Lidocaine infusions for refractory chronic migraine: a retrospective analysis

Introduction Patients with refractory chronic migraine have poor quality of life. Intravenous infusions are indicated to rapidly 'break the cycle' of pain. Lidocaine infusions may be effective but evidence is limited. Methods The records of 832 hospital admissions involving continuous multiday lidocaine infusions for migraine were reviewed. All patients met criteria for refractory chronic migraine. During hospitalization, patients received additional migraine medications including ketorolac, magnesium, dihydroergotamine, methylprednisolone, and neuroleptics. The primary outcome was change in headache pain from baseline to hospital discharge. Secondary outcomes measured at the post-discharge office visit (25-65 days after treatment) included headache pain and the number of headache days, and percentage of sustained responders. Percentage of acute responders, plasma lidocaine levels, and adverse drug effects were also determined. Results In total, 609 patient admissions met criteria. The mean age was 46 +/- 14 years; 81.1% were female. Median pain rating decreased from baseline of 7.0 (5.0-8.0) to 1.0 (0.0-3.0) at end of hospitalization (p<0.001); 87.8% of patients were acute responders. Average pain (N=261) remained below baseline at office visit 1 (5.5 (4.0-7.0); p<0.001). Forty-three percent of patients were sustained responders at 1 month. Headache days (N=266) decreased from 26.8 +/- 3.9 at baseline to 22.5 +/- 8.3 at the post-discharge office visit (p<0.001). Nausea and vomiting were the most common adverse drug effects and all were mild. Conclusion Lidocaine infusions may be associated with short-term and medium-term pain relief in refractory chronic migraine. Prospective studies should confirm these results.