[IN4-1.005] Transcranial Magnetic Stimulation for the Treatment of Migraine Aura

Philip R. Holland, San Francisco, CA, Carol T. Schembri, Joe P. Fredrick, Sunnyvale, CA, Peter J. Goadsby, San Francisco, CA

OBJECTIVE: To study the effects of transcranial magnetic stimulation (TMS) on cortical spreading depression (CSD), the experimental correlate of aura.

BACKGROUND: TMS relies on the conversion of electrical pulses to magnetic fields which generate small intracranial currents and it has been suggested as a possible therapeutic opportunity. In a recent study TMS was shown to be a potential novel treatment for migraine with aura.

DESIGN/METHODS: Rats were anaesthetized with pentobarbitone (60 mg/kg-1) and cannulated for measurement of blood pressure, administration of experimental drugs and anesthesia. Three cranial burr holes were drilled and laser Doppler probes were used to record the blood flow changes characteristic of CSD. A needle was lowered into the cortex to induce CSD and a single pulse of TMS was applied over the corresponding hemisphere. TMS was delivered using a bespoke in vivo TMS system manufactured by Neuralieve, CA, with variable Kopf mountable coils.

RESULTS: Needle prick (NP) induced characteristic changes in cerebral blood flow, with an initial hyperemic then oligemic response. Coil 1 (rise time 100 s) failed to inhibit the majority of CSD's with only 1 of 8 blocked up to a maximum 600 V (1.38 T). Coil 2 (rise time 170 s) was able to inhibit 5 of 9 CSD's when administered post NP, and 2 of 8 when administered pre-NP, with a range of 400 600 V (1.11 1.63 T).

CONCLUSIONS/RELEVANCE: The results demonstrate a biological rationale for the use of TMS to treat migraine aura. CSD, the animal correlate of aura was susceptible to TMS, with the wave of neuronal excitation blocked in over 50% of tests with a bespoke coil. The studies identify that the time to peak intensity of stimulation may be an important component in the response to TMS and highlight the need for further characterization to optimize treatment strategies. Category - Headache - Therapeutics

Wednesday, April 29, 2009 3:00 PM

Integrated Neuroscience: Advances in Headache (2:00 PM-6:00 PM)

CAUTION: Investigational Device. Federal or (United States) law limits device to investigational use.