Corticomuscular Coherence: a Novel Tool to Assess the Pyramidal Tract Dysfunction in Spinocerebellar Ataxia Type 2

• Published in: Cerebellum (London, England) England), 2017-04, Vol.16 (2), p.602-606
• Main Authors: Velázquez-Pérez, Luis, Tünnerhoff, Johannes, Rodríguez-Labrada, Roberto, Torres-Vega, Reidenis, Belardinelli, Paolo, Medrano-Montero, Jacqueline, Peña-Acosta, Arnoy, Canales-Ochoa, Nalia, Vázquez-Mojena, Yaimeé, González-Zaldivar, Yanetza, Auburger, Georg, Ziemann, Ulf
• Format: Article
• Language: English
• Subjects: Adult; Aged; Ataxin-2 - genetics; Biomedical and Life Sciences; Biomedicine; Electroencephalography; Electromyography; Female; Humans; Lower Extremity - physiopathology; Male; Middle Aged; Muscle, Skeletal - physiopathology; Mutation; Neural Conduction - physiology; Neurobiology; Neurology; Neurosciences; Pyramidal Tracts - physiopathology; Severity of Illness Index; Short Report; Signal Processing, Computer-Assisted; Spinocerebellar Ataxias - diagnosis; Spinocerebellar Ataxias - genetics; Spinocerebellar Ataxias - physiopathology; Transcranial Magnetic Stimulation; Upper Extremity - physiopathology; Young Adult
• ISSN: 1473-4222; 1473-4230
• DOI: 10.1007/s12311-016-0827-4

Clinical signs of corticospinal tract dysfunction are a common feature of spinocerebellar ataxia type 2 (SCA2) patients. The objective of this study is to assess dysfunction of the corticospinal tract in SCA2 using corticomuscular coherence. Testing corticomuscular coherence and rating of ataxia severity and non-ataxia symptoms were performed in 19 SCA2 patients and 24 age-matched controls. Central motor conduction times (CMCT) to upper and lower right limbs were obtained for the SCA2 group using Transcraneal magnetic stimulation (TMS). SCA2 patients exhibited a significant reduction of corticomuscular coherence for lower limbs, but not for upper limbs. This difference remained significant, even when excluding those individuals with clinical signs of corticospinal tract dysfunction. Corticomuscular coherence for lower limbs correlated inversely with CMCT to tibialis anterior muscle. Corticomuscular coherence could be a valuable electrophysiological tool to assess the corticospinal tract involvement in SCA2, even in the absence of clinical signs of corticospinal tract dysfunction.