A nonsense TMEM43 variant leads to disruption of connexin-linked function and autosomal dominant auditory neuropathy spectrum disorder.

Genes that are primarily expressed in cochlear glia-like supporting cells (GLSs) have not been clearly associated with progressive deafness. Herein, we present a deafness locus mapped to chromosome 3p25.1 and an auditory neuropathy spectrum disorder (ANSD) gene, TMEM43, mainly expressed in GLSs. We identify p.(Arg372Ter) of TMEM43 by linkage analysis and exome sequencing in two large Asian families segregating ANSD, which is characterized by inability to discriminate speech despite preserved sensitivity to sound. The knock-in mouse with the p.(Arg372Ter) variant recapitulates a progressive hearing loss with histological abnormalities in GLSs. Mechanistically, TMEM43 interacts with the Connexin26 and Connexin30 gap junction channels, disrupting the passive conductance current in GLSs in a dominant-negative fashion when the p.(Arg372Ter) variant is introduced. Based on these mechanistic insights, cochlear implant was performed on three subjects, and speech discrimination was successfully restored. Our study highlights a pathological role of cochlear GLSs by identifying a deafness gene and its causal relationship with ANSD.

Comprehensive Analysis of Iron Deficiency Anemia and Its Related Disorders in Premenopausal Women Based on a Propensity Score Matching Case Control Study Using National Health Insurance Service Database in Korea.

BACKGROUND: Menorrhagia is a common cause of iron deficiency anemia (IDA) in premenopausal women. However, the effects of menorrhagia on IDA in premenopausal women have been underestimated compared to those on other IDA-related disorders (IRDs) such as gastrointestinal malignancies (GIMs). To better understand the relationship between menorrhagia and IDA in premenopausal women, we analyzed the National Health Insurance Service-National Health Information Database (NHIS-NHID). METHODS: From 2005 to 2008, data about women between the age of 20 and 59 years were extracted from the NHIS-NHID to create a propensity score-matched case (IDA) and control group. The annual incidence of IDA was calculated per age group. A 10-year follow up of the study population was determined to detect IRDs in case and control groups. We compared the risk of detection (ROD) of IRDs, including GIM and gynecological disorders associated with menorrhagia - leiomyoma of uterus (LM) and adenomyosis (AM), in the case and the control group. RESULTS: From 2005 to 2008, women diagnosed with IDA (n = 535,249) and healthy women as a control group (n = 1,070,498) were identified from the NHIS-NHID. The annual incidence of IDA was 767.4 (2005), 948.7 (2006), 981.6 (2007), and 897.7 (2008) per 100,000 women. The age distribution of IDA was similar each year; IDA was common in women aged 30-39 years (36-37%) and 40-49 years (30-32%), and its incidence was significantly decreased in women aged 50-59 years (< 10%). The ROD of IRDs were significantly higher in the IDA group than in the control group (LM: 20.8% vs. 6.9%, AM: 5.6% vs. 1.6%, and GIM: 2.6% vs. 0.7%). The corresponding hazard ratios were 3.89 (95% confidence interval [CI], 3.85-3.93) for LM, 4.99 (95% CI, 4.90-5.09) for AM, and 3.43 (95% CI, 3.32-3.55) for GIM. The ROD of the IRDs varied; the ROD of LM in the IDA group increased with age and decreased in the age group 50-59 years. AM was more frequently detected in women with IDA aged 30-39 years and less in women older than 40 years. The frequency of GIM increased with age. CONCLUSION: In this study, we found that the gynecologic disease is the main cause of IDA in premenopausal women. Gynecological evaluations should be performed more actively in the clinic to prevent and control IDA and IRDs.

Clinical characteristics and prognostic factors of acquired haemophilia A in Korea.

INTRODUCTION: Acquired haemophilia A (AHA) treatment involves the haemostatic treatment for acute haemorrhage and immunosuppressive therapy (IST) to eradicate FVIII inhibitory antibodies. AIM: We assessed the clinical features of AHA and analysed treatment outcomes in Korea. We further identified prognostic factors affecting treatment outcomes. METHODS: Medical records of 55 patients with AHA from 18 institutions were reviewed retrospectively. Logistic and Cox regression analyses were performed to elucidate clinical factors affecting the achievement of complete remission (CR). The primary endpoint was time to CR after IST, and secondary endpoints were time to haemostasis, the achievement of CR, and overall survival (OS). RESULTS: Among the 55 patients, 50 (91%) had bleeding symptoms. Bleeding was severe in 74% of patients. Thirty-six (72%) patients received haemostatic therapy. Of the 42 patients who received IST, 23 (52%) received steroid alone, with a 52% response rate, and 10 (25%) received a combination of steroid and cyclophosphamide, with an 83% response rate. Five (16%) patients relapsed after a median duration of 220 days. There were eight deaths. In the Cox regression analysis, the FVIII inhibitor titre ≥ 20 BU/mL was the only significant prognostic factor affecting time to CR and haemostasis. No significant difference was observed in OS based on the inhibitor titre. CONCLUSION: The present study demonstrated the demographic data of AHA in Korea and showed that FVIII inhibitory antibody titre was a predictor of time to achieve CR after IST.

A comparison study of audiological outcome and compliance of bone conduction implantable hearing implants.

PURPOSE: The present study aimed to evaluate and compare the outcome of different bone conduction hearing implants (BCHIs) in subjects with mixed hearing loss (MHL) and single-sided deafness (SSD) in terms of audiometric results and compliance. METHODS: Twenty-one subjects with MHL and 18 subjects with SSD undergoing implantation of Baha connect, Baha attract, or Bonebridge were enrolled. Functional gain, effective gain, and usage rate of BCHIs were retrospectively reviewed. RESULTS: As for MHL, the functional gain of three devices was not significantly different (p = 0.477), while the effective gain of Bonebridge was higher (- 8.8 [- 15.0, - 3.5] dB) than that of Baha connect (- 20.0 [- 26.3, - 11.3] dB, p = 0.037), especially at 0.5 kHz (p = 0.010) and 1 kHz (p = 0.014). In SSD subjects, the effective gain of Bonebridge was significantly higher than that of Baha attract (- 11.3 [- 15.0, - 7.5] vs - 21.3 [- 21.3, - 16.3] dB, p = 0.012), while the functional gain of Bonebridge and Baha attract was not different. The constant usage rate of BCHIs tends to be higher in MHL subjects [17/21 (82%)] than that in SSD subjects [10/18 (56%)]. In SSD subjects, the constant user group showed higher functional gain than the non-constant user group, with a significant difference at 3 kHz (35.0 [33.8, 45.0] vs 17.5 [10.0, 27.5] dB, p = 0.006). CONCLUSION: Bonebridge shows a higher effective gain than Baha connect in the MHL group and Baha attract in the SSD group. The usage rate of BCHIs is lower in SSD than that in MHL. In SSD subjects, the constant user group tended to show higher functional gain than the non-constant user group. Irrespective of the device type, the tendency of higher functional gain of BCHIs, especially at mid frequencies, may potentially lead to yield good compliance in SSD, mandating a meticulous fitting strategy ensuring a sufficient mid-frequency functional gain in SSD.

Clinical predictors for satisfaction with incus vibroplasty: a preliminary study.

OBJECTIVE: We aimed to evaluate the subjective satisfaction after incus vibroplasty and to determine predictive factors affecting patient satisfaction in sensorineural hearing loss. DESIGN: A retrospective review of audiological data and an additional survey about subjective satisfaction after surgery were performed in 14 patients who underwent incus vibroplasty surgery. A numeric rating scale reflecting the degree of satisfaction after incus vibroplasty, compared with experiences using a conventional hearing aid, was used. Patients who showed median or better satisfaction were deemed the highly satisfied (HS) group, and the others were deemed the less satisfied (LS) group. To find the predictive factors correlated with satisfaction for incus vibroplasty, comparative analysis between two groups was performed. RESULTS: We found that the numeric rating scale for satisfaction was variable, ranged from 0 to 10, and was negatively correlated with age at operation (p < 0.01). The HS group had a younger age (27.6 ± 22.2 years) and better preoperative air conduction threshold at 250 Hz (20.7 ± 7.9 dB) than the LS group (68.0 ± 9.7 years, 32.1 ± 10.7 dB). The LS group (13.6 ± 9.9 dB) showed a larger change of air-bone gap after surgery than the HS group (5.7 ± 6.7 dB) at 250 Hz (p = 0.12). CONCLUSIONS: Age at operation and the preoperative air conduction threshold level at 250 Hz appear to be potential predictive factors for subjective satisfaction with incus vibroplasty. Furthermore, more conservative selection of candidates and caution during surgery, considering inevitable air-bone gap development postoperatively, may be necessary to achieve higher satisfaction for incus vibroplasty.

Pneumatosis cystoides intestinalis associated with sunitinib and a literature review.

BACKGROUND: Pneumatosis cystoides intestinalis (PCI) is a rare self-limiting condition characterized by air-filled cysts within intestinal walls. Diagnosis should be prudent because it can mimic pneumoperitoneum leading to unnecessary treatment such as surgical exploration. Although various drugs including anti-neoplastic agents have been suggested as etiologies, cases related to sunitinib are sparse. Because of the rarity of this unusual side effect by sunitinib, we report the case report. CASE PRESENTATION: A 68-year-old female with pancreatic neuroendocrine tumor who was treated with sunitinb for 4 months visited to our hospital complaining of severe diarrhea and mild abdominal discomfort. The abdominal X-ray showed subdiaphragmatic air mimicking intestinal perforation. After the meticulous evaluation including abdomino-pelvic computed tomography, the patient was diagnosed of PCI induced by sunitinib and fully recovered with conservative management. CONCLUSIONS: It is important to note that PCI can develop after treatment with sunitinib because PCI has not been widely known as an adverse event caused by the agent. Furthemore, emergent surgery while sunitinib was administrated without adequate washout period can result in substantial surgical complications which could be avoided with the precise diagnosis.

Long-term outcomes of first-line treatment with doxycycline in patients with previously untreated ocular adnexal marginal zone B cell lymphoma.

Ocular adnexal lymphoma (OAL) has been associated with Chlamydophila psittaci infection, for which doxycycline has been suggested as a treatment option. We conducted this study to evaluate the long-term results of first-line doxycycline treatment in patients with OAL. Ninety patients with histologically confirmed OAL with marginal zone B cell lymphoma were enrolled. Each patient received one or two cycles of doxycycline (100 mg bid) for 3 weeks. After a median follow-up period of 40.5 months (8-85), the 5-year progression-free survival (PFS) rate was 60.9 %. All patients were alive at the last follow-up date. Thirty-one patients (34 %) showed local treatment failure without systemic spread. However, PFS rate in these patients was 100 % after salvage chemotherapy and/or radiotherapy. PFS was independently predicted in multivariate analysis by the tumor-node-metastasis (TNM) staging (hazard ratio [HR], 4.35; 95 % confidence interval [CI], 2.03-9.32; P < 0.001) and number of cycles of doxycycline (HR, 0.31; 95 % CI, 0.14-0.69; P = 0.004). No serious adverse event was reported during doxycycline therapy. In conclusion, first-line doxycycline therapy was effective and safe. Patients who failed to respond to doxycycline therapy were successfully salvaged with chemotherapy and/or radiotherapy without compromising long-term outcomes. Patients with T1N0M0 disease could be considered good candidates for first-line doxycycline.

Impact of multidrug resistance on outcomes in hematologic cancer patients with bacterial bloodstream infections.

Despite the improved outcomes in patients with hematological malignancies, infections caused by multidrug-resistant organisms (MDROs) pose a new threat to these patients. We retrospectively reviewed the patients with hematological cancer and bacterial bloodstream infections (BSIs) at a tertiary hospital between 2003 and 2022 to assess the impact of MDROs on outcomes. Among 328 BSIs, 81 (24.7%) were caused by MDROs. MDRO rates increased from 10.3% (2003-2007) to 39.7% (2018-2022) (P < 0.001). The 30-day mortality rate was 25.0%, which was significantly higher in MDRO-infected patients than in non-MDRO-infected patients (48.1 vs. 17.4%; P < 0.001). The observed trend was more pronounced in patients with newly diagnosed diseases and relapsed/refractory disease but less prominent in patients in complete remission. Among MDROs, carbapenem-resistant Gram-negative bacteria exhibited the highest mortality, followed by vancomycin-resistant enterococci, methicillin-resistant Staphylococcus aureus, and extended-spectrum ß-lactamase-producing Enterobacteriaceae. Multivariate analysis identified independent risk factors for 30-day mortality as age ≥ 65 years, newly diagnosed disease, relapsed/refractory disease, MDROs, polymicrobial infection, CRP ≥ 20 mg/L, and inappropriate initial antibiotic therapy. In conclusion, MDROs contribute to adverse outcomes in patients with hematological cancer and bacterial BSIs, with effects varying based on the underlying disease status and causative pathogens. Appropriate initial antibiotic therapy may improve patient outcomes.

Treatment-free remission after discontinuation of imatinib, dasatinib, and nilotinib in patients with chronic myeloid leukemia.

Patients with chronic myeloid leukemia (CML) in the chronic phase receiving tyrosine kinase inhibitor (TKI) therapy are expected to have long-term survival outcomes comparable to those of the general population. Many clinical trials have confirmed that some patients sustain molecular responses without continuing TKI therapy. Treatment-free remission (TFR) is a new goal in treating chronic CML. The safety and outcome of TFR were studied in clinical trials after discontinuing imatinib or the second-generation TKIs dasatinib or nilotinib. TFR was safe in approximately 50% of patients who achieved a deep molecular response to TKI therapy. Patients who relapsed after discontinuing TKI responded immediately to the reintroduction of TKI. The mechanism by which TFR increases the success rate still needs to be understood. The hypothesis that the modulation of immune function and targeting of leukemic stem cells could improve the TFR is under investigation. Despite the remaining questions, the TFR has become a routine consideration for clinicians in the practice of molecular remission in patients with CML.

Lambert-Eaton myasthenic syndrome (LEMS) in a patient with lung cancer under treatment with pembrolizumab: a case study.

Pembrolizumab is an immune checkpoint inhibitor (ICI) against the programmed death-1 receptor. Herein, we introduce a rare adverse effect during using pembrolizumab. We present the case of an 80-year-old man with biopsy-proven unresectable double primary squamous cell carcinoma and large cell neuroendocrine carcinoma of the lung. After using pembrolizumab for 10 months, he complained of muscle weakness of both upper and lower extremities. In a nerve conduction study, the repetitive nerve stimulation test in the abductor digiti minimi was diagnostic of Lambert-Eaton myasthenic syndrome (LEMS): low in the amplitude of compound muscle action potential (1.4 mV), 28.6% decrement in the 5-Hz stimulation, and 579% increment in the 50-Hz stimulation. The disease did not progress after the discontinuation of pembrolizumab, even without any anti-cancer treatment for 12 months. We believe our clinical experience of this rare and unexpected adverse effect should be shared.

Audiogram Configuration, Molecular Etiology, and Outcome of Cochlear Implantation in Postlingual Auditory Neuropathy Spectrum Disorder.

OBJECTIVE: To explore the diverse molecular etiologies of postlingual auditory neuropathy spectrum disorder (ANSD) and report on the electrically evoked compound action potential (ECAP) thresholds and the outcome of cochlear implantation (CI). METHODS: Patients with late-onset, progressive hearing loss who went through molecular genetic testing were enrolled. Type of sensorineural hearing loss (SNHL) was classified as flat, reverse-slope, midfrequency, downsloping, or ski slope. We identified postlingual ANSD subjects through diagnostic tracts applied differently depending on the degree of SNHL. For CI recipients, individual ECAP thresholds, postoperative speech perception abilities, and the genetic cause were analyzed. RESULTS: The detection rate of ANSD among patients with postlingual SNHL was 5.1% (15/293 probands). Diverse genetic etiologies were identified in 7 (46.6%) of the 15 postlingual ANSD subjects, the genetic cause being found exclusively in subjects with reverse-slope SNHL. The pattern of intraoperative ECAP responses was also diverse and showed some correlation with the genetic etiology. Despite the diverse molecular etiology and ECAP responses, CI in postlingual ANSD patients, including those with features involving the postsynaptic component, yielded significant improvements in speech understanding. CONCLUSIONS: This study proposes a differentiated diagnostic approach that focuses on both poor speech discrimination and reverse-slope hearing loss for the diagnosis of ANSD. Based on the improvement of speech understanding from all cochlear implantees with ANSD as well as the correlation between the genetic etiology and ECAP thresholds, we suggest that CI can significantly benefit ANSD subjects even those with unknown etiologies unless there is overt peripheral neuropathy.

Ramifications of POU4F3 variants associated with autosomal dominant hearing loss in various molecular aspects.

POU4F3, a member of the POU family of transcription factors, commonly causes autosomal dominant deafness. Exome sequencing was used to identify four novel variants in POU4F3 (NM_002700.2), including c.564dupA: p.Ala189SerfsTer26, c.743T > C:p.Leu248Pro, c.879C > A:p.Phe293Leu, and c.952G > A:p.Val318Met, and diverse aspects of the molecular consequences of their protein expression, stability, subcellular localization, and transcriptional activity were investigated. The expression of three mutant proteins, encoded by missense variants, was reduced compared to the wild-type protein, demonstrating that the mutants were unstable and vulnerable to degradation. Additionally, all the mutant proteins had distinct subcellular localization patterns. A mutant protein carrying p.Ala189SerfsTer26, in which both mono- and bi-partite nuclear localization signals were disrupted, showed abnormal subcellular localization. Resultantly, all the mutant proteins significantly reduced the transcriptional activity required to regulate the downstream target gene expression. Furthermore, we identified the altered expression of 14 downstream target genes associated with inner ear development using patient-derived lymphoblastoid cell lines. There was a significant correlation of the expression profile between patient-derived cells and the cochlear hair cells, which provided a breakthrough for cases where the collection of human cochlear samples for transcriptome studies was unfeasible. This study expanded the genotypic spectrum of POU4F3 in DFNA15, and further refined the molecular mechanisms underlying POU4F3-associated DFNA15.

Treatment pattern of chronic lymphocytic leukemia/small lymphocytic lymphoma in Korea: a multicenter retrospective study (KCSG LY20-06).

BACKGROUND/AIMS: Little attention is paid to chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL) in Korea due to the rarity of the disease. With its rising incidence, we aimed to evaluate recent changes in treatment patterns and survival outcomes of patients with CLL/SLL. METHODS: A total of 141 patients diagnosed with CLL/SLL between January 2010 and March 2020 who received systemic therapy were analyzed in this multicenter retrospective study. RESULTS: The median patient age was 66 years at diagnosis, and 68.1% were male. The median interval from diagnosis to initial treatment was 0.9 months (range: 0-77.6 months), and the most common treatment indication was progressive marrow failure (50.4%). Regarding first-line therapy, 46.8% received fludarabine, cyclophosphamide, plus rituximab (FCR), followed by chlorambucil (19.9%), and obinutuzumab plus chlorambucil (GC) (12.1%). The median progression-free survival (PFS) was 49.3 months (95% confidence interval [CI], 32.7-61.4), and median overall survival was not reached (95% CI, 98.4 mo- not reached). Multivariable analysis revealed younger age (≤ 65 yr) (hazard ratio [HR], 0.46; p < 0.001) and first-line therapy with FCR (HR, 0.64; p = 0.019) were independently associated with improved PFS. TP53 aberrations were observed in 7.0% (4/57) of evaluable patients. Following reimbursement, GC became the most common therapy among patients over 65 years and second in the overall population after 2017. CONCLUSION: Age and reimbursement mainly influenced treatment strategies. Greater effort to apply risk stratifications into practice and clinical trials for novel agents could help improve treatment outcomes in Korean patients.

Radioimmunotherapy with 131 I-rituximab for patients with relapsed or refractory follicular or mantle cell lymphoma.

AIM: This study aimed to evaluate the safety and efficacy of 131 I-rituximab in patients with relapsed or refractory follicular or mantle cell lymphoma. METHODS: Twenty-four patients with relapsed or refractory follicular or mantle cell lymphoma were administered unlabeled rituximab (70 mg) immediately before receiving a therapeutic dose of 131 I-rituximab. Contrast-enhanced 18F-fluorodeoxyglucose positron emission tomography/computed tomography was used a month later to assess tumor response. RESULTS: This study enrolled 24 patients between June 2012 and 2022. Depending on how they responded to radioimmunotherapy (RIT), 131 I-rituximab was administered one to five times. Of the 24 patients, 9 achieved complete response after RIT and 8 achieved partial response. The median progression-free and overall survival was 5.9 and 37.9 months, respectively. During the follow-up period of 64.2 months, three patients were diagnosed with a secondary malignancy. Among treatment-related adverse events, hematologic toxicities were common, and grade 3-4 thrombocytopenia and neutropenia were reported in 66.6% of cases. CONCLUSION: 131 I-rituximab has an effective and favorable safety profile in patients with relapsed or refractory follicular lymphoma and mantle cell lymphoma. This suggests that RIT may also be considered a treatment option for patients with relapsed or refractory follicular lymphoma and mantle cell lymphoma.

Pulmonary Metastasizing Low-Grade Endometrial Stromal Sarcoma: Case Report and Review of Diagnostic Pitfalls.

Pulmonary manifestations of benign metastasizing leiomyoma (BML) usually include multiple well-defined, round, bilateral nodules. Low-grade endometrial stromal sarcoma (LG-ESS) is a rare uterine tumor. A 70-year-old woman visited the clinic complaining of acute cough and dyspnea in April 2017. Chest computed tomography (CT) revealed pneumothorax and multiple pulmonary nodules. She had a history of hysterectomy for uterine leiomyoma 23 years ago. Biopsy revealed that the pulmonary masses were consistent with BML. However, the patient had two subsequent episodes of acute, recurrent respiratory distress, accompanied by massive pleural effusions and hydropneumothorax over the next two years. A chest CT performed for acute dyspnea revealed large and multiple hydropneumothoraces. The size and distribution of pulmonary masses were aggravated along with cystic changes and bilateral pleural effusions. Given this aggressive feature, additional immunohistochemical findings and gynecologic pathologist review confirmed the correct diagnosis to be LG-ESS. After initiating anti-estrogen therapy, the patient achieved a partial response, without recurrence of symptoms, for 28 months. Metastatic LG-ESS responds well to anti-hormonal therapy. If the clinical pattern of a disease is different than expected, the possibility of a correction in the diagnosis should be considered.

Effect of Acupuncture on Delayed Emesis for the Patients Who Received High-Emetogenic Chemotherapy with Standard Antiemetic Prophylaxis (KHMC-HO-01): An Open-Label, Randomized Study.

Background: Chemotherapy-induced nausea and vomiting (CINV) is one of the most important issues associated with chemotherapy. The additional or synergistic effect of acupuncture on CINV remains controversial. Methods: Patients were randomized into either the group that received standard antiemetics with acupuncture (Arm A) or standard antiemetics only (Arm C). Acupuncture with manual stimulation was applied at eight predefined points and was started before the first cycle of chemotherapy on the first day and two additional sessions were administered on the second day of chemotherapy. Acute and delayed CINV was assessed using the Rhodes Index of Nausea, Vomiting, and Retching (RINVR) and the MASCC Antiemesis Tool (MAT). The primary outcome was the delayed nausea score assessed using the RINVR. Results: Overall, 42 patients were included. In the delay phase, the severity of delayed nausea was slightly lower without significance in Arm A than in Arm C (5.35 vs. 5.98, p = 0.3011). Similarly, patients in Arm A reported less severe vomiting than those in Arm C (0.75 vs. 1.25, p = 0.3064). Delayed nausea and vomiting assessed by the MAT showed significant relief with acupuncture compared to standard antiemesis alone. In terms of acute emesis, there was no significant difference between the two arms according to either scoring method. Conclusions: Delayed nausea after HEC tended to decrease with acupuncture using the RINVR score, though it was also not significant. With the MAT assessment, delayed emesis (nausea and vomiting) was significantly improved with acupuncture, suggesting a promising effect of acupuncture. This trial is registered with KCT0006477.

Synaptic Remodeling of the Auditory Cortex Following Bilateral Blindness: Evidence of Cross-modal Plasticity.

We aimed to evaluate structural dynamic changes of neurons in the auditory cortex after visual deprivation. We longitudinally tracked dendritic spines for 3 weeks after visual deprivation in vivo using a two-photon microscope. GFP-labeled dendritic spines in the auditory cortex were serially followed after bilateral enucleation. The turnover rate, density, and size of the spines in the dendrites were evaluated 1, 2, and 3 weeks after visual deprivation. The turnover rate of the dendritic spines in the auditory cortex increased at 1 week (20.1±7.3%) after bilateral enucleation compared to baseline (12.5±7.9%); the increase persisted for up to 3 weeks (20.9±11.0%). The spine loss rate was slightly higher than the spine gain rate. The average spine density (number of spines per 1 µm of dendrite) was significantly lower at 2 weeks (2W; 0.22±0.06 1/µm) and 3 W (0.22±0.08 1/µm) post-nucleation compared to baseline (0.026±0.09 1/µm). We evaluated the change of synaptic strength in the stable spines at each time point. The normalized spine size in the auditory cortex was significantly increased after bilateral blindness at 1 W postoperatively (1.36±0.92), 2 W postoperatively (1.40±1.18), and 3 W postoperatively (1.36±0.88) compared to baseline. Sensory deprivation resulted in remodeling of the neural circuitry in the spared cortex, via cross-modal plasticity in the direction of partial breakdown of synapses, and enhanced strength of the remaining synapses.

Cross-Modal Cortical Activity in the Brain Can Predict Cochlear Implantation Outcome in Adults: A Machine Learning Study.

OBJECTIVES: Prediction of cochlear implantation (CI) outcome is often difficult because outcomes vary among patients. Though the brain plasticity across modalities during deafness is associated with individual CI outcomes, longitudinal observations in multiple patients are scarce. Therefore, we sought a prediction system based on cross-modal plasticity in a longitudinal study with multiple patients. METHODS: Classification of CI outcomes between excellent or poor was tested based on the features of brain cross-modal plasticity, measured using event-related responses and their corresponding electromagnetic sources. A machine learning estimation model was applied to 13 datasets from 3 patients based on linear supervised training. Classification efficiency was evaluated comparing prediction accuracy, sensitivity/specificity, total mis-classification cost, and training time among feature set conditions. RESULTS: Combined feature sets with the sensor and source levels dramatically improved classification accuracy between excellent and poor outcomes. Specifically, the tactile feature set best explained CI outcome (accuracy, 98.83 ± 2.57%; sensitivity, 98.00 ± 0.01%; specificity, 98.15 ± 4.26%; total misclassification cost, 0.17 ± 0.38; training time, 0.51 ± 0.09 sec), followed by the visual feature (accuracy, 93.50 ± 4.89%; sensitivity, 89.17 ± 8.16%; specificity, 98.00 ± 0.01%; total misclassification cost, 0.65 ± 0.49; training time, 0.38 ± 0.50 sec). CONCLUSION: Individual tactile and visual processing in the brain best classified the current status when classified by combined sensor-source level features. Our results suggest that cross-modal brain plasticity due to deafness may provide a basis for classifying the status. We expect this novel method to contribute to the evaluation and prediction of CI outcomes.