Technical Notes & Surgical TechniquesStraightening the trigeminal nerve axis by complete dissection of arachnoidal adhesion and its neuroendoscopic confirmation for trigeminal neuralgia without neurovascular compression

•We performed straightening of the trigeminal nerve axis by complete dissection of the arachnoidal adhesion around the trigeminal nerve.•The patient demonstrated complete resolution of the trigeminal neuralgia without facial numbness and dysesthesia after the operation.•Arachnoid dissection was confirmed under a neuroendoscopic view•Operative injury of trigeminal and cochlear nerves was not detected by electrophysiological monitoring.

BackgroundMicrovascular decompression has been used as an effective surgical treatment for typical trigeminal neuralgia with neurovascular compression. Since microvascular decompression cannot be performed in patients with typical trigeminal neuralgia without neurovascular compression, it has recently been suggested that nerve combing or neurolysis (longitudinally splitting the trigeminal nerve from the root entry zone to the pons by microneedle) be used as a primary surgical treatment. However, postoperative numbness and dysesthesia were present in the patients.Case descriptionWe present a case of a 57-year-old woman with typical trigeminal neuralgia without neurovascular compression, which was evaluated by magnetic resonance imaging. A neurosurgical operation was performed in a supine-lateral position for the retromastoid approach under monitoring by electrophysiological evoked potentials. Since neurovascular compression could not be found, we performed straightening of the trigeminal nerve axis by complete dissection of the arachnoidal adhesion around the trigeminal nerve. Results were confirmed by a neuroendoscope. The patient demonstrated complete resolution of the trigeminal neuralgia without facial numbness and dysesthesia during the three years after the operation.ConclusionsStraightening the trigeminal nerve axis by complete dissection of the arachnoidal adhesion around the trigeminal nerve was effective for typical trigeminal neuralgia without neurovascular compression.