Crossed aphasia in a dextral patient with logopenic/phonological variant of primary progressive aphasia

Crossed aphasia is a rare phenomenon, with a prevalence of 1% to 2% among all right-handed patients. Two crossed aphasic patients with a nonfluent variant of primary progressive aphasia (PPA) have been reported previously. This report aims to document for the first time the occurrence of crossed logopenic progressive aphasia in a dextral patient.

A 57-year-old monolingual housewife presented with word-finding difficulties. She was strongly right handed, had no clinical history for brain damage to the left hemisphere, and no left handers in her family history. Her language comprised simple, grammatically correct sentences with a fluctuating speech rate and intermittent word-finding pauses. Rare phonological errors were noted. Sentence repetition tasks showed impairments with grammatically complex sentences. Comprehension was intact as were writing and reading. The language disability remained isolated for 3 years. Cranial magnetic resonance imaging depicted somewhat asymmetrical atrophy of the parietal lobes (R>L), whereas single-photon-emitted computed tomographic imaging demonstrated hypoperfusion in the right parietal cortex, indicating right hemisphere dominance for language.

This case report provides evidence that crossed PPA can present with a logopenic variant in addition to the nonfluent type demonstrated by others. Functional neuroimaging showed unexpected right-sided hypoperfusion in this case with only subtle structural brain asymmetry, implicating a reverse pattern of language dominance.