Treating a semantic word production deficit in aphasia with verbal and gesture methods

from Aphasiology

Background: Anomia is a common and pervasive word production deficit following stroke. One type of word production deficit concerns primary impairment at the lexical-semantic level. Overall, there is a lack of published studies reporting the effects of therapy for specific semantic-level impairments (Nickels, 2002), and the results from the few existing studies focusing on verbal treatments have varied considerably. Arm and hand gestures have also been suggested as a possible treatment method/modality for word production impairments (Rao, 2001; Rose, Douglas, & Matyas, 2002; Skelly, Schinsky, Smith, & Fust, 1974). Multi-modality treatments have been promoted as being more efficacious than single-modality treatments in the field of speech language pathology, but there is minimal empirical evidence to support this proposal. Overall, speech-language pathologists have little evidence on which to base their choice of gesture or verbal treatment methods.

Aims: This study aimed to investigate the relative efficacy of gesture, verbal, and combined verbal plus gesture treatments for an individual with chronic, mild, aphasic word production difficulties arising from lexical-semantic impairment.

Methods & Procedures: JB, a 51-year-old female, participated in the study. JB sustained a singe, left, discrete peri-sylvian infarction 40 months prior to the study, which resulted in a mild category-specific anomic aphasia. JB participated in a controlled multiple-baseline single-case experiment comparing the efficacy of the three treatments in the context of carefully balanced sets of words selected from the categories of tools, animals, and musical instruments.

Outcomes & Results: Large, statistically significant, and clinically relevant treatment effects were found for all three treatment conditions and there were no significant differences between conditions. Improvements made in word production were maintained at both the 1-month and 3-month follow-up assessments. Generalisation of enhanced word production was found for untrained exemplars of trained items, and for some untrained items, as well as to use in procedural discourse tasks.

Conclusions: The results support the potency of a semantic feature analysis type treatment for lexical-semantic impairment. However, the results caution clinicians to question the superiority of combined gesture and verbal treatments for semantic-level word production impairments. Consistent with our previous work (Rose & Douglas, 2001, 2002, in press), it is suggested that the underlying treatment strategy, in this case knowledge about object shape and function, was a more potent factor in treatment outcome than the modality (gesture versus verbal) in which the strategy was presented.