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In a volunteer-based self-organizing network, such as a peer-to-peer (P2P) network, a wireless ad-hoc network, and a device-to-device (D2D) network, participation and cooperation of volunteer nodes are crucial for the network to sustain. We call this kind of network a “decentralized” network in this paper as we cannot assume any centralized global management nor control. Rewarding by auction has been thought to be effective to keep or promote incen-tives to participation and cooperation in many studies. This short paper proposes a simple and light-weight mechanism for decentralized networks based on the con-cept of Vickrey auction. This paper focuses on two problems of fair execution and participation incentives in particular. Results of the simulation-based experiments and evaluations confirm that the proposed mechanism is effective in promoting participation incentives. Keywords: Participation incentives, Free-rider problem, Auction, Decentralized networks.

An IoT system comprises servers or a cloud at the center,30000 possibly surrounded by edge cloudlets and fog computing devices, a group of sensors on one side, and a group of actuators on the other side if the purpose of the system is not only data analysis but also automated control. Actuators are connected to the central servers or a cloud via an actuator network. Due to progress in smart robotics and related technologies, actuator networks are now getting large, wide, and complex, and should be decentralized and self-organizing as well as sensor networks are. However, as far as we know, there have been no noticeable researches on actuator networks yet. In this paper, we propose a new routing protocol for actuator networks based on an inverse of Directed Diffusion, which is one of the most well-known protocols for sensor networks. Our protocol aims at realizing efficient dissemination and delivery of signals, commands, and data for control, and exhibits good results in simulation-based experiments regarding network traffic reduction. Keywords: Internet of Things, Actuator networks, Directed Diffusion.

In a volunteer-based self-organizing network, such as a peer-to-peer network and a wireless ad-hoc network, trustworthiness of each participant node is crucial to assure information security and resilience of the whole network. We call this kind of network a “decentralized” network. In a decentralized network, mutual evaluation of trust among nodes are considered useful to manage trustworthiness in many studies. As far as we know, all the preceding related studies discussed trust management upon stable mature networks. However, most decentralized networks in reality begin with initial states comprised of a small number of nodes, and grow gradually with new-comer nodes joining in. This paper proposes a new trust management method for a growing decentralized network. The network grows from the initial stage where we assume all the initial nodes are trustworthy enough. This paper exhibits that our method extending GossipTrust brings better performance and better quality of trust evaluation than the original GossipTrust. Keywords: Trust, Reputation, P2P networks, Ad-hoc networks, Network growth.

The term carcinoma of unknown primary (CUP) refers to a malignant tumor whose histology suggests strongly that it is a metastasis, yet the primary lesion is unknown despite sufficient whole body evaluation at the time of examination. CUP has similar incidences in men and women and the average age at diagnosis is 60 years. While its overall incidence varies depending on the report, it generally accounts for 1-5% of all cancers. Thus, it is rare. We encountered a case of squamous cell carcinoma of the inguinal region that seemed to be a metastasis and for which we could not find the primary lesion. This case is reported here along with a literature review on CUP to increase awareness of this rare lesion.

Swarm behavior is collective behavior of creatures moving with their neighbors, such as a flock of birds or a school of fishes. From the system optimization standpoint of view, there have been a number of “bioinspired” models proposed to apply the swarm behavior to organize complex systems and/or to incorporate robustness and flexibility. Territorial behavior is another group form of homogeneous individuals in which each one lives in a separate region (territory) from each other. For system optimization. The most notable application is coverage control. There are some creatures which exhibit either swarm behavior and territorial behavior according to their circumstances and conditions. However, as far as we know, there is no attempt toward any model or algorithm to combine both the swarm behavior and territorial behavior to make systems adapt to the change of circumstances and conditions. This paper proposes a phase transition model to combine swarm behavior and territorial behavior. The model is expected to apply to network optimization in dynamic environments, especially transition between cloud computing and edge computing. Through simulation-based experiments, we verify the convergence behavior of the model. Keywords: Swarm behavior, Territorial behavior, Dynamic transition

The concept of hair transparency has been claimed widely in the Japan (and now it is spreading to Asian) hair color market. Despite the general use of this concept, to date, there is no clear and objective description to accurately explain what it is. In this work, we have decoded and gave clarity to the concept of hair transparency via a technical model (validated for both Japan and China markets) composed of measurable parameters of hair property using a single device.A comprehensive study composed of various tests was used, starting with a qualitative identification of key parameters via in-depth workshop discussions with over 40 Japanese stylists and a panel of 12 consumers. These identified parameters (luminosity, color visibility, and Shine) were then translated into technically measurable parameters of the hair fiber (Diffused light intensity, ratio of RGB channel intensities of Diffused light, and luster) via a single instrument-Hair SAMBA (a dual-polarized imaging system). Afterward, 10 carefully selected anchor shades were used as visual stimuli in an online pairwise comparison (PC) study with 100 Japanese stylists to generate quantitative transparency perception data of the swatches. Technical parameters of these swatches were measured by SAMBA and consolidated with the PC output, for the creation and validation of the mathematical model. After, with another PC study (N = 100) in China, with seven shades from Japan study and 6 additional Chinese market shades, the applicability of the model in China market was validated.We have clarified and quantified the concept of hair transparency through a consumer centric approach and with objective data. Our findings will enable the development of optimum transparent shades which better suits consumer needs. Lastly, we would like to highlight the beauty of digitalization in the study: The digital evaluation pathways chosen allowed us to collect quantitative consumer data from two countries for the creation of a robust model under the impact of COVID-19 and would definitely be the way to go for our future consumer evaluation studies.

Introduction: Intracerebral hemorrhage (ICH) is a devastating hemorrhagic event and is associated with high mortality or severe neurological sequelae. Age-associated differences in hematoma location for nonlobar ICH are not well known. The aims of the present study were to elucidate the relationship between age and hematoma location and to assess the differences in small-vessel disease (SVD) burden as a potential surrogate marker for longstanding hypertension among various hematoma locations. Methods: From September 2014 through July 2019, consecutive patients with acute, spontaneous ICH were retrospectively enrolled from a prospective registry. Magnetic resonance imaging was performed during admission, and the total SVD burden score (including microbleeds, lacunes, enlarged perivascular spaces, and white matter hyperintensities) was calculated. The relationships of hematoma location with aging and SVD burden were assessed by using multivariate logistic regression analyses. Results: A total of 444 patients (156 women [35%]; median age 69 [interquartile range 59–79] years; National Institutes of Health Stroke Scale score 9 [17][3–17]) were enrolled in the present study. Multivariate logistic regression analyses showed that advanced age was independently associated with thalamic (odds ratio [OR]: 1.48, 95% confidence interval [CI]: 1.19–1.84, p < 0.001 for 10-year increment) and lobar hemorrhage (OR: 1.58, 95% CI: 1.19–2.09, p = 0.002) and was independently and negatively related to putaminal hemorrhage (OR: 0.55, 95% CI: 0.44–0.68, p < 0.001). The total SVD burden score was independently and positively associated with thalamic hemorrhage (OR: 1.27, 95% CI: 1.01–1.59, p = 0.045) and negatively with lobar hemorrhage (OR: 0.74, 95% CI: 0.55–0.99, p = 0.042), even after adjusting by age, but not with putaminal hemorrhage (OR: 0.91, 95% CI: 0.73–1.14, p = 0.395). Conclusion: Putaminal, thalamic, and lobar hemorrhages are prone to occur in specific ages and SVD states: putaminal in young patients, thalamic in old and high SVD burden patients, and lobar hemorrhages in old and low SVD burden patients. Susceptibility to bleeding with aging or severe SVD accumulation seems to differ considerably among brain locations.

A field-effect transistor (FET) using CAAC-IGZO, a crystalline oxide semiconductor having a c-axis alignment, is considered for application to various circuits. In particular, its extremely low off-state leakage current[1,2] enables design of non-volatile memory and analog memory devices[3], allowing AI tasks to be run in non-von-Neumann architectures. Furthermore, CAAC-IGZO FET can be applied to use cases other than memory, such as RF applications. CAAC-IGZO FET can be integrated in the back-end-of-line processes of CMOS technologies[4], and allows higher power supply voltages than conventional CMOS devices[4]. This may contribute to reduced chip area, which can create smaller packages, which are demanded for IoT endpoints. As there are not many applications that currently use scaled CAAC-IGZO FET, CAAC-IGZO FET is not yet applied to quasi-millimeter-wave applications. In addition, circuit design for high-frequency applications of CAAC-IGZO FETs will require extraction of FET characteristics that will be utilized in this application. Compact models are available for large IGZO FETs [5], but not for scaled CAAC-IGZO FETs. For this work, we have prototyped and evaluated scaled CAAC-IGZO FETs (Fig. 1(a)) that are suitable for high-frequency applications in addition to memory applications. From network measurements, it was found that the CAAC-IGZO FET exhibits a cutoff frequency of 60 GHz (Fig. 1(b)) and a maximum oscillation frequency of 16 GHz, which is promising for quasi-millimeter-wave designs. In addition, we have designed equivalent circuits of the scaled CAAC-IGZO FET using linear devices. This circuit shows not only the characteristics of the scaled CAAC-IGZO FET, but also the potential for circuit designs with the device. This work compiles the characteristics of the scaled CAAC-IGZO FET, and proposes a novel circuit application for the device. Fig. 1 (a) L-direction cross section of the scaled CAAC-IGZO FET. (b) Network measurment result of the scaled CAAC-IGZO FET References [1] N. Kimizuka and S. Yamazaki, “Physics and Technology of Crystalline Oxide Semiconductor CAAC-IGZO FUNDAMENTALS,” WILEY, 2017. [2] S. Yamazaki and M. Fujita, “Physics and Technology of Crystalline Oxide Semiconductor CAAC-IGZO Application to LSI,” WILEY, 2017. [3] Y. Kurokawa et al., JJAP, vol. 59, pp. (SGGB03-1)-(SGGB03-11), 2020. [4] H. Kunitake et al., J-EDS, vol. 7, pp.495-502, 2019. [5] L. J. Giacoletto et al., JSSC, vol. 4, issue 2, pp.80-83, 1969. Figure 1

BackgroundT cell immunoglobulin and mucin domain-containing protein 3 (TIM-3) is a part of modules expressed on dysfunctional or exhausted T cells as well as dendritic cells and has emerged as a target for several therapeutic antibodies that are under clinical development. Co-blockade of TIM-3 and PD-1 results in tumor regression in preclinical models and improves anticancer T cell responses in patients with advanced cancers. TIM-3 has been reported to have multiple ligands including galectin-9, phosphatidylserine, CEACAM-1 and HMGB1, which bind to different regions on the extracellular domain of TIM-3. Most of the TIM-3 antibodies developed to date are intended to inhibit phosphatidylserine that binds to the pocket in TIM-3 immunoglobulin V domain. Galectin-9 binds to carbohydrate motifs on the opposite side of phosphatidylserine-binding site in immunoglobulin V domain and thereby induces cell death in TIM-3+ T cells. We report herein novel antibodies that block TIM-3 binding to multiple ligands including these two important ligands simultaneously.MethodsAnti-TIM-3 antibodies were generated by immunizing mice with a purified recombinant TIM-3 protein and TIM-3-expressing mammalian cell line. Phage display libraries were constructed using cDNAs of splenocytes and lymph node cells of the immunized mice, then subjected to the biopanning using recombinant TIM-3 proteins. After analyzing specificities and affinities to the TIM-3 protein, scFvs obtained were classified by epitope bin and inhibitory effects on TIM-3 binding to the multiple ligands. The scFvs were converted to scFv-Fc to generate biparatopic (bispecific) antibodies.ResultsAt least five classes of TIM-3 antibodies were obtained, and each class was grouped into different epitope bins and has unique inhibitory profiles for multiple ligands of TIM-3. Their biparatopic (bispecific) forms were produced from the scFv clones and subjected to the analyses of TIM-3 binding, inhibition of ligand binding, and immune activation. As expected, the biparatopic antibodies that recognize two different epitopes showed higher affinity and specificity to TIM-3 than monospecific forms. A lead biparatopic antibody that block the binding of TIM-3 to galectin-9 and phosphatidylserine showed remarkable potency on T cell activation, protection from exhaustion and apoptotic cell death of T cells as well as more potent anti-tumor efficacy.ConclusionsThis study demonstrates the successful development of a novel biparatopic antibody that blocks the binding of TIM-3 to phosphatidylserine and galectin-9 simultaneously. The antibody shows the advantages over conventional TIM-3 antibodies in reducing T cell exhaustion and potentially manipulated for the development of human monoclonal antibodies for therapeutic treatment of cancer.

Photoimmunotherapy (PIT) is a new type of tumor‐specific treatment utilizing monoclonal antibody (mAb)‐photosensitizer conjugates and near‐infrared (NIR) light irradiation. One potential PIT target, the type I transmembrane protein TROP2, is expressed at high levels in many cancers, including pancreatic carcinoma (PC) and cholangiocarcinoma (CC), in which its expression is correlated with poor prognosis and tumor aggressiveness. In this study, we assessed the efficacy of PIT utilizing newly developed humanized anti‐TROP2 mAb conjugated to the photosensitizer IR700 (TROP2‐IR700) for PC and CC. Immunohistochemistry on PC and CC tissue microarrays confirmed that TROP2 is overexpressed in about half of PC and CC specimens. Using cultured PC and CC cells, TROP2‐IR700 localized TROP2‐specific and target‐specific cell killing was observed after NIR light irradiation. In addition, TROP2‐IR700 was localized to mouse xenograft tumors expressing TROP2 after intravenous injection. PC and CC xenograft tumor growth was significantly inhibited by TROP2‐targeted PIT relative to controls. The efficacy of TROP2‐targeted PIT in vitro and against xenografted tumors in vivo suggests promise as a therapy for human PC and CC, both of which currently have dismal prognoses and limited therapeutic options., The recently developed photoimmunotherapy (PIT) method targets and disrupts cancer cell membranes by combining monoclonal antibody (mAb)‐based targeting with a photosensitizer IR700. By using newly developed humanized anti‐TROP2 mAb conjugated to the IR700 (TROP2‐IR700), both pancreatic cancer and cholangiocarcinoma cells were successfully treated with near‐infrared light both in vitro and in vivo. Given that there is no molecular‐targeted therapy in the standard of care for pancreatic cancer and cholangiocarcinoma patients, TROP2‐targeted PIT is an attractive candidate for clinical trials and ultimately treatment.

We fabricated a field-effect transistor (FET) with a gate length of 21 nm whose channel material is a ${c}$ -axis-aligned crystalline In-Ga-Zn oxide (CAAC-IGZO). A CAAC-IGZO FET with a gate length of 21 nm has an extremely low off-state leakage current, a practical driving capability, and tolerance against high temperatures. CAAC-IGZO FETs enable low-power integrated circuits, such as logic and memory in high-temperature environments. Performance estimation of a memory cell using the CAAC-IGZO FET with a gate length of 21 nm revealed that a write time of less than 1 ns and a data retention time of more than 1 h would be possible at 85 °C.

Background: CD73, also known as ecto-5’-nucleotidase (NT5E), is a GPI-anchored cell surface enzyme expressed on certain types of immune cells and tumor cells. This enzyme catalyzes the hydrolytic conversion of extracellular adenosine monophosphate (AMP) to adenosine (Ado) that suppresses tumor-infiltrating immune cells via the adenosine receptors, allowing tumors to escape the immune system. Here, we introduce a novel anti-human CD73 antibody called BP1200 that strongly blocks the generation of Ado by CD73 and thereby reverses immune suppression in tumors. Methods: We screened anti-CD73 antibodies by antigen-specific single B cell sorting from mice immunized with recombinant human CD73. CDRs of the antibodies that inhibit the enzyme activity of CD73 were engrafted into human IgG1 framework carrying the mutations of Fc silent. The proliferation and cytotoxicity of T cells were analyzed using human peripheral blood mononuclear cells (PBMC) in the presence of ATP. Efficacy of BP1200 in vivo was investigated by using mice bearing human CD73 knock-in-MC38 cells and mice implanted with human NSCLC cell line (NCI-H292) and PBMC. Results: The humanized anti-CD73 antibody (BP1200) binds to both human and cynomolgus CD73 expressed on cell surface with KD value of 0.2 nM (human CD73). BP1200 blocked the hydrolysis of AMP by CD73 expressed as both membrane-bound and soluble form without the hook effect. BP1200 induced internalization of CD73 and remarkably decreased the cell surface CD73, indicating that BP1200 inhibits the enzyme activity as well as downregulates the protein level of CD73 at the cell surface. BP1200 induced in vitro proliferation, cytokine production, and cytotoxic activity of T cells even in the presence of high level of ATP, suggesting that BP1200 enhances the T cell immunity in immunosuppressive tumor micro-envelopment (TME). In vivo studies showed that the combination treatment of BP1200 with anti-PD-1/PD-L1 antibodies remarkably retarded tumor growth. Moreover, the mice administrated with BP1200 and anti-PD-1 exhibited long-term immune memory effects that rendered them resistant to rechallenge with tumors. Conclusions: The novel anti-human CD73 antibody, BP1200, ameliorates immunosuppressive TME caused by adenosine and enhances antitumor immune responses. The combination of BP1200 and immune-checkpoint inhibitors for cancer treatment will be a promising therapeutic option in clinical practice. Citation Format: Noriko Matsumoto, Yuji Mishima, Toshifumi Obonai, Haruka Ban, Motoya Mie, Norihiro Nakamura. A novel therapeutic antibody against CD73 that ameliorates the tumor microenvironment and improves the efficacy of cancer immunotherapy [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 2905.

Background: Personalized neoantigen cancer vaccines have recently showed marked therapeutic potential in both preclinical and early phase clinical studies. However, significant challenges remain in the accurate prediction of neoepitopes and the efficient delivery of the vaccine components for eliciting potent antitumor T cell responses. To overcome these challenges, we have developed novel vaccine platform designated BP1209, which is characterized by being composed of neoantigen peptides that contain a high affinity binding motif for human antibodies. Methods: We developed vaccine with enhanced efficacy designed to form a complex with checkpoint antibodies. The vaccine instantly assembles a divalent peptide-antibody complex by simply mixing with therapeutic antibodies in physiological condition. We evaluated the efficacy of BP1209 vaccine in combination with DC-targeting antibodies in vivo. Next, we generated a series of neoantigen peptides in both murine and human origins using in-house bioinformatic algorithms and evaluated the advantages of BP1209 vaccine. Results: BP1209 vaccine showed robust T-cell response and anti-tumor activity when combined with anti-CD40 agonistic antibody or atezolizumab compared with a control peptide vaccine or the antibody alone. Treatment of BP1209 murine neoantigen vaccine to syngeneic tumor bearing mice exhibited robust anti-tumor response resulting in complete tumor regression in therapeutic setting. Preclinical evaluation of neoantigen vaccines from murine and human tumors showed notably increased CD8+ T cell response even for epitopes that do not respond with a conventional long peptide vaccine. Further analysis of DCs and T cells induced by BP1209 suggested that peptide delivery was mediated by increased cross-presentation of epitope peptides on DCs supported by DC maturation by the checkpoint antibody and increased vaccine peptide uptake by the antibody mediating peptide delivery. TCR repertoire analysis of the tumor infiltrating lymphocytes (TILs) of vaccinated mice revealed remarkable accumulation of clonal CTLs in the BP1209 vaccinated group. Conclusions: BP1209 cancer vaccine dramatically improves T-cell response and anti-tumor activity over conventional long-peptide vaccines. We demonstrated that the enhancement of vaccine potency was achieved not only by the function of the antibodies on DCs but mainly by the increased antigen delivery to DCs. Enhanced T-cell response was more remarkable in CD8+ T cells, especially in clonal expansion of the CTL in TILs, suggesting that BP1209 vaccine facilitates antigen cross-presentation and inducing functional CTLs. Analysis using a number of predicted neoantigen peptides showed that the BP1209 vaccine enhances the vaccine efficacy independent of epitope sequences. Thus, our new platform of cancer vaccines provides a critical solution to enhance personalized neoantigen vaccines. Citation Format: Yuji Mishima, Fumiko Isoda, Noriko Matsumoto, Noriko Watanabe, Kazushi Hiranuka, Takashi Yamada, Norihiro Fujinami, Manami Shimomura, Toshihiro Suzuki, Tetsuya Nakatsura, Norihiro Nakamura. Personalized neoantigen cancer vaccine assembled on DC targeting antibody improves cancer immunity [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 3552.

e14508 Background: Immunotherapy using immune-checkpoint inhibitors (ICIs) has shown remarkable clinical efficacy in patients with cancer. However, it is crucial to utilize appropriate combination of immunotherapy for patient condition, as most patients do not benefit or sustain responses of immunotherapy. We focused on CD39 that is highly expressed in some tumors and tumor infiltrating immune cells (e.g. exhausted T cells and Tregs) as a target for cancer immunotherapy. CD39 is an ectoenzyme that converts extracellular ATP to immunosuppressive adenosine. Since the ATP-adenosine pathway is a key modulator of innate and adaptive immunity within the tumor microenvironment (TME), we presume that anti-CD39 antibodies suppress the production of adenosine and limit the immunosuppressive state in TMEs. Methods: Anti-human CD39 antibodies were screened by sorting B cells of mice immunized with human CD39 protein. The obtained clones that inhibit enzyme activity of CD39 were humanized on IgG1 and IgG4. PBMC were used in proliferation and functional assays. The anti-tumor effect was investigated with mouse xenograft model. Results: Analyzing gene expression profiles from TCGA data, high CD39 expression is associated with a poor prognosis in several cancers. There was a strong correlation between them in multiple myeloma treated with chemotherapies. The expression of CD39 was upregulated in some cancer cell lines treated with chemotherapeutic agents. A novel humanized anti-CD39 antibody, BP1202, which has a high affinity for the recombinant CD39 protein (KD: 481 pM) and inhibits the enzyme activity of CD39 expressed on a cancer cell line (IC50: 1 nM) and human Tregs. The antibody showed a high potency to enhance T cell activity including their proliferation, cytokine production, and cytotoxicity against a cancer cell line. We examined the anti-tumor effect of BP1202 in vivo using tumor-bearing mice and found that the combination treatment of BP1202 with chemotherapeutic agents significantly reduced tumor volume. Conclusions: We developed a new humanized antibody that enhances anti-tumor immunity by inhibiting CD39 expressed on exhausted T cells and intra-tumor T cells. These data suggest the scientific rationale for the clinical development of BP1202 and their use in combination with ICIs, with ATP-adenosine pathway inhibitors, and with chemotherapies. BP1202 is currently being developed as a new antibody agent for cancer immunotherapy.

Purpose An all-case, single-arm, observational, postmarketing surveillance is underway to assess the safety of tafamidis in patients with hereditary transthyretin (ATTRv) amyloidosis with peripheral polyneuropathy, also called transthyretin-type familial amyloid polyneuropathy, in Japan. Results from an interim analysis (data cutoff date, May 15, 2018) are presented in this preliminary report. Methods Patients were registered and treated with tafamidis meglumine 20 mg/d in routine clinical practice (observation period, 156 weeks). Data on patient demographic and clinical characteristics and adverse drug reactions (ADRs) were captured using case-report forms. Findings Of 219 patients included (mean age, 59.7 years; patients with age at disease onset ≥50 years, 61.2%; mean treatment duration, 95.5 weeks), 143 (65.3%) were male, 126 (57.5%) had a family history of ATTRv amyloidosis, and 149 (68.0%) originated from nonendemic areas. The most common ADRs were diarrhea (1.4%) and hematuria (0.9%). Six serious ADRs (pneumonia, bacteremia, malignant melanoma, pancreatic carcinoma, hematuria, and hereditary neuropathic amyloidosis [primary disease exacerbation]) were reported; no ADRs leading to death were recorded. Implications This interim analysis successfully provided comprehensive, nationwide epidemiologic data from 219 Japanese patients with ATTRv amyloidosis. The safety profile of tafamidis was largely consistent with that obtained from previous research. No new safety concerns were identified to date. Data presented in this interim analysis are subject to change following completion of the study, and we will continue to assess the safety and effectiveness of tafamidis throughout the study. ClinicalTrials.gov identifier: NCT02146378.

Background It is difficult to diagnose Bickerstaff’s brainstem encephalitis (BBE) in the acute phase, and emergency physicians could diagnose BBE as an unknown cause of consciousness disturbance. Case presentation A 75‐year‐old woman presented with dizziness and weakness in both arms 1 week after an upper respiratory infection. She experienced gradual worsening of consciousness, had dilated pupils and no light reflex. She was suspected of brainstem dysfunction at the upper part of the brainstem; however, there were not significant findings on magnetic resonance imaging, cerebrospinal fluid, or electroencephalography. The auditory brainstem response demonstrated a low voltage, but there was no prolonged latency. At a later date, she was diagnosed with BBE based on serum immunoglobulin G anti‐GQ1b antibody. She was discharged home without any neurological sequelae. Conclusion It is necessary to analyze serum immunoglobulin G anti‐GQ1b antibodies to diagnose BBE. Auditory brainstem response would be helpful in detecting lesions and predicting functional recovery., Auditory brainstem response of patients with Bickerstaff’s brainstem encephalitis demonstrated a low voltage, but there was no prolonged latency.