Treating Apraxia of Speech as a Result of Postencephalitic Parkinsonism Using Discourse
Savage, Meghan C., Stead, Amanda L., Hoffman, Paul R., Journal of Medical Speech - Language Pathology
Keywords: apraxia, apraxia of speech, Postencephalitic parkinsonism, apraxia therapy, phoneme production
Background: The purpose of this single-subject study was to investigate if phonologic placement treatment seated in spontaneous discourse would improve phonetic accuracy and increase intelligibility in an individual with postencephalitic parkinsonism resulting in apraxia of speech.
Methods: The participant was a 60-year-old male with postencephalitic parkinsonism, oral and speech apraxia, and dysarthria. A single-subject ABAB design using pre-and posttesting and repeated measurement of phonemes during baseline and treatment was used. Phonological and visual supports were embedded within conversational discourse related to current events. Data were analyzed using visual inspection and effect sizes.
Results: Results showed a treatment effect for all targeted phonemes as well as posttest measures of overall intelligibility. Assessment of Intelligibility of Dysarthric Speech scores rose from 0% to 24% intelligible at the single word level. Large effect sizes were found for all target phonemes, /b/ (d = 2.89), /m/ (d = 4.76), (d = 1.18) and /n/ (d = 1.94).
Conclusions: A phonologically based treatment embedded in discourse was effective in facilitating basic verbal communication in a previously nonverbal individual.
Apraxia of speech (AOS) is a neurogenic speech disorder caused by unilateral damage to the left cerebral hemisphere, which results in impaired positioning and movement of articulators during volitional production of speech. It can occur without significant weakness or neuromuscular slowness and in the absence of disturbances of conscious thought or language (Duffy, 2005). Clinical manifestations of AOS include problems of speech initiation; articulatory groping; reduced rate of speech; perseverations; slow transitions between sounds, syllables, and words; and disordered prosody (Wambaugh, Duffy, McNeil, Robin, & Rogers, 2006a).
The majority of AOS treatments have been impairment oriented. Impairment-based approaches seek to remediate the underlying linguistic impairment using models of normal language and cognitive processing to structure units and levels of language organization for practice (Martin, Thompson, & Worrall, 2008). The basic tenet of this approach is that the primary access to language units is damaged. Therapy uses static noninteractive tasks that target the linguistic forms of language (Sarno, 2004). Speech tasks are presented in clinician-directed stimulus--response--feedback activities targeting an increased ability to access various sized language units. However, there is a need for more functional approaches to AOS treatments. Functional approaches, also termed social, participation, or psychosocial, address the consequences the disorder has on the person's life. Intervention targets the use of speech and language to accomplish social needs in authentic, relevant, and natural contexts such as conversations (Simmons-Mackie, 2008b). The interventionist acts as a collaborator seeking to facilitate the person's participation in the social context.
Current AOS treatments, including articulatory kinematic, rate or rhythm, intersystemic facilitation or reorganization, and alternative or augmentative communication (Wambaugh, Duffy, McNeil, Robin, & Rogers, 2006b) are primarily impairment based and rooted in principles of motor learning. Motor learning typically involves intensive practice in repetition of movement patterns that are organized in hierarchies from simple to more complex (Austermann Hula, 2007; Maas et al., 2008; McNeil, Doyle, & Wambaugh, 2000).
Articulatory-kinematic approaches currently demonstrate the highest levels of evidence (Wambaugh, 2010). Articulatory-kinematic approaches involve practice in production of: individual phonemes and syllables (Knock, Ballard, Robin, & Schmidt, 2000; Raymer, Haley, & Kendall, 2002), single words (Knock, et al. …