Updated: Jul 6, 2020
Apraxia of speech (AOS) is a "neurologic speech disorder that reflects an impaired capacity to plan or program sensorimotor commands necessary for directing movements that result in phonetically and prosodically normal speech"- ASHA. AOS has also been referred to in the clinical literature as verbal apraxia or dyspraxia.
AOS frequently co-occurs with dysarthria and/or aphasia and sometimes with limb apraxia, oral apraxia, apraxia of gait, and/or apraxia of swallowing. AOS does not directly involve muscle weakness, paralysis, spasticity, or involuntary movements typically associated with dysarthria, or language comprehension or production deficits that characterize aphasia.
The salient features of AOS might include:
Reduced overall speech rate
Phoneme distortions and distorted substitutions, additions, or complications
Syllable segregation with extended intra- and inter-segmental durations
Equal stress across adjacent syllables.
These features are consistent with deficits in the planning and programming of movements for speech and are noted to increase with greater syllable length and motoric complexity.
AOS can improve over time (e.g., in acute stages of stroke recovery, in response to therapy), remain stable, or worsen overtime (e.g., primary progressive apraxia of speech).
Other Perceptual Speech Characteristics
The following other speech characteristics may not be unique to AOS and can also occur with co-existing dysarthria or aphasia.