Latorre Anna, Humaidan Kais, Sanna Mauro, Lavena Maria Lucrezia, Pittalis Sara, Raimondi Clio, Casula Elias Paolo, Rocchi Lorenzo
Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, University College London, London WC1N 3BG, UK.
Department of Medical Sciences and Public Health, University of Cagliari, 09124 Cagliari, Italy.
Brain Sci. 2025 Apr 24;15(5):440. doi: 10.3390/brainsci15050440.
: The cerebellum plays a crucial role in motor control, but its direct electrophysiological investigation in humans is challenging. Electrocerebellograms (ECeGs), recorded via surface electrodes below the inion, have been proposed as a non-invasive method to assess cerebellar activity. However, its interpretation is complicated by potential interference from occipital alpha rhythms and neck muscle signals. This study aimed to investigate whether ECeG signals genuinely reflect cerebellar involvement during upper limb movement and to explore possible confounding influences. : We recorded electroencephalograms (EEGs) from occipital (Oz) and cerebellar electrodes (Cb1 and Cb2), alongside EMGs from forearm muscles in healthy individuals performing sinusoidal (1 Hz) and tremor-like (4 Hz) wrist movements. To assess occipital contamination, recordings were obtained under both eyes-open and eyes-closed conditions. : Occipital alpha power was present in Cb1 and Cb2 but was less affected by eye-opening than at Oz, suggesting a partially distinct neural source. During the tremor condition, movement-frequency power increased at Cb2 and C3 (corresponding to the ipsilateral cerebellar hemisphere and contralateral motor cortex), indicating authentic cerebellar activity. No significant movement-related EEG changes were observed during sinusoidal movements, likely due to weaker neuronal synchronization. : These findings suggest that ECeGs can detect cerebellar signals linked to movement, especially during faster and rhythmic motions, and are only moderately affected by occipital contamination. This supports the feasibility of non-invasive cerebellar electrophysiology and underscores the need for further methodological refinement to enhance signal specificity.
小脑在运动控制中起着关键作用，但其在人体中的直接电生理研究具有挑战性。通过枕外隆凸下方的表面电极记录的脑电小脑图（ECeGs）已被提议作为一种评估小脑活动的非侵入性方法。然而，枕部阿尔法节律和颈部肌肉信号的潜在干扰使其解读变得复杂。本研究旨在调查ECeG信号是否真的反映上肢运动过程中小脑的参与情况，并探讨可能的混杂影响。：我们记录了健康个体在进行正弦波（1 Hz）和震颤样（4 Hz）腕部运动时，枕部（Oz）和小脑电极（Cb1和Cb2）的脑电图（EEGs），以及前臂肌肉的肌电图。为了评估枕部污染情况，在睁眼和闭眼条件下均进行了记录。：Cb1和Cb2存在枕部阿尔法功率，但比Oz受睁眼的影响小，这表明其神经源部分不同。在震颤状态下，Cb2和C3（分别对应同侧小脑半球和对侧运动皮层）的运动频率功率增加，表明存在真实的小脑活动。在正弦波运动期间未观察到与运动相关的显著脑电图变化，可能是由于神经元同步性较弱。：这些发现表明，ECeGs能够检测与运动相关的小脑信号，尤其是在更快和有节律的运动期间，并且仅受到枕部污染的中度影响。这支持了非侵入性小脑电生理学的可行性，并强调了进一步完善方法以提高信号特异性的必要性。
