Lexical retrieval treatment in primary progressive aphasia: An investigation of treatment duration in a heterogeneous case series.

Word-finding difficulty is typically an early and frustrating symptom of primary progressive aphasia (PPA), prompting investigations of lexical retrieval treatment in PPA. This study aimed to investigate immediate treatment gains following two versus four weeks of treatment, item generalisation, and maintenance of gains with ongoing treatment in a single case series of eight individuals with heterogeneous PPA presentations (three non-fluent/agrammatic, two logopenic, two semantic, and one mixed PPA). Three individuals made initial gains in picture naming and maintained them over 6 months or more with ongoing treatment. By contrast, three individuals made marginal initial gains but were unable to continue treatment, and two individuals did not make the typically-reported initial gains with two or four weeks of treatment. There was little evidence of generalisation to untreated items. Our results add to the evidence that daily home practice of Repetition and Reading in the Presence of a Picture over extended periods can increase and maintain retrieval of personally-relevant words in picture naming for some individuals with semantic or nonfluent/agrammatic variant PPA. Further research is needed into the factors associated with long-term treatment adherence and gains, and the factors associated with nonadherence to treatment.