Neurological Aspects of Foreign Accent Syndrome in Stroke Patients

Foreign Accent Syndrome (FAS) is an intriguing motor speech disorder which has captured the interest of the scientific community and media for decades. At the moment, there is no comprehensive model which can account for the pathophysiology of this disorder. This paper presents a review of 112 FAS cases published between 1907 and October 2016: these were analyzed with respect to demographic characteristics, lesion location, associated neurocognitive symptoms, and comorbid speech and language disorders. The analysis revealed that organic-neurogenic FAS is more frequent in women than in men. In organic-neurogenic FAS over half of the patients acquired the foreign accent after a stroke. Their lesions are typically located in the left supratentorial regions of the brain, and generally involve the primary motor cortex and premotor cortex (BA 4 and 6), and/or the basal ganglia. Although neurocognitive data are not consistently reported, vascular FAS patients regularly suffer frontal executive dysfunctions. On the basis of a careful comparison of the cognitive and theoretical accounts of FAS, AoS and ataxic dysarthria, it is concluded that FAS should be regarded a dual component motor speech disorder in which both planning and motor execution of speech may be affected.