Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “VESTIBULAR APPARATUS”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,207 records · Page 67Linked to original sources
PubMed1989

[The intermediate nerve and its place in the system of cranial nerves].

The intermediate nerve (IN) in embryogenesis of man, cat and white rat is formed similarly. From the common with the VIII cranial nerve anlage the geniculum node, the vestibular and cochlear ganglia are emerged. A separated root of the IN connects the geniculum node with the nuclei, situating in the CNS. From the geniculum node main branches of the IN get off: the greater petrosal nerve and the cord of the tympanum, its fibers in the temporal bone canal run in the facial nerve trunk. In the periphery the IN branches unite with other cranial nerves, make connections with branches of vegetative (parasympathetic) ganglia and plexuses. They spread along a large territory, forming a system of parasympathetic innervation in the area of the head and ensuring with specific nervous apparatuses the gustatory organ. It is expedient to select the IN into an independent cranial nerve and confirm it the number of the regular pair.

Animals↗
PubMed1986

Eye movements induced by lateral tilt and testing of otolithic function.

In the last few years, we have studied ocular reflexes caused by tilting stimulations in test subjects placed in an upright sitting position on a chair apparatus which tilts continuously. In healthy persons, a weak nystagmus can be observed, and involves a nystagmus of minor amplitude and showing a small number of beats. The actual incidence of nystagmus in the younger group was minimal, but it tended to increase with age. This occurrence is considered to be due to age-related degeneration of the otolithic organ. Patients with vertigo and/or dizziness clearly develop nystagmus. These responses are classified as follows: type I is of fixed direction; type II is of changed direction; and type III is a combination of the first and second types. Among the peripheral vestibular disorders, particularly involving those patients with benign paroxysmal positional vertigo, a nystagmus of changed direction was found. This type was rarely seen in patients with other vestibular disorders, but was a common occurrence in healthy individuals who readily experienced motion sickness. These observations have led us to conclude that patients with benign paroxysmal positional vertigo have definite reactions which are similar to those of individuals with motion sickness, and that such depends on the susceptibility of the otolithic organs.

Adult↗
PubMed1994

Sequential clinical comparison between two commercially available rhinomanometers.

To assess nasal resistance in the treated as well as decongested states, two custom-built rhinomanometers (Rhino-Comp, manufactured by Cintec, Sweden, and Rhinomanometer 200, manufactured by Atmos, Germany) were sequentially employed in 53 non-selected consecutive patients referred for chronic or recurring nasal obstruction complaints, using the same active anterior rhinomanometric method. Final mean results from both equipments were submitted to paired statistical analysis. No correlation was found between the R150 results provided by the two rhinomanometers, albeit a 1.26 to 1.30 difference was encountered in the Rhinomanometer 200/Rhino-Comp ratio when the averaged mean values of all R150 results from both equipments were compared, suggesting that the discrepancy could be due to technical specificities intrinsic to each apparatus, with a tendency to produce systematic R150 differences. When the graphic aspect of the curves from both equipments were compared using the Broms system parameter V2 values, a remarkable correlation was seen between Rhino-Comp and Rhinomanometer 200 in expiratory (but not inspiratory) results, suggesting that the expiratory curves produced by the two equipments are graphically similar, at least until the Broms system radius 2 interception. Enough data was also found to support the possibility that the manufacturer's option to use a nose adaptor instead of adhesive tape for anterior nares occlusion with the Rhinomanometer 200 equipment could interfere with nasal vestibular function and thus artificially affect resistance measurements. Finally, patients' preference for either equipment examination procedures are discussed.

Adolescent↗
PubMed2005

Degradation of head direction cell activity during inverted locomotion.

Head direction (HD) cells in the rat limbic system carry information about the direction the head is pointing in the horizontal plane. Most previous studies of HD functioning have used animals locomoting in an upright position or ascending/descending a vertical wall. In the present study, we recorded HD cell activity from the anterodorsal thalamic nucleus while the animal was locomoting in an upside-down orientation. Rats performed a shuttle-box task requiring them to climb a vertical wall and locomote across the ceiling of the apparatus while inverted to reach an adjoining wall before ascending into the reward compartment. The apparatus was oriented toward the preferred direction of the recorded cell, or the 180 degrees opposite direction. When the animal was traversing the vertical walls of the apparatus, the HD cells remained directionally tuned as if the walls were an extension of the floor. When the animal was locomoting inverted on the ceiling, however, cells showed a dramatic change in activity. Nearly one-half (47%) of the recorded cells exhibited no directional specificity during inverted locomotion, despite showing robust directional tuning on the walls before and after inversion. The remaining cells showed significantly degraded measures of directional tuning and random shifts of the preferred direction relative to the floor condition while the animal was inverted. It has previously been suggested that the HD system uses head angular velocity signals from the vestibular system to maintain a consistent representation of allocentric direction. These findings suggest that being in an inverted position causes a distortion of the vestibular signal controlling the HD system.

Action Potentials↗
PubMed2000

Anatomy and histology of the lacrimal fluid drainage system.

Five human specimens of the lacrimal canaliculus and sac were examined by light and scanning electron microscopy. The superior and inferior lacrimal canaliculi are lined with stratified squamous epithelium that is non-keratinized and non-mucin-producing. The common canaliculus is also lined with stratified squamous epithelium, but its lumen is much narrower than the lumen of the superior and inferior canaliculi. The common canaliculus opens into an ample space called the vestibule, where the epithelium changes to high pseudostratified columnar and then low pseudostratified columnar. The vestibule continues to the infundibulum of the lacrimal sac. The infundibulum is formed by several epithelial folds that radiate from the vestibular opening to the lacrimal sac. The vestibule and infundibulum are consistent transitional structures from the common canaliculus to the lacrimal sac. The connective tissue of the lamina propria from the common canaliculus to the lacrimal sac has two histological characteristics: numerous free cell aggregates (= lymphoid structure) and numerous venules and capillaries (= cavernous structure).

Aged↗
PubMed2004

[Cogan síndrome. Audio-vestibular findings in a patient and literature review].

Cogan Sindrome is described as the association of non-syphilic interstitial keratitis with vestibulo-auditory symptoms in its typical form. We are reporting a case corresponding to a 32 years old male who consulted at first place for ophthalmic clinic and, two months later, affected of bilateral neurosensorial hearing loss with tinnitus and vestibular dysfunction. In spite of the corticoid treatment our patient has not improved. His hearing disorder was even worse after one year-follow up. A bibliographic review has been performed related to this pathology whose etiology is still unknown.

Adult↗
PubMed1991

Ultrastructural evidence of a merocrine secretion in the human endolymphatic sac.

The results of a light and transmission electron microscopic analysis of an endolymphatic sac (ES) from a patient suffering from episodic vertigo, tinnitus, and hearing loss are presented. A biopsy of the intraosseous portion of the ES was obtained during a translabyrinthine approach to section the vestibular nerve in the internal acoustic meatus. The material consisted mainly of tubular epithelial structures filled with heavily stained material. Pathologically dilated and degranulated rough endoplasmic reticuli and disaggregation of polyribosomes with accumulation of solitary ribosomes in the cytosol and endoplasmic reticulum suggested a disturbed epithelial cell protein synthesis. Ultrastructural evidence of an increased merocrine secretion of glycoprotein conjugates into the ES was noted. This made it possible to analyze the presumed intracellular secretory pathways. An increased number of intraepithelial lymphocytes and monocytes was observed. Since the inner ear had been subjected to surgical intervention before the vestibular nerve section, no conclusions can be drawn as to whether the patient's symptoms were related to the disturbed protein metabolism and hypersecretion of glycoprotein conjugates into the ES. The findings support earlier experimental results that indicate that the ES has not only a resorptive function but also a secretory one.

Adult↗
PubMed2003

Trunk sway measures of postural stability during clinical balance tests in patients with chronic whiplash injury symptoms.

STUDY DESIGN: Trunk sway occurring during clinical stance and gait tasks was compared between a group of subjects with a chronic whiplash injury, resulting from an automobile collision, and a normal collective. OBJECTIVES: To examine if population specific trunk sway patterns for stance and gait could be identified for chronic whiplash injury patients. SUMMARY OF BACKGROUND DATA: Our previous work has established that it is possible to identify specific patterns of stance and gait deficits for vestibular loss (both acute and compensated) patients and those with Parkinson's disease. Our question was whether it was possible to use the same stance and gait tasks to identify patterns of trunk sway differences with respect to those of healthy subjects and individuals with a chronic whiplash injury. METHODS: Twenty-five subjects with history of whiplash injury and 170 healthy age-matched control subjects participated in the study. Trunk sway angular displacements in chronic whiplash patients were assessed for a number of stance and gait tasks similar to those of the Tinetti and Clinical Test of Sensory Interaction and Balance (CTSIB) protocols. We used a lightweight, easy-to-attach, body-worn apparatus to measure trunk angular displacements and velocities in the roll (lateral) and the pitch (forward-backward) planes. RESULTS: Data analysis revealed several significant differences between the two groups. A pattern could be identified, showing greater trunk sway for stance tasks and for complex gait tasks that required task-specific gaze control such as walking up and down stairs. Trunk sway was less, however, for simple gait tasks that demanded large head movements but no task-specific gaze control, such as walking while rotating the head. CONCLUSIONS: Subjects who have a chronic whiplash injury show a characteristic pattern of trunk sway that is different from that of other patient groups with balance disorders. Balance was most unstable during gait involving task-specific head movements which possibly enhance a pathologic vestibulo-cervical interaction.

Abdomen↗
PubMedDate not supplied

[Periodontic-endodontic lesions: diagnostic and therapeutic indications].

The presence of connections between periodontium and endodontium can lead to the diffusion of an infection from one apparatus to another. The involvement of both periodontium and endodontium is defined as Combined Periodontic-Endodontic lesions. This definition is not based on the initial etiology of the lesion and either the endodontic or periodontal lesion may be the cause or the result of the other or both may develop independently. The lesions must be correctly diagnosed for the best therapeutic approach. The diagnosis is based on clinical symptoms and radiographic analysis; clinical signs must show the presence of periodontal probing and pulpal necrosis. Radiographic examination can confirm the involvement of both periodontium and endodontium only if the lesion is present on the mesial and distal part of the diseased tooth; in the case of a palatal/lingual or vestibular lesion such evidence will not be detectable. The therapeutic approach is always based on an initial endodontic treatment followed, if needed, by the proper periodontal treatment.

Dental Pulp Diseases↗
PubMed1980

Granule formation in rat mast cells. Study with serial ultrathin sections.

The process of granule formation in mast cells was investigated with young mast cells in the milky spot of adult rats, seven days after an intraperitoneal injection of distilled water. Serial ultrathin sections were made and examined with an electron microscope to reveal the following results. The early step of granule formation is observed as a complex which consists of an irregularly shaped narrow vestibular space and several primary aggregate granules which are bowl-like in form, attached to the vestibular space and contain a few subgranules. The vestibular space has microvilli. The precursor materials seem to be secreted from the microvilli and transported through the vestibular space into the primary aggregate granules, being coagulated to become subgranules. As the subgranules increase in number, the primary aggregate granules become aggregate granules which grow further to their maximum size. With further addition of the materials, the aggregate granules become, through a step of ropy cord granule, mature dense homogeneous granules. The complex seems to remain as a unit after the maturation of granules and to react as a whole to any stimulus.

Animals↗
PubMed1983

[Measurement of the latencies of voluntary and corrective ocular saccades. Value in otoneurology].

The delay between the stimulus and the voluntary eye saccade is the only parameter of the saccadic system which can be measured by using standard apparatus. Taking manually the measurements made on records obtained by using minicomputer; the authors show that such manual measurement of latencies is easy and yet sufficiently accurate to be of great clinical value. The latencies of voluntary saccades are normal in peripheral pathology (less than 250 milliseconds). Latencies of voluntary saccades are significantly increased in extrinsic brain stem lesions: tumours (in particular ponto cerebellar tumours), meningitis, head injury; but the velocity of the saccade is normal. This effect goes in parallel with impairement of the smooth pursuit. In intrinsic brain stem lesions (multiple sclerosis, acute brain stem stroke, oculomotor paralysis) latencies are increased bilaterally and above all, there is a significant slowing of the saccade. The role of fatigue increased latencies in some patients of this series. Two populations can be discerned in vestibular neuritis: one normal and one with abnormal smooth pursuit and increased saccadic latencies.

Brain Diseases↗
PubMed1997

Image-interactive orientation in the middle cranial fossa approach to the internal auditory canal: an experimental study.

Approaches through the middle cranial fossa directed at reaching the internal auditory canal (IAC) invariably employ exposure of the geniculate ganglion, the superior semicircular canal (SSC) or the epitympanum. This involves risk to the facial nerve and hearing apparatus. To minimize this risk, we conducted a laboratory study on 9 cadaver temporal bones by using an image-interactive guidance system (StealthStation) to provide topographic orientation in the middle fossa approach. Surface anatomic fiducials such as the umbo of the tympanic membrane, Henle's spine, the root of the zygoma and various sutures were used as fiducials for registration of CT-images of the temporal bone. Accurate localization of the IAC was achieved in every specimen. Mean target localization error varied from 1.20 to 1.38 mm for critical structures in the temporal bone such as the apex of the cochlea, crus commune, ampula of the SSC and facial hiatus. Our results suggest that frameless stereotaxy may be used as an alternative to current methods in localizing the IAC in patients with small vestibular schwannomas or intractable vertigo undergoing middle fossa surgery.

Cadaver↗
PubMed1985

The vestibuloocular reflex of the adult flatfish. I. Oculomotor organization.

The flatfish species constitute a natural paradigm for investigating adaptive changes in the vertebrate central nervous system. During metamorphosis all species of flatfish experience a 90 degree change in orientation between their vestibular and extraocular coordinate axes. As a result, the optic axes of both eyes maintain their orientation with respect to earth horizontal, but the horizontal semicircular canals become oriented vertically. Since the flatfish propels its body with the same swimming movements when referenced to the body as a normal fish, the horizontal canals are exposed to identical accelerations, but in the flatfish these accelerations occur in a vertical plane. The appropriate compensatory eye movements are simultaneous rotations of both eyes forward or backward (i.e., parallel), in contrast to the symmetric eye movements in upright fish (i.e., one eye moves forward, the other backward). Therefore, changes in the extraocular muscle arrangement and/or the neuronal connectivity are required. This study describes the peripheral and central oculomotor organization in the adult winter flounder, Pseudopleuronectes americanus. At the level of the peripheral oculomotor apparatus, the sizes of the horizontal extraocular muscles (lateral and medial rectus) were considerably smaller than those of the vertical eye muscles, as quantified by fiber counts and area measurements of cross sections of individual muscles. However, the spatial orientations and the kinematic characteristics of all six extraocular muscles were not different from those described in comparable lateral-eyed animals. There were no detectable asymmetries between the left and the right eye. Central oculomotor organization was investigated by extracellular horseradish peroxidase injections into individual eye muscles. Commonly described distributions of extraocular motor neurons in the oculomotor, trochlear, and abducens nuclei were found. These motor neuron pools consisted of two contralateral (superior rectus and superior oblique) and four ipsilateral populations (inferior oblique, inferior rectus, medial rectus, and lateral rectus). The labeled cells formed distinct motor neuron populations, which overlapped little. As expected, the numbers of labeled motoneurons differed in horizontal and vertical eye movers. The numerical difference was especially prominent in comparing the abducens nucleus with one of the vertical recti subdivisions. Nevertheless, there was bilateral symmetry between the motoneurons projecting to the left and right eyes.(ABSTRACT TRUNCATED AT 400 WORDS)

Abducens Nerve↗
PubMedDate not supplied

Spindle cell lipoma within the larynx: a case report with correlated light and electron microscopy.

A spindle cell lipoma was removed surgically from the right intralaryngeal lesion of a 68-year-old man. Laryngoscopy demonstrated a spherical protrusion with intact mucosa near the vestibular fold. CT scan examination showed a low-density mass just medial to the thyroid cartilage. Light microscopy revealed that the circumscribed tumor consisted of mature lipocytes and spindle cells. Electron microscopy revealed that the spindle cells lacked a typical basal lamina. Such tumors are more frequent in the posterior aspect of the neck and shoulder regions. To our knowledge, this is the first reported case of a spindle cell lipoma within the larynx.

Aged↗
PubMed1993

Effects of increased inertial load in dynamic and randomized perturbed posturography.

Muscular weakness is present in many diseases. The present study attempted to model a relative weakness of postural control muscles by loading the subjects with extra weight, and the effects on EquiTest dynamic posturography and randomized perturbed posturography were assessed. Ten healthy subjects aged 15-39 years (mean 26 years) were used. Their weights ranged 53-82 kg. Equilibrium was measured with and without an extra 20% of body weight attached to the upper part of the trunk by means of pieces of lead metal placed in a specially sewn shirt. Dynamic posturography (EquiTest) comprises a sensory organization test in which the support surface and visual surround are either stable or referenced to the patient's sway, his or her eyes open or closed. In a movement coordination part the platform makes active movements. Antero-posterior sway on a stable support surface with absent or distorted visual cues was marred, and the correction pattern was altered on a movable support surface when the vision was absent. Furthermore, the EquiTest apparatus was driven by special software to produce randomized antero-posterior movements during 45 s. In addition to stable conditions, small and large amplitude perturbations were used. The subject's ability to remain in equilibrium was estimated by the sway velocity and a confidence ellipse sway area during 45 s. During weightbearing, sway areas were larger on the stable support surface both with and without vision. Postural sway velocity was lower when vision was absent both using small and large amplitudes.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1995

Ocular movement during reading in patients with congenital nystagmus.

When a healthy person reads sentences arranged horizontally, the eye movement pattern is a series of regular saccades and rest periods. However, eye movements while patients with oculomotor disturbances are reading remain to be defined. In this study, 4 patients with congenital nystagmus (CN) were studied. Coordinated movements of eye and head are also studied by a new apparatus with terrestrial magnetism sensor. While subjects were reading, an eye movement pattern was superimposed by the CN waveform and showed few rest periods. Eye velocity of less than 4 degrees/s was noted in almost every cycle of the eye movements while the patients with CN were reading. When they were requested to read sentences and simultaneously rotate their head naturally, the head movements had the effect of cancelling the eye instability. This finding may be interpreted as a kind of "eye-head coordination".

Attention↗
PubMed2004

Responses to whole head-and-body tilts with and without passive ankle dorsiflexion in the absence of visual feedback.

OBJECTIVES: We have investigated lower limb responses in seven blindfolded healthy subjects to well controlled tilts in the standing position. Our aims were (1) to determine the effect of head acceleration magnitude on responses evoked by whole head-and-body tilts, and (2) to establish whether tilt-evoked responses are modifiable by passive ankle dorsiflexion. Whole head-and-body tilts evoked responses in the biceps femoris, medial gastrocnemius and tibialis anterior muscles. METHODS: Seven young healthy subjects stood on a spring-activated tilting apparatus and underwent sudden whole head-and-body tilts of about 15 degrees from the vertical position, with or without passive ankle dorsiflexion. Head acceleration was recorded with a linear accelerometer and ankle angular displacement with a potentiometer. Surface EMG signals were recorded in the right biceps femoris, medial gastrocnemius and tibialis anterior muscles. RESULTS: As the peak of head acceleration was increased from 0.5 g to 1.8 g, the frequency of occurrence of tilt-evoked responses increased from 7% to 60% of trials in the biceps femoris muscle during whole head-and-body tilts. In general, the more proximal muscle (biceps femoris) was activated before the more distal muscle (medial gastrocnemius) during whole head-and-body tilts, while the opposite pattern was found during tilt with dorsiflexion. CONCLUSIONS: Our results indicate that the occurrence of tilt-evoked responses increases with an increase in the amplitude of tilting acceleration. This suggests that tilt-evoked responses are dependent, at least in part, on vestibular stimulation. In addition, the spatio-temporal pattern of biceps femoris and medial gastrocnemius muscle activation was opposite during whole head-and-body tilts and tilts with dorsiflexion. This finding suggests that foot/ankle somatosensory inputs can modify tilt-evoked responses.

Adolescent↗
PubMed1989

Carbohydrates of the guinea pig vestibular supporting cells.

Ultrastructural localization of glycoconjugates with special reference to the synthesizing process was studied in the guinea pig vestibular supporting cells using the tannic acid and ruthenium red staining technique. The extracellular glycoconjugate (glycocalyx) was well stained by the ruthenium red which may be synthesized by GERL complex. The supporting cell has a numerous number of granules which also contain tannic acid positive glycoconjugate. These granules were closely related to the Golgi complex as well as the apical cell surface. It may be indicated that the glycoconjugate of the supporting cells is glycosylated at the Golgi complex, stored in the granules, transported, secreted, and form otoconial membrane and the cupula.

Acoustic Maculae↗