Case Presentation: A 50-year-old female with no known past medical history presented with a thunderclap headache (TCH). CT head without contrast and CT angiogram of the head were unremarkable. MRI brain findings were consistent with Reversible Cerebral Vasoconstriction Syndrome (RCVS). She was started on Verapamil 80 mg PO Q8H and Acetaminophen 1g IV Q6H with no resolution of symptoms. Cerebral angiogram confirmed the diagnosis of RCVS and intra-arterial (IA) Verapamil and Nitroglycerin were administered. She had slight improvement in her headache, but developed left upper extremity numbness and left ear tinnitus. Repeat MRI showed acute infarcts within the right temporal and frontal lobes, right ventral thalamus, and left parietal lobe. Repeat cerebral angiogram demonstrated persistent findings of RCVS. IA verapamil was given and she was started on a Phenylephrine (Phe) drip that was titrated to increase her systolic blood pressures to 140-160 mmHg. Verapamil 120 mg od was continued and she was maintained on Phe for 9 days with improvement in her headache and neurological symptoms. She was discharged on Verapamil 120 mg od, Aspirin 81 mg od and Midodrine 5 mg od. Follow-up MRI brain 1 month later was unremarkable.

Discussion: RCVS is a rare condition that usually presents with recurrent TCH and is characterized by multifocal reversible vasoconstriction of cerebral arteries. The pathophysiology of this disorder is not well understood. Many conditions are associated with RCVS including pregnancy and trauma, and certain drugs including pseudoephedrine and selective serotonin reuptake inhibitors may also be associated. Resolution of findings on imaging within 3 months supports the diagnosis (1).Currently, there are no randomized controlled trials to guide treatment. Recommendations are based on large observational studies and expert opinion (1). Calcium channel blockers (CCBs) of which Nimodipine is the most common, seem to be the standard of care. Medically refractory cases, defined by persistent headache despite oral CCBs, are usually managed with IA CCBs (2). Multiple doses of IA CCBs are often required with no expected timeline for response (3).Given her refractory symptoms, a vasopressor was used to increase systemic blood pressure as a means to increase cerebral perfusion in our patient. Vasopressor use in RCVS is controversial. Bouchard et al noted success with intravenous (IV) infusion of Milrinone followed by iatrogenic hypertension (HTN) with norepinephrine (4); however, the majority of the research on this topic cites vasopressors as precipitants of RCVS and not treatment options (5).

Conclusions: Although the use of vasopressors for RCVS is controversial with no Level A evidence to support its use, our patient had a favorable response to iatrogenic HTN using Phe. More data is needed to fully support its use; however, Phe should be considered as a treatment option in patients with refractory symptoms related to RCVS.