Single-pulse transcranial magnetic stimulation has been in clinical use for 30 years, first diagnostically, then as therapy. The mechanism of benefit has been mapped out. The treatment’s safety is very well established; indeed, the FDA has classified it as a nonsignificant risk technology, he noted.
The major technical advance that’s occurred in single-pulse transcranial magnetic stimulation has been a radical reduction in capacitor size. The equipment has shrunk from refrigerator-size in the therapy’s early development, which took place in London, to the highly portable Spring TMS device that patients can stick in a briefcase and utilize unobtrusively at work, Dr. Shields observed.
The contraindications to use of the device are a history of epilepsy; the presence of metal objects in the head, neck, or upper body; and pacemakers or other cardiac devices.
Dr. Fayyaz Ahmed
The evidence base supporting the safety and efficacy of the Spring TMS device includes a published randomized, double-blind, sham-controlled clinical trial conducted in patients with migraine with aura (Lancet Neurol. 2010;9:373-80).
In addition, at the international congress Dr. Mark W. Weatherall of the University of Edinburgh, Scotland, presented the first results of an ongoing multicenter U.K. postmarketing study of the single-pulse transcranial magnetic stimulation device as used in clinical practice. The study population consisted of 13 patients with migraine without aura and 24 having migraine with aura who had been using the device for at least 3 months and collectively had treated 777 attacks.
Efficacy reports were:
• 73% of patients said the device showed good to excellent efficacy, reducing or even alleviating migraine pain. Sixty-three percent pronounced the therapy effective in diminishing other migraine symptoms.
• 55% reported a reduction in the number of headache days per month.
The mean attack duration was 2.46 days before transcranial magnetic stimulation therapy and 0.77 days after subjects started using the device. The benefits were reproducible over the 3-month study period and beyond, and no adverse events were reported, he said.
Dr. Jean Schoenen presented the first randomized trial data on the Cefaly device. The supraorbital transcutaneous neurostimulation device has been available in Europe for 5 years, but until now it had no supporting data from controlled trials.
Dr. Jean Schoenen
The device consists of a thin silver band that looks like something out of Star Trek. It is hooked over the ears and worn across the forehead like futuristic sunglasses. Patients don it once daily for 20 minutes. The investigators set the programmable device to deliver a square pulse at 60 Hz, 300 microseconds, and a maximum of 14.99 mA.
The 3-month, multicenter, double-blind, sham-controlled Belgian study involved 67 patients with episodic migraine. The mean number of headache-days per month dropped significantly, from 6.9 at baseline to 4.9 at 3 months in the Cefaly group but was unchanged in controls. Thirty-eight percent of patients using the active device experienced at least a 50% reduction in their number of headache-days per month, compared with 12% of controls. Monthly consumption of triptans for acute therapy was reduced by 36% in the Cefaly-treated patients as a whole and by 75% in the Cefaly responders, reported Dr. Schoenen of the University of Liege, Belgium.
To get a crude idea of how supraorbital transcutaneous neurostimulation stacks up against standard prophylactic drug therapy, Dr. Schoenen turned to the extensive published randomized trial literature on topiramate. While the 50% or greater responder rate in the Cefaly trial was 38%, in the pooled topiramate data it’s 45%. Moreover, topiramate was associated with an impressive average 48% reduction in the number of migraine attacks per month, compared with a 19% decrease with the Cefaly device.
On the other hand, one in four patients assigned to topiramate in the randomized trials dropped out due to side effects. No one experienced any adverse effects from the device therapy, he noted.
This was an investigator-initiated study carried out by the Belgian Headache Society and sponsored by STX-Med, which markets the Cefaly device in Europe. Dr. Schoenen is on the advisory boards of St. Jude Medical, Allergan, and ATI. Dr. Ahmed, Dr. Shields, and Dr. Weatherall are on the speakers bureau for eNeura Therapeutics.