Gaymard B, Giannitelli M, Challes G, Rivaud-Péchoux S, Bonnot O, Cohen D, Xavier J
Service de Neurophysiologie Clinique, AP-HP, Hôpital de la Salpêtrière, Paris, France.
AP-HP, Hôpital de la Salpêtrière, 75651, Paris, France.
Cerebellum. 2017 Apr;16(2):411-420. doi: 10.1007/s12311-016-0817-6.
Children with developmental dyspraxia (DD) express impairments in the acquisition of various motor skills and in the development of their social cognition abilities. Although the neural bases of this condition are not fully understood, they are thought to involve frontal cortical areas, subcortical structures, and the cerebellum. Although cerebellar dysfunction is typically difficult to assess and quantify using traditional neurophysiological methods, oculomotor analysis may provide insight into specific cerebellar patterns. The aim of the present study was to investigate, in dyspraxic and typically developing subjects, various oculomotor saccade tasks specifically designed to reveal frontal and cerebellar dysfunction. In addition to evidence supporting prefrontal dysfunction, our results revealed increased variability of saccade accuracy consistent with cerebellar impairments. Furthermore, we found that dyspraxic patients showed decreased velocities of non-visually guided saccades. A closer analysis revealed significant differences in saccade velocity profiles with slightly decreased maximum saccade velocities but markedly prolonged deceleration phases. We show that this pattern was not related to a decreased state of alertness but was suggestive of cerebellar dysfunction. However, the clear predominance of this pattern in non-visually guided saccades warrants alternative hypotheses. In light of previous experimental and anatomical studies, we propose that this unusual pattern may be a consequence of impaired connections between frontal areas and cerebellar oculomotor structures.
患有发育性运动障碍（DD）的儿童在各种运动技能的习得以及社会认知能力的发展方面表现出缺陷。尽管这种病症的神经基础尚未完全明确，但人们认为其涉及额叶皮质区域、皮质下结构和小脑。虽然使用传统神经生理学方法通常难以评估和量化小脑功能障碍，但眼动分析可能有助于洞察特定的小脑模式。本研究的目的是在患有运动障碍和发育正常的受试者中，调查专门设计用于揭示额叶和小脑功能障碍的各种眼动扫视任务。除了支持前额叶功能障碍的证据外，我们的结果还显示扫视准确性的变异性增加，这与小脑损伤一致。此外，我们发现患有运动障碍的患者非视觉引导扫视的速度降低。进一步分析显示，扫视速度曲线存在显著差异，最大扫视速度略有降低，但减速阶段明显延长。我们表明，这种模式与警觉性降低无关，而是提示小脑功能障碍。然而，这种模式在非视觉引导扫视中明显占主导地位，这需要其他假设。根据先前的实验和解剖学研究，我们提出这种异常模式可能是额叶区域与小脑眼动结构之间连接受损的结果。
