Creutzfeldt-Jakob disease (CJD) can occasionally present with a clinical picture resembling a corticobasal degeneration (CBD). Transcallosal inhibition, as tested by focal transcranial magnetic stimulation, is frequently absent or highly disrupted in CBD patients. We report a case of CJD presenting at the beginning of the disease as a CBD in which the ipsilateral silent period (iSP) was present and well detectable. This brief report shows that study of the iSP may be a useful diagnostic tool in order to differentiate CBD from syndromes presenting with similar clinical features.