Electroencephalography in Primary Progressive Aphasia and Apraxia of Speech.

This was a preliminary report of only three patients with nonfluent/agrammatic progressive aphasia and five patients with primary progressive apraxia of speech, so the findings cannot be treated as diagnostic evidence. The authors state that the small sample size limits interpretation. Diagnoses were made from clinical presentation, and the authors note the absence of imaging-supported criteria for nonfluent/agrammatic progressive aphasia as a limitation. MRI findings were non-specific and age-related, so they did not differentiate the clinical groups. One patient with nonfluent/agrammatic progressive aphasia was the exception to theta slowing and showed excess beta activity, and the authors say alternative explanations have not been identified. The study did not use quantitative EEG or longitudinal follow-up, which the authors identify as needed for future work.

Do not conclude that EEG can diagnose or separate apraxia of speech from aphasia in routine practice. This was a preliminary clinical series of only three patients with nonfluent/agrammatic progressive aphasia and five patients with primary progressive apraxia of speech, and the authors state that the small sample size limits interpretation.