SECT and MAST: new tests to assess grammatical abilities in primary progressive aphasia

Abstract

Background: The presence/absence of agrammatism is critical for the classification of the different subtypes of primary progressive aphasia (PPA). Its quantitative evaluation is, however, a challenge in clinical practice because there are few brief, reliable, and easy-to-administer tests. Linguistic analysis of connected speech is the gold standard but is impractical outside the research setting.Aims: To tackle the need for brief grammatical tests, we developed the SEntence Comprehension Test (with auditory and visual versions, SECT A and V) and the Make A Sentence Test (MAST).Methods & Procedures: The tests were given to 92 participants (41 PPA patients, 21 Alzheimer’s disease patients, and 30 controls) from the Cambridge Longitudinal Study of PPA. Classification of the different subtypes of PPA was made purely on clinical assessment to avoid circularity from using the tests for diagnostic purposes. In addition, speech samples were recorded during a face-to-face semi-structured interview and all participants completed a standard neuropsychological battery as well as the three new tests.Outcomes & Results: All patients were impaired relative to controls on the SECT A and V. After controlling for semantic impairment, only the mixed variant of PPA (mPPA) and the non-fluent variant of PPA were impaired on the MAST. When controlling for working memory in SECT A, the mPPA only remained impaired. Regression analyses demonstrated that performance on the SECT A and V, and the MAST, was strongly related to measures of the patients’ spontaneous speech, particularly the number of grammatical errors and the percentage of abandoned and elliptical sentences. Performance on the SECT A was also significantly predicted by speech rate.Conclusion: The SECT and the MAST are brief tests capable of reflecting grammatical difficulty in spontaneous speech.