Scientific Study

Current Research

Science Leads to Answers

Want to keep up-to-date on current research into the diagnosis and treatment of vestibular disorders? Search the National Institutes of Health Library of Medicine database. 

Following are summaries of select research papers.

*VeDA partners with the Journal of Vestibular Research to give a platform to the latest developments in vestibular research.Journal of Vestibular Research


Vestibular migraine and recurrent vertigo of childhood

Diagnostic criteria consensus document of the Classification Committee of Vestibular Disorders of the Bárány Society and the International Headache Society

“Benign Paroxysmal Vertigo of Childhood” and Vestibular Migraine (VM) are believed to be the most frequent causes of vertigo and dizziness in children. “Benign Paroxysmal Vertigo of Childhood” is defined as “recurrent spontaneous attacks of vertigo which may be associated with vomiting, pallor, fearfulness, postural imbalance, ataxia, and/or nystagmus in otherwise healthy children.” VM is defined as at least five episodes with vestibular symptoms of moderate/severe intensity, lasting between five minutes and 72 hours, with migraine headaches or symptoms during most of the attacks. Pediatric patients may likely fit both of these criteria.

This consensus document aims to classify “Vestibular Migraine of Childhood” (VMC) and “probable Vestibular Migraine of Childhood.” Also, this article strives to introduce a new term and classification of recurrent vertigo in children, named “Recurrent Vertigo of Childhood” (RVC) which should replace the term “Benign Paroxysmal Vertigo of Childhood.” This is part of an ongoing project to develop an International Classification of Vestibular Disorders (ICVD), being overseen by the Classification Committee of the Bárány Society and the International Headache Society. The Diagnostic Criteria are listed in the chart below:

Diagnostic Criteria

Vestibular Migraine of Childhood (VMC) Probable Vestibular Migraine of Childhood (probable VMC) Recurrent Vertigo of Childhood (RVC)
At least 5 episodes with vestibular symptoms moderate/severe intensity, lasting 5 min to 72 hrs At least 3 episodes with vestibular symptoms moderate/severe intensity, lasting 5 min to 72 hrs At least 3 episodes with vestibular symptoms moderate/severe intensity, lasting 1 min to 72 hrs
Current or past history of migraine with or without aura** Only one of the criteria listed under VMC** None of the criteria listed under VMC**
At least ½ episodes associated with: headache on one side, pulsating quality, moderate/severe pain intensity; or aggravated by physical activity; or light/sound sensitivity; or visual aura**
Age < 18 years Age < 18 years Age < 18 years
Not better accounted for by another headache/vestibular disorder or other condition Not better accounted for by another headache/vestibular disorder or other condition Not better accounted for by another headache/vestibular disorder or other condition

 

Children typically have a more difficult time describing their vestibular symptoms compared to adults. Vestibular symptoms can include spontaneous vertigo, positional vertigo, visually-induced vertigo, head motion-induced vertigo, or head motion-induced dizziness with nausea. Vestibular symptoms of moderate intensity interfere with, but do not prevent daily activities. Vestibular symptoms of severe intensity prevent continuation of daily activities.

There are many other conditions to consider in children experiencing vestibular symptoms, including psychiatric causes, benign paroxysmal positional vertigo, vestibular paroxysmia, Ménière’s disease, vestibular epilepsy/epileptic vertigo/nystagmus, episodic ataxias, tumors, orthostatic (blood pressure related) dizziness, and recurrent ear infections. Consult your child’s doctor to determine what additional testing and consultations may be required to arrive at an appropriate diagnosis and to move forward with suitable treatment strategies.

Summary written by Danielle Beatty, DPT.

Source: van de Berg, Raymond et al. Vestibular Migraine and Recurrent Vertigo of Childhood: Diagnostic Criteria Consensus Document of the Classification Committee of Vestibular Disorders of the Bárány Society and the International Headache Society. Journal of Vestibular Research, 31 (1) : 1–9.


Mal de Debarquement Syndrome Diagnostic Criteria

The Barany Society and the Classification Committee of the Barany Society (CCBS) have created diagnostic criteria for Mal de Débarquement Syndrome (MdDS) with the goal of creating common terminology for diagnosis and research. These criteria will be included in the International Classification of Vestibular Disorders (ICVD).

Vestibular disorders can be due to functional alterations within the central nervous system without a concurrent structural injury, so it is important to determine the differences between MdDS and other similar functional vestibular disorders. MdDS has appeared in the medical literature for over 300 years with individuals describing symptoms as non-spinning vertigo, dizziness, and imbalance after sea voyages.

In March 2017, the CCBS introduced a format for developing criteria for MdDS. In June 2018, a committee of international specialists was formed and drafted criteria. The draft was presented to CCBS members in June 2019, and then the completed criteria were presented to the Barany Society membership in January 2020.

In terms of diagnostic criteria, there are differences between short-term land sickness lasting less than 48 hours and the syndrome lasting beyond 48 hours. Therefore, the criteria created constitute the disorder of MdDS:

  1. Non-spinning vertigo characterized by an oscillatory perception (‘rocking,’ ‘bobbing,’ or ‘swaying’) present continuously or for most of the day.
  2. Onset occurs within 48 hours after the end of exposure to passive motion.
  3. Symptoms temporarily reduce with exposure to passive motion.
  4. Symptoms continue for more than 48 hours.
    1. MdDS in evolution: Symptoms are ongoing but the observation period has been less than one month.
    2. Transient MdDS: Symptoms resolve at or before one month and the observation period extends at least to the resolution point.
    3. Persistent MdDS: Symptoms last for more than one month.
  5. Symptoms not better accounted for by another disease or disorder.

MdDS is frequently misdiagnosed as other disorders in the general medical community. It is significantly represented in women with onset peak between 40–49 years.  More than one lifetime episode of MdDS can occur with subsequent episodes usually lasting longer than previous episodes and a decreased chance of a spontaneous recovery. Symptom severity can fluctuate due to multiple factors, including stress, sleep deprivation, and hormonal factors. The vertigo of MdDS persists in different body positions. Common additional symptoms include sensations of spatial disorientation, fatigue, visual motion intolerance, headaches, and anxiety. Diagnosis is based on clinical history alone. There are no findings on physical examination, laboratory testing, or imaging that are indicative of MdDS. Differential diagnoses include vestibular migraine, motion sickness, and persistent postural perceptual dizziness.

Future research investigations are required to bring into line foundations of MdDS with ICVD nomenclature and to more clearly identify its differences from similar disorders.

Creating a uniform set of diagnostic criteria for MdDS would improve accuracy of diagnosis in order to apply the appropriate treatment strategies in a timely manner.

Source: Cha, Y., Baloh, R. W., Cho, C., Magnusson, M., Song, J., Strupp, M., Wuytsg, F., Staab, J. P. (2020). Mal de débarquement syndrome diagnostic criteria: Consensus document of the Classification Committee of the Bárány Society. Journal of Vestibular Research, 30(5), 285-293. doi:10.3233/ves-200714

Summary written by Sonia Vovan, MPT.


Gaze Stability in Young Adults with a History of Previous Concussion

Background: The period immediately following a concussion generally receives the most attention and scrutiny, as many symptoms resolve within 7-10 days. However, recent studies have shown that concussion symptoms can persist for months after the initial injury.

The Vestibular System: The vestibular and visual systems work together to calibrate eye and head movements. A disruption in the normal functioning of the vestibular system, the visual system, or the pathway that integrates these systems can result in slippage of the visual image on the retina, which can affect gaze stability.

A normally functioning vestibular system helps maintain gaze stability while the head is in motion through the vestibulo-ocular reflex (VOR), which produces commensurate eye movements in a direction opposite to head movements. Blurred vision results when there is a dysfunction in the VOR and images are not held steady on the retina. 

Purpose: To study the long-term impact of concussion on gaze stability and sleep.

Methods: Dynamic Visual Acuity (DVA, the ability to see clearly during head movement) was measured using a computerized test that detects peripheral vestibular impairment. All participants completed two questionnaires to assess sleep quality and daytime sleepiness. For those with a history of concussion, the Post-Concussion Symptom Scale (PCSS) was used to measure 22 self-reported symptoms, such as dizziness and headache. Time since injury and number of concussions were also recorded.

Results: Mean DVA was significantly lower in chronic concussion patients compared to healthy young adults. The concussion group also reported lower sleep quality.

SummaryThis paper showed a significant difference in dynamic visual acuity in young adults with a history of concussion. Loss of DVA is associated with lower sleep quality and increased sleepiness. Further studies are needed to evaluate the benefit of vestibular rehabilitation and early sleep education on this population.

Source: D’Silva, L. J., Siengsukon, C. F., & Devos, H. (2020). Gaze stability in young adults with previous concussion history. Journal of Vestibular Research, 30(4), 259-266.

Summary prepared by: 

Mona Fazzina, PT, DPT

Certificate in Vestibular Rehabilitation, 2020

Board Certified Clinical Specialist in Geriatric Physical Therapy (GCS) 

Certified Exercise Expert for Aging Adults (CEEAA)


Summary of Balance performance when responding to visual stimuli in patients with Benign Paroxysmal Positional Vertigo

BPPV is a common condition in which the inner ear crystals (otoconia) become displaced and land in an area where they are not supposed to be. This confuses the brain and causes vertigo whenever the head moves to a certain position.

Although most of the time vertigo symptoms in BPPV occur immediately following head movements, many patients complain of imbalance throughout the day. That is most likely related to the fact that we have to constantly monitor our orientation by integrating information from our vestibular system – our eyes, muscles and joints. If the vestibular system does not provide accurate information about our orientation we may develop an altered sensation of balance with respect to the surrounding environment. In particular, the mismatch between the vestibular and visual information may lead to visually-induced imbalance.

In this study, 30 patients with a history of BPPV were assessed BEFORE canalith repositioning maneuvers. The diagnosis of BPPV was confirmed by positioning tests and by excluding other vestibular and central abnormalities. Two other groups, one consisting of 30 healthy individuals ages 20 to 25 years and another consisting of 30 healthy individuals ages greater than 60 years, were included in the study.

The test involved the subjects standing on a plate that measured body movements in the front-to-back and side-to-side directions. The test was conducted under three different conditions of eyes open without goggles while watching a static image displayed in head-mounted goggles and while watching a moving image with the same goggles. Each test condition lasted 30 seconds.

The study demonstrated that both BPPV patients and older healthy subjects had more body movements compared to the younger group. Increased movements in the front-to-back direction occurred for all visual conditions, whereas increased movements in the side-side directions occurred only during the first 20 seconds of the test. In addition, body movements in the front-to-back direction were influenced by the static and moving images.

Previous studies have shown that the vestibular system deteriorates with aging. Furthermore, older individuals become more dependent on vision for maintaining balance. This study demonstrates that BPPV patients behave similarly to the older individuals. Increased body sway in patients with BPPV may increase the risk of fall in these patients. Therefore, balance training exercises may help these patients use more effective postural control strategies.

It should be noted that the value of this paper is diminished because it did not repeat the test after repositioning maneuvers. Therefore, it is not clear if these findings are related to misplaced particles that can be resolved by repositioning maneuvers or if they reflect a long-term deterioration of the vestibular structures.

Summary written by Jennifer Robbins, MPT, with contributions from Kamran Barin, PhD

Source: Journal of Vestibular Research 30 (2020) 267–274 267 DOI:10.3233/VES-200709

Balance performance when responding to visual stimuli in patients with Benign Paroxysmal Positional Vertigo (BPPV) Sang-I Lin, Yi-Ju Tsai and Pei-Yun Lee∗
Department of Physical Therapy, College of Medicine, National Cheng Kung University, Tainan, Taiwan


Cost-effectiveness of internet-based vestibular rehabilitation with and without physiotherapy support for adults aged 50 and older with a chronic vestibular syndrome in general practice

Patients with vestibular symptoms such as vertigo, dizziness, and imbalance often seek treatment from their primary care physicians, who may order various testing and treatment. Having vestibular symptoms can also affect one’s ability to work. Therefore, the overall cost in managing vestibular conditions can be quite high. The treatment of choice according to guidelines in the US, UK, and the Netherlands is vestibular rehabilitation (VR). This is an exercise-based program administered by a healthcare professional, which is designed to reduce vestibular symptoms, improve balance, and restore the ability to perform daily activities.

Individuals have used internet-based programs to facilitate vestibular rehabilitation. These programs are often inexpensive, easily accessible, and can be personalized according to the needs of each patient. Combining an internet-based intervention with face-to-face support by a healthcare professional is called blended care. Stand-alone internet-based programs are generally less expensive than blended internet-based programs, but the risk of non-adherence is also higher. This study aimed to evaluate the cost-effectiveness of stand-alone and blended internet-based VR versus usual care for general practice patients with a chronic vestibular syndrome.

Participants were selected from 59 general practices in the Netherlands, for a total of 322 participants, aged 50 years and older, having symptoms for at least one month that were exacerbated or triggered by head movements. Subjects were placed into one of three groups. The internet-based VR group had treatment which lasted for 6 weeks, with weekly online sessions with daily VR exercises. The patients logged the intensity of their symptoms, and the program was modified for the next week depending on patients’ report. Participants in the blended VR group received the same internet-based VR treatment, however they were also visited twice at home by a trained physiotherapist (physical therapist). Participants in the usual care group received standard care by their general practitioners. Researchers looked at patients’ quality of life, vestibular symptoms, and medical and productivity costs. Costs included healthcare costs, costs related to help from family/friends, reduced efficiency at work due to symptoms, and missing work/housework due to symptoms.

Researchers found that there were significant improvements in vestibular symptoms for the stand-alone and blended VR groups at 6 months follow-up compared with usual care participants. In using the Dizziness Handicap Inventory (DHI), which quantifies the impact of symptoms on daily life, there was not a significant difference in score improvement when comparing the three groups. Total societal costs for both the VR groups were higher than the costs of usual care, however this was not a significant difference based on calculations. The researchers included all healthcare costs into their calculation, so some of these expenses may have been from care that was not due to vestibular symptoms. The researchers conducted further analysis attempting to exclude costs that were likely unrelated to vestibular symptoms, and the stand-alone VR group became less expensive when compared to usual care.  Researchers also assessed quality of life through a questionnaire and used this to calculate quality-adjusted life years (QALYs). One QALY is equivalent to one life-year of perfect health. A gain in QALYs was then considered an improvement in the quantity and/or quality of life. Both VR groups did demonstrate a gain in QALYs compared to usual care, however this change was not significant.

This study followed participants for a period of only 6 months, so it is hard to determine the long-term cost effectiveness between the three groups and whether one would be superior. Also, adherence to any exercise program can be quite a challenge, and it is unclear whether the researchers verified patients’ consistency with performing their VR program. Healthcare costs will also vary from country to country.

In conclusion, stand-alone and blended internet based vestibular rehabilitation both led to gains in QALYs compared to usual care (however not significant). Both VR groups demonstrated a significant reduction in vestibular symptoms compared to usual care. Usual care was determined to be lower cost compared to both VR groups; however, this was not a significant difference. Vestibular rehabilitation, whether internet based, in person, or a combination, is an important treatment regimen for those with vestibular symptoms. The researchers concluded, “Internet-based VR is an easily accessible, effective form of treatment that could potentially improve care for a largely undertreated group of patients with a chronic vestibular syndrome in general practice.”

Summary by Danielle Beatty, DPT

Source: van Vugt VA, Bosmans JE, Finch AP, et al

Cost-effectiveness of internet-based vestibular rehabilitation with and without physiotherapy support for adults aged 50 and older with a chronic vestibular syndrome in general practice

BMJ Open 2020;10:e035583. doi: 10.1136/bmjopen-2019-035583


Implantation Criteria for Vestibular Implant Research

The paper reviewed proposes criteria for determining which patients with bilateral vestibulopathy (BVP) might be good candidates to participate in research studying the efficacy of vestibular implants (VI).

BVP is a condition characterized by significantly reduced vestibular function in both ears. Symptoms include dizziness, imbalance, and oscillopsia (a visual blurring that occurs during head movements). BVP negatively affects the patient’s quality of life and increases their risk of falls. BVP can be caused by a number of secondary conditions, including ototoxicity and autoimmune disorders, or occur for unknown reasons. Current treatments include vestibular rehabilitation therapy to improve balance and visual acuity during head movements. Unfortunately, most BVP patients do not regain full function.

The vestibular implant (VI) has been proposed to facilitate restoration of vestibular function for BVP patients who meet stringent criteria. The VI is a prosthetic device that provides continuous, long-term, motion-modulated stimulation via electrodes to the three semi-circular canals in the inner ear . VI surgery is irreversible. Therefore, a comprehensive risk-benefit analysis is critical for determining which patients might benefit from this procedure, despite the potential risks.

This paper sought to provide a basis for determining criteria for VI as a foundation for future research.

VI implantation criteria are not the same as diagnostic criteria for BVP. The major difference between VI-implantation criteria and the approved diagnostic criteria for BVP is that all included vestibular tests of semicircular canal function (head impulse test, caloric test, and rotatory chair test) need to show significant impairments of vestibular function in the implantation criteria.

The provisional VI criteria recommended include (but are not limited to):

1. Chronic vestibular syndrome with unsteadiness when walking or standing, especially in darkness or on uneven ground, and movement-induced blurred vision.
2. Symptoms are greatest during head movement.
3. Bilaterally (on both sides) reduced VOR (vestibular ocular reflex – reflexive eye movements used for stabilizing your vision).
4. Symptoms are not accounted for by another disease.
5. Test results to demonstrate deficiencies in all three tests of semicircular function: the head impulse test, the caloric test and the rotatory chair test.

The authors state that the VI is not a treatment technique for decreased function of the vestibular nerve or the central vestibular system.

VI surgery can adversely affect residual vestibular function irreversibly. Other potential and serious complications from VI surgery include hearing loss and facial nerve paralysis.

For appropriate patients, the success in benefitting from the VI depends in part on the patient’s understanding and ability to use it, tolerate it, and participate actively and effectively in the post-implantation rehabilitation phase. A six-month waiting period following onset of symptoms is strongly recommended to determine the course and prognosis of BVP before considering VI. The entire vestibular team must agree on the operability of the patient. Psychological and psychiatric disorders complicate the process of evaluating a patient for the VI.

There are two versions of the VI. One to restore just vestibular function and another that includes a cochlear implant, which could also help restore hearing .

Source: Berg R, Ramos A, van Rompaey V, et al. The vestibular implant: Opinion statement on implantation criteria for research. Journal of Vestibular Research: Equilibrium & Orientation. 2020;30(3):213. https://archive-ouverte.unige.ch/unige:138787. Accessed Aug 24, 2020. doi: 10.3233/VES-200701.

Summary prepared by: Mona Fazzina, PT, DPT


Dizziness in Patients with Cognitive Impairment

This paper attempted to determine the effect of dizziness on cognitive function. The paper made the assumption that cognitive decline correlates to the increased perception of dizziness. The result was that cognitive decline could exist without dizziness, but the presence of dizziness increased the cognitive impairment if they coexisted in the same person. The study also confirmed that postural instability is an important determinant of dizziness. This is not a new thought, as patients will often use the word “dizzy” when referring to postural stability.

Source: Lee, Ho-Won, Lim, Yong-Hyun, and Kim, Sung-Hee. ‘Dizziness in Patients with Cognitive Impairment’. 1 Jan. 2020 : 17 – 23.

Summary written by Dr. Dennis Fitzgerald


Characteristics of Assessment and Treatment in Benign Paroxysmal Positional Vertigo (BPPV)

This article explains the results of a study performed in a physiotherapy clinic in Australia intended to explore the incidence of BPPV and its varied forms of presentation, evaluation and treatment. The observational study included 314 patients with BPPV, specifically involving the posterior semicircular canal (PC) or horizontal semicircular canal (HC). The diagnostic maneuvers used were the Dix-Hallpike (DHP) and the Supine roll test (SRT) respectively.

In a significant majority of the patients it took one or two canalith repositioning maneuvers (CRMs) to effectively treat PC BPPV (91%), and HC BPPV (88%). More than two CRMs were required to effectively treat patients with bilateral PC BPPV, multiple canal involvement, or canal conversions.

Patients who had nystagmus and vertiginous symptoms during the Epley Maneuver (EM) and those who did not have nystagmus and vertiginous symptoms during the EM had similar treatment outcomes. Of note, 19% of patients experienced down-beating nystagmus (DBN) and vertigo after the first or even the second EM.

As a result of this observational study of 314 patients, three arguments were put forth:

  • Firstly, it was posited that repeatedly testing and treating for BPPV within the same clinic session can be considered safe and effective, and need not increase the risk for canal conversion.
  • Secondly, the presence of vertigo and nystagmus throughout the EM need not necessarily be indicative of successful treatment.
  • Thirdly, the risk of an otolithic crisis following CRM is not lessened and therefore clinicians need to be ever mindful of the risk of falls, and prepared to prevent the occurrence of falls in patients especially immediately following CRM.

Other protocols followed during this observational study include the adherence to the clinical practice guidelines for BPPV. Therefore, patients were not given post-treatment precautions.

The financial and personal time benefits to the patient and the public are considerable with the implementation of repeated CRMs within the same session. An additional benefit of this practice is that the efficacy of the treatment is known within the same session. The benefits and advantages of repeated CRMs over consecutive sessions is greater than supposed risks.

Source: Power, Laura, Murray, Katherine, and Szmulewicz, David J. ‘Characteristics of Assessment and Treatment in Benign Paroxysmal Positional Vertigo (BPPV)’. 1 Jan. 2020 : 55 – 62.

Summary prepared by: Mona Fazzina, PT, DPT


Effects of long-term vestibular rehabilitation with vibrotactile sensory augmentation for people with unilateral vestibular disorders

Coordination of the body involves the prioritizing of sensory systems depending on the movement the person is doing. The brain needs vision, touch, joint movement, inner ear (vestibular) information, sound (and sometimes smell) to control the body smoothly. When someone has a vestibular disorder, the brain’s ability to prioritize the senses is affected, and it is not able to use the inner ear/vestibular input effectively. The purpose of vestibular rehabilitation is to help the brain to re-learn how to prioritize the sensory systems, and compensate for any loses. This study indicated that vibration stimulation on the lower back may enhance traditional vestibular rehabilitation, encouraging the body to reorganize which sensory systems it uses at what time. This study included a group of eight people with vestibular disorders on one side of the body (unilateral). A neurologist evaluated and diagnosed them. They all performed vestibular rehabilitation balance training for six weeks. The treatment for one group (the experimental group) also included sensory stimulation involving a customized, vibrating device attached to their lower back with a belt. The sensors in the device detected when the person was shifting his/her torso and provided the vibration then. A physical therapist who did not know which participants received the sensory stimulation performed several tests to determine whether the vibrational sensory stimulation was making a difference. The results were measured with body sway, standing dynamic gait tests, and surveys specific to vestibular disorders. They were tested one month and six months after the treatment had ended as well. All participant improved, but the group with the sensory stimulation performed better. Furthermore, they maintained their abilities six months after the treatment had ended. This study is encouraging because it may enable people suffering from unilateral vestibular disorders to make further and or more complete recovery. There are other types of sensory stimulation that may be used to improve vestibular rehabilitation, namely auditory, visual, and electro-tactile combinations. They will need to be tested in future studies.

Source: Bao, Tian et al. Journal of Vestibular Research, vol. 29, no. 6, pp. 323-334, 2019. DOI: 10.3233/VES-190683Summary written by Jennifer A. Robbins, MPT


Estimating loss of canal function in the video head impulse test (vHIT)

Historically, the caloric test has been the most common clinical method for evaluating vestibular function. The caloric test has a number of limitations and sometimes causes unpleasant symptoms for patients suffering from dizziness.

In the past 10 years or so the video head impulse test (vHIT) has gained popularity for evaluating vestibular abnormalities. vHIT can test parts of the vestibular system, namely the vertical semicircular canals, that are not tested in the caloric test. So far, vHIT is not considered a replacement for the caloric test, and in most clinics the two tests are used in conjunction with each other for a broader evaluation of the vestibular pathway. In a somewhat oversimplified analogy with the hearing evaluation, one can describe the caloric test and vHIT as testing two different sound frequencies in the audiogram.

Unlike with the caloric test, the extent of semicircular canal dysfunction was not readily available from vHIT. This paper uses a computer simulation of the vestibular pathways to determine a simple formula that can relate the loss of canal function to the measured parameters of vHIT. This can also help in clarifying the relationship between vHIT and other vestibular tests, including the caloric test.

Source:  Barin, Kamran, Journal: Journal of Vestibular Research, vol. 29, no. 6, pp. 295-307, 2019. DOI: 10.3233/VES-190688


Third Window Syndrome: Surgical Management of Cochlea-Facial Nerve Dehiscence

Ninety years ago, Tullio described the physiologic outcomes of creating a third mobile window in the semicircular canals of pigeons. Since that time, many locations of third mobile windows have been described; however, the sound-induced dizziness and/or nystagmus has been memorialized by the eponym ‘Tullio phenomenon.’ Clinically, the most thoroughly characterized third mobile window is superior semicircular canal dehiscence (SSCD). Over the years, many other sites of a mobile third window have been reported (15 to date). They all produce, to varying degrees, the spectrum of symptoms and findings seen in third window syndrome (TWS).

This communication is the first assessment of outcomes after surgical repair of cochlea-facial nerve dehiscence (CFD) in a series of patients. Pre- and postoperative quantitative measurement of validated survey instruments, symptoms, diagnostic findings and anonymous video descriptions of symptoms in a cohort of 16 patients with CFD and TWS symptoms were systematically studied.

Overall there was a marked and clinically significant improvement in Dizziness Handicap Inventory (DHI), Headache Impact Test (HIT-6) and TWS symptoms postoperatively for the CFD cohort who had round window reinforcement (RWR) surgery. A statistically significant reduction in cVEMP thresholds was observed in patients with radiographic evidence of CFD. Surgical management with RWR in patients with CFD was associated with improved symptoms and outcomes measures. There was no statistically significant change of hearing in the patients with CFD who underwent RWR. It was emphasized that radiographic CFD is not in itself an indication for surgery and that the most important factor in decision-making should be in the context of clinical symptoms and other diagnostic findings. There are 3 important presenting symptoms and physical findings that are critical when identifying a TWS, including CFD: 1) sound-induced dizziness; 2) hearing internal sounds; and 3) hearing or feeling low frequency tuning forks in an involved ear when applied to a patient’s knee or elbow. Another important observation in the study was that multiple sites of dehiscence in temporal bones with TWS occur and this finding is important to consider when faced with recurrent or incompletely resolved TWS symptoms after plugging a SSCD.

Source: Wackym, P. Ashley, et. al. Front. Neurol., 13 December 2019


Adult neurogenesis promotes balance recovery after vestibular loss

When the vestibule in our inner ear is damaged, information about the position or movement of our body in space is altered or missing. This situation is serious since our brain can no longer provide the motor responses necessary to maintain our balance. The major risk is of course the fall. To prevent this, our brain has an extraordinary ability to adapt called “vestibular compensation”. This fascinating neurobiological process allows our brain to use information from other sensory sensors, such as those of vision or posture, to detect the movements of our body in its environment. To achieve this, it is necessary to reshape our brain connectivity, a bit like old telephone terminals. This is a complex process that involves a mosaic of structural rearrangements, among which the birth of new neurons plays a central role. In the review published in Progress in Neurobiology, we describe how the adult brain produces new neurons to restore balance after vestibular loss. This discovery can be considered as the best example so far of causal reparative role of adult neurogenesis.
Authors: Christian Chabbert & Brahim Tighilet
Source: Progress in Neurobiology, 2019