Trigeminal Sensory Neuropathy Predicts Chemosensory Dysfunction After Skull Base Surgery

Abstract

BACKGROUND:Trigeminal sensory neuropathy, characterized by diminished or exaggerated/painful sensation along the distribution of trigeminal branches, is one of the complications after skull base surgery. These procedures can also affect chemosensory functions and compromise the patients' quality of life.OBJECTIVE:To examine those postoperative complications in chemosensory and facial cutaneous sensory functions as well as their interaction.METHODS:A total of 61 patients being operated for various pathologies in the vicinity of trigeminal pathway (17 with trigeminal neuralgia, 20 with meningiomas, and 24 with vestibular schwannomas) and 50 healthy controls were enrolled in this case-control study. Postoperative trigeminal neuropathic symptoms were evaluated. The olfactory, gustatory, and intranasal trigeminal functions were assessed using the Sniffin’ Stick olfactory test, lateralized taste strip test, and the lateralized intranasal trigeminal CO2detection thresholds, respectively.RESULTS:Patients with trigeminal neuralgia and meningioma had relatively decreased olfactory function, whereas those with vestibular schwannoma had a relative decrease in taste function. As for the relationship between the distribution of trigeminal neuropathy and chemosensory dysfunction, we found that V3 involvement predicted lower side-specific taste function. In addition, V2/V3 involvement predicted relatively lower side-specific intranasal trigeminal function.CONCLUSION:The present results suggest a differential involvement of the chemical senses in relation to the site and pathology of the lesions after surgery. The presence of trigeminal neuropathy is associated with taste and intranasal trigeminal dysfunction. The results serve as a basis for consultation regarding outcome prediction and patient education.