Innovations in Migraine Research: 6 Questions

HEADACHE & MIGRAINE

Dr Moawad is a neurologist and Clinical Assistant Professor at Case Western Reserve University and John Carroll University in Cleveland, OH, where she teaches undergraduate and medical students. She reports no conflicts of interest regarding the subject matter of this article. Dr Moawad is Editor in Chief of Neurology Times.

In this podcast, Dr Heidi Moawad interviews Nina Riggins, MD, PhD, a neurologist and researcher at the University of California Headache Center, San Francisco, CA. Dr Riggins discusses new, available treatments in headache medicine, including ongoing research about topical applications and other modes of treatment.

Heidi Moawad, MD (HM): You have done research about symptoms that predict necessity to repeat botulinum toxin injections. Can you describe any surprises?

Nina Riggins, MD, PhD (NR): Our study (currently in press) objectives were to determine whether the presence of cranial autonomic symptoms (CAS) can be a predictor of the effect of botulinum toxin injections on headache and whether the injections improve CAS in patients with chronic migraine.

In addition to a chart review, a survey was administered to current botulinum toxin patients at their visits to the UCSF Headache Center. Survey included questions on CAS such as redness of the white part of the eye, tearing from the eye, nasal congestion, runny nose, swelling around the eye, facial sweating, flushing, pupil looking smaller than usual, ear fullness.

Of the 93 patients enrolled in the study, 85 had at least 2 rounds of botulinum toxin and were included in the data analysis. Patients without CAS were more likely to improve from the treatment for chronic migraine, independently of medication overuse headache. Participants with moderate or severe CAS at baseline were less likely to respond to treatment

It appears that botulinum toxin could improve CAS and as symptoms improve, the efficacy of the drug could continue to improve after multiple rounds. Future studies need to explore whether patients with moderate to severe CAS would require more rounds of botulinum toxin in order to show improvement.

HM: When should neurologists anticipate hearing more about results of your study?

NR: The study (with Peter Goadsby, PhD) is in press, and the poster, “Does the Presence of Cranial Autonomic Symptoms in Chronic Migraine Patients Predict Efficacy of Botox Injections?”, was submitted to the 2019 AAN Meeting in Philadelphia.

HM: You are currently doing research about topical applications for migraine prevention. Which medications do you use and where do you place them?

NR: Topical applications are done with anesthetic medications, such as lidocaine, bupivacaine, and ropivacaine. These medications are delivered by a Sphenocath®, an FDA-cleared device, to the region of sphenopalatine ganglion (SPG). The device does not have a needle and could be described as flexible catheter. A non-invasive procedure known as an SPG block places one of three different anesthetics under the study (lidocaine, bupivacaine, ropivacaine) into the nasal cavity and diffuses to the target in order to block the SPG nerve.

The SPG is located in the pterygopalatine fossa and has multiple connections to facial, trigeminal, parasympathetic, and sympathetic systems which make it a promising target for migraine treatment. SPG blocks are quite commonly performed at the headache center at UCSF to treat chronic migraine, and patients have reported significant relief.

We presented a poster at the American Headache Society Scientific Meeting in 2018 titled “Preventive Effects of SPG Blocks in Chronic Migraine Patients Increases With Number of Repeated Blocks.” It was a chart review study that concluded that the SPG block is a safe and effective preventive treatment in chronic migraine. It helped to reduce use of acute (as needed) headache medications in 18 out of 20 patients who received 4 or more SPG blocks with lidocaine.

We would like to determine if the frequency and medications that we use as our standard of care in the clinic prove to be significantly better than placebo and also to see if there is a difference in the anesthetics we use. We submitted the study to the IRB (Institutional Review Board) and received approval for the SPG block randomized placebo-controlled trial.

Study aims

1. To determine whether SPG blocks can be effective in migraine headache prevention at a lower frequency of administration than in previous studies.

2. To determine if there is a difference in efficacy between lidocaine, bupivacaine, and ropivacaine.

3. To determine whether the repeated use of SPG blocks every 2 to 4 months for 3 treatments will have a cumulative effect, with subsequent treatments providing better and longer lasting effects on headache frequency and severity.

4. To determine if repetitive SPG blocks can reduce the need and use of acute treatments and emergency room visits

HM: Is there a certain patient subtype that is more likely to respond to treatment?

NR: There is a possibility that patients with post-traumatic chronic migraine could greatly benefit from this procedure. We noted that the SPG block was the treatment that broke the daily cycle of pain for the patients in this group. Whether it is statistically significant needs to be determined by the future studies.

HM: You mentioned a bad taste as an adverse effect of the procedure. How long does it last?

NR: Bad taste usually resolves within a few minutes, up to an hour after procedure.

HM: Do neurologists need special training to learn how to use the topical treatment?

NR: There are various methods for performing SPG blocks, some of which are more invasive and risk-prone than using catheter applications. The new catheter application option, which we started to utilize a couple of years ago, is easy to use and we are teaching our headache fellows and other colleagues in neurology how to use it with success.

Editor's note: This article was posted on February 6, 2019 and has since been updated.