Central motor conduction to lower limb after transcranial magnetic stimulation in spinocerebellar ataxia type 2 (SCA2)

Objectives: To evaluate central motor conduction to lower limbs in spinocerebellar ataxia type 2 (SCA2). Methods: Transcranial magnetic stimulation was performed to study the corticospinal tracts of 18 patients with SCA2. Results: Central motor conduction time (CMCT) to lower limbs and thresholds were abnormal in 8 patients (44%); CMCT and thresholds were signi®cantly correlated with disease duration and disability. Conclusions: Corticospinal tract involvement is more frequent than previously reported in SCA2. Prolonged CMCT and increased threshold should not be used to differentiate between various type of autosomal dominant cerebellar ataxia. Similar to that reported in Friedreichʹs ataxia, we suggest that examining central motor conduction to the lower limbs may assist in evaluating the progressive steps of neurodegeneration in SCA2.