Pure anarthria due to precentral gyrus infarction: fMRI study

Isolated pure anarthria (aphemia) due to precentral gyrus lesion is considered rare1, 2, 3. We describe five patients who presented with pure anarthria as their isolated or major symptom following a precentral gyrus infarction. Their speech were effortful, non fluent and dysprosodic. However, their language comprehension, repetition and naming abilities were normal. There were no buccofacial or pharyngeal muscle dysfunction. The demography and clinical characteristics of the patients are summarized in the table. The lesions were located on the left precentral gyrus in two (case 1 and 2) and on the right in three (case 3, 4, and 5) (figure). All patients were right handed. Four patients (case. 1, 2, 4 and 5) had atrial fibrillation and one (case 3) had patent foramen ovale with right to left shunt. The patients were studied using whole brain functional magnetic resonance imaging (fMRI) (Semens, 1.5T, echo planner imaging, bloodoxygenation-level dependent) with three tasks (naming, verb generation, categorization) to assess language dominant hemisphere4. fMRI showed left dominance of language in all patients. These results showed that pure anarthria was not related to language lateralization. Then, pure anarthria may not be aphasia but may be motor dysfunction or dysfunction of the lower system of language.