Otolith Function Testing

Two technically simple tests, vestibular evoked myogenic potential (VEMP) and subjective visual vertical/horizontal (SVV/H) test, have the potential to transform otolith function testing from the research laboratory to the outpatient clinic. Cervical- and ocular-VEMPs are short latency surface potentials produced through the activation of saccular and utricular afferents by sound and vibration. They are tests of dynamic otolith function. The SVV/H test in peripheral lesions probes static asymmetries in utricular function and represents a perceptual error in perceived gravitational vertical/horizontal. VEMPs and SVV/H enable the characterization of patterns and severity of otolith dysfunction in common vestibular disorders. Combined with tests of semicircular canal function, they provide a useful tool for eliciting diagnostic profiles in vestibular neuritis and Ménière's disease. VEMPs are valuable in the pre-surgical confirmation of superior semicircular canal dehiscence and in some cases, may alert the clinician to the presence of a vestibular schwannoma in patients with symmetrical hearing.

Closed-Loop Control of the Centre of Pressure in Post-Stroke Patients With Balance Impairments

When a lightly touched surface is moved according to a closed-loop control law, it has been shown in young adults that the centre of pressure (CoP) can be displaced in a controllable way without the conscious cooperation of participants. In this closed-loop paradigm, the surface velocity was continuously adjusted according to the CoP position. Since the closed-loop control of the CoP does not require the participant's voluntary cooperation, it could be of interest for the development of innovative biofeedback devices in balance rehabilitation. Before anticipating the implementation of this closed-loop control paradigm with patients, it is necessary to establish its effects on people suffering from balance impairments. The aim of this paper was to assess the effects of this CoP closed-loop control in post-stroke (PS) patients and aged-matched healthy controls. Efficacy of the closed-loop control for driving the patients' CoP was assessed using the saturation time and two scores computing the error between the predefined and the current CoP trajectories. 68% and 83% of the trials were considered as successful in patients and controls, respectively. The global tracking error of the closed-loop score was similar between the two groups. However, when examining the real CoP displacement from the starting position to the desired one, PS patients responded to the closed-loop control to a lesser extent than controls. These results, obtained in the same conditions for healthy and PS individuals could be improved by tuning the closed-loop parameters according to individual characteristics. This paper paves the road towards the development of involuntary/automatic biofeedback techniques in more ecological conditions.

Increased Prevalence of Vestibular Loss in Mild Cognitive Impairment and Alzheimer's Disease

BACKGROUND/AIMS

Recent evidence has shown that Alzheimer's Disease (AD) patients have reduced vestibular function relative to healthy controls. In this study, we evaluated whether patients with Mild Cognitive Impairment (MCI) also have reduced vestibular function relative to controls, and compared the level of vestibular impairment between MCI and AD patients.

METHODS

Vestibular physiologic function was assessed in 77 patients (26 MCI, 51 AD) and 295 matched controls using 3 clinical vestibular tests. The association between vestibular loss and cognitive impairment was evaluated using conditional logistic regression models.

RESULTS

Individuals with vestibular impairment had a 3 to 4-fold increased odds of being in the MCI vs. control group (p-values < 0.05). MCI patients had a level of vestibular impairment that was intermediate between controls and AD.

CONCLUSION

These findings suggest a dose-response relationship between vestibular loss and cognitive status, and support the hypothesis that vestibular loss contributes to cognitive decline.

Modulation of vection latencies in the full-body illusion

Current neuroscientific models of bodily self-consciousness (BSC) argue that inaccurate integration of sensory signals leads to altered states of BSC. Indeed, using virtual reality technology, observers viewing a fake or virtual body while being exposed to tactile stimulation of the real body, can experience illusory ownership over-and mislocalization towards-the virtual body (Full-Body Illusion, FBI). Among the sensory inputs contributing to BSC, the vestibular system is believed to play a central role due to its importance in estimating self-motion and orientation. This theory is supported by clinical evidence that vestibular loss patients are more prone to altered BSC states, and by recent experimental evidence that visuo-vestibular conflicts can disrupt BSC in healthy individuals. Nevertheless, the contribution of vestibular information and self-motion perception to BSC remains largely unexplored. Here, we investigate the relationship between alterations of BSC and self-motion sensitivity in healthy individuals. Fifteen participants were exposed to visuo-vibrotactile conflicts designed to induce an FBI, and subsequently to visual rotations that evoked illusory self-motion (vection). We found that synchronous visuo-vibrotactile stimulation successfully induced the FBI, and further observed a relationship between the strength of the FBI and the time necessary for complete vection to arise. Specifically, higher self-reported FBI scores across synchronous and asynchronous conditions were associated to shorter vection latencies. Our findings are in agreement with clinical observations that vestibular loss patients have higher FBI susceptibility and lower vection latencies, and argue for increased visual over vestibular dependency during altered states of BSC.

[Clinical significance of bedside dynamic visual acuity test]

Objective: Dynamic visual acuity (DVA) is defined as the visual acuity when there are relative movements between subjects and visual targets. The purpose of this study was to discuss the correlation between bedside DVA test and other examinations of vestibular function, and to assess the value of DVA test for clinical diagnosis. Methods: Retrospective analysis of 323 cases with peripheral vestibular disorder, and analyzing the correlation between bedside DVA results and caloric test were performed. Results: Out of these 323 cases, 113 cases showed positive results of DVA.Among these 113 cases with positive DVA test, 109 cases were bilateral or unilateral vestibular function loss according to the results of caloric test or VEMP. The disease with the highest positive rate of DVA was bilateral vestibulopathy(BVP), followed by vestibular neuritis (VN) and profound sudden sensorineural hearing loss (pSSNHL). Conclusions: Bedside DVA is effective to determine the cases with BVP and severe unilateral vestibular function loss.

Hyperglycemia and diabetes mellitus are related to vestibular organs dysfunction: truth or suggestion? A literature review

Diabetes mellitus is an independent risk factor for falling, particularly in the elderly. Due to chronic hyperglycemia and hyperinsulinemia patients with diabetes mellitus may have neurological deficits as peripheral neuropathy that is a debilitating micro-vascular complication affecting the proximal and distal peripheral sensory and motor nerves. Sensory neuropathy is prominent and represents the chief contributor to postural instability in diabetic subjects. Diabetic retinopathy is another complication consequent to a breakdown of the inner blood-retinal barrier with accumulation of extracellular fluids in the macula and growth of new vessels causing retinal detachment. Together peripheral neuropathy and retinopathy contribute to increase the risk of falls in diabetic patients, but a certain vestibular organs impairment should not be underestimated. Nevertheless, the exact mechanism and localization of peripheral vestibular damage consequent to chronic hyperglycemia and hyperinsulinemia are currently not still understood. Moreover it is not defined the possible role of these two blood conditions in worsening the prognosis of typical vestibular pathologies like "benign paroxysmal positional vertigo" and "Meniere disease". The aim of this review was to retrieve all studies investigating about the balance system alterations in patients suffering of diabetes. A search thorough Ovid MEDLINE was performed to enroll all eligible articles. Fourteen studies comprising a total of 1364 patients were included and analyzed in detail. On the basis of data reported in our review it appears plausible to hypothesize a direct connection among chronic hyperglycemic/hyperinsulinemic damage and peripheral vestibular organ dysfunction.

Semicircular Canal Dehiscence Syndrome and Vestibular Dysfunction Disqualify a Military Student Pilot

BACKGROUND

Humans detect motion and gravity via the labyrinthine system of the inner ear, which consists of the vestibule and the semicircular canals. The vestibular system provides three major functions for maintaining balance and orientation. First, it maximizes the effectiveness of the visual system. Second, it provides orientational information necessary for performing both skilled and reflexive motor activities. Third, in the absence of vision, the vestibular system provides a reasonably accurate perception of motion and position. Although these organs provide important cues for basic orientation on the ground, they often provide misleading information during flight. A superior semicircular canal dehiscence can cause an individual to experience disorientation and vertigo-like symptoms.

CASE REPORT

A 30-yr-old male student pilot experienced airsickness on his first several flights in the T-6A Texan II aircraft. Airsickness is common among student pilots in the early stages of flight training; however, the subject pilot's symptoms lasted well beyond the normal 24 h, and included vertiginous symptoms lasting days after his last flight. His persistent symptoms required he be held out of training for further evaluation. Comprehensive vestibular and audiological testing were normal; however, a CT scan of the temporal bones showed a left superior semicircular canal dehiscence, and he was diagnosed with left labyrinthine fistula as the cause of his vertigo. He was medically eliminated from pilot training and permanently disqualified from U.S. Air Force flying duties.

DISCUSSION

Spatial disorientation remains one of the deadliest factors related to aircraft mishaps every year. In this case, an abnormal presentation of airsickness that prompted further evaluation may have prevented a dangerous situation in the air. In standard airsickness, the goal is to keep the pilot flying to expedite adaptation, so this case highlights the importance of distinguishing between normal airsickness and a spatially disorienting medical condition.Dreibelbis JA, Organ BE. Semicircular canal dehiscence syndrome and vestibular dysfunction disqualify a military student pilot. Aerosp Med Hum Perform. 2018; 89(10):923-926.

Progressive spasticity, supranuclear gaze palsy and postural instability, without parkinsonism: what's in a phenotype?

We present a series of patients with vertical supranuclear gaze palsy, postural instability with falls, and progressive spasticity, who mimic Progressive Supranuclear Palsy - Richardson's syndrome (PSP-R) but have no parkinsonism, and in whom dopamine transporter imaging is normal. We suggest possible aetiologies for this constellation of symptoms, discuss the possible origin of these signs and highlight this phenotype as it may mimic atypical parkinsonism and in particular PSP.

Characteristics of vestibular corrective saccades in patients with slow visual saccades, vestibular disorders and controls: A descriptive analysis

OBJECTIVE

Our aim was to determine whether overt catch up saccades (OS) provoked by vestibular stimuli, as observed in the video head impulse test (vHIT), have comparable metrics as visually triggered horizontal saccades (VS), indicating a common saccadic brainstem generator.

METHODS

Three groups of patients were studied: patients with neurological disorders causing slow saccades (group 1, n = 12), patients with peripheral vestibular lesions (group 2, n = 43), and normal controls (group 3, = 24). All patients underwent vHIT and Videooculographic testing. OS velocity, acceleration, amplitude and duration and VS velocity in this group was compared between the groups.

RESULTS

There was significant reduction in the velocity of visually guided saccades in group 1, as expected from the patient selection constraints of this study. Group 1 also exhibited saccades which were longer in duration and of reduced acceleration when compared to subjects without saccadic slowing to visual targets (Group 2 and 3). There were significant positive correlations between OS acceleration and amplitude in both normal saccade groups (2 and 3) which was not observed in the slow saccade group (1).

CONCLUSIONS

The metrics of overt saccades measured by the vHIT in patients with slow saccades and normal controls are similar to visually guided saccades. This supports the hypothesis that overt saccades associated with vestibular stimuli and visually triggered saccades share common circuitry that controls metrics.

Using visual stimuli to enhance gait control

Gait control challenges commonly coincide with vestibular dysfunction and there is a long history in using balance and gait activities to enhance functional mobility in this population. While much has been learned using traditional rehabilitation exercises, there is a new line of research emerging that is using visual stimuli in a very specific way to enhance gait control. For example, avatars can be created in an individualized manner to incorporate specific gait characteristics. The avatar could then be used as a visual stimulus to which the patient can synchronize their own gait cycle. This line of research builds upon the rich history of sensorimotor control research in which augmented sensory information (visual, haptic, or auditory) is used to probe, and even enhance, human motor control. This review paper focuses on gait control challenges in patients with vestibular dysfunction, provides a brief historical perspective on how various visual displays have been used to probe sensorimotor and gait control, and offers some recommendations for future research.

An adaptive vestibular rehabilitation technique

OBJECTIVES/HYPOTHESIS

There is a large variation in vestibular rehabilitation (VR) results depending on type of therapy, adherence, and the appropriateness for the patient's level of function. A novel adaptive vestibular rehabilitation (AVR) program was developed and evaluated.

STUDY DESIGN

Technology and procedure development, and prospective multicenter trial.

METHODS

Those with complete unilateral vestibular hypofunction and symptomatic at least 3 months with a Dizziness Handicap Inventory (DHI) >30 were eligible. Patients were given a device to use with their own computer. They were instructed to use the program daily, with each session lasting about 10 minutes. The task consisted of reporting orientation of the letter C, which appeared when their angular head velocity exceeded a threshold. The letter size and head velocity required were adjusted based on prior performance. Performance on the task was remotely collected by the investigator as well as a weekly DHI score.

RESULTS

Four patients aged 31 to 74 years (mean = 51 years) were enrolled in this feasibility study to demonstrate efficacy. Two had treated vestibular schwannomas and two had vestibular neuritis. Starting DHI was 32 to 56 (mean = 42), which was reduced to 0 to 16 (mean = 11.5) after a month of therapy, a clinically and statistically significant (P < .05) improvement. The three who continued therapy an additional month improved to a DHI of 4.

CONCLUSIONS

This AVR method has advantages over traditional VR in terms of cost and customization for patient ability and obtained a major improvement in symptoms. This study demonstrated a clinically and statistically significant decrease in symptoms after 4 weeks of therapy.

LEVEL OF EVIDENCE

2b. Laryngoscope, 128:713-718, 2018.

About the pathophysiology of acute unilateral vestibular deficit - vestibular neuritis (VN) or peripheral vestibulopathy (PVP)?

OBJECTIVE

To determine whether patients with acute unilateral peripheral vestibulopathy (PVP), often called "vestibular neuritis/neuronitis or neuropathy" (VN) have a vestibular lesion pattern consistent with the distribution of the neurological afferents.

BACKGROUND

Much is known about the clinical nature of PVP, however less so about its etiology and pathogenesis. Due to the frequency with which VN is used to describe the syndrome, an inflammation of the vestibular nerve or of one of its branches is often assumed to be the cause of PVP, though there is insufficient data so far to support this assumption.

METHODS

We conducted a retrospective study of 25 patients who had presented to our clinic with PVP and had all vestibular receptor organs tested shortly after start of symptoms. We analysed their vestibular lesion patterns in order to determine whether they were consistent with the neuritis hypothesis (NH).

RESULTS

The lesion patterns varied conspicuously. 76% did not follow an innervation pattern, thereby contradicting the NH and only 24% had a lesion pattern that either definitely (16%) or probably (8%) supported the NH.

CONCLUSION

These results should remind us to be careful before jumping to quick conclusions about the pathogenetic nature of PVP. With any reason to question VN as the only cause of PVP, we should reconsider the treatment approach to PVP. If the cause probably or even possibly lies inside the vestibular labyrinth, an intratympanic steroid injection might prove to be a more effective measure, even in first-line treatment. If the etiology is unsure, a combination of systemic and intratympanic steroid treatment may be adequate.

Brain responses to virtual reality visual motion stimulation are affected by neurotic personality traits in patients with persistent postural-perceptual dizziness

OBJECTIVE

Persistent postural perceptual dizziness (PPPD) is a common vestibular disorder of persistent dizziness and unsteadiness, exacerbated by upright posture, self-motion, and exposure to complex or moving visual stimuli. Previous functional magnetic resonance imaging (fMRI) studies found dysfunctional activity in the visual-vestibular cortices in patients with PPPD. Clinical studies showed that the anxiety-related personality traits of neuroticism and introversion may predispose individuals to PPPD. However, the effects of these traits on brain function in patients with PPPD versus healthy controls (HCs) have not been studied.

METHODS

To investigate potential differential effects of neuroticism and introversion on functioning of their visuo-vestibular networks, 15 patients with PPPD and 15 HCs matched for demographics and motion sickness susceptibility underwent fMRI during virtual reality simulation of a rollercoaster ride in vertical and horizontal directions.

RESULTS

Neuroticism positively correlated with activity in the inferior frontal gyrus (IFg), and enhanced connectivity between the IFg and occipital regions in patients with PPPD relative to HCs during vertical versus horizontal motion comparison.

CONCLUSIONS

In patients with PPPD, neuroticism increased the activity and connectivity of neural networks that mediate attention to visual motion cues during vertical motion. This mechanism may mediate visual control of balance in neurotic patients with PPPD.

Clinical and Neurobehavioral Features of Three Novel Kabuki Syndrome Patients with Mosaic KMT2D Mutations and a Review of Literature

Kabuki syndrome (KS) is a rare disorder characterized by multiple congenital anomalies and variable intellectual disability caused by mutations in KMT2D/MLL2 and KDM6A/UTX, two interacting chromatin modifier responsible respectively for 56-75% and 5-8% of the cases. To date, three KS patients with mosaic KMT2D deletions in blood lymphocytes have been described. We report on three additional subjects displaying KMT2D gene mosaics including one in which a single nucleotide change results in a new frameshift mutation (p.L1199HfsX7), and two with already-known nonsense mutations (p.R4484X and p.R5021X). Consistent with previously published cases, mosaic KMT2D mutations may result in mild KS facial dysmorphisms and clinical and neurobehavioral features, suggesting that these characteristics could represent the handles for genetic testing of individuals with slight KS-like traits.

Central vestibular disorder due to ischemic injury on the parieto-insular vestibular cortex in patients with middle cerebral artery territory infarction: Observational study

Central vestibular disorder is common after middle cerebral artery (MCA) territory infarction. The MCA supplies blood to the parieto-insular vestibular cortex (PIVC), a core region of central vestibular symptoms. We report on patients that sustained injuries of the core vestibular pathway to the PIVC with central vestibular disorder following MCA territory infarction, demonstrated on diffusion tensor imaging (DTI). Nineteen patients with MCA territory infarction and 12 control subjects were recruited. To reconstruct the core vestibular pathway to the PIVC, we defined seed region of interest (ROI) as vestibular nuclei of pons and target ROI as the PIVC. Fractional anisotropy (FA), mean diffusivity, and tract volume were measured. In the affected hemisphere, FA value of the core vestibular pathway to the PIVC revealed significant difference between all patient groups and the control group (P < .05). In contrast, patients with symptoms of ataxia only revealed significant decrement of tract volume compared with the control group (P < .05). Additionally, subgroup B revealed significant decrement of tract volume compared with that of subgroup A and the control group (P < .05). In the unaffected hemisphere, there was no significant difference in all DTI parameters between all patient groups and the control group (P < .05). Injury to the core vestibular pathway to the PIVC was demonstrated in patients that revealed typical central vestibular disorder following MCA territory infarction. Analysis of the core vestibular pathway to the PIVC using DTI would be beneficial in clinical evaluation and management of patients with MCA territory infarction.

Adjustment of the dynamic weight distribution as a sensitive parameter for diagnosis of postural alteration in a rodent model of vestibular deficit

Vestibular disorders, by inducing significant posturo-locomotor and cognitive disorders, can significantly impair the most basic tasks of everyday life. Their precise diagnosis is essential to implement appropriate therapeutic countermeasures. Monitoring their evolution is also very important to validate or, on the contrary, to adapt the undertaken therapeutic actions. To date, the diagnosis methods of posturo-locomotor impairments are restricted to examinations that most often lack sensitivity and precision. In the present work we studied the alterations of the dynamic weight distribution in a rodent model of sudden and complete unilateral vestibular loss. We used a system of force sensors connected to a data analysis system to quantify in real time and in an automated way the weight bearing of the animal on the ground. We show here that sudden, unilateral, complete and permanent loss of the vestibular inputs causes a severe alteration of the dynamic ground weight distribution of vestibulo lesioned rodents. Characteristics of alterations in the dynamic weight distribution vary over time and follow the sequence of appearance and disappearance of the various symptoms that compose the vestibular syndrome. This study reveals for the first time that dynamic weight bearing is a very sensitive parameter for evaluating posturo-locomotor function impairment. Associated with more classical vestibular examinations, this paradigm can considerably enrich the methods for assessing and monitoring vestibular disorders. Systematic application of this type of evaluation to the dizzy or unstable patient could improve the detection of vestibular deficits and allow predicting better their impact on posture and walk. Thus it could also allow a better follow-up of the therapeutic approaches for rehabilitating gait and balance.

New mouse model for inducing and evaluating unilateral vestibular deafferentation syndrome

BACKGROUND

Unilateral vestibular deafferentation syndrome (uVDS) holds a particular place in the vestibular pathology domain. Due to its suddenness, the violence of its symptoms that often result in emergency hospitalization, and its associated original neurophysiological properties, this syndrome is a major source of questioning for the otoneurology community. Also, its putative pathogenic causes remain to be determined. There is currently a strong medical need for the development of targeted and effective countermeasures to improve the therapeutic management of uVDS.

NEW METHODS

The present study reports the development of a new mouse model for inducing and evaluating uVDS. Both the method for generating controlled excitotoxic-type peripheral vestibular damages, through transtympanic administration of the glutamate receptors agonist kainate (TTK), and the procedure for evaluating the ensuing clinical signs are detailed.

COMPARISON WITH EXISTING METHODS

Through extensive analysis of the clinical symptoms characteristics, this new animal model provides the opportunity to better follow the temporal evolution of various uVDS specific symptoms, while better appreciating the different phases that composed this syndrome.

RESULTS

The uVDS evoked in the TTK mouse model displays two main phases distinguishable by their kinetics and amplitudes. Several parameters of the altered vestibular behaviour mimic those observed in the human syndrome.

CONCLUSION

This new murine model brings concrete information about how uVDS develops and how it affects global behaviour. In addition, it opens new opportunity to decipher the etiopathological substrate of this pathology by authorizing the use of genetically modified mouse models.

Sensitivity of caloric test and video head impulse as screening test for chronic vestibular complaints

OBJECTIVE:

This study compared the results of the caloric test with those of the video head impulse test obtained during the same session and evaluated whether the former can be used to screen for non-acute vestibular dysfunction.

METHODS:

A total of 157 participants complaining of dizziness with vestibular characteristics of varying durations and clinical courses completed the caloric test and video head impulse test.

RESULTS:

Significantly more caloric test results than video head impulse test results were abnormal.

CONCLUSIONS:

The results of the caloric test and video head impulse test are distinct but complement each other. Within our sample, the caloric test was more sensitive for vestibular dysfunction. Therefore, the video head impulse test is not a suitable screening tool of the vestibular system in patients with chronic complaints.

Use of neck torsion as a specific test of neck related postural instability

BACKGROUND

Disturbed postural stability in neck pain (NP) is likely due to abnormal cervical afferent function. Several potential causes requires specific diagnostic tests. The neck torsion (head still body rotated) manoeuvre stimulates cervical but not vestibular receptors and identified abnormal cervical afferent input as the cause in patients with NP compared to healthy controls. Comparison between vestibular and NP subjects is now needed.

AIMS

To compare individuals with unilateral vestibular loss (UVL), persistent NP and asymptomatic controls. It was hypothesized that neck torsion will increase postural stability in NP compared to both the asymptomatic and UVL groups.

METHODS

Twenty UVL, 20 persistent NP and 20 asymptomatic control subjects underwent measurement of postural stability on a computerised force plate with eyes closed in comfortable stance under 5 conditions: neutral head, head rotated 45° (left and right) and neck torsion (left and right). Root mean square (rms) amplitude of sway was measured in the anterior posterior (AP) and medial lateral (ML) directions. Average torsion and torsion difference (average torsion - neutral neck) were calculated.

RESULTS

NP subjects had significantly greater (p < 0.05) AP sway with average torsion and torsion difference compared to both control and UVL. There were no significant differences between control and UVL and no between group differences for neutral neck, rotation or rotation difference.

CONCLUSION

The results of the study suggest that the torsion manouever may identify cervical afferent causes of disturbed postural stability. This is important for guiding assessment and management of balance disturbances in patients.

Patients with chronic dizziness following traumatic head injury typically have multiple diagnoses involving combined peripheral and central vestibular dysfunction

OBJECTIVE

We hypothesised that chronic vestibular symptoms (CVS) of imbalance and dizziness post-traumatic head injury (THI) may relate to: (i) the occurrence of multiple simultaneous vestibular diagnoses including both peripheral and central vestibular dysfunction in individual patients increasing the chance of missed diagnoses and suboptimal treatment; (ii) an impaired response to vestibular rehabilitation since the central mechanisms that mediate rehabilitation related brain plasticity may themselves be disrupted.

METHODS

We report the results of a retrospective analysis of both the comprehensive clinical and vestibular laboratory testing of 20 consecutive THI patients with prominent and persisting vestibular symptoms still present at least 6months post THI.

RESULTS

Individual THI patients typically had multiple vestibular diagnoses and unique to this group of vestibular patients, often displayed both peripheral and central vestibular dysfunction. Despite expert neuro-otological management, at two years 20% of patients still had persisting vestibular symptoms.

CONCLUSION

In summary, chronic vestibular dysfunction in THI could relate to: (i) the presence of multiple vestibular diagnoses, increasing the risk of 'missed' vestibular diagnoses leading to persisting symptoms; (ii) the impact of brain trauma which may impair brain plasticity mediated repair mechanisms. Apart from alerting physicians to the potential for multiple vestibular diagnoses in THI, future work to identify the specific deficits in brain function mediating poor recovery from post-THI vestibular dysfunction could provide the rationale for developing new therapy for head injury patients whose vestibular symptoms are resistant to treatment.

[The significance of directional preponderance in the evaluation of vestibular function in patients with vertigo]

Objective: To analyze the relationship between directional preponderance (DP), spontaneous nystagmus(SN) and vestibular disorders, and to investigate the significance of DP in directing peripheral vestibular function in patients with vertigo. Methods: This was a retrospective analysis of 394 cases diagnosed with peripheral vestibular disease accompanied by vertigo from March 2012 to June 2014 in the Outpatient Department of the Eye & ENT Hospital of Fudan University. Results of static and dynamic posture equilibrium tests, SN, unilateral weakness(UW), and DP in videonystagmography(VNG) were analyzed and compared. Results: The mean interval time between the last vertigo attack and examination in patients with SN or DP in caloric test were 4.4 d and 7.3 d respectively, and those without SN or DP were 18.3 d and 17.5 d respectively. The patients were divided into two groups according to DP results of caloric test. DP-normal group had 203 cases and DP-abnormal group had 191 cases. Spontaneous nystagmus was presented in 44 cases in the DP-normal group (21.67%) and four in the DP-abnormal group (2.09%). A significant difference was found between the two groups (χ²=35.27, P=0.000). Deficiency of vestibular function was noted in 165 cases in the DP-normal group (81.28%) and 123 (64.40%) in the DP-abnormal group in static and dynamic posture equilibrium tests. The difference between the two groups was statistically significant (χ²=14.26, P=0.000). Conclusion: Compared with DP-normal patients, DP-abnormal patients are more likely to have spontaneous nystagmus and balance disorders due to vestibular dysfunction.

Vestibular disorders following different types of head and neck trauma

This review focuses on the published literature on vestibular disorders following different types of head and neck trauma. Current knowledge of the different causes and underlying mechanisms of vestibular disorders, as well as the sites of organic damage, is presented. Non-organic mechanisms are also surveyed. The frequency of occurrence of vestibular symptoms, and of other accompanying subjective complaints, associated with different types of trauma is presented and related to the specific causes. Hypotheses about the pathogenesis of traumatic vestibular disorders are presented, and the knowledge derived from animal experiments is also discussed. We believe this to be a very important topic, since vestibular complaints in traumatic patients often remain undiagnosed or underestimated in clinical practice. This review article aims to suggest directions for additional research and to provide guidance to both the scientific and clinical practice communities.

[The influence of Memoplant monotherapy on the dizziness]

The objective of the present work was to study the influence of the dry extract from the leaves of Ginkgo biloba EGb 761 (used as monotherapy at a dose of 120 mg twice daily during 4 months) on the vestibular function of the patients presenting with cochleovestibular pathology of peripheral and mixed genesis. We present the results obtained by the objective and subjective methods for the evaluation of the vestibular function as well as the neurological and psychoemotional state of the 40 patients that was carried out during the four months of memoplant monotherapy. It is concluded that monotherapy with the use of the dry extract from Ginkgo biloba leaves can be applied for the purpose of improvement of static and dynamic balancing state. Moreover, this memoplant preparation can be used as a means of prophylaxis of recurrent dizziness that in addition reduces the severity of anxiety and depression without producing adverse side effects.