Surgical Resolution of Trigeminal Neuralgia Complicating Vestibular Schwannoma Removal

Abstract

This work illustrates the case of surgical treatment of trigeminal neuralgia (TN), as a tardive complication after vestibular schwannoma (VS) removal (Koos III, Figure 1), in a female patient. After VS surgery, the postoperative computed tomography scan did not show any significant complication, although a thin blood clot was present in the surgical bed (Figure 2). However, 3 months later, our patient developed a TN involving the territories V2-V3. Medical therapies were ineffective. Several magnetic resonance imaging scans confirmed a left dislocation of the brainstem (Figures 3 and 4), probably due to the previous clot retraction. The anatomic-functional preservation of the left Tn was documented using the laser-evoked potentials. Fifteen months after surgery, our patient underwent a second operation aimed at exploring the Tn territory, with the use of the intraoperative monitoring and mapping the fifth and seventh cranial nerves. A neurovascular conflict, caused by scar tissue involving the superior cerebellar artery, a small vein, and the Tn, was detected and surgically solved (Figure 5). Postoperative analgesic treatment was progressively reduced and suspended. The case is illustrated and explained in the Video 1. The paucity of cases reported in the literature lead us to think that TN as complication of VS removal is underestimated because it may be responsive to medical treatment. Laser-evoked potentials may be useful to study the integrity of the Tn, ensuring that no anatomic damage has been done during surgery. On the basis of our experience, surgery can be an effective treatment option when TN is not responsive to medical therapy and the anatomic-functional integrity of the Tn has been preserved.