BACKGROUND: The prognosis of recovery following microneurosurgery for injured lingual nerves varies among individual cases. This study aimed to investigate if recovery ratios of sensory and taste functions are improved by the microneurosurgery within 6 months after lingual nerve injury. METHODS: We retrospectively assessed 70 patients who underwent microneurosurgery at the Wakayama Medical University Hospital for lingual nerve injuries between July 2004 and December 2016. Sensory and taste functions in lingual nerves were preoperatively evaluated using a static two-point discrimination test, an intact superficial pain/tactile sensation test, and a taste discrimination test. They were evaluated again at 12 and at 24 months postoperatively. The abundance ratio of Schwann cells in the excised traumatic neuromas was analyzed with ImageJ software following immunohistochemistry with anti S-100β antibody. RESULTS: In early cases (microneurosurgery within 6 months after the injury), recovery ratios of sensory and taste functions were not significantly different at 24 months after microneurosurgery compared with later cases (microneurosurgery more than 6 months after the injury). Meanwhile, the ratio of patients with taste recovery within 12 months after microneurosurgery was significantly decreased in late cases compared with early cases. The abundance ratio of Schwann cells in traumatic neuroma was also significantly lower in later cases. CONCLUSION Microneurosurgery more than 6 months after lingual nerve injury did not lead to decreased recovery ratio of sensory and taste functions, but it did lead to prolonged recovery of taste. This delay may be associated with a decrease in the abundance ratio of Schwann cells in traumatic neuromas.

Background/Aims: Rosemont classification (RC) with en-doscopic ultrasonography (EUS) is important for diagnosing chronic pancreatitis (CP) but is based only on subjective judgement. EUS shear wave measurement (EUS-SWM) is a precise modality based on objective judgment, but its usefulness has not been extensively studied yet. This study evaluated the utility of EUS-SWM for diagnosing CP and esti-mating CP severity by determining the presence of endocrine dysfunction along with diabetes mellitus (DM). Methods: Between June 2018 and December 2018, 52 patients who underwent EUS and EUS-SWM were classified into two groups according to RC: non-CP (indeterminate CP and normal) and CP (consistent and suggestive of CP). The EUSSWM value by shear wave velocity was evaluated with a me-dian value. The EUS-SWM value was compared with RC and the number of EUS features. The diagnostic accuracy and cutoff value of EUS-SWM for CP and DM and its sensitivity and specificity were calculated. Results: The EUS-SWM value significantly positively correlated with the RC and the number of EUS features. The EUS-SWM values that were consistent and suggestive of CP were significantly higher than that of normal. The area under the receiver operating characteristic (AUROC) curve for the diagnostic accuracy of EUS-SWM for CP was 0.97. The cutoff value of 2.19 had 100% sensitivity and 94% specificity. For endocrine dysfunction in CP, the AUROC was 0.75. The cutoff value of 2.78 had 70% sensitiv-ity and 56% specificity. Conclusions EUS-SWM provides an objective assessment and can be an alternative diagnostic tool for diagnosing CP. EUS-SWM may also be useful for pre-dicting the presence of endocrine dysfunction.