To characterize the initial diagnosis and time to final diagnosis in patients with progressive apraxia of speech (PAOS) in order to better understand the reasons for possible delays.

PAOS is a neurodegenerative disorder of speech programming distinct from aphasia and dysarthria due to a 4-repeat tauopathy. Emerging from our observations in the behavioral neurology clinic, patients with PAOS may receive delayed or misdiagnosis. 

Seventy-seven consecutive PAOS research participants from the Neurodegenerative Research Group were included in this study.  Clinical data abstracted included the date of onset of symptoms, the initial and final clinical diagnoses, and demographic features. For each speech-related visit, data such as the chief complaint, clinical findings, and neuroimaging findings were recorded.

Apraxia of speech was the initial diagnosis in 20.1% of participants.  Other common diagnosis included primary progressive aphasia (20.1%), dysarthria (18.18%), MCI/Dementia (6.5%), and motor neuron disease (3.9%).  Mean time from symptom onset to initial diagnosis was 2.4 years (Range: 0.16-8.18) and mean time to a diagnosis of PAOS was  3.4 years (Range: 0.49-9.42).  Those who received an correct initial diagnosis of PAOS were more likely to have been evaluated by a speech-language pathologist (14/16) compared to those who were not (34/61) (p=0.02).

Approximately 80% of patients with PAOS were misdiagnosed at first visit, with it taking on average 3.4 years from symptom onset to receiving a diagnosis of PAOS.  Being seen by a speech-language pathologist during the initial evaluation increased the likelihood of an early apraxia of speech diagnosis.