Aphasia
Broca area refers to the pars triangularis (PT) and pars opercularis (POP) of the dominant (typically left) inferior frontal gyrus. The pars orbitalis (POR), PT and POP comprise the inferior frontal gyrus. The POR is separated from the PT by the anterior horizontal ramus (AHR) of the lateral sulcus. The anterior ascending ramus (AAR) of the lateral sulcus separates PT from POP. [IFS = inferior frontal sulcus; PCS = inferior extent of the precentral sulcus]
In this exam, axial T2, sagittal T1 post contrast and coronal FLAIR MR images of the brain demonstrate an expansile T2/FLAIR hyperintense non enhancing mass involving the left pars triangularis (PT) and pars opercularis (POP) of the left inferior frontal gyrus as well as the insula. The mass was resected and pathology was consistent with an oligodendroglioma.
Broca area is involved in the motor component of speech production. Broca aphasia is an expressive aphasia characterized by non-fluent, scarce production of speech, with poor articulation in the form of short sentences with only a few words.
Axial diffusion-weighted and sagittal T2-FLAIR images demonstrate areas of restricted diffusion with associated T2-FLAIR hyperintense signal involving the left posterior superior temporal (STG) and supramarginal gyri (SMG), consistent with early subacute infarct
Wernicke’s area was classically thought to be involved in speech comprehension, although modern evidence indicates a role in speech production, including phonologic retrieval, as well as the monitoring, feedback and correction of self-produced speech.
Lesions involving Wernicke’s area lead to speech errors known as phonemic paraphasic errors, in which the phonemes (consonant or vowel sounds distinguishing one word from a different but similar word) are chosen incorrectly. These errors are cardinal features of Wernicke’s aphasia, a type of fluent aphasia.