Vestibular Weakness Research Articles

What is vestibular weakness?

Patients with this balance disorder require an interprofessional team to promote safety and quality of life.

Video-nystagmographic evidence in more than 700 consecutive cases of road traffic whiplash injury

PurposeWhiplash injury is a frequent traumatic lesion occurring mainly in road accidents, which may also cause dizziness severe enough to impact everyday life. Vestibular examination is routinely performed on these patients, although the role of the neuro-otologist is still not clearly defined. The main endpoint of this study was to describe the videonystagmography (VNG) evidence in a large cohort of patients who underwent road traffic whiplash injury. Methods717 consecutive patients who reported whiplash-associated disorders due to a road traffic accident underwent clinical examination and VNG. ResultsPatients with saccadic test latency anomalies more frequently complained of vertigo, nausea and cochlear symptoms after trauma (p = 0.031, 0.028 and 0.006), while patients with bilateral vestibular weakness at caloric stimulation more often displayed neck pain after trauma (p = 0.005). Patients complaining of positional or cochlear symptoms or with accuracy anomalies at the saccadic test were significantly older than those with no positional, no cochlear symptoms and without accuracy anomalies (p = 0.022, p = 0.034 and p = 0.001). Patients with bilateral vestibular hypofunction were significantly younger (p < 0.001). ConclusionsVNG evidence, particularly vestibular function and saccadic tests, may be related to damage in the cervical region due to whiplash trauma. These findings suggest that neuro-otologic examination may play a role in properly identifying those who suffer damage caused by whiplash trauma, and in characterizing the severity and prognosis of whiplash-associated disorders.

Can Type of Dizziness Influence the Vestibular Caloric Test Result?

Background:The broad range of vestibular tests used to diagnose labyrinth diseases allows for a functional assessment of the vestibular system. Among the many tests performed, the caloric test is considered the gold standard by providing an objective measurement of the vestibular function for each labyrinth.Objective:to correlate the different types of dizziness with the caloric test result.Methods:a descriptive study was performed based on the previous records of vestibular tests performed on patients with body balance disorders evaluated at Audiology Service between 2000 and 2020. The variables evaluated were sex, age, hearing loss, tinnitus, and caloric test result.Results:the sample was composed of 892 patients, 654 (73.4%) women, and 238 (26.6%) men. Normal results were obtained for 57.4% (N = 514) of the individuals, while peripheral disease 40.1% (N = 357), and central disease 2.5% (N = 21) accounted for the remaining. Complaint of vertigo was not common in central disorders (P = .02; OR = 0.17) and instability was associated with bilateral vestibular weakness (P = 0.02; OR = 5.92). Vertigo associated with tinnitus and/or hearing loss was more frequent in the caloric test with peripheral abnormality (P = 0.008).Conclusion:complaints of vertigo associated with tinnitus and/or hearing loss must be directed for clinical observation of unilateral peripheral lesion and instability to central disease or bilateral peripheral lesion.

Efficacy of transmastoidal galvanic stimulation on recovery outcomes in patients with unilateral peripheral vestibular disorders: a randomized controlled trial

BackgroundPeripheral vestibular disorders are common disorders among population with increased prevalence with age advancement, manifested by balance disorders and postural instability that negatively affect daily activities and social participation.ObjectivesTo investigate the effect of transmastoidal galvanic stimulation added to a designed vestibular rehabilitation program on recovery outcomes in Egyptian patients with unilateral peripheral vestibular disorders.Subjects and methodsForty patients (from both sexes) diagnosed with unilateral peripheral vestibular weakness were evenly and randomly designated into two groups: study and control groups. The study group received transmastoidal galvanic stimulation, in addition to a vestibular rehabilitation program, whereas control group undergone vestibular rehabilitation program only. Treatment sessions were conducted three times weekly for four successive weeks. Assessment of vestibular canal weakness was carried out using videonystagmography, postural stability using computerized posturography, while participation in daily activities was carried out using Vestibular Disorders Activities of Daily Living Scale (VADL). All assessment measures were carried out pre- and post-treatment.ResultsStudy group showed improvement of post-treatment scores of canal weakness, postural stability parameters, and VADL scale in reverse to control group that showed improvement of scores of preference and VADL only. A statistically significant difference was found between both groups in post-treatment scores of canal weakness, total equilibrium composite, and vestibular component with more improvement in the study group.ConclusionAdding transmastoidal galvanic stimulation to vestibular rehabilitation exercises for unilateral peripheral vestibular disorders improves the recovery outcomes of vestibular canal weakness, equilibrium, and vestibular components of postural stability.Trial registrationClinical trials identification number (NCT04010435). Registered 7 March 2019—retrospectively registered, https://register.clinicaltrials.gov/prs/app/action/LoginUser?ts=1&cx=-jg9qo4

The Role for Imaging in the Investigation of Isolated Objective Vestibular Weakness.

Unilateral vestibular weakness has considerable potential etiologies. One source is a vestibular schwannoma. This article evaluates, in the absence of other symptoms and signs, if unilateral vestibular weakness is an analogue to asymmetric sensorineural hearing loss and serves as an indication for lateral skull base imaging. Retrospective chart review. Academic tertiary center. All patients undergoing caloric assessment between January 1, 2012, and June 30, 2018, were investigated. Patients with unilateral vestibular weakness (a left-right difference >25% on electronystagmography) were included in the study. A provincial encompassing image library was surveyed for potential adequate imaging (computed tomography internal auditory canal infused, magnetic resonance imaging [MRI] brain, MRI internal auditory canal) of the target population within the preceding 5 years. Presence/absence of vestibular schwannoma on imaging was determined. Of the 3531 electronystagmography reports reviewed during the period, 864 patients were identified with unilateral vestibular weakness. Of these, 542 had sufficient imaging, and 14 vestibular schwannomas were identified. Only 1 individual had a vestibular weakness in isolation, while the remaining 13 patients also suffered from documented sensorineural hearing loss that would have mandated MRI scanning. The results of our study suggest that, in isolation, vestibular weakness is an insufficient indicator for lateral skull base imaging.

Temporal Bone and Cerebellopontine Angle Epidermoid Resulting in Facial Nerve Paralysis: Resection and Facial Nerve Coaptation.

Objectives Demonstrate the utilization of a transcochlear approach for resection of an epidermoid involving the temporal bone and cerebellopontine angle (CPA) with end-to-end facial nerve coaptation. Designs Single case-based operative video. Setting Tertiary center with dedicated skull base team. Participants The patient is a 50-year-old left handed male with a history of a remote left Bell's palsy, left sudden sensorineural hearing loss, and a rapidly progressive facial nerve paralysis. His balance was impaired, and his videonystagmography showed a significant left sided peripheral vestibular weakness. Computed tomography (CT) scan showed an erosive lesion of his left temporal bone involving the cochlea and semicircular canals, and magnetic resonance imaging (MRI) showed a T2 hyperintense lesion with restricted diffusion and no enhancement on postcontrast T1 sequences. Main Outcome Measures Gross total resection of the epidermoid, recovery of facial nerve function, balance improvement. Results The patient underwent resection via a transcochlear approach. The tumor involved the epitympanum and eroded the semicircular canals, vestibule, and basal turn of the cochlea. Gross total tumor resection was attained. The facial nerve was isolated in the mastoid and tympanic segments, traced proximally to the geniculate ganglion, and then into the internal auditory canal (IAC). The nerve was discontinuous in the distal IAC and a reactive neuroma was resected. The facial nerve was mobilized and an end-to-end coaptation was performed in the CPA using a collagen tubule. The 3-month postoperative MRI showed no residual or recurrent disease. His postoperative balance was improved. Partial facial nerve recovery is not expected prior to 9 to 12 months. The link to the video can be found at: https://youtu.be/C6N8qPwBt2Y .

Etiology of dizziness among patients referring to an Iranian ear, nose and throat clinic

Background and Aim: Dizziness is one the most common complaints of patients in the emergency rooms. It has various etiologies and can lead to falling and other life-threatening injuries, especially in the elderly. Dizziness aff­ects the quality of life and results in negative emotional reactions. This research studied the etiology of dizziness in a three-year study. Methods: This study was conducted on 650 patients with the complaint of dizziness, whose specialists suspected them of having possible vestibular involvement, referred to a tertiary audiology clinic from 2015 to 2018. Videonys­tagmography, electrocochleography and cervical vestibular evoked myogenic potentials were administered. Other medical tests including neu­rologic examinations, blood analysis, and brain imaging were performed based on patients’ complaints. * Corresponding author: Department of Audiology, School of Rehabilitation, Tehran University of Medical Sciences, Piche-Shemiran, Enghelab Ave., Tehran, 1148965141, Iran. Tel: 009821-77530636, E-mail: audiology_zamiri@yahoo.com Results: This was a descriptive study of dizzi­ness prevalence with different etiologies. Patie­nts’ age range was 18-85 years with mean (SD) age: 42.34 (13.12), including 377 (58%) females and 273 (42%) males. Patients’ chief complaints included vertigo in 64.8%, dizziness in 20.2% and imbalance in 15.1%. Vestibular disorders were identified in 49.2% of the referred patients. The patients’ final diagnosis in order of preva­lence were as follows: systemic involvement (292 cases), benign paroxysmal positional ver­tigo (187 cases), unilateral vestibular weakness (63 cases), endolymphatic hydrops (51 cases), bilateral vestibular weakness (37 cases), central involvement (20 cases), cervical (10 cases) and migraine-associated vertigo (8 cases). Conclusion: About 49.2% of the patients refe­rred to the ENT clinic had actual vestibular involvement. Careful history taking, teamwork, and comprehensive evaluations are necessary to differentiate underlying cause and selecting app­ropriate treatment.

Bilateral Vestibular Weakness.

Bilateral vestibular weakness (BVW) is a rare cause of imbalance. Patients with BVW complain of oscillopsia. In approximately half of the patients with BVW, the cause remains undetermined; in the remainder, the most common etiology by far is gentamicin ototoxicity, followed by much rarer entities such as autoimmune inner ear disease, meningitis, bilateral Ménière’s disease, bilateral vestibular neuritis, and bilateral vestibular schwannomas. While a number of bedside tests may raise the suspicion of BVW, the diagnosis should be confirmed by rotatory chair testing. Treatment of BVW is largely supportive. Medications with the unintended effect of vestibular suppression should be avoided.

Prediction of Vestibular Imbalance in Acute Peripheral Vestibulopathy by Measuring Horizontal Ocular Deviation on Magnetic Resonance Imaging.

The aim of the study is to evaluate whether horizontal ocular deviation (OD) from MR imaging in the emergency room (ER) reflects vestibular imbalance, by comparing the horizontal OD in patients with acute vestibulopathy to controls. Retrospective review. A total of 69 patients with acute unilateral peripheral vestibulopathy and 30 healthy subjects were included. Horizontal OD was quantified by using the axial T2-weighted fast-spin echo (FSE) images of the brain at 1.5 T. In the study group, the results of VFTs (videonystagmography [VNG], caloric test, rotary chair test, and cervical vestibular evoked myogenic potentials [cVEMP]) were also reviewed. The averaged angle of right and left horizontal ODs was compared between patients with acute unilateral vestibulopathy and healthy controls. Also, the correlation between horizontal OD and results of VFTs was analyzed in the study group. The averaged angle of horizontal OD in study group (23.7° ± 11.6°) was significantly greater than that of control group (4.27° ± 3.7°) (p < 0.05). Horizontal OD significantly correlated with slow phase velocity of spontaneous nystagmus (SN), the value of caloric paresis (CP) on caloric testing, rotary chair gain, asymmetry ratio of rotary chair test and interaural difference (IAD) of cVEMP, regardless of time intervals between magnetic resonance imaging (MRI) and VFTs. Horizontal OD significantly correlated with parameters of VFT which reflect the vestibular imbalance. Therefore, horizontal OD can be used as an indicator of unilateral peripheral vestibular weakness.

Efficacy of vestibular rehabilitation on quality of life of patients with unilateral vestibular dysfunction

Objective: The aim of this study is to determine the efficacy of vestibular rehabilitation (VR) exercise of patients with uncompensated unilateral peripheral vestibular dysfunction. Materials and Methods: An intervention study was conducted on 20 patients their age ranging from 20 to 60 years. The main complaint of the participants was chronic dizziness (dizziness for >3 months). Dizzy patients were recruited from the Ear, Nose, and Throat department. The study was conducted in the audiovestibular unit. All participants in the study were subjected to basic audiological evaluation and vestibular evaluation (videonystagmography). The Dizziness handicap inventory questionnaire (DHI) was carried out twice (pre and post) rehabilitation program. The VR therapy was performed according to the protocol established by Cawthorne and Cooksey and Norre exercises. Results: All the DHI scores reduced significantly after VR. There were no differences among genders; adults and elderly patients. Conclusion: The result of this study proved the importance and the efficacy of VR. It considered a useful therapeutic approach for improvement in the quality of life of individuals with unilateral peripheral vestibular weakness. The improvement was not influenced by sex, age, or duration of disease. It considered a low-cost, short, and safe treatment technique which can be widely used in outpatients without the need for sophisticated tools.

Short-term galvanic vestibular stimulation promotes functional recovery and neurogenesis in unilaterally labyrinthectomized rats

Current experimental research on the therapeutic effects of galvanic vestibular stimulation (GVS) has mainly focused on neurodegenerative disorders. However, it primarily stimulates the vestibular nuclei and could be potentially effective in modulating imbalance between them in the case of unilateral labyrinthectomy (UL).Fifty male Wistar rats (180–220g) were used in 5 groups of 10: intact, sham, right-UL (RUL; without intervention), and two other right-UL groups with GVS intervention [one group treated with low rate GVS (GVS.LF; 6–7Hz), and the other treated with high rate GVS (GVS.HF; 17–18Hz)]. The UL models were prepared by intratympanic injection of sodium arsanilate. GVS protocols were implemented 30min/day and continued for 14 days via ring-shaped copper electrodes inserted subcutaneously over each mastoid. Functional recovery was assessed by several postural tests including support surface area, landing and air-righting reflexes, and rotarod procedure. Immunohistochemical investigations were performed on ipsi- and contra-lesional medial vestibular nuclei (MVN) using bromodeoxyuridine (BrdU) and Ki67, as markers of cell proliferation.Behavioral evaluations showed significant functional recovery of GVS-treated groups compared to RUL group. The percent of marked cells with BrdU and Ki67 were significantly higher in the ipsilesional MVN of both GVS-treated groups compared with other groups.Our findings confirmed the effectiveness of GVS-intervention in accelerating static and dynamic vestibular compensation. This could be explained by the cell proliferation in ipsilesional MVN cells and rapid rebalancing of the VNs and the modulation of their motor outputs. Therefore, GVS could be promising for rehabilitating patients with unilateral vestibular weakness.

Video head impulse test: a review of the literature.

Video head impulse test (vHIT) is a new testing which able to identify the overt and covert saccades and study the gain of vestibulo-ocular reflex (VOR) of each semicircular canal. The aim of this study is to review the clinical use of vHIT in patients with vestibular disorders in different diseases. PubMed and Cochrane databases were searched for all articles that defined vHIT, compared vHIT with another clinical test, and studied the efficacy of vHIT as diagnostic tools with vestibular disease. 37 articles about vHIT were reviewed. All articles studied the vHIT in English and French languages up to May 2015 were included in the review. Editorial articles or short comments, conference abstracts, animal studies, and language restriction were excluded from the review. Four systems were used in the literature to do the vHIT. vHIT is physiological quick test, which studied the VOR at high frequency of each semicircular canal by calculating the duration ratio between the head impulse and gaze deviation. vHIT is more sensitive than clinical head impulse test (cHIT), especially in patient with isolated covert saccades. vHIT test is diagnostic of vestibular weakness by gain reduction and the appearance of overt and covert saccades. If the vHIT is normal, then caloric test is mandatory to rule out a peripheral origin of vertigo. It is recommended to test each semicircular canal, as isolated vertical canal weakness was identified in the literature. More investigation would be required to determine the evolution of the VOR gain with the progression of the vestibular disease.

Recommendation application for video head impulse test based on fuzzy logic control

Vestibulo-ocular reflex (VOR) is an important biological reflex that controls eye movement to ensure clear vision while the head is in motion. Nowadays, VOR measurement is commonly done with a video head impulse test based on a velocity gain algorithm or a position gain algorithm, in which velocity gain is a VOR calculation on head and eye velocity, whereas position gain is calculated from head and eye position. The aim of this work is first to compare the two algorithms’ performance and to detect covert catch-up saccade, then to propose a stand-alone recommendation application for the patient’s diagnosis. In the first experiment, for ipsilesional and contralesional sides, the calculated position gain (0.94±0.17) is higher than velocity gain (0.84±0.19). Moreover, gain asymmetry of both lesion and intact sides using velocity gain is mostly higher than that from using position gain (four out of five subjects). Consequently, for subjects who have unilateral vestibular neuritis diagnosed from clinical symptoms and a vestibular function test, vestibular weakness is depicted by velocity gain much better than by position gain. Covert catch-up saccade and position gain then are used as inputs for recommendation applications.

Ocular Motor Function in Patients with Bilateral Vestibular Weakness.

Patients with bilateral weakness (BW) have many difficulties in gaze stability that interfere with their normal function. The aim of this study was to evaluate ocular motor functions in patients with BW to better understand the problem of gaze instability in these patients. Patients were referred from the Otolaryngology Department for Vestibular Assessment to our clinic between November 2014 and March 2015. We assessed ocular motor function (gaze, saccade, and smooth pursuit) in patients over the age of 18 years with BW, as verified by a caloric test. Seventy-eight patients completed all the tests. The mean age of patients was 51.9 (±15.9) years, and 47 (60%) were female. Abnormal results were found in five (6.4%), 32 (41%), and seven (9%) patients with respect to gaze, smooth pursuit, and saccade, respectively. There were positive but relatively weak relationships between age and ocular motor results. Patients with BW suffer from dizziness and unsteadiness. These patients have abnormal function in ocular motor (especially smooth pursuit) tests. The ocular motor dysfunction is responsible for gaze instability in static positions such as standing.

The relationship between senile hearing loss and vestibular activity

IntroductionA considerable high number of SNHL patients also suffer from dizziness and related vestibular symptoms. ObjectiveTo evaluate the association of vestibular dysfunction and sensorineural hearing loss (SNHL) in adult patients. MethodsProspective, double-blinded, controlled studies composed by 63 adult patients without any vestibular symptoms or diagnosed vestibular diseases. Audiological status was measured with pure tone audiometry and the vestibular system was tested with vestibular evoked myogenic potential (VEMP). Patients were divided into two groups: a study group (patients with SNHL) and a control group (patients without SNHL). VEMP results of the groups were calculated and compared. ResultsMean P1 (23.54) and N1 (30.70) latencies were prolonged in the study group (p<0.001) and the amplitudes of the study group were significantly reduced (p<0.001). Both parameters of the VEMP test were abnormal in the study group when compared to the control group. ConclusionsThese findings suggest that age-related SNHL may be accompanied by vestibular weakness without any possible predisposing factors for vestibulopathy.

Treatment of Menière’s Disease

Diagnosis of Menière's disease is made with a characteristic patient history, including discrete episodes of vertigo lasting 20min or longer, accompanied by sensorineural hearing loss, which is typically low frequency at first, aural fullness, and tinnitus. Workup includes audiometry, a contrast enhanced MRI of the internal auditory canals, and exclusion of other diseases that can produce similar symptoms, like otosyphilis, autoimmune inner ear disease, perilymphatic fistula, superior semicircular canal syndrome, Lyme disease, multiple sclerosis, vestibular paroxysmia, and temporal bone tumors. A history of migraine should be sought as well because of a high rate of co-occurrence (Rauch, Otolaryngol Clin North Am 43:1011-1017, 2010). Treatment begins with conservative measures, including low salt diet, avoidance of stress and caffeine, and sleep hygiene. Medical therapy with a diuretic is the usual next step. If that fails to control symptoms, then the options of intratympanic (IT) steroids and betahistine are discussed. Next tier treatments include the Meniett device and endolymphatic sac surgery, but the efficacy of both is controversial. If the above measures fail to provide symptomatic control of vertigo, then ablative therapies like intratympanic gentamicin are considered. Rarely, vestibular nerve section or labyrinthectomy is considered for a patient with severe symptoms who does not show a reduction in vestibular function with gentamicin. Benzodiazepines and anti-emetics are used for symptomatic control during vertigo episodes. Rehabilitative options for unilateral vestibular weakness include physical therapy and for unilateral hearing loss include conventional hearing aids, contralateral routing of sound (CROS) and osseointegrated hearing aids.

Cost-effective analysis of unilateral vestibular weakness investigation.

To evaluate the cost-effectiveness of obtaining a magnetic resonance imaging (MRI) in patients with abnormal electronystagmography (ENG) or videonystagmography (VNG) results. Retrospective chart review. Academic specialty center. Patients presenting with vertigo between January 1, 2010, and August 30, 2013. Patients who fit the following abnormal criteria were included in the study: unilateral caloric weakness (≥20%), abnormal ocular motor testing, and nystagmus on positional testing. Patients with abnormal findings who then underwent MRI with gadolinium were evaluated. Of the 1,996 charts reviewed, there were 1,358 patients who met the inclusion criteria. The average age of these patients was 62 years (12-94 yr). The male:female ratio was approximately 1:2. Of the 1,358 patients, 253 received an MRI with the following pathologies: four vestibular schwannomas, three subcortical/periventricular white matter changes suspicious for demyelinating disease, four acute cerebellar/posterior circulation infarct, two vertebral artery narrowing, one pseudomeningocele of internal auditory canal, and two white matter changes indicative of migraines. The positive detection rate on MRI was 5.5% based on MRI findings of treatable pathologies causing vertigo. Average cost of an MRI is $1,200, thereby making the average cost of identifying a patient with a positive MRI finding $15,180. In our study, those patients with a positive MRI had a constellation of symptoms and findings (asymmetric sensorineural hearing loss, tinnitus, vertigo, and abnormal ENG/VNG). Cost-effectiveness can be improved by ordering an MRI only when clinical examination and VNG point toward a central pathology. Clinical examination and appropriate testing should be factored when considering the cost-effectiveness of obtaining an MRI in patients with abnormal ENG/VNG findings.

Vestibular Testing Data in Migraine‐Associated Vertigo

Objectives: (1) Describe data on comprehensive vestibular testing in migraine-associated vertigo patients. (2) Delineate specific findings in vestibular testing that can assist in the diagnosis and treatment of migraine-associated vertigo. Methods: A retrospective case review of individuals diagnosed with migraine-associated vertigo after evaluation by an otologist, a neurologist, and who had vestibular testing between January 1, 2010, and June 31, 2012, at a tertiary referral center. Videonystagmography (VNG), sinusoidal harmonic acceleration (SHA) testing, and cervical vestibular evoked myogenic potential (cVEMP) testing were analyzed. Results: Eighty-three patients met inclusion criteria; 63 had a diagnosis of primary migraine-associated vertigo. An additional 20 patients had a secondary diagnosis including Ménières disease, intracranial hypertension, and a history of cranial surgery (secondary migraine-associated vertigo). The average patient was 49 years old, with 82% being female. There was no statistically significant difference between the 2 groups. Overall, 30% of migraine-associated vertigo patients had abnormal caloric testing with a 60% average unilateral weakness. The unilateral weakness was to the right 77% of the time. When VNG, SHA, and cVEMP testing were combined, 24 patients (29%) had an identifiable vestibular weakness; 75% had a peripheral source and 25% had central vestibular findings. A total of 50% of patients with a peripheral weakness were fully compensated, 33% were partially compensated, and 17% were poorly compensated. Conclusions: In patients with primary and secondary migraine-associated vertigo, approximately two-thirds of patients were found to have normal vestibular testing. When there was an identifiable vestibular weakness, 75% were peripheral with only 50% fully compensated.

Effects of distance and duration on vertical dynamic visual acuity in screening healthy adults and people with vestibular disorders

Dynamic visual acuity (DVA) testing may be a useful, indirect indicator of vestibulo-ocular reflex function. Previous evidence shows that acuity for 2 m targets differs little between patients and normals using a 75 ms display duration and that healthy subjects do not differ in acuity when standing and walking while viewing a far target but they do differ when viewing a near target. Improve the protocol of a screening tool by testing the hypothesis that healthy control subjects and patients and with unilateral peripheral vestibular weakness differ on DVA when viewing far targets while seated. Controls and patients were tested while they were seated in a chair that oscillated vertically at 2 Hz. They viewed a computer screen 4 m away, while stationary and while moving, with viewing times of either 75 ms or 500 ms. The amount of change between static and dynamic conditions did not differ significantly between patients and controls for the 75 ms condition but controls had lower difference scores than patients when using the 500 ms duration. The ROC value was low, 0.68. Compared to historical data using the 75 ms duration at a distance of 2 m, subjects in both diagnostic groups had better visual acuity at the 75 ms/4 m distance. These results suggest that using the longer duration is better for differentiating patients from healthy controls and they support previous evidence showing that near target viewing is more challenging.

Hot or Cold? Is Monothermal Caloric Testing Useful and Cost-Effective?

Videonystagmography (VNG) is used widely in the assessment of balance dysfunction. The full test battery can be time-consuming and can induce patient discomfort. The purpose of this study was to examine the value of monothermal caloric testing in predicting unilateral caloric weakness, as well as abnormal VNG vestibular and nonvestibular eye movement, while considering the time and reimbursement associated with these tests. In a retrospective review of 645 patients who completed a comprehensive VNG test battery with bithermal caloric testing, we calculated the specificity, sensitivity, and predictive values of monothermal caloric testing in relation to bithermal caloric results and noncaloric VNG results. With unilateral vestibular weakness (UVW) defined as a 25% interear difference, warm-air monothermal caloric testing yielded a sensitivity of 87% and a negative predictive value of 90% for predicting UVW. With a 10% UVW definition, the warm-air caloric testing sensitivity increased to 95% and the negative predictive value to 92%. Warm-air monothermal caloric testing had a positive predictive value of 85% and a negative predictive value of 18% for predicting noncaloric VNG findings; cold-air monothermal and bithermal testing displayed similar results. Isolated monothermal testing is a sensitive screening tool for detecting UVW, but is not adequate for predicting noncaloric VNG results.