Hlavatá Pavlína, Linhartová Pavla, Šumec Rastislav, Filip Pavel, Světlák Miroslav, Baláž Marek, Kašpárek Tomáš, Bareš Martin
Department of Psychiatry, Faculty of Medicine, Masaryk University Brno and University Hospital, Brno, Czechia.
Behavioral and Social Neuroscience Research Group, CEITEC-Central European Institute of Technology, Masaryk University, Brno, Czechia.
Front Neurol. 2020 Jan 10;10:1338. doi: 10.3389/fneur.2019.01338. eCollection 2019.
Impulse control disorder (ICD) is a major non-motor complication of Parkinson's disease (PD) with often devastating consequences for patients' quality of life. In this study, we aimed to characterize the phenotype of impulsivity in PD and its neuroanatomical correlates. Thirty-seven PD patients (15 patients with ICD, 22 patients without ICD) and 36 healthy controls underwent a neuropsychological battery. The test battery consisted of anxiety and depression scales, self-report measures of impulsivity (Barratt scale and UPPS-P), behavioral measures of impulsive action (Go/No-Go task, Stop signal task) and impulsive choice (Delay discounting, Iowa gambling task), and measures of cognitive abilities (working memory, attention, executive function). Patients and controls underwent structural MRI scanning. Patients with ICD had significantly higher levels of self-reported impulsivity (Barratt scale and Lack of perseverance from UPPS-P) in comparison with healthy controls and non-impulsive PD patients, but they performed similarly in behavioral tasks, except for the Iowa gambling task. In this task, patients with ICD made significantly less risky decisions than patients without ICD and healthy controls. Patients without ICD did not differ from healthy controls in self-reported impulsivity or behavioral measurements. Both patient groups were more anxious and depressive than healthy controls. MRI scanning revealed structural differences in cortical areas related to impulse control in both patient groups. Patients without ICD had lower volumes and cortical thickness of bilateral inferior frontal gyrus. Patients with ICD had higher volumes of right caudal anterior cingulate and rostral middle frontal cortex. Despite the presence of ICD as confirmed by both clinical follow-up and self-reported impulsivity scales and supported by structural differences in various neural nodes related to inhibitory control and reward processing, patients with ICD performed no worse than healthy controls in various behavioral tasks previously hypothesized as robust impulsivity measures. These results call for caution against impetuous interpretation of behavioral tests, since various factors may and will influence the ultimate outcomes, be it the lack of sensitivity in specific, limited ICD subtypes, excessive caution of ICD patients during testing due to previous negative experience rendering simplistic tasks insufficient, or other, as of now unknown aspects, calling for further research.
冲动控制障碍（ICD）是帕金森病（PD）的一种主要非运动并发症，常常对患者的生活质量造成毁灭性影响。在本研究中，我们旨在描述帕金森病患者冲动性的表型及其神经解剖学相关性。37名帕金森病患者（15名患有冲动控制障碍，22名未患冲动控制障碍）和36名健康对照者接受了一套神经心理学测试。测试组合包括焦虑和抑郁量表、冲动性的自我报告测量（巴拉特量表和UPPS-P）、冲动行为的行为测量（Go/No-Go任务、停止信号任务）和冲动选择（延迟折扣、爱荷华赌博任务），以及认知能力测量（工作记忆、注意力、执行功能）。患者和对照者均接受了结构MRI扫描。与健康对照者和无冲动性的帕金森病患者相比，患有冲动控制障碍的患者自我报告的冲动性水平（巴拉特量表和UPPS-P中的缺乏毅力）显著更高，但除了爱荷华赌博任务外，他们在行为任务中的表现相似。在该任务中，患有冲动控制障碍的患者做出的风险决策明显少于未患冲动控制障碍的患者和健康对照者。未患冲动控制障碍的患者在自我报告的冲动性或行为测量方面与健康对照者没有差异。两组患者均比健康对照者更焦虑和抑郁。MRI扫描显示两组患者中与冲动控制相关的皮质区域存在结构差异。未患冲动控制障碍的患者双侧额下回体积和皮质厚度较低。患有冲动控制障碍的患者右侧尾侧前扣带回和额中回前部体积较大。尽管临床随访和自我报告的冲动性量表均证实存在冲动控制障碍，且与抑制控制和奖励处理相关的各个神经节点的结构差异也支持这一点，但患有冲动控制障碍的患者在先前被假设为可靠冲动性测量指标的各种行为任务中的表现并不比健康对照者差。这些结果提醒我们在对行为测试结果进行轻率解释时要谨慎，因为各种因素可能且将会影响最终结果，可能是特定、有限的冲动控制障碍亚型缺乏敏感性，也可能是由于先前的负面经历导致冲动控制障碍患者在测试期间过度谨慎，使得简单任务不足以反映情况，或者是其他目前未知的方面，这需要进一步研究。
