Neuromodulation can provide both prevention and acute treatment.
Noninvasive neuromodulation devices are safe, well tolerated, and clinically approved for migraine and episodic cluster headache, a researcher said here.
In recent years, the FDA has cleared single-pulse transcranial magnetic stimulation (Cerena, Spring TMS), noninvasive vagus nerve stimulation (gammaCORE), and external trigeminal nerve stimulation devices (Cefaly) to treat primary headache disorders, said Amaal Starling, MD, of the Mayo Clinic facility here, in a plenary session at the American Headache Association’s Scottsdale Headache Symposium.
Anatomical targets in neuromodulation range from central to peripheral, Starling noted. In general, noninvasive neuromodulation devices have fewer risks and are preferred over invasive ones. Currently available devices may be effective for both prevention and acute treatment: “We’re starting to see a blurring of acute and preventive lines,” she said.
Single-pulse transcranial magnetic stimulation (sTMS), which is approved for acute and preventive treatment for migraine, demonstrated improved pain-free response rates over sham treatment and is effective for migraine prevention, Starling stated. “It is dependent on the concept of electromagnetic induction, where electrical current is delivered across resistive layers of the scalp, skull, meninges, cerebrospinal fluid, and into the superficial layers of the cortex,” she explained. “When it gets into that area, it modulates the electrical environment.”
By altering the electrical environment of cortical neurons, sTMS inhibits cortical spreading depression and alters neuronal excitability, Starling added. Transcranial magnetic stimulation has been used safely for decades to treat several neurologic and psychiatric disorders without significant side effects, but it is contraindicated in patients with epilepsy or who have pacemakers or implants made of metal or other conductive materials, she noted.
Noninvasive vagus nerve stimulation (nVNS) is approved for the acute treatment of episodic cluster headache attacks and migraine. In a recent study, nVNS significantly increased the probability of having mild pain or being pain-free 2 hours after using the device. “There’s still a lot more we need to learn about the targets for vagal nerve stimulation,” Starling observed. But in preclinical models, nVNS has been shown to reduce pain-induced activation of neurons in the trigeminal nucleus caudalis and reduce trigeminal allodynia. There also may be potential anti-inflammatory effects from vagus nerve stimulation, she noted.
Noninvasive vagus nerve stimulation appears to be safe, with no serious adverse events, including no cardiovascular events, but patients with pacemakers or metal implants should not use it, as well as patients with carotid atherosclerotic disease. Patients with a history of cervical vagotomy, or who have significant hyper/hypotension or brady/tachycardia also should not use the device.
External trigeminal nerve stimulation(eTNS) — also called transcutaneous supraorbital neurostimulation (sTNS) — is approved for acute and preventive treatment for migraine. It transmits electrical impulses through an adhesive electrode to stimulate supraorbital nerves. Supraorbital neurostimulation likely inhibits nociceptive transmission in small pain-transmitting fibers, resulting in modulation of nociceptive activity in the trigeminal ganglion.