A 32-year-old woman with a history of migraine headaches comes to the emergency department with severe left-sided headache and nausea that started 3 hours ago. Earlier in the morning she had blurry vision and saw halos around lights. She took ibuprofen an hour ago but vomited shortly afterward.
Her vital signs are within normal limits. The patient feels uncomfortable when her eyes are examined with a flashlight. The pupils are equal and reactive. Muscle strength and tone are normal and deep-tendon reflexes are symmetrical. She is treated with intravenous metoclopramide. One hour later, she complains of neck pain. Physical examination shows sustained contraction of the posterior neck muscles associated with neck extension and tenderness.
What is the best next step in management of this patient?

Question

A 32-year-old woman with a history of migraine headaches comes to the emergency department with severe left-sided headache and nausea that started 3 hours ago.  Earlier in the morning she had blurry vision and saw halos around lights.  She took ibuprofen an hour ago but vomited shortly afterward.
Her vital signs are within normal limits.  The patient feels uncomfortable when her eyes are examined with a flashlight.  The pupils are equal and reactive.  Muscle strength and tone are normal and deep-tendon reflexes are symmetrical.  She is treated with intravenous metoclopramide.  One hour later, she complains of neck pain.  Physical examination shows sustained contraction of the posterior neck muscles associated with neck extension and tenderness.
What is the best next step in management of this patient?

Quizplus · Accepted Answer

This patient has likely developed metoclopramide-induced acute dystonia. Metoclopramide is a dopamine receptor antagonist that also blocks serotonin receptors at higher doses. The drug is often used in the emergency department as monotherapy for acute migraine associated with nausea/vomiting. It may also be effective for diabetic gastroparesis. Potential side effects include akathisia, dystonia, and tardive dyskinesia. Acute dystonia presents with sustained muscular contractions resulting in twisting or abnormal postures (eg, torticollis, retrocollis, oculogyric crisis). Retrocollis is characterized by sustained contraction of the posterior neck muscles resulting in neck extension and pain, as seen in this patient. Patients with suspected drug-induced dystonia should stop the offending agent. Treatment also involves anticholinergics (eg, benztropine, trihexyphenidyl) or agents with both anticholinergic and antihistamine effects (eg, diphenhydramine). These treatments should be started at low doses with slow titration to achieve improvement. They should also be tapered off gradually due to the risk of withdrawal side effects. (Choice A) Haloperidol can control acute agitation, but it is also a dopamine receptor blocker that can further exacerbate extrapyramidal symptoms. (Choice C) Lumbar puncture can diagnose meningitis, but this patient's lack of fever makes the diagnosis unlikely. (Choice D) Noncontrast head CT scan can diagnose subarachnoid hemorrhage (SAH), which usually presents as a sudden, severe ("thunderclap") headache. This patient's headache was preceded by visual symptoms, which is more typical of migraine with aura. Although meningismus is present in 35% of patients with SAH, this patient's sustained posterior neck extension is more consistent with retrocollis. (Choice E) Subcutaneous sumatriptan may be effective for abortive migraine treatment, but it would not address this patient's acute dystonia. Educational objective: Acute dystonic reactions can be caused by antidopaminergic agents (eg, metoclopramide). Treatment involves discontinuation of the drug and administration of anticholinergic agents (eg, benztropine, trihexyphenidyl) or agents with both anticholinergic and antihistamine effects (eg, diphenhydramine). __________ References: Drug insight: from disturbed motility to disordered movement--a review of the clinical benefits and medicolegal risks of metoclopramide. (http://www.ncbi.nlm.nih.gov/pubmed/16511548) Acute dystonic reaction caused by metoclopramide, versus tetanus. (http://www.ncbi.nlm.nih.gov/pubmed/17463462)

A 32-Year-Old Woman with a History of Migraine Headaches Comes