Review Question - QID 217290

This patient with a history of stroke who is able to comprehend and follow simple commands but cannot communicate verbally or via written text has Broca aphasia, which results from a lesion involving Broadman area 44 and 45. This is due to an infarct of the superior division of the left middle cerebral artery as denoted in area B of the figure.

Broca aphasia is a non-fluent type of aphasia due to a lesion to a region supplied by the middle cerebral artery (Broadmann area 44 and 45) of the dominant hemisphere of the brain, which controls language. It results in a condition in which the output of spontaneous speech is markedly diminished and there is a loss of normal grammatical structure. Characteristically, patients can become very frustrated as their comprehension is intact. The ability to communicate via writing is also affected. The most common cause is a stroke involving the dominant inferior frontal lobe or Broca area. There is no therapy for this type of aphasia although ongoing speech and language therapy are essential.

Acharya et al. describe the nuanced differences between aphasia, dysarthria, and how Broca aphasia is a manifestation of cortical lesion resulting in expressive aphasia but not dysarthria.

Figure A/Illustration A depicts that Broca aphasia involves a lesion of Broadman area 44 and 45 as denoted by the letter B.

Incorrect Answers:
Answer 1: A denotes a lesion to the brain stem in the area of the red nucleus, which could result in “locked-in syndrome”, which is a condition in which patients are conscious and awake, but have no ability to produce movements apart from eye motions. They are unable to speak. However, functionally, they are incapable of anything more than communication via eye movements, unlike this patient who is able to follow commands.

Answer 3: C denotes a lesion to the Wernicke area (Broadmann area 22), representing a lesion to the inferior division of the left middle cerebral artery. It results in no deficits in fluency, however, patients are unable to comprehend what is being said to them. As such, they are able to speak unhindered but seemingly nonsensically, unlike this patient who is unable to speak but can follow commands.

Answer 4: D denotes a lesion to the arcuate fasciculus that leads to conduction aphasia, which results in deficits in repetition. Patients have comprehension and fluency of speech but are unable to repeat what is said to them. This is unlike in this patient who has expressive aphasia.

Answer 5: E denotes a lesion in the cerebellum, which would present with ataxia and dysdiadochokinesia. While motor function is affected with lesions to this region, aphasia is not present.

Bullet Summary:
Broca aphasia results from a lesion involving Broadman’s area 44 and 45, which is due to an infarct of the superior division of the left middle cerebral artery.