Aphasia in vascular lesions of the basal ganglia: A comprehensive review

- Past attempts to set an aphasia profile in basal ganglia lesions was unfruitful.
- Perfusion studies disclosed that such aphasias were often due to cortical lesions.
- Our aim was to review clinico-anatomical correlations in subcortical aphasia.
- Lenticular nucleus was the most associated with aphasic symptoms.
- Follow-up studies support a role of cortical hypoperfusion in basal ganglia aphasia.

Between 1970 and 1990, the study of aphasia secondary to subcortical lesions (including the basal ganglia - BG) was largely driven by the advent of modern neuroimaging techniques such as MRI and PET. However, attempts to characterize a pattern of language abnormalities in patients with basal ganglia lesions proved unfruitful. We conducted a comprehensive review of language disturbances after vascular lesions in the BG. Literature search in Medline and LILACS (1966-2016) and PsychINFO (last 25 years) was conducted, and returned 145 articles, with 57 eligible for the review yielding data on 303 patients. We report the clinical and neuroimaging features of these cases. Results showed that aphasias caused by BG lesions are heterogeneous with weak clinicoanatomical correlations. Data derived from follow-up and flow/metabolism studies suggest that subcortical aphasia caused by BG lesions involves hypoperfusion in the cortical territories of the middle cerebral/internal carotid arteries (MCA/ICA) and their branches.