The minimally invasive intranasal sphenopalatine ganglion (SPG) block is a safe, effective treatment for children with frequent migraine headaches, according to study results presented at the Society of Interventional Radiology 2017 Annual Scientific Meeting.

“To the best of our knowledge, this is the first sphenopalatine ganglion block study in a pediatric population,” said principal investigator Robin Kaye, MD, section chief of interventional radiology in the Department of Medical Imaging at Phoenix Children’s Hospital.

The technique is performed the same way as in adults. “Because children and teenagers may be more anxious about this treatment, they may require more emotional support than adult patients,” Dr. Kaye said.

The inspiration for the 200-patient study of children between 7 and 18 years of age at Phoenix Children’s Hospital was two hospital neurologists who treat mainly headache. “They attended a neurology conference, where they heard about the SPG block,” Dr. Kaye said. “Upon returning, they asked if we would be willing to try it on our headache patient population, and we were eager to test this technique on patients who are often in need of additional treatment options.”

However, unlike the adult population, for which the SPG block is used for a variety of indications—including chronic and episodic migraine, cluster headaches, and trigeminal neuralgia—the investigators limited their criteria to a diagnosis of migraine and status migrainosus. “In other words, the patient’s primary medications had failed, and their rescue strategies had failed before coming to us for an SPG block,” Dr. Kaye said.

The investigators deliberately designed such tight criteria in order to assess whether treatment would be effective in a fairly controlled group before expanding treatment indications. Study patients were roughly evenly split between inpatient and outpatient.

Dr. Kaye and her team conducted a total of 310 SPG block treatments on the 200 patients, of whom 149 patients had a single session; 29 patients underwent two sessions; 11 patients had three sessions; and the remaining 11 patients were treated with more than four sessions (between four and 10). The interval between treatment sessions was typically one to two months.

Before the intervention, the patient’s pain level was recorded on a scale of 1 to 10. Then, 10 minutes after treatment, patients were asked to compare their pain level, using the same scale. There was an average pain score reduction of slightly more than 2 points, which is a statistically significant difference.

“These results are promising,” Dr. Kaye said. “If you look at the adult literature, our outcomes are not quite as good. However, we did not evaluate durability of the relief, effectiveness of medication or, in the case of inpatients, whether it shortened hospital stay.”

Still, more than 70% of the pediatric study population obtained some migraine relief. “A lot of the patients told us they do not care if their headache did not completely go away,” Dr. Kaye said. “The fact that their headache pain decreased from a 7 to a 3 on the pain scale, for instance, is good enough. Patients say this is the best they have felt in weeks or months, so the patients themselves are very encouraging.”

Dr. Kaye speculated that headache relief from the SPG block in children lasts weeks to one or two months. “As we did more of these blocks, we trended more toward outpatient therapy,” she said. “Fewer patients are being hospitalized for migraine headache.”

A lidocaine gel is used to numb the nasal mucosa on both sides, “so patients will often say that their nose feels stuffy,” Dr. Kaye said. The anesthesia used to numb the nose drips to the back of the throat, resulting in a numbing sensation. Patients also often report that the anesthesia has a bitter taste.

On the positive side, the catheter used is very small, even thinner than a coffee stirrer. “Some patients, though, are just more sensitive to having the catheter in their nose,” Dr. Kaye said. “But I would not characterize the treatment as painful.”

There is also no downtime associated with the therapy, and the study reported no adverse events.

The average age of a treated patient at Phoenix Children’s Hospital is about 15 years, with 85% girls. “Hormones play a big role in headache,” Dr. Kaye said. “Headaches in teenagers may be caused by a wide variety of factors, so it is important that the clinician be supportive and positive about treatment.”

In addition, after the SPG block, patients are asked to refrain from using a computer or mobile devices, or engaging in sports or other heavy physical activity, for the rest of the day as a way to decrease visual and aural stimulation, if at all possible. “Our neurologists think that is really important to let the effect of the block really take hold,” Dr. Kaye said.

A follow-up study is planned. “After looking at our data, we realized there are some glaring holes to make any hard, conclusive evidence,” Dr. Kaye said.

Meanwhile, the study illuminated for Dr. Kaye how common migraine headaches are in children. “If you look at the adult literature, it is hugely debilitating, and equally debilitating for kids,” she said. “I believe SPG block can have a great impact on patients, maybe decrease their medication, hospitalization and length of stay.”

There is also the belief that headaches are somewhat similar to seizures, in that they can start in childhood and become more escalating, she said. “Many believe that if you can minimize the frequency and severity of a child’s headache, you may minimize the progressive nature of migraines in adulthood.”

—Bob Kronemyer