Primary progressive “anarthria / apraxia of speech (AOS)”

Abstract

   Apraxia of anarthria/ apraxia of speech (ASO) and dysarthria are two major components of motor speech disorder. Recently, progressive anarthria/ASO has attracted much attention in the diagnosis of progressive nonfluent aphasia. So far only a few cases of primary progressive anarthria/ASO have been reported. Although about half the patients with FTLD-Tauopathy exhibit frontal lobe signs, the clinicopathology is unclear.
   Here, we describe two patients with primary progressive “anarthria/ASO”. We retrospectively analyzed the clinical features of two cases of neurodegenerative disease, whose symptoms were primary progressive “anarthria/ASO” and dementia. One of them came to autopsy. We compared distributions of pathological findings with clinical features. The main symptom of speech disorder was “anarthria/ASO”, involving effortful, halting speech with inconsistent speech, sound errors and distortions. Neither atrophy nor fasciculation of the tongue was observed. Neuropathologically, frontal lobe degeneration including the precentral gyrus was observed.