Single pulse transcranial magnetic stimulation may prevent migraines

Single pulse transcranial magnetic stimulation (sTMS), is a noninvasive, well-tolerated, and effective preventive treatment for migraines, according to results from a recently published open-label study in Cephalalgia. 

Migraine is one of the most prevalent and disabling illnesses in the world. Unfortunately, less than 20% of people with migraines can tolerate preventive medications during a treatment period of 1 year.

"For certain patients, treatment options for migraines, such as oral medications, are not effective, well-tolerated or preferred. The sTMS may be a great option for these patients and allow doctors to better meet their unique needs," said lead researcher Amaal J Starling, MD, neurologist, Mayo Clinic, Phoenix, AZ.

Transcranial magnetic stimulation sends an electric current across the scalp, skull, meninges, and cerebrospinal fluid to reach the superficial layers of the cortex. In these cortical layers, the current changes the neuronal electrical environment.

Currently, sTMS is approved for the treatment of migraine with aura. Experts suggest that sTMS treats acute migraine attacks by inhibiting cortical spread depression (CSD). Furthermore, repetitive transcranial magnetic stimulation (rTMS) may prevent migraines by changing cortical excitability. Nevertheless, studies in which rTMS is used as migraine prevention have demonstrated mixed results.

Patient experiences with sTMS in the United Kingdom suggest that it may work to not only treat but also prevent migraines.

“Given that CSD inhibition is a shared mechanism in many effective migraine preventive therapies,” wrote Starling and co-authors, “the ability to raise the threshold for CSD and inhibit dural specific thalamic sensory neurons may be a plausible underlying mechanism resulting in acute and preventive benefits in patients with migraine with or without aura.”

The eNeura SpringTMX Post-market Observational U.S. Study of Migraine (ESPOUSE) study was prospective, nonrandomized, and single-arm, with a goal of extending the FDA label for eNeura (the sTMS device being tested) to include migraine prevention, in addition to treatment of acute migraine with aura.

The researchers recruited patients from subspecialty headache clinics. Initially, 263 patients with migraine consented to completing a 1-month baseline headache diary of which 217 participants were given the eNeura device to use during the 3-month duration of the study. In all, researchers included 132 participants in the final analysis.

Eligible participants in this study were aged 18 to 65 years and had migraine with or without aura as defined by the International Classification of Headache Disorders. Exclusion criteria for participants included a history of epilepsy or seizures, implants containing metal, or concurrent use of other neurostimulation devices.

Those taking preventive medications for migraine were told to continue the medications at current dosages without adjustment for the duration of the study.

Subjects received both preventive and acute treatment with eNeura for 3 months. The portable sTMS device was placed by the patient at the base of the occiput. Preventive treatment comprised four pulses twice per day. Acute treatment comprised one dose of three consecutive pulses. If the patient felt no pain relief after 15 minutes, this dose of three consecutive pulses could be repeated twice. Researchers allowed the participants to use rescue treatments with acute migraine medications 30 minutes after the first dose, as needed.

Subjects used a monthly paper headache diary to record daily headache status, medication use, and device use.

During analysis, researchers used a statistically derived placebo response, or performance goal, to estimate response to placebo.

The primary endpoint for this study was the average reduction in headache days experienced by participants. This endpoint was measured during a 28-day period between weeks 9 and 12 of the study. Participants experienced a mean reduction of -2.75 days (9.06 days) compared with that of -0.63 as estimated by the performance goal (P < 0.0001).

Significant secondary endpoints of this study included the following

• A significantly higher 50% responder rate of 46% (95% CI: 37%, 56%) compared with the performance goal of 20% (P < 0.0001);
• A reduction from baseline in acute medication use of -2.93 (5.24) days in participants using sTMS (P < 0.0001);
• A reduction from baseline of total headache days of any pain type (mild, moderate, or severe) by -3.16 (5.21) days compared with the performance goal of -0.63 days (P < 0.0001).

“This study adds to the current evidence for acute migraine treatment that sTMS is a safe and possibly effective preventive treatment for migraine,” conclude the researchers. “Prior studies have demonstrated acute treatment benefits in those who have migraine with aura. Prior open label patient experience suggested a preventive benefit, and this current open label study provides additional evidence for the preventive benefit in patients with migraine when used daily.”