Corben Louise A, Klopper Felicity, Stagnitti Monique, Georgiou-Karistianis Nellie, Bradshaw John L, Rance Gary, Delatycki Martin B
Experimental Neuropsychology Research Unit, School of Psychological Sciences, Monash University, Clayton, Victoria, Australia.
Bruce Lefroy Centre for Genetic Health Research, Murdoch Childrens Research Institute, Flemington Road, Parkville, Victoria, Australia.
Cerebellum. 2017 Aug;16(4):757-763. doi: 10.1007/s12311-017-0848-7.
Friedreich ataxia (FRDA) is an autosomal recessive neurodegenerative disorder with subtle impact on cognition. Inhibitory processes and cognitive flexibility were examined in FRDA by assessing the ability to suppress a predictable verbal response. We administered the Hayling Sentence Completion Test (HSCT), the Trail Making Test, and the Stroop Test to 43 individuals with FRDA and 42 gender- and age-matched control participants. There were no significant group differences in performance on the Stroop or Trail Making Test whereas significant impairment in cognitive flexibility including the ability to predict and inhibit a pre-potent response as measured in the HSCT was evident in individuals with FRDA. These deficits did not correlate with clinical characteristics of FRDA (age of disease onset, disease duration, number of guanine-adenine-adenine repeats on the shorter or larger FXN allele, or Friedreich Ataxia Rating Scale score), suggesting that such impairment may not be related to the disease process in a straightforward way. The observed specific impairment of inhibition and predictive capacity in individuals with FRDA on the HSCT task, in the absence of impairment in associated executive functions, supports cerebellar dysfunction in conjunction with disturbance to cortico-thalamo-cerebellar connectivity, perhaps via inability to access frontal areas necessary for successful task completion.
弗里德赖希共济失调（FRDA）是一种常染色体隐性神经退行性疾病，对认知有细微影响。通过评估抑制可预测言语反应的能力，对FRDA患者的抑制过程和认知灵活性进行了研究。我们对43名FRDA患者和42名年龄及性别匹配的对照参与者进行了海林句子完成测试（HSCT）、连线测验和斯特鲁普测验。在斯特鲁普测验或连线测验中，两组表现无显著差异；而在FRDA患者中，HSCT所测量的认知灵活性存在显著损害，包括预测和抑制优势反应的能力。这些缺陷与FRDA的临床特征（疾病发病年龄、病程、较短或较长的FXN等位基因上鸟嘌呤-腺嘌呤-腺嘌呤重复序列的数量，或弗里德赖希共济失调评定量表评分）无关，这表明这种损害可能并非以直接的方式与疾病进程相关。在HSCT任务中，FRDA患者观察到的抑制和预测能力的特定损害，在相关执行功能未受损的情况下，支持小脑功能障碍以及皮质-丘脑-小脑连接紊乱，可能是由于无法进入成功完成任务所需的额叶区域。
