Adverse effect profile of Lidocaine injections for occipital nerve block in occipital neuralgia

To determine whether there are differences in the adverse effect profile between 1, 2 and 5% Lidocaine when used for occipital nerve blocks (ONB) in patients with occipital neuralgia. Occipital neuralgia is an uncommon cause of headaches. Little is known regarding the safety of Lidocaine injections for treatment in larger series of patients. Retrospective chart analysis of all ONB was performed at our headache clinic during a 6-year period on occipital neuralgia patients. 89 consecutive patients with occipital neuralgia underwent a total of 315 ONB. All the patients fulfilled the IHS criteria for Occipital Neuralgia. Demographic data were collected including age, gender, and ethnicity. The average age of this cohort was 53.25 years, and the majority of patients were females 69 (78%). Ethnicity of patients was diverse, with Caucasian 48(54%), Hispanics 31(35%), and others 10 (11%). 69 patients had 1%, 18 patients had 2% and 29 patient were given 5% Lidocaine. All Lidocaine injections were given with 20 mg Depo-medrol and the same injection technique and location were used for all the procedures. Eight patients (9%)had adverse effects to the Lidocaine and Depo-medrol injections, of which 5 received 5% and 3 received 1% Lidocaine. Majority of patients who had adverse effects were female 7(87%), and had received bilateral blocks (75%). ONB is a safe procedure with 1% Lidocaine; however, caution should be exerted with 5% in elderly patients, 70 or older, especially when administering bilateral injections.