A Case of MET Exon 14 Skipping Mutation: Positive Lung Adenocarcinoma Complicated by Paraneoplastic Neurological Syndrome.

A 67-year-old man with cervical spondylotic myelopathy undergoing conservative treatment presented with subacute progression of fine motor and ambulatory disturbances, leading to admission at a previous hospital. Pre-cervical laminoplasty chest computed tomography (CT) revealed a tumor in the left upper lobe of the lung, prompting transfer to our institution. Transbronchial biopsy findings were consistent with adenocarcinoma, diagnosed as clinical stage T2bN0M0, Stage IIA. The neurological abnormalities could not be solely attributed to cervical spondylotic myelopathy, leading to a diagnosis of concurrent paraneoplastic neurological syndrome (PNS). During hospitalization, the patient's condition progressed to a state of constant bed rest within two weeks. On the 17th hospital day, a left upper lobectomy was performed, resulting in significant improvement, allowing the patient to ambulate with assistance after two weeks, and transfer to a convalescent rehabilitation hospital on the 58th hospital day. Subsequent cancer multigene panel testing revealed a positive MET exon 14 skipping mutation. Given the absence of reports on this mutation in lung adenocarcinoma associated with PNS, we consider it rare and thus report this case.

Cylindrical abdominoperineal resection for rectal cancer using the Hugo RAS system: The first ever case report for rectal cancer.

In May 2023, the Hugo RAS system obtained pharmaceutical approval for use in gastroenterological surgery in Japan. It is expected to be particularly effective in rectal cancer surgery, which require the manipulation of the deep pelvic cavity and communication with surgeons operating from the intraperitoneal and anal approaches. A 68-year-old woman presented to our hospital with bloody stools and was diagnosed with cStage I (cT2N0M0) rectal cancer and underwent abdominoperineal resection employing the Hugo RAS system. Two arm carts were placed on the left and right lateral sides with an interleg space, and trocars were placed in a straight line between the right superior iliac spine and umbilicus. Herein, we report the first abdominoperineal resection for rectal cancer using the Hugo RAS system.

Infectious Pulmonary Artery Pseudoaneurysm Secondary to a Lung Abscess Treated With Pulmonary Artery Coil Embolization: A Case Report.

Pulmonary artery pseudoaneurysms (PAPs) are uncommon, yet they frequently result in hemoptysis and are associated with a poor prognosis. We report a case of an 87-year-old male patient. Initially, he was admitted to a previous hospital, and diagnosed with a lung abscess in the left lower lobe. On the second hospital day, he developed hemoptysis. A contrast-enhanced chest computed tomography (CT) identified an infectious pulmonary artery pseudoaneurysm. On the ninth hospital day, pulmonary artery coil embolization was successfully performed, significantly improving the patient's condition.

Lateral Collateral Ligament Reconstruction Using the Triceps Brachii Fascia for Posterolateral Rotatory Instability in Cubitus Varus: A Report of Two Cases.

A combination of osteotomy and ligament reconstruction is recommended for posterolateral rotatory instability (PLRI) with large cubitus varus deformities. There is a lack of reports regarding ligament donor selection for ligament reconstruction of PLRI with cubitus varus. Two cases of PLRI with cubitus varus have been described. In case one, a 40-year-old woman presented with left elbow pain. She had a cubitus varus deformity, resulting from a childhood elbow fracture. Radiographs showed an 18-degree cubitus varus deformity. A lateral closing wedge osteotomy and double plate osteosynthesis were performed. The lateral collateral ligament (LCL) was reconstructed with autologous triceps fascia. Postoperative radiographs confirmed correction with 10 degrees of the carrying angle (CA). Bone union at the osteotomy site occurred six months later with excellent results. In case two, a 45-year-old man presented an arm with persistent right elbow instability with cubitus varus deformity. This was due to a childhood supracondylar fracture of the right humerus. Radiographs showed a cubitus varus deformity of 25 degrees on the right. The surgical procedure included a lateral wedge osteotomy, double plate fixation, and LCL reconstruction with autologous triceps fascia. Postoperative radiographs confirmed a corrected CA of 5 degrees. Bone union was achieved at the six-month follow-up with satisfactory results. The use of triceps fascia for LCL reconstruction for PLRI due to cubitus varus would provide a minimally invasive and reasonable treatment option.

Misleading presentations in functional food trials led by contract research organizations were frequently observed in Japan: meta-epidemiological study.

OBJECTIVES: The functional food market has experienced significant growth, leading to an uptick in clinical trials conducted by contract research organizations (CROs). Research focusing on CRO-managed trials and the communication of trial outcomes to the consumer market remains underexplored. This metaepidemiological study aims to evaluate the quality of randomized controlled trials (RCTs) facilitated by prominent CROs in Japan and to examine the quality of the representations used to convey their results to consumers. STUDY DESIGN AND SETTING: This study focused on the food trials that were registered in the University Hospital Medical Information Network Clinical Trial Registry or the International Clinical Trials Registry Platform by the top 5 CROs. Press releases of study results or advertisements of food products based on the study results were identified by conducting a Google search. The risk of bias in the RCT publications was independently assessed by 2 reviewers, who also evaluated the presence of "spin" in the abstracts and full texts. An assessment of "spin" in press releases/advertisements was undertaken. RESULTS: A total of 76 RCT registrations, 32 RCT publications, and 11 press releases/advertisements were included. Approximately 72% of the RCT publications exhibited a high risk of bias due to selective outcome reporting. "Spin" was present in the results of the abstract (72%), abstract conclusion (81%), full-text results (44%), and full-text conclusion (84%). "Spin" appeared in 73% of press releases/advertisements due to the selective outcome reporting. CONCLUSION: Functional food presentations in Japan frequently contained "spin." The Japanese government should more rigorously check whether food manufacturers report outcomes selectively.

Restrictive Allograft Syndrome After COVID-19 Pneumonia: A Case Report.

Chronic lung allograft dysfunction (CLAD) continues to be the leading cause of death in the long term after lung transplantation (LTx). CLAD has the following two main subtypes: bronchiolitis obliterans syndrome (BOS) and restrictive allograft syndrome (RAS). BOS features obstructive lung dysfunction, while RAS features restrictive lung dysfunction. Overall, RAS has a worse prognosis. The pathophysiology of CLAD is not fully understood; however, pulmonary infections can trigger CLAD, including coronavirus disease 2019 (COVID-19) pneumonia. Here, we describe a case of a 55-year-old female who received LTx about seven years ago and developed RAS after COVID-19 pneumonia. RAS was ultimately diagnosed based on the clinical course and imaging findings. Steroid pulse therapy and empirical antimicrobial therapy were initiated, but respiratory failure progressed, and the patient died 139 days after COVID-19 diagnosis, and 83 days after dyspnea progression. Clinicians should be aware of unusual stair-step clinical courses and imaging features in a given setting of pulmonary infection including COVID-19 to suspect CLAD in lung transplant patients.

Lemierre's Syndrome after Head and Neck Photoimmunotherapy for Local Recurrence of Nasopharyngeal Carcinoma.

Introduction: Head and neck photoimmunotherapy (HN-PIT) uses a combination of drugs and laser illumination to specifically destroy tumor cells. Lemierre's syndrome is an infectious disease with severe systemic symptoms caused by prior infection in the pharyngeal region, leading to thrombophlebitis. Here, we report a case of Lemierre's syndrome that developed after HN-PIT for recurrent nasopharyngeal carcinoma. Case Presentation: A 68-year-old male with nasopharyngeal carcinoma (squamous cell carcinoma) underwent HN-PIT after local recurrence with chemoradiation therapy. Three months after HN-PIT, the patient developed fever and neck pain, which led to a diagnosis of Lemierre's syndrome. The patient was treated with antibiotics and anticoagulants for at least 1 month. The patient's general condition and inflammatory findings on blood sampling showed gradual improvement, and a follow-up cervicothoracic computed tomography imaging showed that the venous thrombus had been obscured and the patient was doing well. Conclusion: HN-PIT is a high-risk procedure for the development of Lemierre's syndrome due to irradiation-induced mucositis, and anticipating the development of Lemierre's syndrome during HN-PIT is important.

Impairment of Social-Related Quality of Life in COVID-19 Pneumonia Survivors: A Prospective Longitudinal Study.

The post-acute sequelae of SARS-CoV-2 (PASC) pose a threat to patients' health-related quality of life (HRQOL). Here, the impact of COVID-19 on HRQOL and the clinical factors associated with impaired HRQOL were examined. Discharged COVID-19 patients were assessed at 3 and 6 months after disease onset. The patients completed a medical examination and the SF-36 questionnaire at these two time points and underwent pulmonary function testing at 6 months after disease onset. All had undergone computed tomography (CT) imaging upon hospital admission. Of the 74 included patients, 38% reported respiratory symptoms at 3 months, and 26% reported respiratory symptoms at 6 months after disease onset. The aggregated SF-36 scores declined in the role/social component summary (RCS), a category related to social activity. Patients with lower RCS tended to have respiratory sequelae or a relatively lower forced vital capacity. The CT score that reflected the extent of COVID-19 pneumonia was inversely correlated with the RCS score (3 months, p = 0.0024; 6 months, p = 0.0464). A high CT score (≥10 points) predicted a low RCS score at 6 months (p = 0.013). This study highlights the impairment of RCS and its associations with respiratory sequelae. The study also emphasizes the importance of radiological findings in predicting long-term HRQOL outcomes after COVID-19.

Longitudinal changes in skin perfusion pressure after endovascular therapy in patients with chronic limb-threatening ischemia.

PURPOSE: The skin perfusion pressure (SPP) increases after endovascular treatment (EVT) for up to 1 month, although changes beyond 1 month remain unreported. This study aimed to investigate the changes in the SPP over time after EVT. MATERIALS AND METHODS: This was a single-center, prospective, observational study. We included patients with chronic limb-threatening ischemia who underwent EVT between January 2019 and July 2022. We evaluated the SPP after EVT monthly for up to 3 months and compared the changes in the SPP between patients with different comorbidities. Moreover, we investigated the independent predictors of recurrent foot ischemia using a multivariate analysis. RESULTS: Overall, 87 patients were included in the study. The mean preprocedural dorsal and plantar SPP was 33.9 ± 14.7 and 33.4 ± 13.1 mmHg, respectively. After the procedure, the SPP significantly increased at 1 month but decreased during months 2 and 3 (the dorsal SPP at 1, 2, and 3 months was 59.6 ± 20.3, 48.3 ± 20.9, and 39.7 ± 14.7, respectively, p < 0.01; the plantar SPP at 1, 2, and 3 months was 57.3 ± 18.2, 48.2 ± 15.6, and 40.5 ± 15.3, respectively, p < 0.01). Changes in the SPP did not differ among patients with different comorbidities. The multivariate analysis revealed that severe infrapopliteal calcification was an independent predictor of recurrent foot ischemia (odds ratio, 3.8; 95% confidence interval, 1.1-13.4; p = 0.04). CONCLUSION: The SPP after EVT significantly increased at 1 month and decreased monthly for up to 3 months. Severe infrapopliteal calcification was the sole predictor of foot ischemia recurrence. Meticulous follow-up after EVT and regular hemodynamic examinations are important.

A Case of Oropharyngeal Carcinoma with an Oblique Neck that Benefited from Transoral Robotic Surgery.

Transoral robotic surgery (TORS) and transoral videolaryngoscopic surgery (TOVS) are minimally invasive procedures for early-stage head and neck cancers. However, due to its unique nature, transoral resection often leads to skeletal and anatomical disorders. We describe a case in which TORS was used in a 71-year-old man with a skeletal disorder, spastic stridor, and a T2N1M0 stage I p16-positive oropharyngeal carcinoma. Prior to the procedure, he underwent right cervical dissection (levels II-IV). Although he had an oblique neck, the right side of his neck was naturally hyperextended because the dissection was performed on the right side. The right facial, lingual, and external carotid arteries were ligated in preparation for TORS. Postoperative pathological examination revealed no extranodal involvement of the metastatic lymph nodes. A two-stage TOVS procedure was performed for the oropharyngeal tumor, in which the surgeon was required to be positioned at the patient's head to allow direct manipulation. This makes the neck and oral cavity more susceptible to the skeletal effects. In contrast, in TORS, the da Vinci insertion angle can be set to match the angle of the neck, allowing surgeons to operate with less skeletal influence. TORS is more useful in this setting.

World-first report of low anterior resection for rectal cancer with the hinotori™ Surgical Robot System: a case report.

BACKGROUND: The hinotori™ Surgical Robot System was approved for use in colorectal cancer surgery in Japan in 2022. This robot has advantages, such as an operation arm with eight axes, an adjustable arm base, and a flexible three-dimensional viewer, and is expected to be utilized in rectal cancer surgery. Herein, we report the world's first surgery for rectal cancer using the hinotori™ Surgical Robot System. CASE PRESENTATION: A 71-year-old woman presented to our hospital with bloody stools. A colonoscopy revealed type 2 advanced cancer in the rectum, and a histological examination exposed a well-differentiated adenocarcinoma. Abdominal enhanced computed tomography divulged rectal wall thickening without significant swelling of the lymph nodes or distant metastasis. Pelvic magnetic resonance imaging showed tumor invasion beyond the intrinsic rectal muscle layer. The patient was diagnosed with cStage IIa (cT3N0M0) rectal cancer and underwent low anterior resection using the hinotori™ Surgical Robot System. Based on an adequate simulation, surgery was safely performed with appropriate port placement and arm base-angle adjustment. The operating time was 262 min, with a cockpit time of 134 min. Subsequently, the patient was discharged 10 days postoperatively without complications. The pathological diagnosis was pStage IIA (cT3N0M0) and the circumferential resection margin was 6 mm. CONCLUSIONS: We report the first case of low anterior resection for rectal cancer using the hinotori™ Surgical Robot System, in which a safe and appropriate oncological surgery was performed.

Impact of coronary bifurcation angle on stent malapposition in a randomized comparison between proximal optimization technique followed by side branch dilatation and kissing balloon inflation.

Background: The impact of coronary bifurcation angle (BA) on incomplete stent apposition (ISA) after crossover stenting followed by side branch (SB) intervention has not been established. Methods: A total of 100 crossover stentings randomly treated with proximal optimization technique followed by short balloon dilation in the SB (POT-SBD group, 48 patients) and final kissing balloon technique (KBT group, 52 patients) were analyzed in the PROPOT trial. Major ISA with maximum distance > 400 µm and its location was determined using optical coherence tomography before SB intervention and at the final procedure. The BA was defined as the angle between the distal main vessel and SB. Optimal POT was determined when the difference in stent volume index between the proximal and distal bifurcation was greater than the median value (0.86 mm3/mm) before SB intervention. Result: Major ISA was more frequently observed in the POT-SBD than in the KBT group (35% versus 17%, p < 0.05). In the POT-SBD group, worsening ISA after SBD was prominent at the distal bifurcation. The BA was an independent predictor of major ISA (odds ratio 1.04, 95% confidence interval 1.00-1.07, p < 0.05) with a cut-off value of 59.5° (p < 0.05). However, the cases treated with optimal POT in the short BA (<60°) indicated the lowest incidence of major ISA. In the KBT group, BA had no significant impact. Conclusion: A wide BA has a potential risk for the occurrence of major ISA after POT followed by SBD in coronary bifurcation stenting.

Home transfusions are implemented using diverse approaches in Japan.

BACKGROUND AND OBJECTIVES: Japan's ageing society has increased the need for home healthcare, including home transfusions. We hence aimed to elucidate the purpose and utilization of home transfusions in Japan, which has not been clarified to date. MATERIALS AND METHODS: Clinics throughout Japan that provide home care and have experience in performing blood transfusions were surveyed. The study period was February to December 2019, and information of patients receiving home red blood cell transfusions, including patient background, pre-transfusion laboratory data and the purpose of the transfusions, was collected. RESULTS: Haematological malignancies and solid tumours accounted for 70% of the patients' underlying diseases, with the former being significantly more common in urban areas. Regarding the purpose of the home transfusions, haematologists focused on symptom improvement, whereas gastroenterology surgeons focused on life support. Furthermore, maintenance of life was more likely to be the aim in the group of patients with the lowest level of activities of daily living. The main items that were significantly associated with a low haemoglobin level before transfusion included age ≥90 years and a gastroenterologist being the physician in charge. CONCLUSION: Home transfusions were found to be performed in a restrictive and diverse manner in Japan. Life support is the second most common purpose of home transfusion in Japan, and optimizing effective home transfusion remains a challenge.

Efficacy of Nivolumab and Pembrolizumab in Platinum-sensitive Recurrent or Metastatic Head and Neck Squamous Cell Carcinoma.

BACKGROUND/AIM: This study evaluated the efficacy of nivolumab and pembrolizumab in treating platinum-sensitive recurrent or metastatic head and neck squamous cell carcinomas (R/M-HNSCC). PATIENTS AND METHODS: Platinum-sensitive patients with R/M-HNSCC were selected at Tokyo Medical University Hospital from May 1, 2017, to June 30, 2022. Patients with a history of treatment with nivolumab or pembrolizumab were included. Nivolumab was used in 21 cases and pembrolizumab in 15 cases. RESULTS: The median overall survival (OS) was 16.9 months in the nivolumab group and 19.2 months in the pembrolizumab group and no significant differences were observed between the two groups. The median progression-free survival (PFS) was 4.8 months in the nivolumab group and 9.3 months in the pembrolizumab group. No significant differences were observed between the two groups. The objective response rates (ORR) were 38% and 47% in the nivolumab and pembrolizumab groups, respectively. CONCLUSION: Nivolumab as well as pembrolizumab were found to be effective in platinum-sensitive patients with R/M-HNSCC. Nivolumab can be considered a potential treatment option for platinum-sensitive R/M-HNSCC in the future.

A high-hydrostatic pressure device for nevus tissue inactivation and dermal regeneration for reconstructing skin defects after giant congenital melanocytic nevus excision: a clinical trial.

Background: A novel treatment has been developed to reconstruct large skin defects caused by the excision of giant congenital melanocytic nevi. It involves the reimplantation of high-hydrostatic pressurized nevus tissue as a cell-inactivated autologous scaffold for dermal regeneration, followed by the implantation of cultured epithelial autografts on the regenerated dermis. Because this treatment has shown promise in a first-in-human clinical trial which used a prototype pressure machine, a novel pressure device was specifically designed for clinical use. Methods: In a prospective investigator-initiated clinical trial involving three patients, we evaluated the safety and efficacy of the skin regeneration treatment using a pressure device. All three patients underwent surgical excision of the nevus tissue, primary reimplantation of the inactivated nevus tissue, and secondary implantation of cultured epithelial autografts. Results: Engraftment of inactivated nevus tissue and cultured epithelial autografts was successful in all three cases, with over 90% epithelialization at 8 weeks post-surgery. No serious adverse events or device malfunction were observed during the trial. Conclusion: The novel pressure device safely and effectively enabled dermal regeneration using the nevus tissue as an autologous scaffold. This innovative approach offers several advantages, including reduced invasiveness due to minimal sacrifice of normal skin for skin grafting and high curative potential resulting from full-thickness removal of the nevus tissue.

Pd2 MnGa Metamagnetic Shape Memory Alloy with Small Energy Loss.

Metamagnetic shape memory alloys (MMSMAs) are attractive functional materials owing to their unique properties such as magnetostrain, magnetoresistance, and the magnetocaloric effect caused by magnetic-field-induced transitions. However, the energy loss during the martensitic transformation, that is, the dissipation energy, Edis , is sometimes large for these alloys, which limits their applications. In this paper, a new Pd2 MnGa Heusler-type MMSMA with an extremely small Edis and hysteresis is reported. The microstructures, crystal structures, magnetic properties, martensitic transformations, and magnetic-field-induced strain of aged Pd2 MnGa alloys are investigated. A martensitic transformation from L21 to 10M structures is seen at 127.4 K with a small thermal hysteresis of 1.3 K. The reverse martensitic transformation is induced by applying a magnetic field with a small Edis (= 0.3 J mol-1 only) and a small magnetic-field hysteresis (= 7 kOe) at 120 K. The low values of Edis and the hysteresis may be attributed to good lattice compatibility in the martensitic transformation. A large magnetic-field-induced strain of 0.26% is recorded, indicating the proposed MMSMA's potential as an actuator. The Pd2 MnGa alloy with low values of Edis and hysteresis may enable new possibilities for high-efficiency MMSMAs.

Right hemicolectomy for ascending colon cancer using the hinotori surgical robot system: The first ever case report for colon cancer.

The hinotori Surgical Robot System obtained pharmaceutical approval for use in colorectal cancer surgery in October 2022 in Japan, and its advantages, including its operating arm with eight axes, adjustable arm base, and flexible 3D viewer, are expected to be utilized in colon cancer surgery. A 68-year-old woman presented to our hospital with abdominal pain and was diagnosed with cStageIIa (cT3N0M0) ascending colon cancer and underwent right hemicolectomy using the hinotori Surgical Robot System with the appropriate port placement on the arc around the hepatic flexure, which was available for both ileocecal manipulation and lymph node dissection, and adjustment of the angle of the arm base to further reduce interference. Herein we report the world's first surgery for colorectal cancer using the hinotori Surgical Robot System.

Effects of Pembrolizumab in Recurrent/Metastatic Squamous Cell Head and Neck Carcinoma: A Multicenter Retrospective Study.

BACKGROUND/AIM: Pembrolizumab exhibits anticancer efficacy in platinum-sensitive or platinum-unfit patients with recurrent/metastatic squamous cell carcinoma of the head and neck (R/M SCCHN). However, no large-scale retrospective real-world data are available. This retrospective study aimed to examine the efficacy and safety of pembrolizumab in multiple facilities. PATIENTS AND METHODS: Data of 167 patients with R/M SCCHN treated with pembrolizumab between December 2019 and February 2022 were analyzed. The endpoint was overall survival (OS), progression-free survival (PFS), and immune-related adverse events (irAEs). OS and PFS were analyzed comparatively with and without irAEs, and complete response (CR) or partial response (PR), and stable disease (SD) or progressive disease (PD) were compared. RESULTS: One hundred thirty-five patients received pembrolizumab alone, whereas the others received pembrolizumab with chemotherapy. For the pembrolizumab only group, the median OS and PFS were 22.7 and 5.1 months, respectively. There were significant differences in OS and PFS between CR or PR and SD or PD (p<0.01, p<0.01, respectively). For pembrolizumab with chemotherapy, the OS was not reached and median PFS was 7.0 months. There was a significant difference in PFS between CR or PR and SD or PD (p<0.01). There was a significant difference in PFS between patients with and without irAEs (p=0.02). CONCLUSION: The real-world therapeutic effect of pembrolizumab for R/M SCCHN was comparable to that observed in the KEYNOTE048 trial. In addition, irAEs and best overall response were considered as prognostic factors.

Feasibility and impact of extra-vascular ultrasound-guided endovascular treatment for infrapopliteal artery occlusive disease.

PURPOSE: This study aimed to examine the feasibility and impact of extra-vascular ultrasound (EVUS)-guided intervention for infrapopliteal (IP) artery occlusive disease. MATERIALS AND METHODS: A retrospective analysis was performed using data collected from patients who underwent endovascular treatment (EVT) for IP artery occlusive disease between January 2018 and December 2020 at our institution. A total of 63 consecutive de novoocclusive lesions were compared according to the recanalization method utilized. Propensity score matching analysis was performed to compare the clinical outcomes of the methods utilized. The prognostic value was analyzed based on the technical success rate, distal puncture rate, radiation exposure, amount of contrast media, postprocedural skin perfusion pressure (SPP), and procedural complication rate. RESULTS: Eighteen matched pairs of patients were analyzed using propensity score-matched analysis. Radiation exposure was significantly lower in the EVUS-guided group than in the angio-guided group, with 135 and 287 mGy (p = 0.04) exposure on average, respectively. There were no significant differences between the two groups in terms of technical success rate, distal puncture rate, the amount of contrast media, postprocedural SPP, and procedural complication rate. CONCLUSION: EVUS-guided EVT for IP occlusive disease achieved a feasible technical success rate and significantly reduced radiation exposure.

Utility of the tibial nerve somatosensory evoked potentials in differentiating between neuromyelitis optica spectrum disorders and multiple sclerosis.

BACKGROUND: Somatosensory evoked potentials (SEPs) are widely used for the diagnosis and evaluation of neuromyelitis optica spectrum disorder (NMOSD) and multiple sclerosis (MS). However, whether the parameters of tibial nerve SEPs can help to distinguish NMOSD from MS remains unclear. Thus, the aim of this study was to investigate the utility of tibial nerve SEP parameters in differentiating patients with NMOSD and MS. METHODS: The clinical data of patients with NMOSD or MS treated in our institution between 2005 and 2021 were retrospectively extracted from our electronic database. Additional inclusion criteria were presentation with sensory symptoms in the lower extremities with corresponding lesions in the magnetic resonance images as well as available data on anti-aquaporin-4 antibodies and tibial nerve SEPs. The Z-scores of the N21-P38 interval (central sensory conduction time), P38 latency, and P38 amplitude were compared between the patients with NMOSD and MS. The relationship of disease severity with the parameters of the tibial nerve SEPs was also evaluated. RESULTS: Twenty patients with NMOSD and 13 patients with MS were enrolled. The Z-scores of the N21-P38 interval and P38 latency were significantly higher in the MS group than in the NMOSD group (p < 0.05 and p < 0.01, respectively), whereas there was no difference in the Z-scores of the P38 amplitude between the two groups. In the MS group, only the N21-P38 interval and P38 latency were significantly correlated with disease severity (p < 0.05 and p < 0.01, respectively). In contrast, none of the tibial nerve SEP parameters were significantly correlated with disease severity in the NMOSD group. CONCLUSION: Evaluation of the N21-P38 interval and P38 latency in tibial nerve SEPs potentially helps in differentiating between NMOSD and MS.