Primary progressive aphasia (PPA) is a neurodegenerative disorder characterized by progressive deterioration of language. Being rare, reports of PPA in multilingual individuals are scarce, despite more than half of the world population being multilingual.
We describe clinical characteristics of 33 bilingual patients with PPA, including symptom presentation and language deficits pattern in their first (L1) and second language (L2), through a systematic literature review and new cases retrospectively identified in 5 countries.
In total, 14 patients presented with nonfluent/agrammatic variant, 6 with semantic variant, and 13 with logopenic variant, with a median symptom onset of 2 years. Word-finding difficulties was the first symptom in 65% of all cases, initially noticed in L2, and not always the dominant language. Our group had 22 different languages as L1, and 9 as L2. At the whole-group level there was a tendency for parallel impairment in both languages, in line with the shared bilingual neural substrate hypothesis, but each PPA variant showed some heterogeneity.
Each PPA variant showed heterogeneity, showing the need for comprehensive language and cognitive assessment across languages, as well as further clarification on the role of language mediators.
*Neurocognition Unit, Department of Neurology, Hospital de Braga, Sete Fontes‐São Victor, Braga, Portugal
§Rotman Research Institute, 3560 Bathurst Street, North York, Ontario
∥University of Toronto, 500 University Avenue, Toronto, Canada
¶Department of Neurology, Hospital 12 de Octubre
#Imas12. CIBERNED. Universidad Complutense de Madrid, Avda. de Córdoba, Madrid, Spain
**Department of Neurology, University of Washington, 325 Ninth Ave Box 359791, Seattle, WA
†Department of Neurology, RWTH Aachen University, Pauwelsstr, Aachen
‡JARA-BRAIN Institute Molecular Neuroscience and Neuroimaging, Forschungszentrum Jülich GmbH, Jülich and RWTH Aachen University, Aachen, Germany
The authors declare no conflicts of interest.
Reprints: Ana S. Costa, PhD, Department of Neurology, RWTH Aachen University, Pauwelsstr. 30, 52074 Aachen, Germany (e-mail: firstname.lastname@example.org).
Received May 9, 2018
Accepted October 22, 2018