Making the Diagnosis

To accurately assess and diagnose this patient’s condition, the clinician needs to eliminate other possible causes of transient visual changes such as hyperglycemia, hypoglycemia, transient ischemic attack (TIA), pseudotumor, and migraine. Hyperglycemia and hypoglycemia are unlikely due to normal blood work, though both could cause blurry vision. Hyperglycemia, however, would likely cause ongoing blurry vision. Hypoglycemia could cause transient blurry vision and headache, which could return to normal if the body was able to bring the glucose level back up on its own with adrenalin release, but would typically be accompanied by sweating or light-headedness. Although strokes can cause headaches, TIAs should not, making the diagnosis of TIA unlikely. Pseudotumor can cause transient vision changes but is almost always preceded by an ongoing headache. Migraine is a possible diagnosis, however, it would typically cause a blind spot rather than blurry vision, which would resolve prior to headache onset. In addition, new-onset migraines at the patient’s age would be atypical.


The correct diagnosis is arterial venous malformation (AVM), which is seen in the left cerebellum on MRI. This is a rare disease with a myriad of presentations that may include any of the following: headache, seizure, stroke, TIA, or intracranial bleeding. Symptoms of AVM vary by presentation and/or complication. In this case, the presenting symptoms most likely are due to posterior circulation TIA plus headache from AVM.

Posterior circulation TIA can cause bilateral vision changes, but TIA alone should not typically cause headache. The presentation also mimics migraine but is atypical in that the headache started before the visual changes resolved and the patient had no known history of migraine. Stroke is unlikely here as all symptoms resolved; seizure is also unlikely because no involuntary motor activity was found. Fortunately, no intracranial bleed was seen on MRI.

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Treatment of cerebral AVMs typically involves surgery or embolization. Both neurosurgery and interventional radiology should be consulted, if available; if not, the patient should be transferred to a neurosurgeon at a larger medical center. Supportive care with medications should be tailored to the presentation; aspirin can be started in patients with evidence of TIA and antiepileptic agents can be initiated in patients with seizures.

Brady Pregerson, MD, is an emergency physician at Tri-City Medical Center, Palomar Health System, and Scripps Coastal Urgent Care, all in San Diego, California.


Pregerson DB. Neurosurgery chapter. Emergency Medicine 1-Minute Consult. 5th ed. 2017;5.

This article originally appeared on Clinical Advisor