Four patients with primary progressive aphasia displayed a greater deficit in understanding words they heard than words they read, and a further deficiency in naming objects orally rather than in writing. All four had frontotemporal lobar degeneration-transactive response DNA binding protein Type A neuropathology, three determined postmortem and one surmised on the basis of granulin gene (GRN) mutation. These features of language impairment are not characteristic of any currently recognized primary progressive aphasia variant. They can be operationalized as manifestations of dysfunction centered on a putative auditory word-form area located in the superior temporal gyrus of the left hemisphere. The small size of our sample makes the conclusions related to underlying pathology and auditory word-form area dysfunction tentative. Nonetheless, a deeper assessment of such patients may clarify the nature of pathways that link modality-specific word-form information to the associations that mediate their recognition as concepts. From a practical point of view, the identification of these features in patients with primary progressive aphasia should help in the design of therapeutic interventions where written communication modalities are promoted to circumvent some of the oral communication deficits.
*Mesulam Center for Cognitive Neurology and Alzheimer’s Disease
§Department of Pathology, Northwestern University Feinberg School of Medicine, Chicago, Illinois
†Department of Psychology, Cleveland State University, Cleveland, Ohio
‡Department of Neuroscience, Mayo Clinic, Jacksonville, Florida
Present address: JungMoon Hyun, PhD, Hunter College, New York, New York.
Supported in part by grants from the National Institute on Deafness and Other Communication Disorders (RO1 008552) and the National Institute on Aging (AG13854) to M.-M.M., and from the National Institute of Neurological Disorders and Stroke (R35 NS097261 to R.R., T32 NS047987).
The authors declare no conflicts of interest.
Correspondence: Marek-Marsel Mesulam, MD, Mesulam Center for Cognitive Neurology and Alzheimer’s Disease, Northwestern University, 320 East Superior St, Chicago, Illinois 60610 (e-mail: firstname.lastname@example.org).
Received August 10, 2018
Accepted December 7, 2018