Progressive crossed-apraxia of speech as a first manifestation of a probable corticobasal degeneration.

We present the longitudinal neurolinguistic, neuropsychological and neurologic follow-up of a 64 y.o. right-handed woman, who developed progressive apraxia of speech (PAOS), followed by peripheral agraphia then a left corticobasal syndrome (CBS). Neuroimaging (CT, MRI and FDG-PET) unequivocally showed progressive right hemispheric atrophy and hypometabolism. This particular evolution first confirms that PAOS is a phenotype of probable corticobasal degeneration (CBD). More importantly, this case underpins the neural organisation of motor planning processing in relation with speech, as well as graphic and limb praxis impairments, and constitutes a rare example of crossed-PAOS.