Sidtis John J, Ahn Ji Sook, Gomez Christopher, Sidtis Diana
Brain and Behavior Laboratory, Geriatrics Division, The Nathan Kline Institute, Orangeburg, New York 10962, USA.
J Commun Disord. 2011 Jul-Aug;44(4):478-92. doi: 10.1016/j.jcomdis.2011.03.002. Epub 2011 Apr 15.
Advances in neurobiology are providing new opportunities to investigate the neurological systems underlying motor speech control. This study explores the perceptual characteristics of the speech of three genotypes of spino-cerebellar ataxia (SCA) as manifest in four different speech tasks.
Speech samples from 26 speakers with SCA were perceptually rated by experienced listeners. The genotypes were: SCA1, SCA5, or SCA6. The speech tasks were: diadochokinesis, word repetition, sentence reading, and picture description. The speech samples were rated using two sets of dimensions characterized as primary (e.g., articulation, rate, and rhythm) or secondary (e.g., imprecise consonants, excess and equal stress, and harsh voice).
On primary dimensions, SCA6 was the most impaired generally. Articulation was the most severely affected dimension and the diadochokinesis task was most effective in revealing speech impairments. On secondary dimensions, picture description was the task most likely to produce abnormal speech. The SCA groups shared articulatory problems but differed with respect to abnormal voice features.
These results support previous characterizations of ataxic dysarthria, and provide further information about the speech characteristics of genetic subtypes. Task demands affect perceptual ratings. Voice characteristics may be key to differentiating ataxic subtypes. As the genetic disorders that affect speech become better understood, more detailed characterizations of motor control systems should emerge.
神经生物学的进展为研究运动言语控制的神经系统提供了新的机会。本研究探讨了三种基因型的脊髓小脑共济失调（SCA）患者在四种不同言语任务中所表现出的言语感知特征。
26名SCA患者的言语样本由经验丰富的听众进行感知评分。基因型包括：SCA1、SCA5或SCA6。言语任务包括：轮替运动、单词重复、句子朗读和图片描述。言语样本根据两组维度进行评分，分别为主要维度（如清晰度、语速和节奏）或次要维度（如辅音不准确、重音过多或均等、声音刺耳）。
在主要维度上，SCA6总体受损最严重。清晰度是受影响最严重的维度，轮替运动任务在揭示言语障碍方面最有效。在次要维度上，图片描述任务最容易产生异常言语。SCA各基因型组存在共同的发音问题，但在异常嗓音特征方面存在差异。
这些结果支持了之前对共济失调性构音障碍的描述，并提供了有关基因亚型言语特征的进一步信息。任务要求会影响感知评分。嗓音特征可能是区分共济失调亚型的关键。随着对影响言语的基因疾病的理解不断深入，运动控制系统的更详细特征应会显现出来。
