Involvement of round and oval windows in the vestibular response to pressure changes in the middle ear of guinea pigs

Evaluation of Balance with Computerized Dynamic Posturography in Children with Otitis Media

BACKGROUND

Otitis media with effusion (OME) frequently leads to vestibular symptoms in children. However, young children face difficulty expressing their symptoms due to their limited language abilities.

METHODS

The balance of study and patient group evaluated with computer dynamic posturography, single-leg stance test with eyes closed and regular Head Impulse Test. The study group was assessed once again after the insertion of a ventilation tube two months later.

RESULTS

In the Sensory Organization Test, the scores for conditions 5, 6, and composite equilibrium of the preoperative patient group were notably lower compared with both the control and postoperative patient groups (p < 0.05). Additionally, a significant correlation was found between single-leg stance test with eyes closed results and conditions 5, 6, and composite equilibrium scores.

CONCLUSION

The impact of OME on the vestibular system is negative. This effect can be objectively assessed using Computer Dynamic Posturography and following tube insertion, there is a notable improvement in vestibular function. Furthermore, the single-leg stance (SLS) test with eyes closed has shown its reliability in assessing balance disorders, notably in children with OME.

LEVEL OF EVIDENCE

Level 2 Laryngoscope, 2024.

Pediatric Vestibular Assessment: Clinical Framework

OBJECTIVES

Although vestibular deficits can have severe repercussions on the early motor development in children, vestibular assessment in young children has not yet been routinely integrated in clinical practice and clear diagnostic criteria to detect early vestibular deficits are lacking. In young children, specific adjustments of the test protocol are needed, and normative data are age-dependent as the vestibular pathways mature through childhood. Therefore, this study aims to demonstrate the feasibility of an extensive age-dependent vestibular test battery, to provide pediatric normative data with the concurrent age trends, and to offer a clinical framework for pediatric vestibular testing.

DESIGN

This normative study included 133 healthy children below the age of 4 years (mean: 22 mo, standard deviation: 12.3 mo, range: 5-47 mo) without history of hearing loss or vestibular symptoms. Children were divided into four age categories: 38 children younger than 1 year old, 37 one-year olds, 33 two-year olds, and 25 three-year olds. Children younger than 3 years of age were examined with the video Head Impulse Test (vHIT) of the horizontal semicircular canals, cervical vestibular evoked myogenic potentials (cVEMP) with bone conduction stimuli, and the rotatory test at 0.16, 0.04, and 0.01 Hz. In 3-year old children, the vHIT of the vertical semicircular canals and ocular vestibular evoked myogenic potentials (oVEMP) using a minishaker were added to the protocol.

RESULTS

The horizontal vHIT appeared to be the most feasible test across age categories, except for children younger than 1-year old in which the success rate was the highest for the cVEMP. Success rates of the rotatory test varied the most across age categories. Age trends were found for the vHIT as the mean vestibulo-ocular reflex (VOR) gain increased significantly with age (r = 0.446, p < 0.001). Concerning the cVEMP, a significant increase with age was found for latency P1 (r = 0.420, p < 0.001), rectified interpeak amplitude P1-N1 (r = 0.574, p < 0.001), and averaged electromyographic (EMG) activity (r = 0.430, p < 0.001), whereas age trends for the latency N1 were less pronounced (r = 0.264, p = 0.004). Overall, the response parameters of the rotatory test did not show significant age effects ( p > 0.01), except for the phase at 0.01 Hz (r = 0.578, p < 0.001). Based on the reported success rates and age-dependent normative vestibular data, straightforward cutoff criteria were proposed (vHIT VOR gain < 0.7, cVEMP rectified interpeak amplitude < 1.3, oVEMP interpeak amplitude < 10 µV) with accompanying clinical recommendations to diagnose early vestibular impairment.

CONCLUSIONS

In this large cohort of typically developing children below the age of 4 years, the vHIT and cVEMP were the most feasible vestibular tests. Moreover, the age-dependent normative vestibular data could specify age trends in this group of young children. Finally, based on the current results and clinical experience of more than ten years at the Ghent University Hospital (Belgium), a clinical framework to diagnose early vestibular deficits in young patients is proposed.

Tympanostomy tube placement for pressure-sensitive vertigo

Objective

To evaluate tympanostomy tube placement in patients with pressure-sensitive vertigo.

Methods

Retrospective case series.

Results

Six patients with pressure-sensitive vertigo reported resolution of their vertigo and other vestibular symptoms after placement of the tympanostomy tubes. All recurrences of symptoms were due to either extrusion or plugging of the tubes. All patients fulfilled the criteria for vestibular migraine. None of the patients had superior canal dehiscence on imaging or precedent event that triggered the problem, and all had a negative fistula test.

Conclusion

Tympanostomy tube placement should be considered in selected patients with vertigo exacerbated by seemingly small changes in atmospheric pressure (e.g., just prior to thunderstorms, air travel, or travel to the mountains). By eliminating the capability of the tympanic membrane to sense changes in pressure with a tube, patients with pressure-induced vertigo (in the absence of perilymph fistula or superior canal dehiscence) may have relief of their symptoms.

Level of Evidence IV

Lowering barometric pressure induces neuronal activation in the superior vestibular nucleus in mice

Weather changes accompanied by decreases in barometric pressure are suggested to trigger meteoropathy, i.e., weather-related pain. We previously reported that neuropathic pain-related behavior in rats is aggravated by lowering barometric pressure, and that this effect is abolished by inner ear lesions. These results suggest that mechanisms that increase vestibular neuronal activity may parallel those that contribute to meteoropathy generation. However, it remains unknown whether changes in barometric pressure activate vestibular neuronal activity. To address this issue, we used expression of c-Fos protein as a marker for neural activation. Male and female mice were placed in a climatic chamber, and the barometric pressure was lowered by 40 hPa, from 1013 hPa, for 50 min (LP stimulation). The total number of c-Fos-positive cells in the vestibular nuclei was counted bilaterally after LP stimulation. We also video-recorded mouse behaviors and calculated the total activity score during the LP stimulation. LP stimulation resulted in significant c-Fos expression in the superior vestibular nucleus (SuVe) of male and female mice. There was no effect of LP stimulation on the total activity score. These data show that distinct neurons in the SuVe respond to LP stimulation. Similar mechanisms may contribute to the generation of meteoropathy in humans.

Dizziness in a Tertiary Care Centre in Sikkim: Our Experience and Limitations

Dizziness is a common symptom and though most of the causes are benign yet some may be potentially life threatening. Diagnosis can be a challenge sometimes due to lack of dedicated vestibular lab and injudicious use of vestibular suppressant medications. A 2 year retrospective study of the hospital records from September 2014 to August 2016 was done to study the causes of dizziness and the limitations and challenges in the diagnosis. 75 complete records of patients presenting with dizziness were accessed and analysed. 54.7% of the patients were males and most patients were young adults. Most of the cases were benign and Benign paroxysmal positional vertigo was the commonest diagnosed case (20%). Potentially life threatening cases diagnosed were cerebellar infarct and posterior fossa space occupying lesion (5.3%). Complete evaluation of a dizzy patient must be done to arrive at a causal diagnosis. Injudicious use of vestibular sedatives should be discouraged. Proper training and education to the primary care physician should be imparted so that they can adopt a practical approach for evaluation and management of a dizzy person.

A case of patulous Eustachian tube associated with dizziness induced by nasal respiration

OBJECTIVE

To determine the relationship between Eustachian tube function and inner ear function in patulous Eustachian tube (pET).

METHODS

We encountered a patient with pET accompanied by dizziness that was induced by nasal respiration. Eye movements were recorded using video-oculography, and Eustachian tube function was assessed using a Eustachian tube function analyzer. Horizontal and vertical components of pupil position were assessed to test fixation, positional, and positioning nystagmus. Impedance testing with a Eustachian tube function analyzer was performed to confirm tympanometry results. We recorded these outcomes until the patient's symptoms improved.

RESULTS

When pET improved, the patient's symptoms were alleviated.

CONCLUSION

The present pET patient had mild vestibular symptoms. Therefore, pET patients with dizziness might be misdiagnosed with, for example, superior semicircular canal dehiscence, psychogenic vertigo, or Ménière's disease. For patients with few clinical symptoms or laboratory findings, clinicians need to consider dizziness-induced pET as a possible diagnosis.

Altered eustachian tube function in SCUBA divers with alternobaric vertigo

OBJECTIVES

The number of people participating in sport self-contained underwater breathing apparatus (SCUBA) diving has increased tremendously, bringing with it a rise in diving accidents. Alternobaric vertigo (AV) is a common problem in SCUBA divers. We investigated the relationship between Eustachian tube function and incidence of AV in sport SCUBA divers. We also followed the progress of these divers after Eustachian tube function improved.

METHOD

Forty-four patients who experienced a SCUBA diving accident affecting the middle ear (11 men and 33 women; mean ± SD: 37.5 ± 11.5 yr) and 20 healthy volunteer divers who did not experience an accident (6 men and 14 women; mean ± SD: 33.5 ± 13.9 yr) were compared. We divided the divers with an accident into two groups (those with AV vs. those without) and then compared the two groups. All patients regularly underwent Eustachian tube function tests (sonotubometry and impedance test).

RESULTS

In sonotubometry and impedance testing, the mean duration (p < 0.001), amplitude (p < 0.002), and maximum air content (p < 0.05) of divers who experienced a diving accident were significantly different from those of healthy volunteers. However, these parameters in divers with AV did not differ significantly from those in divers without AV. In 7 of 15 divers, vestibular symptoms disappeared immediately after ascent. In the remaining eight divers, however, vertigo/dizziness persisted and even was observed at their first clinic visit.

CONCLUSION

To prevent AV or barotraumas in SCUBA divers, we recommend a thorough Eustachian tube function evaluation. Any dysfunction should be treated before engaging in SCUBA diving.

Prevalence and diagnosis of vestibular disorders in children: a review

OBJECTIVES

To systematically review and discuss the main pathologies associated with vertigo and dizziness in children, paying particular attention to recent advances in diagnosis and therapy.

METHODS

One appropriate string was run on PubMed to retrieve articles dealing with the topics mentioned above. A cross-check was performed on citations and full-text articles found using the selected inclusion and exclusion criteria. A non-comparative meta-analysis concerning the rate of singular vertiginous forms was performed.

RESULTS

Ten articles were identified comprising a total of 724 subjects. Overall, the articles we analyzed indicated benign paroxysmal vertigo of childhood (18.7%) and migraine-associated vertigo (17.6%) as the two main entities connected with vertigo and dizziness in children. Head trauma (14%) was the third most common cause of vertigo. The mean (95% CI) rate of every vertiginous form was also calculated in relation to the nine studies analyzed with vestibular migraine (27.82%), benign paroxysmal vertigo (15.68%) and vestibular neuritis (9.81%) being the three most common forms. There appeared to be a paucity of recent literature concerning the development of new diagnostic methods and therapies.

CONCLUSIONS

On the basis of the literature study, when evaluating a young patient with vertigo and dizziness, the otolaryngologist should be aware that, in children, these symptoms are often connected to different pathologies in comparison to the entities observed in the adult population.

[Vertigo in children and adolescents. Part 1: Epidemiology and diagnosis of peripheral vestibular disorders]

Migraine equivalents are the most common cause of vertigo in children and adolescents. Vertigo and balance disorders occur frequently in children during the course of otitis media, middle ear effusion and viral infections. If otitis media is associated with reduced hearing and vertigo, labyrinthitis must be considered. Craniocerebral injury is another important cause of vertigo in children. In contrast, spontaneous benign paroxysmal positional vertigo is rare among children. The isolated cases of endolymphatic hydrops that occur in children are usually secondary. Perilymph fistula can have congenital, infectious or trauma-related causes. The following characteristics are useful for differentiating between different vertiginous syndromes: type and duration of vertigo, triggering/aggravating/alleviating factors and accompanying symptoms. A neuro-ophthalmologic examination is essential to rule out central vestibular disorders.

Persistent alternobaric vertigo at ground level

We recently encountered a 15-year-old female with bilateral tympanostomy tubes who manifested persistent severe vertigo, at ground level, secondary to a unilateral middle-ear pressure of +200 mm H(2)O elicited by an obstructed tympanostomy tube in the presence of chronic nasal obstruction. We believe this is a previously unreported scenario in which closed-nose swallowing insufflated air into her middle ears, resulting in sustained positive middle-ear pressure in the ear with the obstructed tube. Swallowing, when the nose is obstructed, can result in abnormal negative or positive pressures in the middle ear, which has been termed the Toynbee phenomenon. In patients who have vertigo, the possibility that nasal obstruction and the Toynbee phenomenon are involved should be considered.

The inner ear is involved in the aggravation of nociceptive behavior induced by lowering barometric pressure of nerve injured rats

Patients suffering from neuropathic pain often complain of pain aggravation when the weather is changing. The exact mechanism for weather change-induced pain has not been clarified. We have previously demonstrated that experimentally lowering barometric pressure (LP) intensifies pain-related behaviors in rats with chronic constriction injury (CCI). In the present experiment we examined whether this pain aggravating effect of LP exposure in nerve injured rats is still present after lesioning of the inner ear. We used both CCI and spinal nerve ligation (SNL) models for this study. We injected into the middle ear sodium arsanilate solution (100mg/ml, 50microl/ear), which is known to degenerate vestibular hair cells, under anesthesia the day before surgery. Rats were exposed to LP (27hPa decrease over 8min) 7-9 days after CCI or 5-8 days after SNL surgery, and pain-related behavior (number of paw lifts induced by von Frey hair stimuli) was measured. When the inner ear lesioned SNL or CCI rats were exposed to LP, they showed no augmentation of pain-related behavior. On the other hand, the pain aggravating effect of a temperature decrease (from 24 to 17 degrees C) was maintained in both SNL and CCI rats. These results suggest that the barometric sensor/sensing system influencing nociceptive behavior during LP in rats is located in the inner ear.

Alternobaric vertigo: prevalence in Portuguese Air Force pilots

CONCLUSION

Having found a prevalence rate of alternobaric vertigo in Portuguese Air Force pilots that is somewhat higher than previously reported, we underline the importance of implementing education on the management of this condition as part of routine Air Force pilot training programs.

OBJECTIVES

Alternobaric vertigo is a condition in which transient vertigo with spatial disorientation occurs suddenly during flying or diving activities, caused by bilateral asymmetrical changes in middle ear pressure. Its prevalence is very likely underestimated and under-reported, with the 10-17% prevalence rate mentioned in early literature not being challenged by recent data.

SUBJECTS AND METHODS

To assess its actual prevalence, the authors requested all high performance aircraft pilots presently on active duty in the Portuguese Air Force to anonymously answer a questionnaire on alternobaric vertigo symptoms, after a short briefing on the subject.

RESULTS

A 29% prevalence rate of in-flight episodes consistent with alternobaric vertigo was obtained.

Change of guinea pig inner ear pressure by square wave middle ear cavity pressure variation

The inner ear fluid pressure of guinea pigs was measured during square wave middle ear cavity pressure variation. Time constants were derived for the slopes of the inner ear pressure recovery curves after middle ear pressure change. A "single exponential" function did not fit well and therefore more complicated functions were used for this purpose. For middle ear pressure increasing from zero to a few centimetres of water, returning to zero again, decreasing from zero to minus a few centimetres of water and then returning to zero again, time constants for the inner ear pressure recovery curves were on average 15.0, 8.6, 2.5 and 2.5 s, respectively. The results could not be described using a linear model with constant window membrane compliance and cochlear aqueduct flow resistance. A possible explanation for the large difference in time constants for positive or negative middle ear pressure changes is a dependence on aqueduct flow resistance or round window membrane position.

Tympanic pressure gradients and otoacoustic emissions

OBJECTIVE

The purpose of this study was to investigate the immediate effects of tympanic over- and under-pressure, induced by variations in ambient pressure on click-evoked otoacoustic emissions (CEOAEs) in healthy individuals. It was of particular interest to elucidate whether changes in the CEOAE response in both spectral and time domains could be attributed not only to tympanic, but also to cochlear influence.

DESIGN

Nine healthy subjects with normal hearing and middle ear pressure were exposed to ambient pressure changes in a pressure chamber. The pressure was progressively changed in 100 daPa steps to accomplish an increase and a decrease in tympanic pressure. Pressure equilibration of the middle ear was avoided. The relative tympanic over- and under-pressure (+/- 320daPa) was monitored by tympanometry and the CEOAEs recorded at every step of tympanic pressure change.

RESULTS

There was a statistically significant reduction of the otoacoustic emission (OAE) response levels and reproducibility already at 100 daPa of ambient pressure change. The OAE response was progressively reduced by increased pressure gradients. The CEOAEs recorded during progressive tympanic over- and under-pressure also had increasingly shorter latencies. These changes of the OAE response characteristics were most pronounced in the 750 to 3000 Hz frequency bands.

CONCLUSIONS

The progressive attenuation of the OAE response and the concomitant shortening of the OAE response latencies were observed during a combination of altered middle and inner ear pressure. Although the middle and inner ear influence cannot be separated we suggest, based on our findings, that the shortening of latencies may partly be caused by inner ear pressure changes and stiffening of the labyrinthine membranes. Further studies are needed to more specifically clarify the relative contribution of the tympanic and labyrinthine influence, respectively, for the various aspects of pressure influence on the OAE response.