The broad phenotypic spectrum of SCA-3: hereditary spastic paraplegia

Machado-Joseph disease (MJD) is the most frequent dominantly inherited spinocerebellar ataxia. A marked phenotypic variability is a characteristic of this disorder that could involve non-cerebellar presentations. Based on several case reports describing pyramidal dysfunction as the main symptom at onset, a clinical form resembling hereditary spastic paraplegia has been proposed. We report here two further cases of MJD patients whose initial clinical presentation suggested hereditary spastic paraplegia, and a summary of the main findings of previously similar published reports. Our findings lent support to the proposal of a MJD subtype distinguished by a marked pyramidal dysfunction at onset, simulating a clinical picture of hereditary spastic paraplegia.