A 78-year-old, right-handed woman is brought to the emergency department due to confusion. Her husband states that the patient was in her usual state of health when he left the house this morning; he found her confused and exhibiting odd behavior when he returned 2 hours later. She had difficulty handling commonly used things, such as a phone, which she held upside down. Medical history includes hypertension and anxiety. Blood pressure is 138/70 mm Hg and pulse is 110/min and irregular. On physical examination, the patient is alert and attends to the examiner but does not follow instructions. She speaks fluently with clear articulation, although the content of her speech is nonsensical. The gaze is conjugate, and the pupils are equal, round, and reactive to light. Bilateral deep tendon reflexes of the upper and lower extremities are normal. Muscle strength is grossly normal, but examination is limited due to her inability to fully cooperate. Which of the following is the most likely site of the lesion causing this patient's current symptoms?

Question

A 78-year-old, right-handed woman is brought to the emergency department due to confusion.  Her husband states that the patient was in her usual state of health when he left the house this morning; he found her confused and exhibiting odd behavior when he returned 2 hours later.  She had difficulty handling commonly used things, such as a phone, which she held upside down.  Medical history includes hypertension and anxiety.  Blood pressure is 138/70 mm Hg and pulse is 110/min and irregular.  On physical examination, the patient is alert and attends to the examiner but does not follow instructions.  She speaks fluently with clear articulation, although the content of her speech is nonsensical.  The gaze is conjugate, and the pupils are equal, round, and reactive to light.  Bilateral deep tendon reflexes of the upper and lower extremities are normal.  Muscle strength is grossly normal, but examination is limited due to her inability to fully cooperate.  Which of the following is the most likely site of the lesion causing this patient's current symptoms?

Quizplus · Accepted Answer

11ec25c8_d5b2_bc29_bc81_5f961383f9af_MD0003_00 This patient has well-articulated, nonsensical speech and lack of language comprehension, findings consistent with receptive aphasia. This is most commonly caused by a lesion impacting Wernicke area, located in the caudal superior temporal gyrus of the dominant temporal lobe. In a right-handed patient, such as this one, the dominant hemisphere is nearly always the left. Although patients with Wernicke aphasia have difficulty comprehending and following commands, they typically lack insight into their condition. They speak fluently, but it is rambling and without meaning (ie, word salad). The most common cause of Wernicke aphasia is an infarct in the inferior division of the middle cerebral artery (MCA). A right upper visual field deficit is common due to disruption of the optic radiations. A lesion in this area can also impact the somatosensory association cortex, where higher-order processing of somatosensory information takes place, and the lateral parietal and temporal heteromodal association cortex, where integration of functions from multiple sensory modalities (eg, visual, somatosensory) takes place. This can lead to difficulty using objects, as seen in this patient. Because the superior division of the MCA supplies the primary motor cortex, motor function is often spared in Wernicke aphasia. inferior division of the middle cerebral artery (MCA) superior division of the MCA (Choice A) Brainstem strokes could produce cranial nerve dysfunction, which may cause dysarthria (motor speech disorder leading to difficulty producing sounds) but would not cause aphasia (disorder of language processing). (Choice B) Broca area, located in the dominant frontal lobe, is often impacted in strokes of the superior division of the MCA. Lesions in this area lead to expressive aphasia, in which speech is halting and nonfluid. Receptive language is typically preserved. Contralateral hemiparesis is common due to involvement of the primary motor cortex. superior division of the MCA (Choices D and E) Nondominant lobe lesions do not impact speech because hemispheric dominance is defined by the side that most controls speech. However, nondominant frontal lobe lesions can affect how a patient conveys emotion through speech (ie, motor aprosodia); contralateral weakness due to the impact on the primary motor cortex would likely be seen. Nondominant temporal lobe lesions can impair the ability to comprehend emotional gestures (sensory aprosodia); they can also be associated with contralateral homonymous quadrantanopia due to impact on the optic radiations. Educational objective: Wernicke aphasia is characterized by well-articulated nonsensical speech with a lack of language comprehension. Wernicke area is located in the dominant temporal cortex and supplied by the inferior division of the middle cerebral artery.

A 78-Year-Old, Right-Handed Woman Is Brought to the Emergency Department