[Study on changes of face superficial sensory function and its relating factors after intracranial surgery of...

To explore changes of facial sensory function after intracranial surgery in the treatment of idiopathic trigeminal neuralgia (TN) and their possible reasons.

Fifty-six patients of TN receiving trigeminal microvascular decompression (MVD) or nerve combing or coagulation surgery by post-sigmoid approach from 2006 to 2008 were observed. Their sensory score of pain, temperature and tactile were recorded before and 1 week after surgery. These scores as well as status of neurovascular conflict in trigeminal sensory root were analyzed and potential reasons were discussed.

Nineteen (33.9%) cases had normal facial sense after surgery and 37 (66.1%) cases had a decreased sensation. Sensory scores of each divisions 1 week after surgery were significantly lower than those before surgery (P < 0.05). The tactile and temperature sensory score of the first division had not significant difference before and after surgery (P > 0.05 respectively), while the pain sensory had obvious difference (P < 0.01). In the third division the descend score of pain and temperature in the lateral portion was lower than that of the medial portion (P < 0.05), but tactile score had not differences. In all 56 patients, 45 had neurovascular conflict and 26 of them had a decreased facial sense. While in 11 cases without responsible vessel, their facial sense were all abnormal. In the abnormal sensory group, the ratio of conflict vessel presenting at caudal, middle and rostral end of sensory root is 42.3%, 26.9% and 30.8% respectively. In normal sensory group, 63.2% cases had rostral conflict vessel and only 5.3% had caudal conflict vessel.

Intracranial surgery of trigeminal nerve results different changes of superficial sensation on the different portion of the face. In addition to direct injury, stretching of the sensory root (especially at root entry zoon) is an important possible responsibility of postoperative sensory hypesthesia.