A 66-year-old, right-handed man is brought to the emergency department due to left-sided numbness and weakness. The patient woke with left-hand clumsiness that rapidly progressed to profound left-sided weakness, affecting the left arm more than the left leg. He has a history of hypertension and has smoked a pack of cigarettes daily for the past 40 years. Blood pressure is 175/90 mm Hg and pulse is 82/min and regular. Neurologic examination reveals impaired touch discrimination in the left arm with left facial weakness sparing the forehead, 2/5 muscle strength in the left upper limb, and 4/5 muscle strength in the left lower limb. Right-sided strength and visual field examinations are normal. Which of the following labeled arteries is most likely occluded in this patient?

Question

A 66-year-old, right-handed man is brought to the emergency department due to left-sided numbness and weakness.  The patient woke with left-hand clumsiness that rapidly progressed to profound left-sided weakness, affecting the left arm more than the left leg.  He has a history of hypertension and has smoked a pack of cigarettes daily for the past 40 years.  Blood pressure is 175/90 mm Hg and pulse is 82/min and regular.  Neurologic examination reveals impaired touch discrimination in the left arm with left facial weakness sparing the forehead, 2/5 muscle strength in the left upper limb, and 4/5 muscle strength in the left lower limb.  Right-sided strength and visual field examinations are normal.  Which of the following labeled arteries is most likely occluded in this patient?

Quizplus · Accepted Answer

11ec160b_35b4_90dd_9249_1d1ff3db011b_MD0001_00 This patient has most likely had an acute ischemic stroke involving the territory supplied by the right middle cerebral artery (MCA). Patients with MCA occlusion usually present with contralateral hemiparesis and hemisensory loss involving the face and upper limb due to infarction of the corresponding motor and sensory cortices. The contralateral lower limb is typically less affected. Other features may include spatial neglect of the contralateral side (damage to the nondominant parietal lobe) and contralateral homonymous quadrantanopia (damage to the optic radiations in the subcortical temporoparietal lobe). If the stroke affects the dominant (usually left) hemisphere, the speech areas of the brain can be damaged. Consequently, patients with left MCA stroke (right-sided motor and sensory deficits) also often have expressive or receptive aphasia due to infarction of the Broca and Wernicke areas, respectively (Choice H). (Choices A and G) Occlusion of the anterior cerebral artery causes contralateral motor and sensory deficits, with the lower limb being affected more than the upper limb. Bilateral anterior cerebral artery occlusion can cause significant behavioral symptoms (eg, abulia), primitive reflexes (eg, Moro, grasp), and urinary incontinence due to damage of the prefrontal cortex. (Choices C and F) Saccular aneurysms often affect the anterior and posterior communicating arteries in the circle of Willis. Anterior communicating artery aneurysms can compress the central optic chiasm, causing bitemporal hemianopia. Posterior communicating artery aneurysm frequently compresses the oculomotor nerve, producing ipsilateral mydriasis, ptosis, and "down and out" eye deviation. (Choices D and I) Posterior cerebral artery territory infarction typically results in contralateral hemianopia due to infarction of the visual cortex. The macula is often spared due to collateral circulation from the MCA. (Choice E) Basilar artery occlusion usually damages the base of the pons, which contains the corticospinal and corticobulbar tracts, and the paramedian tegmentum. Consequently, patients typically have quadriplegia, bulbar dysfunction (eg, facial weakness, dysarthria), and oculomotor deficits (eg, horizontal gaze palsy). (Choice J) Occlusion of the anterior inferior cerebellar artery causes lateral pontine syndrome. Patients with this condition typically have ipsilateral loss of pain or temperature in the face (trigeminal nucleus), ipsilateral facial weakness (facial nucleus), ipsilateral hearing impairment (cochlear nucleus), contralateral loss of pain and temperature in the trunk and extremities (lateral spinothalamic tract), and cerebellar dysfunction (eg, ataxia, dysmetria). Educational objective: Occlusion of the middle cerebral artery (MCA) typically results in contralateral hemiparesis and hemisensory loss of the face and upper limb with relative preservation of lower limb function. If the occluded MCA is in the dominant (usually left) hemisphere, aphasia may also occur. __________ References: Stroke syndromes and clinical management. (http://www.ncbi.nlm.nih.gov/pubmed/23483140)

A 66-Year-Old, Right-Handed Man Is Brought to the Emergency Department