View source for WBR0579

{{WBRQuestion
|QuestionAuthor={{Rim}} (Reviewed by {{YD}})
|ExamType=USMLE Step 1
|MainCategory=Anatomy, Pathophysiology
|SubCategory=Neurology
|MainCategory=Anatomy, Pathophysiology
|SubCategory=Neurology
|MainCategory=Anatomy, Pathophysiology
|SubCategory=Neurology
|MainCategory=Anatomy, Pathophysiology
|MainCategory=Anatomy, Pathophysiology
|MainCategory=Anatomy, Pathophysiology
|SubCategory=Neurology
|MainCategory=Anatomy, Pathophysiology
|SubCategory=Neurology
|MainCategory=Anatomy, Pathophysiology
|SubCategory=Neurology
|MainCategory=Anatomy, Pathophysiology
|SubCategory=Neurology
|MainCategory=Anatomy, Pathophysiology
|MainCategory=Anatomy, Pathophysiology
|SubCategory=Neurology
|Prompt=A 65-year-old woman is being evaluated for speech dysfunction in the stroke unit. During history taking, she is able to initiate speech and respond fluently in full meaningful sentences. Also, she succeeds in naming objects that the physician points to. During the assessment, the physician asks the patient to repeat the sentence: "No ifs ands or buts"; however, the patient is unable to do so. Which area in the brain is most likely affected by the stroke and is responsible for this patient's speech dysfunction?
|Explanation=The patient suffered from stroke and is exhibiting a form of aphasia characterized by the inability to repeat sentences in the absence of any impairment of comprehension or speech fluency. All these features are consistent with conduction aphasia. Conduction aphasia is caused by involvement of the arcuate fasciculus that links the Wernicke's area to the Broca's area. There are several types of aphasias:
* Wernicke's aphasia: impaired comprehension, intact speech fluency, and impaired repetition.
* [[Broca]]'s aphasia: intact comprehension, impaired speech fluency, and impaired repetition.
* Global aphasia: impaired comprehension, impaired speech fluency, and impaired repetition.
* Conduction aphasia: intact comprehension, intact speech fluency, and impaired repetition.

Shown below is an image that depicts the different areas involved aphasias.<br>
[[Image:Aphasia.gif|500px]]
|AnswerA=Superior temporal gyrus
|AnswerAExp=[[Wernicke's aphasia]] is a speech dysfunction characterized by impaired comprehension, intact speech fluency, and impaired repetition. It results from damage to the superior temporal gyrus.  Wernicke's aphasia is also known as sensory or receptive aphasia.
|AnswerB=Inferior frontal gyrus
|AnswerBExp=[[Broca's aphasia]] is a speech dysfunction characterized by intact comprehension, impaired speech fluency, and impaired repetition. It results from damage to the inferior frontal gyrus. Broca's aphasia is also known as motor or expressive aphasia.
|AnswerC=Superior temporal and frontal gyri
|AnswerCExp=[[Global aphasia]] is a speech dysfunction characterized by impaired comprehension, impaired speech fluency, and impaired repetition. It results from damage to a larger area of the brain involving the superior temporal and inferior frontal gyri.
|AnswerD=Arcuate fasiculus
|AnswerDExp=Conduction aphasia is a speech dysfunction characterized by intact comprehension, intact speech fluency, and impaired repetition. It results from damage to the [[arcuate fasciculus]].
|AnswerE=Area between the supplementary motor area and the frontal perisylvian speech zone
|AnswerEExp=Transcortical motor aphasia is a speech dysfunction characterized by impaired comprehension, impaired speech fluency, and intact repetition. It results from damage to the area between the supplementary motor area and the frontal perisylvian speech zone.
|EducationalObjectives=Conduction aphasia is a speech dysfunction characterized by intact comprehension, intact speech fluency, and impaired repetition. It results from damage to the [[arcuate fasciculus]].
|References=First Aid 2014 page 457
|RightAnswer=D
|WBRKeyword=Aphasia, Conduction aphasia, Arcuate fasciculus, Stroke, Speech, Dysfunction, Speech dysfunction
|Approved=No
}}