Transcranial magnetic stimulation (TMS) is a non-invasive method for stimulating parts of the brain. Electromagnets are placed against the patient’s head, and the magnetic field generated alters the electrical activity of the brain.
This portable handheld TMS device is being developed by Neuralieve, a company based in Sunnyvale California, for the alleviation of migraine symptoms. The comany’s website provides a description of the device and how it should be used:
Investigational TMS device is a self-contained apparatus that delivers treatments consisting of a limited number of pulses of magnetic energy…The patient places the unit on the back of the head and presses a button. The unit emits a pulse of energy lasting a fraction of a second. The total amount of magnetic energy delivered is minuscule (less than 1/1,000 of that to which a person is exposed during an MRI.) For safety, the instrument locks after each treatment and cannot be used again for 60 minutes. The company targets marketing the product in mid-2007.
Triptans (e.g. Sumatriptan) are potent 5HT 1B/ 1D receptor agonists which have been prescribed for migraine since 1992. Triptans are believed to alleviate migraine symptoms by inducing vasoconstriction and reducing inflammation, but are ineffective in one-third of migrain sufferers.
“There’s a need for alternatives,” says Yousef Mohammed, an associate professor of neurology at Ohio State University who ran clinical trials into the use of TMS for the treatment of migraine.
The trials provided some of the first evidence that TMS could alleviate migraine symptoms. The cause of migraines is unknown; they may be due to waves of electrical activity which stimulate neurons in brain regions involved in pain. TMS may alleviate migraine symptoms by interfering with these waves.