ABSTRACT

Up to 35–40% of patients with amyotrophic lateral sclerosis (ALS) present with language deficits falling within the spectrum of frontotemporal lobar degeneration (FTLD). It is currently debated whether frontotemporal involvement occurs or not in motor neuron disease (MND) phenotypes that differ from classical ALS (i.e., both different-from-ALS MNDs and non-classical ALS endo-phenotypes) – this stance being supported by the notion of a common pathology underlying MNDs. To investigate whether language dysfunctions also occur in patients with different-from-classical-ALS adult-onset MNDs can; a) help determine whether the MND-FTLD continuum could be broadened at a neuropsychological level; b) convey relevant entailments to cognitive diagnostics in these populations. The present study thus aimed at reviewing evidence regarding language impairment in different-from-classical-ALS MND patients. Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines were consulted to implement and report the present review. Studies were included if a) language was quantitatively assessed b) in patients diagnosed with different-from-classical-ALS MND phenotypes. Studies assessing demented patients only were excluded. From an original N = 1117 contributions, N = 20 group studies were finally included. Secondary outcomes were taken into account for qualitatively assessing potential biases in generalizing results. Studies were divided into those assessing predominant/pure-upper vs. -lower MND patients (UMND/LMND). Language dysfunctions appeared to be more prevalent and severe in UMND patients. Language screeners were able to detect language deficits in both groups. Lexical-semantic deficits appeared to be highly prevalent in both groups and a selective difficulty in action- vs. object-naming was not infrequently detected. Morpho-syntactic deficits were seldom reported in both groups. Phonological deficits and central dysgraphic features were found in UMND patients only. Patients with different-from-classical-ALS MND phenotypes display language deficits similar to those of classical ALS patients (as far as both prevalence and type are concerned) and thus could be validly included in the MND-FTLD continuum at a neuropsychological level. A greater cortical involvement might account for language deficits being more severe in UMND patients. Consistently with guidelines for cognitive assessment in ALS patients, action-naming tasks might represent a valid and sensitive tool for assessing language in UMND/LMND patients too.

摘要

多达 35-40% 的肌萎缩侧索硬化症 (ALS) 患者出现语言障碍，属于额颞叶变性 (FTLD) 范围内。目前正在争论额颞叶受累是否发生在与经典 ALS 不同的运动神经元疾病 (MND) 表型中（即，不同于 ALS 的 MND 和非经典 ALS 内表型）——这一立场得到了MND 的共同病理学概念。调查患有不同于经典的 ALS 成人发病 MND 的患者是否也会出现语言功能障碍；a) 帮助确定 MND-FTLD连续体可以在神经心理学层面上扩展；b) 在这些人群中传达对认知诊断的相关要求。因此，本研究旨在审查有关不同于经典 ALS MND 患者语言障碍的证据。咨询了系统评价和元分析指南的首选报告项目以实施和报告本次审查。如果 a) 对语言进行定量评估 b) 在诊断为与经典 ALS MND 表型不同的患者中，则纳入研究。仅评估痴呆患者的研究被排除在外。从原始N = 1117 个贡献中，N= 20 组研究最终被纳入。在定性评估概括结果中的潜在偏差时，考虑了次要结果。研究分为评估主要/纯上与下 MND 患者 (UMND/LMND) 的研究。语言功能障碍似乎在 UMND 患者中更为普遍和严重。语言筛选器能够检测到两组的语言缺陷。词汇语义缺陷似乎在两组中都非常普遍，并且在动作与对象命名方面的选择性困难并不少见。两组都很少报告形态句法缺陷。仅在 UMND 患者中发现了语音缺陷和中枢障碍特征。神经心理学层面的连续性。更大的皮层受累可能是 UMND 患者更严重的语言缺陷的原因。与 ALS 患者的认知评估指南一致，动作命名任务也可能代表一种有效且敏感的工具，用于评估 UMND/LMND 患者的语言。