A disturbance in the region of the head can provoke pain in the distribution of the trigeminal and upper cervical nerves due to a convergence of the afferent fibers of the three superior cervical roots on the neurones of the spiral nucleus of the trigeminal nerve. The therapeutic value of greater occipital and supraorbital nerve blockade in 27 patients with migraine, unresponsive to several combinations of pharmacological treatments, was investigated. Patients were given repeated anesthetic blocks, on alternate days, up to a maximum of 10 blocks. Perineural injections of 0.5 to 1.0 mL of 0.5% bupivacaine were given at the epicranial emergence points of the above nerves in relation to the distribution of the cephalic pain only if such nerves were conspicuously pain sensitive to pressure. Clinical evaluation was determined by a monthly Total Pain Index and recording of the number of migraine attacks and analgesic consumption each month. A patient was considered responsive when the Total Pain Index decreased by 50% or more in the first month after treatment. Twenty-three patients (85%) responded beneficially and maintained a favorable response for the 6-month period of observation. The treatment was considered to be of long-lasting effectiveness and without any side effects. Four patients (15%) were unresponsive to treatment.
We hypothesize that the anesthetic blocks extinguished presumed foci of nociceptor discharges maintained by perivascular neurogenic inflammation, thereby reestablishing normal central neurone sensitivity.
In conclusion, blockade of the supraorbital and greater occipital nerves appears to be effective in the treatment of migraine; however, controlled studies are needed to confirm these preliminary findings.