Bilateral Sudden Hearing Loss in Iron Deficiency Anemia.

The present study describes an unusual case of bilateral sudden hearing loss associated with iron deficiency anemia. Although hematologic disorders such as anemia or leukemia have been reported to be associated with sudden hearing loss, bilateral sudden hearing loss, which was presented as the first manifestation of iron deficiency anemia, has not been reported. A 74-year-old man presented with simultaneous bilateral sudden hearing loss without vertigo. A complete blood count test revealed a hemoglobin level of 6.4 g/dL and a ferritin level of 14.5 mg/mL, indicating iron deficiency anemia. Postcontrast 3D FLAIR MRI showed enhancement of the bilateral cochlea, vestibules, and lateral semicircular and posterior semicircular canals. After treatment, the patient's hearing loss partially improved.

Clinical characteristics of benign paroxysmal positional vertigo after traumatic brain injury.

INTRODUCTION: The aim of the present study was to evaluate the characteristics of brain injury and to assess the relationship between them and treatment outcomes in patients with traumatic benign paroxysmal positional vertigo (t-BPPV). MATERIALS AND METHODS: Sixty-three consecutive patients who were diagnosed with BPPV within 2 weeks after head trauma were included. RESULTS: Cerebral concussion, intracranial hemorrhages (ICH), skull fracture without ICH, and hemorrhagic contusion were observed in 68%, 24%, 5%, and 3% of t-BPPV patients, respectively. BPPV with single canal involvement was observed in 52 (83%) patients and that with multiple canal involvement was observed in 11 (17%) patients. The number of treatment sessions was not significantly different according to the cause of head trauma (p = 0.252), type of brain injury (p = 0.308) or location of head trauma (p = 0.287). The number of recurrences was not significantly different according to the cause of head trauma (p = 0.308), type of brain injury (p = 0.536) or location of head trauma (p = 0.138). CONCLUSION: The present study demonstrated that there were no significant differences in treatment sessions until resolution and the mean number of recurrences according to the type of brain injury.

Implantable pH Sensing System Using Vertically Stacked Silicon Nanowire Arrays and Body Channel Communication for Gastroesophageal Reflux Monitoring.

Silicon nanowires (SiNWs) are emerging as versatile components in the fabrication of sensors for implantable medical devices because of their exceptional electrical, optical, and mechanical properties. This paper presents a novel top-down fabrication method for vertically stacked SiNWs, eliminating the need for wet oxidation, wet etching, and nanolithography. The integration of these SiNWs into body channel communication (BCC) circuits was also explored. The fabricated SiNWs were confirmed to be capable of forming arrays with multiple layers and rows. The SiNW-based pH sensors demonstrated a robust response to pH changes, and when tested with BCC circuits, they showed that it was possible to quantize based on pH when transmitting data through the human body. This study successfully developed a novel method for SiNW fabrication and integration into BCC circuits, which could lead to improvements in the reliability and efficiency of implantable medical sensors. The findings demonstrate significant potential for bioelectronic applications and real-time biochemical monitoring.

Clinical diagnoses of patients showing caloric inversion.

OBJECTIVES: When air irrigation is used for caloric stimulation in patients with a perforated ear, warm irrigation may elicit a nystagmus that initially beats in the opposite direction of what is expected for warm irrigations, which is referred to as "caloric inversion". This study aimed to investigate the disease group in which caloric inversion appeared in patients who underwent caloric testing and to classify the patterns of caloric inversion. METHODS: We conducted a retrospective review of bithermal caloric test results that were collected in our dizziness clinic between 2005 and 2022. Caloric inversion was defined when nystagmus induced by caloric stimulation appeared in the opposite direction to that expected. The incidence of caloric inversion among all patients who underwent bithermal caloric tests was calculated. To confirm the clinical diagnoses of the patients with caloric inversion, their clinical records were reviewed. RESULTS: Out of 9923 patients who underwent bithermal caloric tests, 29 patients (0.29%) showed a caloric inversion. The most common clinical diagnosis was chronic otitis media (21 of 29, 72%). Of the 21 patients with chronic otitis media, 20 patients showed a caloric inversion by warm air irrigation and one patient showed caloric inversion by cold air stimulation. Patients with clinical diagnoses other than chronic otitis media such as sudden sensorineural hearing loss, benign paroxysmal vertigo of childhood and recurrent vestibulopathy showed caloric inversion by warm air irrigation. Caloric inversion by warm water irrigation was observed in patients with lateral semicircular canal cupulopathy and recurrent vestibulopathy. Two patients (one with Meniere's disease and one with age-related dizziness) showed caloric inversion by cold water irrigation. CONCLUSION: Caloric inversion can be observed in various diseases other than chronic otitis media with tympanic membrane perforation. Special care should be taken in the interpretation of caloric test results. LEVEL OF EVIDENCE: Level 4.

Cerebellopontine angle tumor presenting as acute audiovestibular syndrome.

BACKGROUND: Acute audiovestibular deficits may be a harbinger of vestibular schwannoma (VS). OBJECTIVE: To investigate clinical and laboratory features of 25 consecutive patients with VS presenting with acute audiovestibular deficits. METHODS: A symptomatic combination of acute audiovestibular deficits was investigated. Audiometric and vestibular function tests, and internal auditory canal magnetic resonance imaging (IAC MRI) results were evaluated. RESULTS: Varying combinations of symptoms may develop in VS patients with acute audiovestibular deficits, of whom sudden hearing loss (HL) without acute vertigo or acute facial nerve palsy (FNP) was most common. The most common audiometric configuration was high-tone hearing loss, and no patient showed low-tone hearing loss. IAC MRI demonstrated that the tumor had an intracanalicular portion and attachment to the bony IAC wall in all patients and widened the IAC wall in some patients. CONCLUSION: Different symptomatic combinations of acute audiovestibular deficits may develop in patients with VS. Awareness about the possibility of VS as a cause of sudden HL, acute vertigo, and acute FNP, as well as subsequent IAC MRI scanning is vital to earlier diagnosis of VS in these patients.

A Single-Center, Randomized, Double-Blind, and Placebo-Controlled Comparative Human Study to Verify the Functionality and Safety of the Lespedeza cuneata G. Don Extract for the Improvement of Aging Male Syndrome.

OBJECTIVE: Aging male syndrome is a clinical biochemical syndrome characterized by typical aging symptoms and serum testosterone deficiency. Although it is accompanied by various health problems, directly affects life satisfaction, and requires proper management, no clear prevention or treatment other than hormone replacement therapy is currently available for this syndrome. Here, we aimed to determine the efficacy and safety of the Lespedeza cuneata extract in the management of the aging male syndrome. METHODS: Males aged 43-70 years who provided consent for participation and had a total Aging Males' Symptom questionnaire score ≥ 37 and testosterone level ≤ 500 ng/dL were enrolled in this study. This study was conducted in a randomized, double-blind manner. Participants were randomly assigned to either the experimental or control groups and orally administered the assigned product twice a day. Efficacy was evaluated by measuring changes in Aging Males' Symptom score, Androgen Deficiency in the Aging Male questionnaire score, International Index of Erectile Function score, International Prostatic Symptom Score, blood test results, and body mass index at 8 weeks. RESULTS: After 8 weeks, the experimental group had significantly improved symptom scores compared to the control group on the Aging Males' Symptom and Androgen Deficiency in the Aging Male questionnaires. However, no significant differences in the International Index of Erectile Function score, International Prostatic Symptom Score score, blood test results, and body mass index were observed between the experimental and control groups. CONCLUSION: Lespedeza cuneata extract safely alleviates andropause symptoms without any significant side effects, suggesting its potential for the treatment of the aging male syndrome.

Boosting oxygen evolution reaction activity with Mo incorporated NiFe-LDH electrocatalyst for efficient water electrolysis.

This work demonstrates a simple and scalable methodology for the binder-free direct growth of Mo-doped NiFe-layered double hydroxides on a nickel substrate via an electrodeposition route at room temperature. A three-dimensional (3D) nanosheet array morphology of the electrocatalyst provides immense electrochemical surface area as well as abundant catalytically active sites. Mo incorporation in the NiFe-LDH plays a crucial role in regulating the catalytic activity of oxygen evolution reaction (OER). The prepared electrocatalyst exhibited low overpotential (i.e., 230 mV) at 30 mA cm-2 for OER in an alkaline electrolyte (i.e., 1 M KOH). Furthermore, the optimized Mo-doped NiFe-LDH electrode was used as an anode in a laboratory-scale in situ single cell test system for alkaline water electrolysis at 80 °C with a continuous flow of 30 wt% KOH, and it shows the efficient electrochemical performance with a lower cell voltage of 1.80 V at a current density of 400 mA cm-2. In addition, an admirable long-term cell durability is also demonstrated by the cell for 24 h. This work encourages new designs and further development of electrode material for alkaline water electrolysis on a commercial scale.

The effects of Korean Red Ginseng on heme oxygenase-1 with a focus on mitochondrial function in pathophysiologic conditions.

Korean Red Ginseng (KRG) plays a key role in heme oxygenase (HO)-1 induction under physical and moderate oxidative stress conditions. The transient and mild induction of HO-1 is beneficial for cell protection, mitochondrial function, regeneration, and intercellular communication. However, chronic HO-1 overexpression is detrimental in severely injured regions. Thus, in a chronic pathological state, diminishing HO-1-mediated ferroptosis is beneficial for a therapeutic approach. The molecular mechanisms by which KRG protects various cell types in the central nervous system have not yet been established, especially in terms of HO-1-mediated mitochondrial functions. Therefore, in this review, we discuss the multiple roles of KRG in the regulation of astrocytic HO-1 under pathophysiological conditions. More specifically, we discuss the role of the KRG-mediated astrocytic HO-1 pathway in regulating mitochondrial functions in acute and chronic neurodegenerative diseases as well as physiological conditions.

Posterior canal benign paroxysmal positional vertigo with long duration: Heavy or light cupula?

Objective: To investigate the characteristics of positional nystagmus in posterior semicircular canal (PSCC) benign paroxysmal positional vertigo (BPPV) patients with longer durations, and to discuss the possible underlying mechanism of this nystagmus. Methods: We conducted a retrospective review, and enrolled 118 consecutive patients with unilateral PSCC BPPV. The duration of nystagmus during a Dix-Hallpike test was classified into short (<1 min) and long (≥1 min) durations. For the identification of a neutral point in PSCC BPPV patients with long durations, the patient's head was turned 45° to the lesioned side to set the affected PSCC on the sagittal plane, and the disappearance of positional nystagmus was investigated in a pitch plane. Results: Among 118 patients with PSCC BPPV, positional nystagmus during a Dix-Hallpike test showed short durations (<1 min) in 112 patients and long durations (≥1 min) in 6 patients. Of 6 PSCC BPPV patients with a long duration, a neutral point was identified in 5 patients whose nystagmus lasted for longer than 2 min; interestingly, a neutral point was observed when the patient's head was slightly tilted backward in all 5 patients. Conclusion: Considering that a neutral position was identified when the patient's head was slightly tilted backward while keeping the head turned 45° to the right or left, we assume that the light cupula condition of the ipsilateral PSCC or the contralateral anterior semicircular canal, and not PSCC BPPV cupulolithiasis, could be responsible for the occurrence of persistent torsional-upbeating nystagmus in a Dix-Hallpike test. Level of Evidence: 4.

Korean Red Ginseng-Induced SIRT3 Promotes the Tom22-HIF-1α Circuit in Normoxic Astrocytes.

Astrocytes play a key role in brain functioning by providing energy to neurons. Increased astrocytic mitochondrial functions by Korean red ginseng extract (KRGE) have been investigated in previous studies. KRGE administration induces hypoxia-inducible factor-1α (HIF-1α) and vascular endothelial growth factor (VEGF) in astrocytes in the adult mouse brain cortex. VEGF expression can be controlled by transcription factors, such as the HIF-1α and estrogen-related receptor α (ERRα). However, the expression of ERRα is unchanged by KRGE in astrocytes of the mouse brain cortex. Instead, sirtuin 3 (SIRT3) expression is induced by KRGE in astrocytes. SIRT3 is a nicotinamide adenine dinucleotide (NAD+)-dependent deacetylase that resides in the mitochondria and maintains mitochondrial homeostasis. Mitochondrial maintenance requires oxygen, and active mitochondria enhance oxygen consumption, resulting in hypoxia. The effects of SIRT3 on HIF-1α-mediated mitochondria functions induced by KRGE are not well established. We aimed to investigate the relationship between SIRT3 and HIF-1α in KRGE-treated normoxic astrocyte cells. Without changing the expression of the ERRα, small interfering ribonucleic acid targeted for SIRT3 in astrocytes substantially lowers the amount of KRGE-induced HIF-1α proteins. Reduced proline hydroxylase 2 (PHD2) expression restores HIF-1α protein levels in SIRT3-depleted astrocytes in normoxic cells treated with KRGE. The translocation of outer mitochondrial membranes 22 (Tom22) and Tom20 is controlled by the SIRT3-HIF-1α axis, which is activated by KRGE. KRGE-induced Tom22 increased oxygen consumption and mitochondrial membrane potential, as well as HIF-1α stability through PHD2. Taken together, in normoxic astrocytes, KRGE-induced SIRT3 activated the Tom22-HIF-1α circuit by increasing oxygen consumption in an ERRα-independent manner.

Implantable nanostructured MEA with biphasic current stimulator for retinal prostheses.

BACKGROUND: In retinal prosthetic systems on multi-channel microelectrodes to effectively stimulate retinal neurons, the electrode-electrolyte interface impedance of a microelectrode should be minimized to drive sufficiently large current at a given supply voltage. OBJECTIVE: This paper presents the fabrication of the nanostructured microelectrode array with simplified fabrication and its characteristic evaluation using biphasic current stimulator. METHODS: The nanostructured microelectrodes with the base diameter of 25 µm, 50 µm, 75 µm are fabricated, and the maximum allowable current injection limits are measured to verify the estimated injection limit. Also, a biphasic stimulator has been fabricated using the 2-stage amplifier and 4 switches based on a stimulator cell. The adjustable load resistance is adopted to control between 5 kΩ to 20 kΩ, and the biphasic stimulator can drive the stimulation current between 50 uA and 200 uA. RESULTS: The proposed electrode-electrolyte interface impedance of the fabricated nanostructured microelectrode is 3178 Ω, 1218 Ω and 798.8 Ω for electrodes with diameter of 25 µm, 50 µm, 75 µm, respectively. CONCLUSION: This paper shows the advantages of the nanostructured microelectrode arrays for high resolution retinal prostheses, which could be a basic experiment for artificial retina research.

Effect of a differential training paradigm with varying frequencies and amplitudes on adaptation of vestibulo-ocular reflex in mice.

The vestibulo-ocular reflex (VOR) functions to maintain eye stability during head movement, and VOR gain can be dynamically increased or decreased by gain-up or gain-down adaptation. In this study, we investigated the impact of a differential training paradigm with varying frequencies and amplitudes on the level of VOR adaptation in mice. Training for gain-up (out of phase) or gain-down (in phase) VOR adaptation was applied for 60 min using two protocols: (1) oscillation of a drum and turntable with fixed frequency and differing amplitudes (0.5 Hz/2.5°, 0.5 Hz/5° and 0.5 Hz/10°). (2) Oscillation of a drum and turntable with fixed amplitude and a differing frequency (0.25 Hz/5°, 0.5 Hz/5° and 1 Hz/5°). VOR adaptation occurred distinctively in gain-up and gain-down learning. In gain-up VOR adaptation, the learned increase in VOR gain was greatest when trained with the same frequency and amplitude as the test stimulation, and VOR gain decreased after gain-up training with too high a frequency or amplitude. In gain-down VOR adaptation, the decrease in VOR gain increased as the training frequency or amplitude increased. These results suggest that different mechanisms are, at least in part, involved in gain-up and gain-down VOR adaptation.

Spontaneous Nystagmus in Patients With Posterior Semicircular Canal Benign Paroxysmal Positional Vertigo.

OBJECTIVE: This study aimed to investigate the incidence of spontaneous nystagmus (SN) in posterior semicircular canal (PSCC) benign paroxysmal positional vertigo (BPPV) and its effect on treatment outcomes. STUDY DESIGN: Retrospective case series. SETTING: Tertiary referral center. METHODS: This study included 50 patients with idiopathic unilateral PSCC BPPV between July 2021 and May 2022. The presence of SN was investigated, and the results of the bithermal caloric test and video head impulse test (vHIT) were compared. RESULTS: SN was observed in 13 (26%) of the 50 patients presenting PSCC BPPV. The direction of SN was mainly unidirectional and horizontal in 12 of the 13 patients with a slow-phase velocity ranging from 2 to 4°/s. One patient presented an upbeating torsional SN at the initial evaluation. The mean vHIT gain of the PSCC on the affected side was significantly lower in patients with SN than those without SN (p = .004, Mann-Whitney U test). The proportion of patients who recovered within 2 sessions of the repositioning maneuver was significantly higher in those without SN than that in those with SN (p < .001, Fisher's exact test). CONCLUSION: This study demonstrated that the treatment outcomes of PSCC BPPV were significantly worse in patients with SN than those without SN. Examining the presence of SN in patients with PSCC BPPV may be helpful in counseling the patients on prognosis, and it is expected that more sessions of canalith repositioning maneuver may be required to treat PSCC BPPV in patients with SN than those without SN.

Direction-changing spontaneous nystagmus in patients with dizziness.

PURPOSE: The present study aimed to investigate the clinical features of patients with direction-changing spontaneous nystagmus (DCSN) and gain insight into its underlying mechanisms. METHODS: Medical records and vestibular function test results collected in our dizziness clinic between February 2013 and February 2020 were retrospectively reviewed. Spontaneous nystagmus was recorded while sitting upright using videonystagmography for 2 min to confirm the spontaneous changes in nystagmus direction. Causative disease diagnoses were based on the patients' clinical history, audiometry results, vestibular function tests, and imaging studies. RESULTS: Of 4786 patients, DCSN was observed in 41 (0.86%). Causative disease diagnoses included vestibular neuritis (n = 9), lateral semicircular canal cupulopathy (n = 9), cerebellopontine angle tumor (n = 8), vestibular paroxysmia (n = 2), vestibular migraine (n = 2), vestibular nucleus infarction (n = 1), sudden sensorineural hearing loss with vertigo (n = 2), Meniere's disease (n = 2), Ramsay Hunt syndrome (n = 1), labyrinthine fistula due to middle ear cholesteatoma (n = 1), lateral semicircular canal dysplasia (n = 1), post tympanomastoidectomy dizziness (n = 1), and head trauma (n = 2). CONCLUSIONS: Although the periodicity of DCSN could not be determined because of insufficiently long observation times, it was observed in various central and peripheral vestibulopathies. Careful examination of spontaneous nystagmus over a sufficient period may ensure the detection of DCSN when evaluating dizziness.

The Light Cupula Phenomenon: A Scoping Review.

Direction-changing positional nystagmus (DCPN), which refers to the change in the direction of nystagmus with different head positions, is a well-known characteristic of horizontal semicircular canal BPPV. The supine head roll test is commonly used to diagnose horizontal canal BPPV. However, persistent geotropic DCPN observed during this test cannot be explained by the conventional explanations of canalolithiasis or cupulolithiasis. To account for this unique nystagmus, the concept of a "light cupula" has been recently introduced. In this review, we provide an overview of the historical background, clinical features and diagnostic methods, proposed mechanisms, and treatment strategies associated with the light cupula phenomenon based on the available literature to date.

Artificial intelligence in urologic oncology: the actual clinical practice results of IBM Watson for Oncology in South Korea.

Background: Artificial intelligence (AI) is changing our life, including the medical field. Repeated machine learning using big data made various fields more predictable and accurate. In medicine, IBM Watson for Oncology (WFO), trained by Memorial Slone Kettering Cancer Center (MSKCC), was first introduced and applied in 14 countries worldwide.Our study was designed to assess the feasibility of WFO in actual clinical practice. We aimed to investigate the concordance rate between WFO and multidisciplinary tumor board (MTB) in Urologic cancer patients. Materials and methods: We reviewed retrospectively collected data for consecutive patients who underwent WFO and MTB simultaneously in the diagnosis of urologic malignancy before determining further treatment between August 2017 and September 2020. We compared the recommendation of the AI system, WFO (IBM Watson Health, Cambridge, MA), with the opinion of MTB for further managing all patients diagnosed with urologic malignancies such as prostate, bladder, and kidney cancer. Results: A total of 55 patients were enrolled in our study. The number of patients with prostate cancer was 48. The number of bladder and kidney cancer patients was 5 and 2, respectively. The overall concordance rate between WFO and MTB was 92.7%. Three patients could not suggest proper treatment options using WFO, and the recommended choice of WFO was not feasible in the Korean Health Insurance Review and Assessment Service. Conclusions: The decision of WFO showed a high concordance rate with a multidisciplinary tumor board for urologic oncology. However, some recommendations of WFO were not feasible in actual practice, and WFO still has some points to improve and modify. Interestingly, applying WFO is likely to facilitate a multidisciplinary team approach.