Neuralgia of the glossopharyngeal nerve in a patient with posttonsillectomy scarring: recovery after local infiltration of procaine-case report and pathophysiologic discussion

We describe a patient with a three-year history of severe progressive left-sided glossopharyngeal neuralgia (GPN) that failed to adequately respond to various drug therapies. The application of lidocaine spray to the posterior pharyngeal wall provided no more than short-term relief. Apart from a large hypertrophic tonsillectomy scar on the left side all clinical and radiologic findings were normal. In terms of therapeutic local anaesthesia, the hypertrophic tonsillectomy scar tissue was completely infiltrated with the local anaesthetic (LA) procaine 1%. The patient has been almost completely pain-free ever since, and the lidocaine spray is no longer needed. Six weeks after the first treatment a repeat infiltration of the tonsillectomy scar led to the complete resolution of all symptoms. The patient has become totally symptom-free without the need to take any medication now for two and a half years. This is the first report of a successful therapeutic infiltration of a tonsillectomy scar using an LA in a patient with GPN that has been refractory to medical treatment for several years. A possible explanation may be that the positive feedback loop maintaining neurogenic inflammation is disrupted and "sympathetically maintained pain" resolved by LA infiltration.