Neuromodulation is a technique used in several neurological disorders, including seizures and different headache types, including migraine, occipital neuralgia among others. It has been shown to be effective in the abortive and preventive treatment of migraine. It can be used alone or as an adjunct with other modes of treatment.
Neuromodulation manipulates peripheral and central pain pathways through electrical or magnetic impulses. There are a few different types of neuromodulation treatments available for helping with migraine. The different modes involve different peripheral nerves.
1- One type of neuromodulation is Remote electrical neuromodulation (REN) which works through a mechanism known as conditioned pain modulation (CPM). It stimulates the peripheral nerves of the upper arm, which then activates descending analgesic pathways in an area of the brain known as the periaqueductal gray, medulla and other areas of brainstem. This stimulation releases differnet neurotransmitters which inhibit pain signals in the trigeminal cervical complex, which is active in migraine. The device is applied to the upper arm during a migraine attack and it can be used with other abortive medications. It has also been recently approved to use as a preventive. It is a wireless battery operated unit that is controlled through a smartphone. The main side effects are transient sensation of mild warmth, redness or numbness in the arm and hand. There is currently one REN device on the market, under the name Nervio, Theranica Bio-Electronics LTD. Each device can provide 12 treatments and costs around $99 on the market.
2- The next device is the Vagus nerve stimulation (VNS), a type of neuromodulation that has been used for refractory treatment of depression and epilepsy. It is a non-invasive VNS device that stimulates the cervical branch of the vagus nerve through the neck, which effects the trigeminal nerve in the trigeminal cervical complex and further in the brain, through connections in the hypothalamus and thalamus. There are multiple trials showing its effectiveness for different types of headaches, including migraine. The vagal nerve stimulator on the market is the GammaCore device, which can be used for both abortive and preventive therapy. It is also approved for use in cluster headaches. It is well tolerated by patients, and it is a non-invasive technique for the treatment of migraine and cluster headaches.
3- Transcranial Magnetic stimulation (TMS) was introduced in 1985 and has been broadly used for diagnosis and treatment in neurology and psychiatry. It is a non invasive method that generates a transient magnetic field and mild currents to the brain cortex, and stimulates sensory and cognitive areas. It has been shown to inhibit cortical spreading depression in migraine. There are two types of TMS depending on the method of stimulation, repetitive or single pulse stimulation. Studies have shown that high frequency TMS delivered to the dorsolateral prefrontal cortex was able to relieve chronic migraines. The eNeura spring TMS® device (sTMS mini) is FDA cleared as a portable device for the treatment of migraine with aura. In 2019 its indications expanded and it was approved for prophylaxis treatment of migraine in adults and adolescents. The most common side effects are discomfort and headaches but no other overall harmful effects.
4- Another type of neuromodulation mode is the trigeminal nerve stimulator (e-TNS) device, commercially known as the Cefaly, which is also used for the acute and preventive treatment of migraine. It is worn on the forehead and works by delivering electrical impulses to stimulate the nerves under the forehead, mainly the supraorbital and supratrochlear nerves, that is a branch of the trigeminal nerve. Cefaly is a device used for the treatment and prevention of migraines. It is worn externally on the forehead, and it delivers electrical impulses that stimulate nerves that are believed to play a role in migraines. It is one of the few devices that is available without a prescription.
5- The last type of neuromodulation device available is one that is a combination of a device that stimulates the occipital and trigeminal nerves. The device is called Relivion and is available for the acute treatment of migraine, available with a prescription. It can cause some mild tingling during use. It is worn like a headband, with the pressure points on the forehead and occipital notches.
Neuromodulation devices are an important mode of treatment that can be helpful for many types of patients. They can be used as acute or preventive therapies, especially if oral or injectable medications are not fully treating migraine attacks. They can be a helpful treatment, either alone or as an add-on. There is more and more data that these are safe therapies in patients who may be pregnant or breast-feeding, although this is not completely clear yet but more studies are being done in this arena.