hod is caused by lesions in the dentatorubral or central tegmental tracts. lesions of the superior cerebellar peduncle can also result in contralateral hod, whereas primary lesions of the central tegmental tract cause ipsilateral hod. lesions involving this circuit may produce palatal myoclonus, one of the few involuntary movements that do not disappear during sleep. palatal myoclonus may be seen as a component of the lateral medullary syndrome (a.k.a. wallenberg syndrome), if the infarction extends to involve the central tegmental tract.