A 65-year-old man comes to the emergency department due to severe headache localized to the left frontal temporal region that began 4 hours ago. At the onset of the headache, he also had transient vision impairment in the left eye, which has now resolved. The patient has never had similar symptoms previously. Medications are acetaminophen for arthritis and metformin for recently diagnosed type 2 diabetes mellitus. He lives in rural Connecticut, smokes a pack of cigarettes per day, and does not use alcohol or illicit drugs. Temperature is 36.7 C (98.1 F), blood pressure is 152/96 mm Hg, and pulse is 89/min. Pulse oximetry shows 99% on room air. Physical examination findings are shown in the exhibit. Laboratory studies are as follows: A noncontrast CT scan of the head shows no intracranial hemorrhage or mass lesion. Which of the following is the most appropriate next step in management of this patient?

Question

A 65-year-old man comes to the emergency department due to severe headache localized to the left frontal temporal region that began 4 hours ago.  At the onset of the headache, he also had transient vision impairment in the left eye, which has now resolved.  The patient has never had similar symptoms previously.  Medications are acetaminophen for arthritis and metformin for recently diagnosed type 2 diabetes mellitus.  He lives in rural Connecticut, smokes a pack of cigarettes per day, and does not use alcohol or illicit drugs.  Temperature is 36.7 C (98.1 F), blood pressure is 152/96 mm Hg, and pulse is 89/min.  Pulse oximetry shows 99% on room air.  Physical examination findings are shown in the exhibit.  Laboratory studies are as follows:  A noncontrast CT scan of the head shows no intracranial hemorrhage or mass lesion.  Which of the following is the most appropriate next step in management of this patient?

Quizplus · Accepted Answer

Explanation: 11ec2b69_bfed_680e_8f63_fbbe6171d647_MD0005_00 The constellation of unilateral headache and partial left-sided Horner syndrome indicates left carotid artery dissection until proven otherwise. This condition can occur due to trauma (eg, whiplash injury, neck manipulation) but often develops spontaneously; connective tissue disease, hypertension, smoking, and recent infection may be underlying contributors. Relatively young patients are often affected (mean age ~45 years), and cerebral ischemia (eg, transient ischemic attack, ischemic stroke) is a frequent complication. Carotid artery dissection leads to the formation of an intramural hematoma/thrombus; due to the relatively small caliber of the carotid artery, most of the adverse neurologic effects result from luminal obstruction by the intramural blood collection. As sympathetic nerves travel along the carotid artery, dissection may cause Horner syndrome (ie, ptosis, miosis, anhidrosis) due to aneurysmal dilation and compression. However, anhidrosis is typically absent in internal carotid artery dissection as sweat nerve fibers branch off at the superior cervical sympathetic ganglion and follow the course of the external carotid artery. Carotid artery dissection superior cervical sympathetic ganglion Diagnosis is typically by CT angiography or MR angiography; if the results are negative but carotid dissection is still suspected, catheter angiography (gold standard) may be performed. Despite concerns of enlargement of the intramural hematoma, management of acute ischemia due to dissection is similar to other ischemic strokes and consists of thrombolysis if ?4.5 hours from symptom onset (preferably ?3 hours) and antiplatelet therapy (eg, aspirin). Evidence suggests that this approach is safe and offers comparable outcomes to ischemia from other causes. Anticoagulation is given in some settings, but its use is controversial. (Choice B) Cluster headache, which can be treated with 100% oxygen, is an important consideration in patients with severe unilateral headache and autonomic symptoms such as ptosis, miosis, lacrimation, sweating (not anhidrosis), and conjunctival injection. However, the painful attacks are episodic and short (15-180 minutes). (Choice C) Tight blood pressure control (goal systolic blood pressure: 100-120 mm Hg) is indicated in acute aortic dissection. It is not routine therapy for carotid artery dissection. (Choice D) Lyme disease is endemic to the northeastern United States (eg, Connecticut), and early disseminated disease (which is typically associated with positive serologic test results for antibodies against Borrelia burgdorferi) can cause headache and cranial nerve palsies. However, Horner syndrome is a rare presentation, and waiting for the results of serologic testing could unnecessarily delay recognition of a life-threatening disease process. (Choice E) Temporal artery biopsy is the diagnostic test of choice for giant cell (temporal) arteritis. However, the diagnosis is unlikely in the setting of a low erythrocyte sedimentation rate and the absence of jaw claudication, fever, and anemia. Additionally, giant cell arteritis is not commonly associated with Horner syndrome. Educational objective: A unilateral headache with partial Horner syndrome should be considered a carotid artery dissection until proven otherwise. Head and neck vasculature imaging (eg, CT angiography) is the initial diagnostic modality of choice. References: Cervical artery dissection: a review of the epidemiology, pathophysiology, treatment, and outcome. (http://www.ncbi.nlm.nih.gov/pubmed/26478890) Spontaneous cervical artery dissection: an update on clinical and diagnostic aspects. (http://www.ncbi.nlm.nih.gov/pubmed/19099146)

A 65-Year-Old Man Comes to the Emergency Department Due to Severe