title: Masseter reflex in the study of spinocerebellar ataxia type 2 and type 3.
abstract: In this investigation we assess the utility of the masseter reflex for diagnostic purposes in autosomal dominant cerebellar ataxias. We studied the masseter reflex electrophysiologically in spinocerebellar ataxia type 2 (SCA2, 10 patients) and type 3 (SCA3/MJD, 13 patients). In SCA2, the masseter reflex was abnormal in 9 (90%) patients. In SCA3/MJD, the masseter reflex was normal in all 13 patients. Our findings suggest that the masseter reflex is a reliable test that provides additional data prior to molecular study in the differentiation between SCA2 and SCA3/MJD. Masseter reflex abnormalities in SCA2 patients could be better explained by dysfunction of the mesencephalic trigeminal nucleus/tract.
authors.affiliation: Service of Clinical Neurophysiology, Marqués de Valdecilla, University Hospital, Centro de Investigación Biomédica en Red de Enfermedades Neurodegenerativas, 39008 Santander, Spain. nflgga@humv.es
authors.forename: Antonio
authors.initials: A
authors.lastname: García
authors.forename: Silvia
authors.initials: S
authors.lastname: Alvarez
authors.forename: Jon
authors.initials: J
authors.lastname: Infante
authors.forename: José
authors.initials: J
authors.lastname: Berciano
mesh_terms: D000328:Adult; D000368:Aged; D003937:Diagnosis, Differential; D004594:Electrophysiology; D005260:Female; D005838:Genotype; D006801:Humans; D017827:Machado-Joseph Disease / Q000145:classification / Q000175:diagnosis* / Q000235:genetics; D008297:Male; D008406:Masseter Muscle / Q000503:physiopathology*; D008875:Middle Aged; D009431:Neural Conduction / Q000187:drug effects; D012018:Reflex / Q000502:physiology*; D020754:Spinocerebellar Ataxias / Q000145:classification / Q000175:diagnosis* / Q000235:genetics; D013497:Sural Nerve / Q000503:physiopathology