Narrative review of the psychometric properties of language tests used in anomia treatment for primary progressive aphasia (PPA)

Background: Primary progressive aphasia (PPA) is a neurodegenerative dementia in which language decline is the first and most prominent symptom. Among several interventions for PPA, language rehabilitation has been the most frequently used.Aims: This narrative review aimed to evaluate existing standardised language tests used in the assessment of PPA, in order to determine whether they are appropriate and psychometrically adequate to detect change over time in the treatment of anomia.Main Contribution: The present findings highlight the scarcity of psychometrically robust instruments used to measure therapy-induced gains in PPA. Additionally, most of these instruments were not validated for use with the PPA population, which consequently might bias the results. There is a need for population-based norms for existing instruments.Conclusions: The accurate assessment of lexico-semantic deficits in PPA should rely on objective, reliable, valid, and responsive outcome measures. Psychometric studies are needed to evaluate and eventually improve the quality of language tests used in clinical practice.