To describe a case of successful percutaneous trigeminal ganglion block guided by electrophysiological monitoring of blink reflex for treatment of refractory trigeminal neuralgia

Several surgical options are available including trigeminal ganglion block, radiofrequency thermocoagulation and microvascular decompression. Electrophysiological monitoring of blink reflex can be used to identify the branches of the trigeminal nerve while performing trigeminal ganglion block.

A 39-year-old woman was diagnosed with refractory trigeminal neuralgia (pain score 9/10 on visual analog scale) having failed multiple medications including carbamazepine, gabapentin, valproate, lamotrigine and baclofen. She then underwent percutaneous trigeminal ganglion blockade with electrophysiological monitoring of blink reflex. The needle was advanced along medial aspect of mandible and zygomatic arch under fluoroscopy into the foramen ovale. Serial assessment of blink reflex was performed by placing the lead on right lower lateral orbicularis oculi muscle with reference electrode along lateral surface of the nose. A total of 20mg 1% lidocaine was injected with corresponding slowing of the blink reflex noted on EMG. Then, 104mg (in 7.8ml) liposomal bupivacaine was injected with complete abolishment of blink reflex noted at the end of injection. Patient then reported having right face anesthesia. Dyna CT head post injection showed the needle in foramen ovale. Patient reported no recurrence of pain one month post procedure.

Refractory trigeminal neuralgia can be treated successfully by percutaneous trigeminal blockade guided by electrophysiological monitoring of blink reflex. Electrophysiological monitoring of blink reflex can be helpful in localizing the branches of trigeminal nerve and suppression response can be used objectively for quantitating the magnitude of trigeminal blockade.