A 67-year-old woman comes to the office for follow-up. Four weeks ago, she experienced sudden-onset right side numbness, and evaluation revealed an ischemic stroke. The patient feels like some of her sensation is returning but experiences transient burning pain in the right upper and lower limbs that can be induced even by a light touch. Her medical history is significant for hypertension and type 2 diabetes mellitus. She smoked a half-pack of cigarettes daily for 30 years but stopped after her stroke. Blood pressure is 125/70 mm Hg, and pulse is 74/min and regular. Neurologic examination shows right side hemianesthesia and mild athetosis of the right hand. There is hyperesthesia on the right side of the body demonstrated by exaggerated pain on light touch. Motor strength is normal in all 4 extremities. Which of the following is the most probable location of the stroke experienced 4 weeks ago by this patient?

Question

A 67-year-old woman comes to the office for follow-up.  Four weeks ago, she experienced sudden-onset right side numbness, and evaluation revealed an ischemic stroke.  The patient feels like some of her sensation is returning but experiences transient burning pain in the right upper and lower limbs that can be induced even by a light touch.  Her medical history is significant for hypertension and type 2 diabetes mellitus.  She smoked a half-pack of cigarettes daily for 30 years but stopped after her stroke.  Blood pressure is 125/70 mm Hg, and pulse is 74/min and regular.  Neurologic examination shows right side hemianesthesia and mild athetosis of the right hand.  There is hyperesthesia on the right side of the body demonstrated by exaggerated pain on light touch.  Motor strength is normal in all 4 extremities.  Which of the following is the most probable location of the stroke experienced 4 weeks ago by this patient?

Quizplus · Accepted Answer

This patient likely experienced a lacunar stroke of the posterolateral thalamus, which typically occurs due to atherothrombotic occlusion of the small, penetrating (thalamogeniculate) branches of the posterior cerebral artery. The ventral posterolateral and ventral posteromedial nuclei of the thalamus transmit sensory information from the contralateral side of the body and face, respectively. Consequently, patients with thalamic stroke in this region often present with sudden-onset contralateral sensory loss involving all sensory modalities (ie, pure sensory stroke). Symptoms can be accompanied by transient hemiparesis, athetosis, or ballistic movements due to disruption of neighboring basal ganglia structures and corticospinal fibers in the posterior limb of the internal capsule. posterior cerebral artery Several weeks to months following the stroke, sensory deficits can improve; however, some patients develop thalamic pain syndrome (Dejerine-Roussy syndrome). This condition is characterized by severe paroxysmal burning pain over the affected area and is classically exacerbated by light touch (allodynia). (Choice A) Damage to the internal capsule can occur with lacunar infarcts, but patients typically have contralateral pure motor or combined sensorimotor deficits due to disruption of the corticospinal and somatosensory fibers in the posterior limb. A central post-stroke pain syndrome is not characteristic. (Choice B) Lateral medullary infarction typically occurs due to posterior inferior cerebellar artery occlusion. Patients develop loss of pain/temperature sense over the ipsilateral face and contralateral body (due to spinal trigeminal and spinothalamic tract injury), ipsilateral bulbar muscle weakness (nucleus ambiguus), vertigo/nystagmus (vestibular nuclei), and Horner syndrome (ascending sympathetic fibers). (Choice C) Midbrain strokes typically present with ipsilateral oculomotor nerve palsy, ataxia (due to damage of the superior cerebellar peduncle), and contralateral hemiparesis (cerebral peduncle). (Choice D) Embolic/thrombotic occlusion of the middle or anterior cerebral artery can result in contralateral sensory loss due to infarction of the somatosensory cortex in the post-central gyrus. However, sensory deficits are typically accompanied by hemiparesis (due to primary motor cortex injury) and cortical signs (eg, aphasia, agnosia). A central post-stroke pain syndrome is not characteristic. (Choice E) The putamen is a common site of hypertensive intraparenchymal brain hemorrhage. The internal capsule that lies adjacent to the putamen is almost always involved, leading to contralateral hemiparesis, sensory loss, and conjugate gaze palsy toward the side of the lesion. Educational objective: Lacunar stroke of the posterolateral thalamus typically presents with sudden-onset contralateral sensory loss involving all sensory modalities (ie, pure sensory stroke). Weeks to months later, patients can develop thalamic pain syndrome, characterized by severe paroxysmal burning pain over the affected area that is exacerbated by light touch (allodynia). References: From thalamic syndrome to central poststroke pain. (http://www.ncbi.nlm.nih.gov/pubmed/8971098) Central poststroke pain: an abstruse outcome. (http://www.ncbi.nlm.nih.gov/pubmed/18301815)

A 67-Year-Old Woman Comes to the Office for Follow-Up