Speech disturbances due to left precentral cortical lesions

We encountered two patients with lesions predominantly localized to the left precentral cortex who presented with speech disorders. Patient 1 had a lesion localized to the anterior part of the left precentral cortex along the precentral sulcus, in the middle part of the convexity. Patient 1 predominantly exhibited disturbance of prosody. Patient 2 had a lesion localized to the left precentral cortex, located slightly more posterior and more inferior in the convexity. Patient 2 predominantly exhibited disturbance of articulation, with distortion of sounds without apparent inconsistency. Even lesions localized to the left precentral cortex present with various types of speech disturbance.