Isolated otolith dysfunction(iOD) involves a group of unexplained vestibular syndromes that manifest clinically as a sense of translation, tilting or floating, and blurred vision with head movement, with normal semicircular canal function but abnormal otolith function on laboratory vestibular testing. As vestibular medicine has gained widespread popularity in recent years, increasing attention has also been paid to iOD and case reports, clinical studies and diagnostic criteria have been published. However, there is no consensus document to guide the diagnosis of this disease in China. In this context, the Special Committee on Vertigo of China Medical Education Association organized a group of domestic experts in vestibular medicine and formulated this diagnostic consensus after thorough discussion based on the latest evidence in China and abroad, in order to promote the best clinical practice for iOD.
Humans ; Otolithic Membrane ; Vestibular Diseases/diagnosis* ; Vertigo/diagnosis* ; Vestibule, Labyrinth ; Semicircular Canals

BACKGROUND: Cervical vestibular evoked myogenic potential (cVEMP) testing is a strong tool that enables objective determination of balance functions in humans. However, it remains unknown whether cVEMP correctly expresses vestibular disorder in mice. OBJECTIVE: In this study, correlations of cVEMP with scores for balance-related behavior tests including rotarod, beam, and air-righting reflex tests were determined in ICR mice with vestibular disorder induced by 3,3'-iminodipropiontrile (IDPN) as a mouse model of vestibular disorder. METHODS: Male ICR mice at 4 weeks of age were orally administered IDPN in saline (28 mmol/kg body weight) once. Rotarod, beam crossing, and air-righting reflex tests were performed before and 3-4 days after oral exposure one time to IDPN to determine balance functions. The saccule and utricles were labeled with fluorescein phalloidin. cVEMP measurements were performed for mice in the control and IDPN groups. Finally, the correlations between the scores of behavior tests and the amplitude or latency of cVEMP were determined with Spearman's rank correlation coefficient. Two-tailed Student's t test and Welch's t test were used to determine a significant difference between the two groups. A difference with p < 0.05 was considered to indicate statistical significance. RESULTS: After oral administration of IDPN at 28 mmol/kg, scores of the rotarod, beam, and air-righting reflex tests in the IDPN group were significantly lower than those in the control group. The numbers of hair cells in the saccule, utricle, and cupula were decreased in the IDPN group. cVEMP in the IDPN group was significantly decreased in amplitude and increased in latency compared to those in the control group. cVEMP amplitude had significant correlations with the numbers of hair cells as well as scores for all of the behavior tests in mice. CONCLUSIONS This study demonstrated impaired cVEMP and correlations of cVEMP with imbalance determined by behavior tests in a mouse model of vestibular disorder.
Animals ; Behavior, Animal ; drug effects ; physiology ; Disease Models, Animal ; Hair Cells, Vestibular ; pathology ; Male ; Mice ; Mice, Inbred ICR ; Nitriles ; adverse effects ; Postural Balance ; drug effects ; physiology ; Saccule and Utricle ; pathology ; Sensation Disorders ; chemically induced ; physiopathology ; Vestibular Diseases ; chemically induced ; diagnosis ; pathology ; physiopathology ; Vestibular Evoked Myogenic Potentials ; drug effects ; physiology ; Vestibular Function Tests

The vestibular symptoms such as dizziness and imbalance that occurred after traumatic head/brain injury were caused by a combination of central factors such as abnormalities of white matter, diffuse axonal injury and microhemorrhage, and peripheral factors like decreased vestibulo-ocular reflex caused by the energy transmitted to the semicircular canal and otolith organs. These symptoms can affect on the patient's overall physical, cognitive, emotional, and quality of life. There have been reports that vestibular rehabilitation for the treatment of dizziness and imbalance after head trauma can promote vestibular compensation, stabilize of the gaze movements, and also affect the treatment outcomes of the associated injuries. The frequency, duration, and number of people participating in vestibular rehabilitation varied with each study, and physical therapy, occupational therapy, cognitive counseling, medication treatment, duration of treatment for associated injuries were also variable. Most studies have shown that many patients who get the vestibular rehabilitation have a significantly reduced time to return to work and sports activities, and may be able to speed up the recovery of vestibular symptoms. However, further research is needed on its long-term effects. In addition, patients with traumatic head/brain injuries are more susceptible to injuries of other organs as well as vestibular disorders, therefore consideration of treatment planning for associated injuries including precise evaluation mental support, and cognitive therapy is expected to be more effective with vestibular rehabilitation therapy.
Cognitive Therapy ; Compensation and Redress ; Counseling ; Craniocerebral Trauma ; Diffuse Axonal Injury ; Dizziness ; Head ; Humans ; Occupational Therapy ; Otolithic Membrane ; Quality of Life ; Reflex, Vestibulo-Ocular ; Rehabilitation ; Return to Work ; Semicircular Canals ; Sports ; White Matter

BACKGROUND AND OBJECTIVES: Dizzy patients with abnormal otolith function tests, despite a normal caloric response, are defined as having specific (isolated) otolith organ dysfunction. This study was performed to compare the differences in clinical presentation between isolated otolith dysfunction (iOD) patients with lab- and Sx-based iOD group and lab-based iOD symptoms. SUBJECTS AND METHODS: The medical records of 23 iOD patients with normal caloric response but abnormal cervical vestibular evoked myogenic potential (VEMP), ocular VEMP, or subjective visual vertical were reviewed. Non-spinning vertigo was considered as otolith-related symptoms. The patients’ age, onset of dizziness, Numeric Rating Scale on the severity of dizziness, and concomitant vestibular disorders were analyzed. RESULTS: Patients in the lab-based iOD group were significantly older than those in the lab- and Sx-based iOD group. Known vestibular disorders were significantly more common in the lab-based iOD group (83.3%) compared to the lab- and Sx-based iOD group (18.2%). Despite the normal caloric response, catch-up saccade was found in the video head impulse test in more than half (54.5%) of the lab-based iOD group patients. There was no catch-up saccade in the lab- and Sx-based iOD group. There were no significant differences in gender ratio, frequency of dizziness attacks, and duration of illness. CONCLUSIONS: We propose new definitions of definite iOD (lab- and Sx-based iOD) and probable iOD (lab- or Sx-based iOD). These new definitions may help researchers to identify patients who are more likely to have true iOD, and facilitate comparisons of results between different studies.
Dizziness ; Head Impulse Test ; Humans ; Medical Records ; Otolaryngology ; Otolithic Membrane ; Saccades ; Vertigo

BACKGROUND AND PURPOSE: Conflicting results about vestibular function in progressive supranuclear palsy (PSP) prompted a systematic examination of the semicircular canal function, otolith function, and postural stability. METHODS: Sixteen patients with probable PSP [9 females, age=72±6 years (mean±SD), mean disease duration=3.6 years, and mean PSP Rating Scale score=31] and 17 age-matched controls were examined using the video head impulse test, caloric testing, ocular and cervical vestibular evoked myogenic potentials (o- and cVEMPs), video-oculography, and posturography. RESULTS: There was no evidence of impaired function of the angular vestibulo-ocular reflex (gain=1.0±0.1), and caloric testing also produced normal findings. In terms of otolith function, there was no significant difference between PSP patients and controls in the absolute peakto-peak amplitude of the oVEMP (13.5±7.2 µV and 12.5±5.6 µV, respectively; p=0.8) or the corrected peak-to-peak amplitude of the cVEMP (0.6±0.3 µV and 0.5±0.2 µV, p=0.3). The total root-mean-square body sway was significantly increased in patients with PSP compared to controls (eyes open/head straight/hard platform: 9.3±3.7 m/min and 6.9±2.1 m/min, respectively; p=0.032). As expected, the saccade velocities were significantly lower in PSP patients than in controls: horizontal, 234±92°/sec and 442±66°/sec, respectively; downward, 109±105°/sec and 344±72°/sec; and upward, 121±110°/sec and 348±78°/sec (all p<0.01). CONCLUSIONS: We found no evidence of impairment of either high- or low-frequency semicircular function or otolith organ function in the examined PSP patients. It therefore appears that other causes such as degeneration of supratentorial pathways lead to postural imbalance and falls in patients with PSP.
Accidental Falls ; Caloric Tests ; Female ; Head Impulse Test ; Humans ; Movement Disorders ; Otolithic Membrane ; Reflex, Vestibulo-Ocular ; Saccades ; Semicircular Canals ; Supranuclear Palsy, Progressive ; Tauopathies ; Vestibular Evoked Myogenic Potentials

BACKGROUND AND OBJECTIVES: Although repositioning maneuvers have shown remarkable success rate in treatments of benign paroxysmal positional vertigo (BPPV), the high recurrence rate of BPPV has been an important issue. The aims of present study were to examine the effects of otolith dysfunction on BPPV recurrence rate and to describe the effect of vestibular rehabilitation exercises on BPPV recurrence in BPPV patients with concomitant otolith dysfunction. SUBJECTS AND METHODS: Forty-five BPPV patients included in this study (three groups). Patients in group 1 had no otolith dysfunction and patients in groups 2 and 3 had concomitant otolith dysfunction. Otolith dysfunction was determined with ocular/cervical vestibular evoked myogenic potential (oVEMP and cVEMP) abnormalities. Epley’s maneuver was performed for the patients in all groups but patients in group 3 also received a 2-month vestibular rehabilitation program (habituation and otolith exercises). RESULTS: This study showed that BPPV recurrent rate was significantly higher in patients with otolith dysfunction in comparison to the group 1 (p < 0.05). Vestibular rehabilitation resulted in BPPV recurrence rate reduction. Utricular dysfunction showed significant correlation with BPPV recurrence rate. CONCLUSIONS: Otolith dysfunction can increase BPPV recurrence rate. Utricular dysfunction in comparison to saccular dysfunction leads to more BPPV recurrence rate. Vestibular rehabilitation program including habituation and otolith exercises may reduce the chance of BPPV recurrence.
Benign Paroxysmal Positional Vertigo ; Exercise ; Humans ; Otolithic Membrane ; Recurrence ; Rehabilitation

Hypotension is one of the potential causes of dizziness. In this review, we summarize the studies published in recent years about the electrophysiological and pharmacological mechanisms of hypotension-induced dizziness and the role of the vestibular system in the control of blood pressure in response to hypotension. It is postulated that ischemic excitation of the peripheral vestibular hair cells as a result of a reduction in blood flow to the inner ear following hypotension leads to excitation of the central vestibular nuclei, which in turn may produce dizziness after hypotension. In addition, excitation of the vestibular nuclei following hypotension elicits the vestibulosympathetic reflex, and the reflex then regulates blood pressure by a dual-control (neurogenic and humoral control) mechanism. In fact, recent studies have shown that peripheral vestibular receptors play a role in the control of blood pressure through neural reflex pathways. This review illustrates the dual-control mechanism of peripheral vestibular receptors in the regulation of blood pressure following hypotension.
Blood Pressure* ; Dizziness ; Ear, Inner ; Epinephrine ; Glutamic Acid ; Hair Cells, Vestibular ; Hypotension* ; Reflex ; Vestibular Nuclei

OBJECTIVES: We aimed to assess the clinical significance of spontaneous nystagmus (SN) in horizontal semicircular canal benign paroxysmal positional vertigo (HC-BPPV). METHODS: Twenty-four patients who were diagnosed with HC-BPPV in Eulji University Hospital from January 2015 to December 2016 were recruited. Various bed-side examinations including SN in both sitting and supine position, head roll test, and bithermal caloric test were evaluated. The number of canalith repositioning maneuvers were counted in all patients. RESULTS: SN was observed in 18.2% of geotropic HC-BPPV and 38.5% of apogeotropic HC-BPPV, respectively. There was no significant difference between presence of SN and the direction of initial nystagmus (p=0.386, 2-tailed Fisher exact test). The mean number of otolith repositioning maneuvers in patients with SN was 3.29±1.799 and this was significantly higher than in patients without SN (1.76±0.831) (p=0.009). Although the mean number of repositioning maneuver in patients in apogeotropic HC-BPPV and SN (3.80±1.924) tended to be higher than those who were diagnosed with apogeotropic HC-BPPV without SN (1.88±1.991) (p=0.035), the post hoc analysis with Bonferroni correction revealed that it was not significant because it was higher than the adjusted p-value (p=0.017). The initial direction of nystagmus was changed into the opposite direction in 29.17% of patient. However, this change was not different according to presence of SN (p=0.374, 2-tailed Fisher exact test). CONCLUSIONS: The presence of SN in HC-BPPV may be associated with lower treatment response. In particular, cautions are needed in patients with apogeotropic HC-BPPV.
Benign Paroxysmal Positional Vertigo ; Caloric Tests ; Head ; Humans ; Otolithic Membrane ; Semicircular Canals ; Supine Position

OBJECTIVES: We aimed to study the role of vestibular input on spatial memory performance in mice that had undergone bilateral surgical labyrinthectomy, semicircular canal (SCC) occlusion and 4G hypergravity exposure. METHODS: Twelve to 16 weeks old ICR mice (n=30) were used for the experiment. The experimental group divided into 3 groups. One group had undergone bilateral chemical labyrinthectomy, and the other group had performed SCC occlusion surgery, and the last group was exposed to 4G hypergravity for 2 weeks. The movement of mice was recorded using camera in Y maze which had 3 radial arms (35 cm long, 7 cm high, 10 cm wide). We counted the number of visiting arms and analyzed the information of arm selection using program we developed before and after procedure. RESULTS: The bilateral labyrinthectomy group which semicircular canal and otolithic function was impaired showed low behavioral performance and spacial memory. The semicircular canal occlusion with CO₂ laser group which only semicircular canal function was impaired showed no difference in performance activity and spatial memory. However the hypergravity exposure group in which only otolithic function impaired showed spatial memory function was affected but the behavioral performance was spared. The impairment of spatial memory recovered after a few days after exposure in hypergravity group. CONCLUSIONS: This spatial memory function was affected by bilateral vestibular loss. Space-related information processing seems to be determined by otolithic organ information rather than semicircular canals. Due to otolithic function impairment, spatial learning was impaired after exposure to gravity changes in animals and this impaired performance was compensated after normal gravity exposure.
Animals ; Arm ; Automatic Data Processing ; Gravitation ; Hypergravity ; Memory ; Mice ; Mice, Inbred ICR ; Otolithic Membrane ; Semicircular Canals ; Spatial Learning ; Spatial Memory

OBJECTIVE: Blunt head injury can lead to isolated damage of the inner ear (cochlear labyrinthine concussion) or damage of the otolith organ (vestibular labyrinthine concussion) due to a bone conduction pressure. We evaluated the clinical characteristics of hearing impairment in patients who suffered from a blunt head trauma without any organic problems, including temporal bone fracture or intracranial hemorrhage. METHODS: This retrospective study examined 9 patients presenting with hearing impairment after blunt head trauma within recent 5 years. This study included only patients without temporal bone fracture or intracranial hemorrhage. RESULTS: Most patients complained of associated auditory symptoms including tinnitus, dizziness, earfullness, and otalgia. Twelve ears of 9 patients showed sensorineural hearing loss; mild (1 ear), moderate (3 ears), moderate-severe (4 ears), severe (2 ears), and profound (2 ears). After high-dose steroid therapy, 2 ears had a significant hearing gain, but 10 ears showed no improvement of hearing. CONCLUSION: Blunt head injury is one of the most common causes of the neurologic disorders. It is important to perform thorough assessment of auditory symptoms as soon as possible. Otologic consultation should be sought in all cases for appropriate management.
Bone Conduction ; Craniocerebral Trauma* ; Dizziness ; Ear ; Ear, Inner ; Earache ; Head Injuries, Closed ; Head* ; Hearing ; Hearing Loss ; Hearing Loss, Sensorineural ; Humans ; Intracranial Hemorrhages ; Nervous System Diseases ; Otolithic Membrane ; Retrospective Studies ; Temporal Bone ; Tinnitus