Introduction

A recent case report published in the journal *Headache* reveals a remarkable potential for erenumab (Aimovig; Amgen), an FDA-approved medication targeting the calcitonin gene-related peptide (CGRP), to alleviate chronic headaches that often follow aneurysmal subarachnoid hemorrhages (aSAH). This finding underscores the promising therapeutic options available for patients suffering from debilitating post-aSAH headaches.

Case Report

In an intriguing case, a 55-year-old man with a medical history of renal artery aneurysm and hypertension, who had not previously experienced headaches, was reported. This patient began dealing with severe, throbbing headaches daily after experiencing a Hunt Hess 3, modified Fischer 4 grade aneurysmal SAH triggered by a burst anterior communicating artery aneurysm at the age of 47. After successful treatment through endovascular coil embolization and open craniotomy, the man was left with persistent pain that significantly impaired his quality of life.

Treatment with Erenumab

Under the guidance of Dr. Pankaj K. Agarwalla, an assistant professor of neurosurgery at Rutgers Medical School, the patient exhausted several treatment options before opting for erenumab, which has been available since 2018. Following a regimen of monthly 70 mg injections, he reported substantial relief from his headaches. Over 18 months of continued therapy, his symptoms decreased dramatically—from daily episodes to merely 1 to 2 brief occurrences monthly—allowing him to discontinue nortriptyline completely.

Impact on Quality of Life

The most remarkable changes included a significant improvement in the patient's sensitivity to sound, contributing to a newfound ability to engage in everyday activities, tolerate louder environments, and even return to work, showcasing the transformative impact of CGRP treatment on his life.

Mechanism of CGRP Release

Previous research indicates that CGRP is released in significant amounts shortly after a subarachnoid hemorrhage, potentially serving as a neuroprotective agent against cerebral vasoconstriction. However, the large increase in CGRP levels may lead to heightened trigeminal nerve sensitivity, resulting in chronic headaches.

Previous Treatment Limitations

Prior to the introduction of erenumab, conventional treatments such as acetaminophen, acupuncture, amitriptyline, and nortriptyline yielded minimal results, with side effects limiting their efficacy. The experience with amitriptyline was notably short-lived due to adverse reactions, further highlighting the need for effective treatments for these patients.

Timing of CGRP Therapy

The study emphasizes the importance of timing in initiating CGRP pathway therapies, proposing that treatment should begin only when the risk of delayed cerebral ischemia (DCI) has significantly diminished, ideally 3 to 6 weeks post-ictus. The duration of therapy may vary, as some patients suffer from post-aSAH headaches for months or even years.

Lower Risk of Interactions

Given that erenumab is not processed by cytochrome P-450 enzymes, it poses a lower risk for drug interactions, making it a viable option for patients also undergoing treatment for seizures.

Conclusion and Future Research

This groundbreaking case opens doors for further research into CGRP-targeting therapies as a standard treatment for individuals suffering from chronic headaches after aSAH. As the medical community continues to explore and understand the nuances of post-SAH complications, patients can hope for enhanced management strategies that prioritize their quality of life. Could this be the game-changer many have been waiting for? Stay tuned for more updates!