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.

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.

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.

Amplitude modulating frequency overrides carrier frequency in tACS-induced phosphene percept.

The amplitude modulated (AM) neural oscillation is an essential feature of neural dynamics to coordinate distant brain areas. The AM transcranial alternating current stimulation (tACS) has recently been adopted to examine various cognitive functions, but its neural mechanism remains unclear. The current study utilized the phosphene phenomenon to investigate whether, in an AM-tACS, the AM frequency could modulate or even override the carrier frequency in phosphene percept. We measured the phosphene threshold and the perceived flash rate/pattern from 12 human subjects (four females, aged from 20-44 years old) under tACS that paired carrier waves (10, 14, 18, 22 Hz) with different envelope conditions (0, 2, 4 Hz) over the mid-occipital and left facial areas. We also examined the phosphene source by adopting a high-density stimulation montage. Our results revealed that (1) phosphene threshold was higher for AM-tACS than sinusoidal tACS and demonstrated different carrier frequency functions in two stimulation montages. (2) AM-tACS slowed down the phosphene flashing and abolished the relation between the carrier frequency and flash percept in sinusoidal tACS. This effect was independent of the intensity change of the stimulation. (3) Left facial stimulation elicited phosphene in the upper-left visual field, while occipital stimulation elicited equally distributed phosphene. (4) The near-eye electrodermal activity (EDA) measured under the threshold-level occipital tACS was greater than the lowest power sufficient to elicit retinal phosphene. Our results show that AM frequency may override the carrier frequency and determine the perceived flashing frequency of AM-tACS-induced phosphene.

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.

Impact of national pneumococcal vaccination program on invasive pneumococcal diseases in South Korea.

Following the introduction of pneumococcal conjugate vaccines (PCVs), the rate of invasive pneumococcal disease (IPD) declined, however, IPDs replaced by serotypes that are not included in the vaccine have emerged. We describe the epidemiology of IPD in South Korea over a 4.5-year period, encompassing the impact following introduction of PCV10/13 and PPSV23 into the public immunization program, and assess serotype dynamics in pediatric and adult population. This was a nationwide, retrospective review of surveillance of all IPD cases in Korea between September 2014 to December 2019. We analyzed VT13 (serotypes included in 13-valent conjugate vaccine) and NVT (nonvaccine type) cases by age, sex, IPD type, vaccination status, and deaths. A total of 893 cases with serotype data were included; 306 (34%) VT13 cases and 587 (66%) NVT cases. Serotype 3 (n = 155) was the most common VT13 serotype, followed by serotypes 19A (n = 70) and 14 (n = 28). Among the NVTs, serotype 10A (n = 74) was the most common serotype, followed by serotypes 23A (n = 60) and 34 (n = 58). Persons who had PCV13 vaccination were at lower risk (aOR = 0.11, 95% CI 0.02-0.73, P = 0.022) of death compared to unvaccinated persons. Introduction of PCV10/13 and PPSV23 vaccination program has had different impacts on the serotype-specific IPD across age groups. The most common serotypes included serotypes 3 and 19A (VT13), and 10A, 23A, and 34 (NVT). Our findings suggest continued monitoring in the midst of new vaccine development, and a need to develop novel strategies to mitigate the IPDs from emerging pneumococcal serotypes.

Change in Diagnosis of Benign Paroxysmal Positional Vertigo During COVID-19 Pandemic.

Purpose: The present study investigated the impact of coronavirus disease 2019 (COVID-19) pandemic on benign paroxysmal positional vertigo (BPPV). Patients and Methods: The medical records of BPPV patients who were evaluated in the outpatient department (OPD) and emergency room (ER) during (435 patients) and before (517 patients) the COVID-19 pandemic were retrospectively reviewed. Dix-Hallpike and supine head-roll tests were used to classify the subtype of BPPV as posterior semicircular canal (PSCC), geotropic lateral semicircular canal (geotropic LSCC), or apogeotropic lateral semicircular canal (apogeotropic LSCC) BPPV. Results: More patients with PSCC BPPV were diagnosed at the OPD compared with those who were diagnosed at the ER both before and during the COVID-19 pandemic; however, more patients with LSCC BPPV were diagnosed at the ER compared with those who were diagnosed at the OPD during the same periods. The mean time interval between vertigo onset and initial evaluation was remarkably longer during the pandemic in patients with PSCC BPPV. Conclusion: This study demonstrated that the incidences of BPPV subtypes according to hospital visit type were not significantly different before and during the COVID-19 pandemic. Because hospital visits were delayed in patients with PSCC BPPV during the COVID-19 pandemic, telemedicine or e-health could be suitable alternatives to face-to-face medical care for these patients.

New Therapeutic Maneuver for Horizontal Semicircular Canal Cupulolithiasis: A Prospective Randomized Trial.

BACKGROUND: There are debates on whether mastoid oscillation has any benefit or harm in treating horizontal semicircular canal (HSCC) cupulolithiasis. The goal of this study was to investigate the therapeutic effects of the new maneuver using only inertia and gravity and compare it with the previously reported cupulolith repositioning maneuver using mastoid vibration (CuRM). METHODS: We enrolled 57 patients diagnosed with HSCC cupulolithiasis. Patients were randomly allocated to the previously reported CuRM or the new maneuver (briefly, 30° head rotation to the affected side and thereafter bidirectional side-lying) using simply inertia and gravity, and their immediate and short-term effects were evaluated. RESULTS: The immediate success rate did not differ significantly between the CuRM (8 of 22, 36.4%) and the new maneuver (10 of 35, 28.6%) groups (p = 0.538, Pearson's chi-square test). The late resolution rates at the first follow-up of the CuRM (75%, 9 of 12) and new maneuver groups (82.6%, 19 of 23) were very high, and there was no statistical difference between them (p = 0.670, Fisher's exact test). CONCLUSIONS: This study showed that the new maneuver was effective for treating HSCC cupulolithiasis with an immediate success rate of 28.6% (10 of 35). Although it did not show better results than the existing maneuver using vibration, there was no statistical difference. Considering the debate on the effectiveness of oscillation, we believe our new maneuver is a conservative alternative that uses only inertia and gravity, and it can be easily performed in clinics where oscillation equipment is not available.

Downbeat Nystagmus and Bilateral Sudden Hearing Loss by Suicidal Aspirin Intoxication.

Ototoxic side effects such as sensorineural hearing loss and tinnitus can be caused by acute salicylate intoxication. Bilateral symmetric sensori- neural hearing loss involving all tested frequencies is a typical pattern of hearing loss in acute salicylate intoxication, which usually resolves within 2 or 3 days without any specific treatment for ototoxicity. Herein, we report a case of suicidal aspirin intoxication resulting in sudden bilateral hearing loss and vertigo. The patient exhibited spontaneous downbeat nystagmus, and the mechanism underlying this characteristic nystagmus is discussed.

Human Acellular Dermal Allograft Patch on Traumatic Tympanic Membrane Perforation.

BACKGROUND: This study aimed to investigate the outcome of using the human acellular dermal allograft patch compared with the conven- tional paper patch in traumatic tympanic membrane perforation. METHODS: This was a retrospective study including 41 patients (42 ears) treated with 22 human acellular dermal allografts and 20 paper patches for acute traumatic tympanic membrane perforation from April 2013 to June 2020. The procedure was performed by applying human acellular dermal allograft or paper patches after trimming of perforation margins under local anesthesia. Patient's age, sex, cause, duration, side, location, size of perforation, and the result of healing was analyzed. The audiologic or computed tomography data were also investigated when available. RESULTS: There was no significant difference in sex, age, affected side ratio, size and duration of perforation, recovery confirmation time, and audiogram results between the two groups. There was no significant difference in the size or duration of perforation between the success and failure groups. The human acellular dermal allograft and paper-patch groups showed no significant difference in the recovery confirmation time (70.7 ± 42.3 vs. 89.9 ± 119.4 days, P = .486) and recovery rate (95.5% vs. 85.0%, P = .333). However, the patch maintenance time of the human acellular dermal allograft group was statistically longer than the paper-patch group (32.9 ± 14.9 vs. 15.6 ± 19.9 days, P = .001). On multivariable regression analysis, patch material was the only parameter associated with patch maintenance time (P = .002). CONCLUSION: Treatment outcomes of traumatic tympanic membrane perforation using human acellular dermal allograft showed better or similar therapeutic efficacy compared to paper patch. The important advantage of this material is to stay in situ for a sufficient time without being detached until successful healing.

Epidemiological characteristics of varicella outbreaks in the Republic of Korea, 2016-2020.

OBJECTIVES: We described the trends and epidemiological characteristics of varicella outbreaks from 2016 to 2020 in the Republic of Korea. METHODS: We investigated variables such as the outbreak setting, age of patients, vaccination status, and lesion count. The collected data were analyzed with the Cochrane-Armitage trend test and Kruskal-Wallis test. These statistical tests were performed using R ver. 4.0.3. RESULTS: The number of varicella outbreaks increased from 2016 to 2018; however, after a slight decrease in the number of outbreaks in 2019, the number fell sharply in 2020. The median size of outbreaks decreased from 8 to 9 cases during 2016-2019 to 6 cases in 2020. The median duration of outbreaks was 18 days during 2016-2017, 28 days in 2018, 29 days in 2019, and 15 days in 2020. Varicella outbreaks occurred most frequently in elementary schools, and vaccination coverage of patients increased from 89.4% in 2016 to 97.2% in 2019. The median age of patients with outbreak-related varicella decreased from 8 years in 2016 to 6 years in 2020. CONCLUSION: Significant changes were observed in the age of patients with outbreak-related varicella. Ongoing monitoring of varicella outbreaks should be conducted. Further research will be needed to measure the disease burden of varicella and enable evidence-based policy decisions.

Objective measurement of HINTS (Head Impulse, Nystagmus, Test of Skew) in peripheral vestibulopathy.

OBJECTIVE: To evaluate how often the positive sign of HINTS (Head-Impulse, Gaze Evoked Nystagmus, Test of Skew) appears in patients with acute peripheral vestibular lesion, HINTS findings were quantitatively measured and analyzed in patients with peripheral vestibulopathy accompanying spontaneous nystagmus. METHODS: HINTS was evaluated in 14 vertigo patients with spontaneous nystagmus. Horizontal vestibulo-ocular reflex (VOR) gain was measured using the video head impulse test (vHIT). To evaluate gaze-evoked nystagmus (GEN), slow-phase velocities at different points of lateral gaze were measured and plotted, then the slope and its inverse value, the neural integrator time constant, were calculated. Skew deviation was tested using anaglyph filters to simulate the alternate cover test, and the degree and latency of vertical eyeball deviation were measured. The ABCD2 score was calculated to evaluate the risk of stroke. RESULTS: Among 13 patients of peripheral vestibulopathy, 7 showed positive signs in HINTS (normal vHIT: 5, direction-changing GEN: 0, skew deviation: 3). One patient with a cerebellopontine angle tumor presented with both a peripheral and central pattern and showed positive HINTS findings (presence of direction-changing GEN). The mean VOR gain of patients with abnormal vHIT was 0.58±0.29 and 1.10±0.11 in the affected and contralateral side, respectively, while those in patients with normal vHIT were 1.04±0.21 and 1.13±0.12, respectively. The neural integrator time constant calculated from the mean slope of horizontal slow-phase velocity according to horizontal eye position was 42.9 s. The mean vertical eyeball deviation of patients with positive skew was 2.14±1.18° while uncovering the eye on the affected side, and -1.97±1.59° while uncovering the eye on the unaffected side. The median ABCD2 score of 14 patients was 2 (range, 1-3). CONCLUSIONS: HINTS findings were objectively measured in vertigo patients with spontaneous nystagmus. Although positive findings of HINTS have been recognized as a central sign, 54% (7/13) of cases with peripheral vestibulopathy showed positive HINTS signs. HINTS results should be interpreted carefully considering that a substantial proportion of peripheral vestibulopathy shows a positive HINTS sign.

Tympanic Membrane Perforation After Intratympanic Steroid Injection: A Systematic Review and Meta-analysis.

OBJECTIVE: We investigated the incidence of tympanic membrane (TM) perforations induced after intratympanic steroid injection (ITSI) in patients with sudden sensorineural hearing loss (SSNHL) through a systematic review and meta-analysis. DATA SOURCES: PubMed, Embase, and MEDLINE. REVIEW METHODS: Primary database searches were performed, and 1901 records were identified. After removal of 1802 articles through abstract screening, the remaining 99 full-text journals were assessed for eligibility to be included in the study. Fifty-eight studies that used either ventilation tubing (VT) or tympanocentesis (TC) for ITSI were selected for analysis. The subjects were divided into VT and TC groups. The rate of TM perforation after ITSI in 2 groups, sites of ITSI, needle gauge, and influence on residual hearing were investigated. RESULTS: The cohorts comprised patients who underwent VT (n = 257, 9.6%) and TC (n = 2415, 90.4%). The proportion of TM perforation after ITSI in each group was 0.073 (95% CI, 0.0469-0.1113) and 0.010 (95% CI, 0.0045-0.0215), respectively, which suggested that the VT group showed a significantly higher TM perforation rate than the TC group (P < .001). In the subgroup analyses, there was no significant difference in the odds ratio for the rate of TM perforation according to the injection site and needle gauge for TC. The proportion of surgical repair showed no significant difference between the 2 groups. CONCLUSION: ITSI via VT may have a significantly higher risk of TM perforation than ITSI via TC, although those are relatively small overall. ITSI should be performed in the direction to minimize possible adverse effects.

Direction-changing spontaneous nystagmus in cerebellopontine angle tumour.

The most common symptoms of tumours involving the cerebellopontine angle (CPA) are unilateral sensorineural hearing loss, dizziness, and asymmetric tinnitus. While the clinical manifestations have been well documented in previous studies, the nystagmus findings in these patients have not been thoroughly investigated yet. This study aimed to investigate the incidence of direction-changing spontaneous nystagmus in patients with CPA tumours, evaluate their radiologic characteristics, and gain insight into the mechanisms underlying nystagmus. Direction-changing spontaneous nystagmus was observed in 6 out of 83 patients (7%) with CPA tumours during the 7-year period. Temporal bone magnetic resonance imaging findings revealed the presence of an intrameatal mass in CPA tumours in all six patients with direction-changing spontaneous nystagmus. Vestibular schwannomas were confined within the internal auditory meatus in four patients, and petroclival meningiomas extended into the internal auditory meatus in two patients. The mechanism of direction-changing spontaneous nystagmus may be explained as paroxysmal secondary central hyperactivity in the vestibular nucleus due to the long-standing pressure effect in the vestibular nerve by tumours, or by ephaptic discharges in the vestibular nerve.

The Research of Toxicity and Sensitization Potential of PEGylated Silver and Gold Nanomaterials.

Polyethylene glycol (PEG) is a polymer used for surface modification of important substances in the modern pharmaceutical industry and biopharmaceutical fields. Despite the many benefits of PEGylation, there is also the possibility that the application and exposure of the substance may cause adverse effects in the body, such as an immune response. Therefore, we aimed to evaluate the sensitization responses that could be induced through the intercomparison of nanomaterials of the PEG-coated group with the original group. We selected gold/silver nanomaterials (NMs) for original group and PEGylated silver/gold NMs in this study. First, we measured the physicochemical properties of the four NMs, such as size and zeta potential under various conditions. Additionally, we performed the test of the NM's sensitization potential using the KeratinoSens™ assay for in vitro test method and the LLNA: 5-bromo-2-deoxyuridine (BrdU)-FCM for in vivo test method. The results showed that PEGylated-NMs did not lead to skin sensitization according to OECD TG 442 (alternative test for skin sensitization). In addition, gold nanomaterial showed that cytotoxicity of PEGylated-AuNMs was lower than AuNMs. These results suggest the possibility that PEG coating does not induce an immune response in the skin tissue and can lower the cytotoxicity of nanomaterials.

Comparison of Therapeutic Effects of Topical Calcineurin Inhibitor and Moisturizing Cream on Pruritic External Auditory Canal.

Although pruritic external auditory canal (PEAC) is a relatively common symptom, particularly in the geriatric population, its pathophysiology and appropriate treatment remain to be elucidated. We compared the therapeutic efficacy of pimecrolimus, a topical calcineurin inhibitor (CI), and a moisturizing cream (MC) in patients with PEAC. Thirty-nine patients (73 ears) were prospectively enrolled and treated topically twice daily with the CI (n = 20, 39 ears) or the MC (n = 19, 34 ears) for two weeks. The change in itching sensation was evaluated subjectively using a self-questionnaire at immediately, one month, and two months after self-application, and objectively by changes in erythema grading. Although topical treatment with the CI resulted in a more rapid improvement than treatment with the MC in patients with PEAC, the final outcomes did not differ between the groups. Furthermore, similar improvements in erythema scores were noted. The results of this study suggest that the MC, which rejuvenates the normal physiological status of the ear canal skin, may greatly benefit those elderly patients more susceptible to PEAC, without any concerns about adverse events and underlying comorbidities. Expanding upon the understanding of the role of moisturizers in the treatment of pruritic ears merits attention, as this knowledge provides a good example of the clinical guidelines for the management of PEAC.

Bubbling tinnitus caused by change in head position.

Because the density of air is lower than the effusion, air bubbles can be passively moved by a head position change, causing a bubbling sound in the affected ear.