Treatment for lexical retrieval impairments in primary progressive aphasia: a research update with implications for clinical practice

Lexical retrieval impairments (also known as anomia or word-finding deficits) are an early and prominent symptom in primary progressive aphasia (PPA), causing distress and frustration to individuals with PPA and their communication partners, and prompting research on lexical retrieval treatment. This paper reviews the research on lexical retrieval treatment in PPA from the earliest reports in the 1990s to early 2018 and considers the implications of this research for clinical practice. The number of published studies has increased markedly over the past decade, consisting primarily of behavioral studies, with rapid recent growth in noninvasive brain stimulation studies. Five general treatment techniques were identified in the behavioral studies, described here as standard naming treatment, Look, Listen, Repeat treatment, cueing hierarchies, semantically focused treatments, and lexical retrieval in context. Across techniques, behavioral studies targeting difficult-to-retrieve items typically report immediate gains, and there is evidence these gains can be maintained over months to years by some participants who continue with long-term treatment. There is also evidence that prophylactic treatment supports retrieval of treated items compared with untreated items. There is limited evidence for generalization of treatment to untreated items, suggesting the primary aim of lexical retrieval treatment in this population is to maintain retrieval of a core vocabulary for as long as possible. Language and cognitive assessment and piloting of the intended treatment can inform decisions about treatment selection and participant suitability for long-term lexical retrieval treatment. The paper concludes with some questions to guide clinical decision making about whether to implement or continue with a behavioral lexical retrieval treatment.