Sensory abnormalities and masticatory function after microvascular decompression or balloon compression for trigeminal neuralgia compared with carbamazepine and healthy controls

Abstract

OBJECT Idiopathic trigeminal neuralgia (iTN) is a neurological condition treated with pharmacotherapy or neurosurgery. There is a lack of comparative papers regarding the outcomes of neurosurgery in patients with iTN. The objective of this study was to investigate sensory thresholds and masticatory function in 78 patients with iTN who underwent microvascular decompression (MVD) or balloon compression (BC), and compare these treatments with carbamazepine and 30 untreated healthy controls. METHODS The authors conducted a case-controlled longitudinal study. Patients were referred to 1 of 3 groups: MVD, BC, or carbamazepine. All patients were evaluated before and after treatment with a systematic protocol composed of a clinical orofacial questionnaire, Research Diagnostic Criteria for temporomandibular disorders, Helkimo indices, and a quantitative sensory-testing protocol (gustative, olfactory, cold, warm, touch, vibration, superficial, and deep pain thresholds). RESULTS Both MVD and BC were effective at reducing pain intensity (p = 0.012) and carbamazepine doses (p < 0.001). Myofascial and articular complaints decreased in both groups (p < 0.001), but only the patients in the MVD group showed improvement in Helkimo indices (p < 0.003). Patients who underwent MVD also showed an increase in sweet (p = 0.014) and salty (p = 0.003) thresholds. The sour threshold decreased (p = 0.003) and cold and warm thresholds increased (p < 0.001) in patients after MVD and BC, but only the patients who underwent BC had an increase in touch threshold (p < 0.001). CONCLUSIONS Microvascular decompression and BC resulted in a reduction in myofascial and jaw articular complaints, and the impact on masticatory function according to Helkimo indices was greater after BC than MVD. MVD resulted in more gustative alterations, and both procedures caused impairment in thermal thresholds (warm and cold). However, only BC also affected touch perception. The sensorial and motor deficits after BC need to be included as targets directly associated with the success of the surgery and need to be assessed and relieved as goals in the treatment of iTN.