Imaging in primary progressive aphasia

Abstract

Primary progressive aphasia (PPA) presents with aphasia, with or without other minor cognitive dysfunction. We report five patients with PPA to show the correlation between their clinical signs and imaging findings. The patients can be divided into those with nonfluent (group 1) and those with fluent (group 2) aphasia. The characteristic speech impairment was bradylalia in group 1 and word amnesia in group 2. Impairment of comprehension was common but mild in both groups. On MRI, patients in group 1 showed predominantly left frontal and perisylvian atrophy with reduced uptake in the same region on single photon emission computed tomography (SPECT) using technetium-99m hexamethyl propyleneamine oxime (99mTc HMPAO). Patients in group 2 showed left temporal atrophy involving the superior, middle and inferior temporal gyri, hippocampus and parahippocampal gyrus on MRI and reduced uptake in the same region on SPECT. These findings correlated well with the functional anatomy of speech impairment.