Chronic electrostimulation of the trigeminal ganglion in trigeminal neuropathy: current state and future prospects

Over two decades ago, the electrostimulation of the trigeminal ganglion (TGES) was established as a treatment option for patients with trigeminopathic pain due to a (iatrogenic) lesion of the trigeminal nerve, on whom the other therapeutic methods, either neurosurgical or conservative have very limited efficacy and usually are associated with a poor outcome. The technique of TGES which uses the setup also used for the thermocoagulation lesion for trigeminal neuralgia was first published by Steude in 1984 and has not been altered substantially. After a percutaneous puncture with a 16 gage needle of the oval foramen, a monopolar electrode (diameter 0.9mm, custom-made) is placed in the postganglionic trigeminal nerve. After a successful test-stimulation phase, a permanent electrode pulse generator system is implanted. Our experience includes more than 300 patients with a minimum follow-up of one year. Of these patients, 52% showed a good to excellent analgesic effect. The TGES-induced analgesia was persistent in long term-follow-up in all patients. The impact of TGES on cerebral pain modulation was proven by electrophysiology and PET. TGES is an effective, minimally invasive and reversible treatment option in selected patients with trigeminopathic pain; it should, therefore, always be considered as the primary treatment-option. Electrodes with two leads and a diameter not exceeding the 0.9 mm, allowing bipolar stimulation might enhance the neuromodulatory efficacy and options of TGES.