De Witte E, Wilssens I, De Surgeloose D, Dua G, Moens M, Verhoeven J, Manto M, Mariën P
Clinical and Experimental Neurolinguistics, CLIN, Vrije Universiteit Brussel, Pleinlaan 2, B-1050 Brussels, Belgium.
Department of Speech and Language Therapy, ZNA Middelheim, Lindendreef 1, B-2020 Antwerp, Belgium.
Cerebellum Ataxias. 2017 Jan 6;4:2. doi: 10.1186/s40673-016-0059-x. eCollection 2017.
Cerebellar mutism syndrome (CMS) or posterior fossa syndrome (PFS) consists of a constellation of neuropsychiatric, neuropsychological and neurogenic speech and language deficits. It is most commonly observed in children after posterior fossa tumor surgery. The most prominent feature of CMS is mutism, which generally starts after a few days after the operation, has a limited duration and is typically followed by motor speech deficits. However, the core speech disorder subserving CMS is still unclear.
This study investigates the speech and language symptoms following posterior fossa medulloblastoma surgery in a 12-year-old right-handed boy. An extensive battery of formal speech (DIAS = Diagnostic Instrument Apraxia of Speech) and language tests were administered during a follow-up of 6 weeks after surgery. Although the neurological and neuropsychological (affective, cognitive) symptoms of this patient are consistent with Schmahmann's syndrome, the speech and language symptoms were markedly different from what is typically described in the literature. In-depth analyses of speech production revealed features consistent with a diagnosis of apraxia of speech (AoS) while ataxic dysarthria was completely absent. In addition, language assessments showed genuine aphasic deficits as reflected by distorted language production and perception, wordfinding difficulties, grammatical disturbances and verbal fluency deficits.
To the best of our knowledge this case might be the first example that clearly demonstrates that a higher level motor planning disorder (apraxia) may be the origin of disrupted speech in CMS. In addition, identification of non-motor linguistic disturbances during follow-up add to the view that the cerebellum not only plays a crucial role in the planning and execution of speech but also in linguistic processing. Whether the cerebellum has a direct or indirect role in motor speech planning needs to be further investigated.
小脑缄默综合征（CMS）或后颅窝综合征（PFS）由一系列神经精神、神经心理以及神经源性言语和语言缺陷组成。它最常见于后颅窝肿瘤手术后的儿童。CMS最突出的特征是缄默，通常在术后几天开始，持续时间有限，随后通常会出现运动性言语缺陷。然而，CMS的核心言语障碍仍不清楚。
本研究调查了一名12岁右利手男孩在后颅窝髓母细胞瘤手术后的言语和语言症状。在术后6周的随访期间进行了一系列广泛的正式言语（DIAS = 言语失用诊断工具）和语言测试。尽管该患者的神经和神经心理（情感、认知）症状与施马曼综合征一致，但其言语和语言症状与文献中通常描述的明显不同。对言语产生的深入分析显示出与言语失用（AoS）诊断一致的特征，而共济失调性构音障碍完全不存在。此外，语言评估显示出真正的失语缺陷，表现为语言产生和感知扭曲、找词困难、语法紊乱和言语流畅性缺陷。
据我们所知，该病例可能是第一个清楚表明高级运动计划障碍（失用）可能是CMS言语障碍根源的例子。此外，随访期间发现的非运动性语言障碍进一步支持了小脑不仅在言语的计划和执行中起关键作用，而且在语言处理中也起关键作用的观点。小脑在运动性言语计划中是直接还是间接起作用需要进一步研究。
