Review Question - QID 108435

This presentation is most consistent with Broca’s aphasia, a nonfluent aphasia that spares language comprehension. Broca’s aphasia is caused by damage to Broca’s area located in the inferior frontal gyrus.

Speech deficits can be divided into motor/articulation disorders (such as dysarthria or airway deficits) and central processing disorders (classified as aphasia). Aphasia is categorized according to three characteristics: language production and fluency (governed by Broca's area in the inferior frontal gyrus), language comprehension and syntax (governed by Wernicke's area in the superior temporal gyrus), and repetition (governed by the arcuate fasciculus that connects these two areas). Each of these aspects should be evaluated for deficits prior to determining the type of aphasia present. The lack of repetition classifies a defect as Broca’s aphasia (whereas preserved repetition would be called a transcortical motor aphasia). Broca’s area is located in the inferior frontal gyrus.

Incorrect Answers:
Answer 2: The superior temporal gyrus contains Wernicke’s area, the major center for language comprehension and meaning. Damage to this area causes Wernicke’s aphasia in which the patient has fluent speech that is lacking in meaning. The patient is also unable to understand instructions nor repeat them.

Answer 3: The arcuate fasciculus serves to connect Broca’s area with Wernicke’s area and allows language to be relayed between the two centers. Loss of the arcuate fasciulus causes conduction aphasia in which both fluency and comprehension are preserved but ability to repeat is lost.

Answer 4: Damage to the watershed zone surrounding the primary language centers leads to loss of both fluency and comprehension. Remarkably, if the arcuate fasciculus is spared, the patient is still able to repeat language despite neither being able to understand nor produce language independently. This syndrome is due to isolation of language from the rest of the brain and is known as mixed transcortical aphasia.

Answer 5: The precentral gyrus contains the primary motor cortex. Damage to this region can lead to language difficulties by causing dysarthria. This patient has an aphasia as discussed above.

Bullet Summary:
Broca's aphasia results from injury to the inferior frontal gyrus causing a nonfluent aphasia with intact comprehension, and repetition is also impaired.