示大量使用大麻者可能存在一种内表型，其可能会累积患精神病的风险。
