A tentative classification of recessively inherited ataxias.

We present a working classification of recessively inherited ataxic syndromes based on the use of simple tools available to every clinician: a good history (particularly pinpointing the age of onset) and a good neurological examination (simplified to the verification of the presence of ataxia, deep tendon reflexes in the knee, optic nerve, retinal and/or 8th nerve signs). In the three groups of disorders (non progressive, intermittent or progressive) patients can be hyper/normo reflexic, or they can be hypo/areflexic. Six principal types of progressive ataxic disorders are further delineated by the age of onset. Sub-types depend on the presence of absence of eye and ear signs, whereas eponymic or regional denominations are used only for simplicity while awaiting exact delineation of the biochemical defects.