Evaluation of the impact of a low dose subcutaneous lignocaine and ketamine infusion utilising nerve excitability studies in a chronic migraine population.
Migraine is a common condition in which the diagnosis is based on clinical grounds. There is no clinically available biophysical marker that can evaluate migraine. Migraines are linked to functional brain changes in the absence of structural abnormalities. A clinically useful tool capable of evaluating functional changes in patients with migraine could be used to aid diagnosis and management.
Patients with chronic migraine have frequent or continuous headache which is accompanied by significant morbidity. There are limited data available regarding treatment options for curtailment of chronic migraine. In this prospective observational study, patients suffering from chronic migraine underwent a prolonged subcutaneous lignocaine and ketamine infusion which has anecdotally been useful in management of chronic migraine. To determine if peripheral nerve excitability studies have a role in assessing patients with chronic migraine and their response to treatment, these studies were performed on patients before, during and after the infusion and at six months and compared to healthy age matched controls.
Most patients (13/14) had significant clinical benefit from the infusion. No changes in excitability studies were identified in patients at baseline, during or after intervention with low-dose lignocaine/ketamine infusion. The lack of detectable change in excitability measurements despite significant clinical improvement resulting from the infusion may implicate a central mechanism of action of the infusion
