Publications by authors named "Athanasia Korda"

Background:  Assessment of nystagmus fixation suppression can be used as an additional diagnostic tool for patients with an acute vestibular syndrome to distinguish between a central or peripheral cause. We investigated the ability of physicians to detect fixation suppression using a nystagmus simulation model.

Methods:  We used a nystagmus simulator to measure the accuracy of the nystagmus fixation suppression test.

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Article Synopsis
  • A study involving 111 neurologists and ENT physicians in Switzerland sought to evaluate how specialists interact with generalists when diagnosing and treating dizzy patients, aiming to improve patient care and education.
  • Results showed that specialists felt more confident diagnosing acute dizziness compared to episodic or chronic cases, with specific knowledge about timing and subtle signs aiding in diagnosis.
  • Additional findings indicated that neurologists referred more acutely dizzy patients compared to ENT specialists, highlighting a disparity in the diagnostic process and revealing unmet needs in patient management.
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  • The study aimed to evaluate the effectiveness of the video Head Impulse Test (vHIT) in diagnosing vestibular strokes in patients presenting with acute vestibular syndrome in the emergency department.
  • Out of 76 patients tested, 24 were confirmed to have vestibular strokes, with the vHIT showing an accuracy of 86.8% based on vestibulo-ocular reflex gain compared to lower accuracy from saccade metrics.
  • While the vestibulo-ocular reflex gain proved to be the most accurate, saccade metrics still offered valuable diagnostic insights, though automated detection methods need improvement to match expert analysis.
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Article Synopsis
  • Vertigo and dizziness are common issues in emergency departments and outpatient centers, prompting consultations with specialists like neurologists and ENT physicians for better patient care.
  • An online survey of 111 specialists in Switzerland revealed that both neurologists and ENT doctors often use specific tests for diagnosing common conditions like BPPV, but there are notable differences in their approaches, particularly in the use of brain MRIs and referrals for physical therapy.
  • The findings emphasize the need for standardized guidelines for diagnosing and treating dizziness across specialties, alongside the importance of training neurologists in specific repositioning techniques for better patient management.
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Objectives: To assess the prevalence of new hearing losses in patients with acute vestibular syndrome (AVS) and to start to evaluate its diagnostic value for the differentiation between peripheral and central causes.

Design: We performed a cross-sectional prospective study in AVS patients presenting to our Emergency Department (ED) from February 2015 to November 2020. All patients received an MRI, Head-impulse test, Nystagmus test and Test of skew ('HINTS'), caloric testing and a pure-tone audiometry.

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Objective: The transmastoid plugging of a superior semicircular canal is considered a safe and effective technique for the management of superior semicircular canal dehiscence (SSCD). The aim of this meta-analysis is to assess the postoperative hearing outcomes after the transmastoid plugging of the superior semicircular canal. Search method and data sources: A systematic database search was performed on the following databases until 30 January 2023: MEDLINE, Embase, Cochrane Library, Web of Science, CINAHL, ICTRP, and clinicaltrials.

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Background: Vertigo and dizziness are among the most frequent presenting symptoms in the primary care physicians' (PCPs) office. With patients facing difficulties in describing their complaints and clinical findings often being subtle and transient, the diagnostic workup of the dizzy patient remains challenging. We aimed to gain more insights into the current state of practice in order to identify the limitations and needs of the PCPs and define strategies to continuously improve their knowledge in the care of the dizzy patient.

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  • Vestibular symptoms in emergency department patients can signal serious conditions like stroke, and accurate identification is critical for effective treatment.
  • A study from 2015 to 2019 examined 1647 ED patients with these symptoms, leading to a focus on 122 confirmed stroke cases through MRI scans.
  • Findings revealed that 13% of dizzy patients had strokes, predominantly in the posterior circulation, with nystagmus present in half of the stroke cases, yet many stroke patients lacked this symptom, making diagnosis challenging.
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Background: The diagnostic workup and treatment decisions for vertigo or dizziness in primary care can be challenging due to the broad range of possible causes and limited time and expertise of physicians. This can lead to delays in treatment and unnecessary tests. We aimed to identify the unmet needs of primary care physicians (PCPs) and strategies to improve care for dizzy patients.

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Objectives: We aimed to determine the frequency of vestibular syndromes, diagnoses, diagnostic errors and resources used in patients with dizziness in the emergency department (ED).

Design: Retrospective cross-sectional study.

Setting: Tertiary referral hospital.

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Strong magnetic fields induce dizziness, vertigo, and nystagmus due to Lorentz forces acting on the cupula in the semi-circular canals, an effect called magnetic vestibular stimulation (MVS). In this article, we present an experimental setup in a 7T MRT scanner (MRI scanner) that allows the investigation of the influence of strong magnetic fields on nystagmus as well as perceptual and cognitive responses. The strength of MVS is manipulated by altering the head positions of the participants.

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When the demands for visual stabilization during head rotations overwhelm the ability of the vestibuloocular reflex (VOR) to produce compensatory eye movements, the brain produces corrective saccades that bring gaze toward the fixation target, even without visual cues (covert saccades). What triggers covert saccades and what might be the role of prediction in their generation are unknown. We studied 14 subjects with acute vestibular neuritis.

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Objective: Measuring the Vestibular-Ocular-Reflex (VOR) gains with the video head impulse test (vHIT) allows for accurate discrimination between peripheral and central causes of acute vestibular syndrome (AVS). In this study, we sought to investigate whether the accuracy of artificial intelligence (AI) based vestibular stroke classification applied in unprocessed vHIT data is comparable to VOR gain classification.

Methods: We performed a prospective study from July 2015 until April 2020 on all patients presenting at the emergency department (ED) with signs of an AVS.

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Article Synopsis
  • A study was conducted to assess the effectiveness of a video-based test called vHINTS for diagnosing strokes in patients with acute vestibular syndrome (AVS), comparing it to traditional expert evaluations.
  • The research included 46 patients with AVS and found that vHINTS had a high accuracy of 94.2%, outperforming expert evaluations, which had an accuracy of 88.3%.
  • The study concluded that vHINTS is a more reliable method for detecting strokes, especially highlighting the challenges in evaluating nystagmus direction during the tests.
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Superior canal dehiscence syndrome (SCDS) is a structural bony defect of the roof of the superior semi-circular canal into the middle cranial fossa and is responsible for the creation of a third window, which alters the dynamics of the inner ear. During humming, vibratory waves entering the vestibulum and cochlea are re-routed through the dehiscence, leading to stimulation of the otolithic and ampullary vestibular organs. This is responsible for the torsional-vertical nystagmus known as "fremitus nystagmus".

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Objective: The alternate cover test (ACT) in patients with acute vestibular syndrome is part of the 'HINTS' battery test. Although quantitative, the ACT is highly dependent on the examiner's experience and could theoretically vary greatly between examiners. In this study, we sought to validate an automated video-oculography (VOG) system based on eye tracking and dedicated glasses.

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Article Synopsis
  • The study investigates skew deviation, a symptom of acute vestibular syndrome (AVS), and its relationship with vertical diplopia and vestibular pathways dysfunction.
  • Data was collected from patients in an emergency department over five years, using clinical assessments and video tests, followed by MRI to confirm strokes.
  • Findings reveal a notable prevalence of skew deviation in patients with AVS, challenging previous beliefs about its rarity, and suggest that while video tests can help quantify skew, they offer limited diagnostic value compared to other established tests.
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Objective: Cold and warm water ear irrigation, also known as bithermal caloric testing, has been considered for over 100 years the 'Gold Standard' for the detection of peripheral vestibular hypofunction. Its discovery was awarded a Nobel Prize. We aimed to investigate the diagnostic accuracy of Caloric Testing when compared to the video head impulse test (vHIT) in differentiating between vestibular neuritis and vestibular strokes in acute dizziness.

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Objective: Gaze-evoked nystagmus (GEN) is a central sign in patients with the acute vestibular syndrome (AVS); however, discriminating between a pathological and a physiologic GEN is a challenge. Here we evaluate GEN in patients with AVS.

Methods: In this prospective cross-sectional study, we used video-oculography (VOG) to compare GEN in the light (target at 15° eccentric) in 64 healthy subjects with 47 patients seen in the emergency department (ED) who had AVS; 35 with vestibular neuritis and 12 with stroke.

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Objective: Failure of fixation suppression of spontaneous nystagmus is sometimes seen in patients with vestibular strokes involving the cerebellum or brainstem; however, the accuracy of this test for the discrimination between peripheral and central causes in patients with an acute vestibular syndrome (AVS) is unknown.

Methods: Patients with AVS were screened and recruited (convenience sample) as part of a prospective cross-sectional study in the emergency department between 2015 and 2020. All patients received neuroimaging, which served as a reference standard.

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Background And Purpose: A peripheral spontaneous nystagmus (SN) is typically enhanced or revealed by removing fixation. Conversely, failure of fixation suppression of SN is usually a sign of a central disorder. Based on Luebke and Robinson (Vision Res 1988, vol.

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The video head impulse test (vHIT) is nowadays a fast and objective method to measure vestibular function. However, its usability is controversial and often considered as a test performed by experts only. We sought to study the learning curve of novices and to document all possible mistakes and pitfalls in the process of learning.

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Alexander's law (AL) states the intensity of nystagmus increases when gaze is toward the direction of the quick phase. What might be its cause? A gaze-holding neural integrator (NI) that becomes imperfect as the result of an adaptive process, or saturation in the discharge of neurons in the vestibular nuclei? We induced nystagmus in normal subjects using a rapid chair acceleration around the yaw (vertical) axis to a constant velocity of 200°/second [s] and then, 90 s later, a sudden stop to induce post-rotatory nystagmus (PRN). Subjects alternated gaze every 2 s between flashing LEDs (right/left or up/down).

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Hypothesis: We aimed to investigate the effect of the head excursion angle on the success of the Sémont Maneuver (SM).

Background: SM is performed with the head turned by 45 degrees toward the unaffected ear. In clinical routine, it is unlikely that physicians can turn the head to a position of exactly 45 degrees.

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Objectives: Clinicians performing a horizontal head impulse test (HIT) are looking for a corrective saccade. The detection of such saccades is a challenge. The aim of this study is to assess an expert's likelihood of detecting corrective saccades in subjects with vestibular hypofunction.

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