A case of severe trigeminal neuralgia: recovery by means of stellate ganglion block with procaine. Discussion of possible mechanisms of action.

Drug and invasive treatment options for trigeminal neuralgia (TN) are often fraught with problems. Knowledge of the involvement of the autonomic nervous system, especially the sympathetic portion, in the pain process has grown rapidly in recent years. Both nociceptive and neuropathic pain can be maintained by the sympathetic nervous system, known as 'sympathetically maintained pain' (SMP). This current case report describes a patient with refractory TN that was treated with a stellate ganglion block (SGB). After the first SGB, the patient experienced significant pain relief that became long-lasting after repeated application of the SGB. These findings suggest that this patient had a high level of SMP. In patients with a low percentage of SMP, SGB may be less or not successful. A literature search did not find any case reports or studies about patients with refractory idiopathic TN treated with sympathetic blocks using local anaesthetics. From our point of view, it might be useful to test by means of SGB the extent to which an individual has SMP present, and, if that is the case, to perform a short series of SGB, as done in this current patient. Studies are needed to provide further insights.