A 64-year-old woman is brought to the emergency department due to stroke-like symptoms. The patient has a history of transient ischemic attacks as well as other risk factors for cerebrovascular disease, including hypertension, type 2 diabetes mellitus, and hyperlipidemia. Urgent brain imaging reveals occlusion of a vessel indicated by the arrow in the exhibit.

Which of the following findings is most likely to be observed in this patient?

Question

A 64-year-old woman is brought to the emergency department due to stroke-like symptoms. The patient has a history of transient ischemic attacks as well as other risk factors for cerebrovascular disease, including hypertension, type 2 diabetes mellitus, and hyperlipidemia. Urgent brain imaging reveals occlusion of a vessel indicated by the arrow in the exhibit.

Which of the following findings is most likely to be observed in this patient?

Quizplus · Accepted Answer

11ec160b_35b8_fdb9_9249_a52cffc3897f_MD0001_00 This patient has occlusion of the right posterior inferior cerebellar artery (PICA), which arises from the vertebral artery. Occlusion of the PICA results in lateral medullary (Wallenberg) syndrome. This disorder classically results in a constellation of symptoms because of damage to specific areas: Horner syndrome (ie, miosis, ptosis, anhidrosis) may also occur in the ipsilateral eye due to damage to descending sympathetic nervous system fibers. (Choice A) Damage to the oculomotor nerve (CN III) can lead to impaired extraocular movements with a down-and-out eye due to unopposed action of the superior oblique muscle (innervated by the trochlear nerve [CN IV]) and the lateral rectus muscle (innervated by the abducens nerve [CN VI]). When this finding (ie, down-and-out eye) is accompanied by contralateral lower facial weakness and hemiplegia, it is suggestive of midbrain infarction due to occlusion of the posterior cerebral artery (ie, Weber syndrome). (Choice B) Weakness of the face, arm, and leg is classically caused by contralateral motor cortex or internal capsule infarction due to occlusion of the middle cerebral artery. (Choice C) Internuclear ophthalmoplegia (ie, loss of conjugate lateral gaze) is caused by damage to the medial longitudinal fasciculus, which can occur with occlusion affecting the pontine arteries. Bilateral loss of conjugate gaze is more likely with other etiologies (eg, multiple sclerosis plaques) because bilateral ischemic injury to the same area is uncommon. (Choice E) Homonymous hemianopia (ie, vision loss in the same half of the visual field in both eyes) with macular sparing is classically caused by occlusion of the posterior cerebral artery; the macula is spared due to collateral blood supply from the middle cerebral artery. Homonymous hemianopia without macular sparing can occur due to damage of the optic tract or optic radiation, which can occur with occlusion of several different vessels (eg, anterior choroidal, middle cerebral artery). Educational objective: Posterior inferior cerebellar artery occlusion causes lateral medullary (Wallenberg) syndrome. This disorder is characterized by vertigo/nystagmus, ipsilateral cerebellar signs, loss of pain/temperature sensation in the ipsilateral face and contralateral body, bulbar weakness, and ipsilateral Horner syndrome.

A 64-Year-Old Woman Is Brought to the Emergency Department Due