BACKGROUND: Bohmer and Straumann have proposed that downbeat nystagmus is due to an asymmetry of the geometry of the vertical semicircular canals of the vestibular labyrinth. This hypothesis does not predict any sustained change in vertical nystagmus when subjects are placed in a head-upside-down position. METHODS: Using the magnetic search coil technique, I measured vertical eye movements in darkness in three normal human subjects while they maintained head-erect or head-upside-down positions. RESULTS: Two subjects had upbeat nystagmus and one downbeat nystagmus with their heads erect (slow-phase velocity < 1 deg/sec). All developed sustained nystagmus with quick phases directed towards their chins while in the head-upside-down position. CONCLUSIONS: These findings suggest that factors other than canal imbalance - otolithic or ocular - may also cause downbeat nystagmus.
Cerebellum ; Chin ; Darkness* ; Eye Movements ; Head ; Humans ; Nystagmus, Pathologic ; Otolithic Membrane ; Semicircular Canals ; Vestibule, Labyrinth

This review focuses on our effort in addressing the development and lesion-induced plasticity of the gravity sensing system. After severance of sensory input from one inner ear, there is a bilateral imbalance in response dynamics and spatial coding behavior between neuronal subpopulations on the two sides. These data provide the basis for deranged spatial coding and motor deficits accompanying unilateral labyrinthectomy. Recent studies have also confirmed that both glutamate receptors and neurotrophin receptors within the bilateral vestibular nuclei are implicated in the plasticity during vestibular compensation and development. Changes in plasticity not only provide insight into the formation of a spatial map and recovery of vestibular function but also on the design of drugs for therapeutic strategies applicable to infants or vestibular disorders such as vertigo and dizziness.
Animals ; Humans ; Neuronal Plasticity ; Neurons ; physiology ; Otolithic Membrane ; innervation ; physiology ; Vestibule, Labyrinth ; innervation ; physiology

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

OBJECTIVETo discuss the characteristics of subjective visual gravity (subjective visual vertical/horizontal, SVV/SVH) and assess its clinical application for peripheral unilateral vestibular compensation.

METHODS69 cases of acute peripheral unilateral vestibular dysfunction patients (case group) accepted SVV/SVH, spontaneous nystagmus (SN), caloric test (CT) and other vestibular function tests. 49 healthy people (control group) accepted SVV/SVH only. SVV/SVH, SN and unilateral weakness (UW) were selected as for the observation indicators. The correlations between SVV/SVH, SN, UW and courses were investigated respectively, as well as the characteristic of SVV/SVH, SN in period of vestibular compensation.

RESULTSAmong case group SVV, SVH positive in 42 patients(60.9%) and 44 patients(63.8%), the absolute values of the skew angle were in the range between 2.1°-20.0°, 2.1°-22.2°. Skew angles of SVV/SVH in control were in the range between -1.5°-2.0° and -2.0°-1.6°, and had no statistical significance with case group(t=5.336 and 5.864, P<0.05). SN-positive 28 cases (40.6%), the range of intensities at 2.4°-17.1°; UW-positive 50 cases (72.5%). In case group, positive correlation between SVV and SVH(r=0.948, P=0.00), negatively correlated between SVV/SVH and SN respectively(r values were -0.720, -0.733, P values were 0.00), no correlation between the skew angle of SVV/SVH, strength of SN and UW value(r values were 0.191, 0.189, and 0.179, P>0.05), there was no correlation between the absolute value of SVV, SVH, SN, UW with the duration (rs values were -0.075, -0.065, -0.212, and 0.126, P>0.05).

CONCLUSIONSubjective visual gravity can be used not only to assess the range of unilateral peripheral vestibular dysfunction, but also help assess the static compensatory of otolithic, guidance and assessment of vestibular rehabilitation.

Caloric Tests ; Gravitation ; Humans ; Otolithic Membrane ; Pilot Projects ; Vestibular Diseases ; physiopathology ; Vestibular Function Tests ; Vestibule, Labyrinth ; physiopathology ; Visual Perception

OBJECTIVE: The purpose of this study is to assess the effects of aging on air-conducted sound elicited cervical vestibular evoked myogenic potential (cVEMP) and ocular vestibular evoked myogenic potential(oVEMP) in normal people. METHOD: Sixty normal subjects were recruited for the vestibular evoked myogenic potential examination. Among them, 20-40 year-old group was setted as the first group, 41-60 year-old group was setted as the second group, > 60-year-old group was setted as the third group. Each group included 20 normal subjects. SPSS 16.0 software was used to analyze the data. RESULT: As the age growing, P1 latency prolonged, N1-P1 amplitude decreased, and amplitude asymmetric ratio increased in cVEMP; N1 latency prolonged, P1-N1 amplitude decreased, and amplitude asymmetric ratio increased in oVEMP. CONCLUSION With the age growing, the time of otolithic organ input pathways prolonged, the function of otolithic organ decreased and the decrease level may be asymeetrical on both sides.
Adult ; Aging ; Eye ; Head ; Hearing ; Humans ; Middle Aged ; Otolithic Membrane ; Vestibular Evoked Myogenic Potentials ; Vestibule, Labyrinth ; Young Adult

Cochlear Implantation ; Humans ; Vestibule, Labyrinth ; physiology

Cognition ; Humans ; Vestibular Diseases ; Vestibule, Labyrinth

OBJECTIVE: Analyze the data of the patients with sensorineural hearing loss in China and study the classification and incidence of inner ear malformationsby the high-resolution computed tomography. METHOD: The investigation took a retrospective review of CT findings relating to the 2,747 cases of outpatients. The inner ear malformations diagnosed by CT were classified according to the methods proposed by Sennaroglu. RESULT: (1)843 cases of inner ear malformations were found in 2747 cases of patients with sensorineural hearing loss by CT examination. The incidence of inner ear malformation was 30.69%(843/2747). (2) The epidemiological information of 843 cases of inner ear malformation according to Sennaroglu's classification was as follows: cochlea was 52. 31%(441/843), simple vestibular aqueduct was 40.33%(340/843), simple vestibular/ semicircular canal/internal auditory canal were 7. 35%(62/843) of the group. (3) 441 cases of cochlea malformation were consisted of these types of malformation: Michel deformity was 1.13% (5/441), cochlear aplasia was 1. 81% (8/441), common cavity deformity was 3. 17% (14/441), incomplete partition type I was 8. 62% (38/441), cochlea hypoplasia was 9. 07% (40/441) and incomplete partition type II was 76. 19% (336/441) of the group. CONCLUSION The results suggested that 30. 69% cases of inner ear malformation can be found in patients with sensorineural hearing loss, which is more higher than reported by the high-resolution computed tomography. Sennaroglu's classification is instructively significant in investigating the status of inner ear malformations.
China ; Cochlea ; Ear, Inner ; abnormalities ; Hearing Loss, Sensorineural ; etiology ; Humans ; Outpatients ; Retrospective Studies ; Semicircular Canals ; Temporal Bone ; Tomography, X-Ray Computed ; Vestibular Aqueduct ; Vestibule, Labyrinth

OBJECTIVETo examine the vesicular glutamate transporters (VGluTs: VGluT1-VGluT3) in the peripheral vestibular system.

METHODSThe vestibular structures, including Scarpa's ganglion (vestibular ganglion, VG), maculae of utricle and saccule, and ampullary cristae, from normal Sprague-Dawley rats were processed immunohistochemically for VGluTs, by avidin-biotinylated peroxidase complex method, with 3-3'-diaminobenzidine (DAB) as chromogen.

RESULTS(1) VGluT1 was localized to partial neurons of VG and to the putative primary afferent fibers innervating vestibular end-organs. (2) Intense VGluT3 immunoreactivity was detected in large number of sensory epithelia cells, and weak labeling of VGluT3-positive afferent fibers was in the maculae and ampullary cristae. (3) No or very weak VGluT2 immunoreactivity was observed in the VG and acoustic maculae.

CONCLUSIONThese results provide the morphological support that glutamate exists in the peripheral vestibular system, and it may play an important role in the centripetal vestibular transmission.

Acoustic Maculae ; metabolism ; Animals ; Neurons ; metabolism ; Rats ; Rats, Sprague-Dawley ; Vesicular Glutamate Transport Proteins ; classification ; metabolism ; Vestibule, Labyrinth ; metabolism ; Vestibulocochlear Nerve ; cytology ; metabolism

OBJECTIVE: To observe the ocular vestibular evoked myogenic potential (oVEMP) and the cervical vestibular evoked myogenic potential (cVEMP) in patients with vestibular diseases. METHOD: From March, 2011 to March, 2012, 13 patients (14 ears) with peripheral vestibular diseases were recruited. Each patient underwent conventional oVEMP and cVEMP examinations elicited by intensive air conducted sound (short tone burst, 500 Hz) in bilateral ears. RESULT: Thirteen cases (14 ears) were included in this study. They were 3 cases (3 ears) with Ramsay Hunt syndrome, 3 cases (4 ears) with acoustic neuroma, 1 case (1 ear) with VII and VIII cranial nerve trauma after head injury, 2 cases (2 ears) with vestibular neuritis, 3 cases (3 ears) with Meniere's disease, and Icase (1 ear) with unilateral hypoplasia of the internal auditory canal. Altogether, oVEMP could be elicited in only 2 ears (14. 3%) and cVEMP were found abnormal in 11 ears (78. 6%). CONCLUSION The otolithic vestibular end organs and their input pathways could be examined by cVEMP and oVEMP examinations in patients with peripheral vestibular disorders.
Acoustic Stimulation ; Eye ; Humans ; Meniere Disease ; Neuroma, Acoustic ; Otolithic Membrane ; Vestibular Diseases ; physiopathology ; Vestibular Evoked Myogenic Potentials ; Vestibular Neuronitis ; Vestibule, Labyrinth