Updated: Jul 6, 2020
Acquired Apraxia of Speech
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 apraxia of swallowing. AOS does not 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; and
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 (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.
Consonant errors greater than vowel errors
Voicing errors (blurred distinctions between boundaries of voiced–voiceless consonants)
Telescoping of syllables (e.g., "disaur" instead of "dinosaur")
Rate and Prosody
Slow overall rate, regardless of accuracy of productions
Alternative motion rates (AMRs) that may be characterized by place or manner errors
Poorly sequenced sequential motor rates (SMRs)
Disrupted fluency with attempts at self-correction
Difficulty initiating articulatory sequences—may be accompanied by audible or silent groping behaviors marking false starts and restarts
Sound and syllable repetitions
Other Problems That Can Co-Occur With AOS
Linguistic and non-speech / non-oromotor features that are observed during clinical presentation typically depend on the site of lesion and comorbid conditions. These include the following:
Aphasia—language comprehension and/or production deficits
Dysarthria—motor speech disorder characterized by impaired neuromuscular speech movements due to weakness or paralysis, spasticity, incoordination, involuntary movements, or reduced movement range
Nonverbal oral apraxia—difficulty programming orofacial musculature for non-speech movements
Apraxia of swallowing—difficulty programming muscles of the head and neck for coordinated swallowing
Limb apraxia—difficulty programming purposeful limb movements, often of both extremities
Varying degrees of right-sided weakness and spasticity
The goal of intervention is to help the patient achieve the highest level of independent function for participation in daily living. Intervention is designed to:
capitalize on strengths and address weaknesses related to underlying structures and functions that affect communication;
facilitate the individual's activities and participation toward the acquisition of new skills and strategies; and
modify contextual factors that serve as barriers and enhance those that facilitate successful communication and participation, including development and use of appropriate accommodations.
For patients with AOS, treatment goals focus on facilitating the efficiency, effectiveness, and naturalness of communication by
improving speech production and intelligibility and, when indicated,
using augmentative and alternative forms of communication (AAC), such as gestures, manual signs, electronic speech output devices, and context-specific communication boards.
Barriers to successful communication and participation can be minimized for individuals with AOS by
modifying the environment (e.g., reducing background noise, maintaining eye contact, and decreasing the distance between speaker and listener);
informing listeners about the individual's communication needs and his or her preferred method of communication; and
encouraging the speaker to use strategies for repairing breakdowns in communication (e.g., repeating, rephrasing, using gestures, writing).
Below are brief descriptions of treatment options for addressing AOS, grouped by approach. This list is not exhaustive
Multiple Input Phoneme Therapy (MIPT)
Sound Production Treatment (SPT)
Speech Motor Learning (SML) Approach
Sensory Cueing Approaches
Integral Stimulation (IS)
Rate and Rhythm Control Approaches
Melodic Intonation Therapy (MIT)
Metrical Pacing Treatment (MPT)
Augmentative and Alternative Communication (AAC)