Lost for words

Primary progressive aphasia (PPA) was first recognized as a clinical syndrome more than two decades ago, as a selective deterioration in language for at least 2 years.¹ Two distinct forms were initially described: fluent and nonfluent. However, the distinction between fluent and nonfluent types of PPA produced little consensus or clarity. Because fluency is multidimensional, there was also little agreement among experts in the field on the language characteristics of “fluent” PPA. For some, the fluent/nonfluent distinction was based on rate or melody of speech, while for others the distinction was based on grammaticality or facility of speech articulation. Patients whose speech was hesitant and anomic, but who did not have a motor speech impairment or agrammatism, were characterized as fluent by some authors and nonfluent by others. This discrepancy may have led to the conflicting results regarding the most common etiology of “nonfluent” PPA,^2,3 if studies included different types of patients in this category. Gorno-Tempini and colleagues⁴ first separated PPA into three subtypes, recognizing that patients …