BACKGROUND Patients with the metabolic disorder classical galactosemia suffer from long-term complications despite a galactose-restricted diet, including a below average intelligence level. The aim of the current review was to investigate the incidence and profile of cognitive impairments in patients with classical galactosemia. METHOD MEDLINE, EMBASE and PsychINFO were searched up to 23 October 2018 for studies examining information processing speed, attention, memory, language, visuospatial functioning, executive functioning and social cognition in patients with confirmed classical galactosemia utilizing standardized neuropsychological tests. Data synthesis followed a narrative approach, since the planned meta-analysis was not possible due to large variability between the neuropsychological assessments. RESULTS Eleven studies were included, including case-studies. The quality of most studies was moderate to low. As a group, patients with classical galactosemia exhibit below average to low scores on all cognitive domains. A large proportion of the patients perform on an impaired level on attention, memory and vocabulary. Evidence for impairments in information processing speed, language, visuospatial functioning and aspects of executive functioning was limited due to the small number of studies investigating these cognitive functions. Social cognition was not examined at all. CONCLUSIONS Given the moderate to low quality of the included studies and the limited evidence in many cognitive domains, the incidence of cognitive impairment in patients with classical galactosemia is not yet clear. Both clinicians and researchers encountering patients with classical galactosemia need to be aware of possible cognitive impairments. Future well-designed studies are needed to determine the cognitive profile of classical galactosemia. This can be the basis for the development of intervention strategies.

中文翻译：

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经典半乳糖血症患者的认知功能：系统评价。

背景技术尽管半乳糖限制饮食，包括低于智力水平的平均水平，但患有代谢紊乱的经典半乳糖血症的患者仍患有长期并发症。本综述的目的是调查经典半乳糖血症患者认知障碍的发生率和概况。方法截至2018年10月23日，对MEDLINE，EMBASE和PsychINFO进行搜索，以通过标准化的神经心理学测试检查确诊的经典半乳糖血症患者的信息处理速度，注意力，记忆力，语言，视觉空间功能，执行功能和社会认知能力。数据合成遵循一种叙述性方法，因为神经心理学评估之间存在较大差异，因此无法进行计划的荟萃分析。结果包括11项研究，包括案例研究。大多数研究的质量为中等到低。作为一个整体，患有经典半乳糖血症的患者在所有认知领域的得分均低于平均水平或较低。很大一部分患者的注意力，记忆力和词汇水平受损。信息处理速度，语言，视觉空间功能和执行功能方面的损伤的证据是有限的，因为研究这些认知功能的研究很少。根本没有检查社会认知。结论鉴于纳入研究的质量中等至低，并且在许多认知领域的证据有限，经典半乳糖血症患者认知障碍的发生率尚不清楚。遇到经典半乳糖血症患者的临床医生和研究人员都需要意识到可能的认知障碍。需要未来设计良好的研究来确定经典半乳糖血症的认知特征。这可以作为制定干预策略的基础。