1/65. Vestibulo-ocular reflex pathways in internuclear ophthalmoplegia.We measured the vestibulo-ocular reflex (VOR) during head impulses in a patient with right-sided internuclear ophthalmoplegia. Head impulses are rapid, passive, high-acceleration, low-amplitude head rotations in the direction of a particular semicircular canal (SCC). Adduction of the right eye was abnormally slow during right lateral SCC head impulses. The VOR during left posterior SCC impulses was severely deficient in both eyes, but the VOR during left anterior SCC impulses was only slightly deficient. We suggest that the vertical vestibulo-ocular pathways in humans are connected in SCC-plane coordinates, not the traditional roll and pitch coordinates, and that anterior SCC signals do not travel exclusively in the medial longitudinal fasciculus.- - - - - - - - - - ranking = 1keywords = canal (Clic here for more details about this article) |
2/65. Acute cerebellar ataxia with human parvovirus B19 infection.A 2 year old boy developed acute cerebellar ataxia in association with erythema infectiosum. During the disease, genomic dna and antibodies against human parvovirus B19 were detected in serum but not in cerebrospinal fluid. parvovirus B19 associated acute cerebellar ataxia might occur due to transient vascular reaction in the cerebellum during infection.- - - - - - - - - - ranking = 0.0013605566564631keywords = spinal (Clic here for more details about this article) |
3/65. Posterior semicircular canal nystagmus is conjugate and its axis is parallel to that of the canal.A patient with a postoperative fistula of the left posterior semicircular canal is presented. Negative pressure in the external ear canal produced upbeat-torsional nystagmus, which was recorded in three dimensions using binocular scleral search coils. The nystagmus was conjugate, without skew deviation, and its trajectory corresponded to the anatomic axis of the left posterior canal. The current study helps validate Ewald's first law in humans: the axis of nystagmus should match the anatomic axis of the semicircular canal that generated it. This law is clinically useful in diagnosing pathology of the vestibular end-organ, such as benign paroxysmal positional vertigo or the superior semicircular canal dehiscence syndrome.- - - - - - - - - - ranking = 13keywords = canal (Clic here for more details about this article) |
4/65. Periodic alternating nystagmus and vestibulo-spinal system facilitating activity.OBJECTIVE: Periodic alternating nystagmus has been associated with the instability of the velocity storage mechanism, which is known to play an important role in both the vestibulo-oculomotor and the optokinetic systems. In the present study we looked for a possible spinal equivalent to PAN. methods AND RESULTS: In 3 PAN patients, the h-reflex amplitude proved to be slightly but significantly influenced by nystagmus direction, in that it was greater when the nystagmus was beating toward the stimulation side. CONCLUSIONS: This finding suggests that projections from velocity storage may play a role not only in the ocular motor but also in assisting postural stability through the vestibulo-spinal system.- - - - - - - - - - ranking = 0.0081633399387785keywords = spinal (Clic here for more details about this article) |
5/65. Clinical effect of canal plugging on paroxysmal positional vertigo.A 63-year-old woman had disabling positional vertigo for four months. She showed intense direction-changing apogeotropic nystagmus. Conservative treatment failed to resolve her vertigo. From the findings of the nystagmus, cupulolithiasis of the right lateral canal was suspected. Plugging of this canal successfully eliminated the nystagmus and positional vertigo. Positional vertigo can sometimes be disabling and unresponsive to conservative therapy. Careful analysis of the nystagmus may allow selection of the most appropriate treatment.- - - - - - - - - - ranking = 6keywords = canal (Clic here for more details about this article) |
6/65. Continuous vertigo and spontaneous nystagmus due to canalolithiasis of the horizontal canal.The authors present a patient with benign paroxysmal positional vertigo of the right horizontal semicircular canal who developed persistent vertigo with spontaneous horizontal nystagmus to the left and caloric hypoexcitability on the right after a head shaking maneuver. Both spontaneous nystagmus and canal paresis resolved after repeated shaking of the head. The most probable mechanism of this type of vertigo is plugging of the horizontal canal by otoconial particles with a negative endolymph pressure between plug and cupula.- - - - - - - - - - ranking = 11keywords = canal (Clic here for more details about this article) |
7/65. Tullio phenomenon with dehiscence of the superior semicircular canal.HYPOTHESIS: The goal of the investigation was to determine if vector analysis of nystagmus in a patient with the Tullio phenomenon could determine the source of the nystagmus. BACKGROUND: The Tullio phenomenon consists of the combination of vertigo and abnormal eye and/or head movements provoked by sound. Dehiscence of the superior semicircular canal can be found in certain patients with the Tullio phenomenon. methods: The patient was tested with pure tones ranging from 250 to 3,000 Hz at 95dB HL. The time course of the three-dimensional vector of eye movement, including torsion and vertical and horizontal displacement angles was determined by individual stop-frame analysis of digitized video. RESULTS: Torsion amplitude varied from 1 to 7 degrees; vertical amplitude varied from 1 to 5 degrees; and horizontal amplitude varied less than 1.5 degrees. The maximal response occurred on stimulation of the right ear with a 1,250-Hz 95-dB HL tone. This elicited a reliable counterclockwise torsional and down-beating fast phase nystagmus as seen from the examiner's point of view. Comparison of the nystagmus with known canal vectors identified the right superior semicircular canal as the source of stimulation. High-resolution computed tomography scan of the temporal bone showed a definite right superior canal dehiscence. CONCLUSION: The origin of nystagmus from the Tullio phenomenon can be identified by calculating the three-dimensional vector of the observed nystagmus. We show that vector analysis of the observed eye movement can be used to infer the source of nystagmus in these patients. The development of real-time, three-dimensional vector analysis of nystagmus is desirable.- - - - - - - - - - ranking = 8keywords = canal (Clic here for more details about this article) |
8/65. A liberatory maneuver for the treatment of horizontal canal paroxysmal positional vertigo.OBJECTIVE: The purpose of this study was to determine the effectiveness of a new liberatory maneuver in the management of the geotropic variant of horizontal canal paroxysmal positional vertigo (HC-PPV). STUDY DESIGN: Case review. SETTING: Outpatient clinic. patients: The diagnosis of HC-PPV was based on the history of recurrent sudden crisis of vertigo associated with bursts of horizontal geotropic paroxysmal nystagmus provoked by turning the head from the supine to either lateral position. The patients were 11 men and 21 women ranging in age from 30 to 85 years (average 55.43 years), and the average duration of symptoms was 7.68 days. INTERVENTIONS: All patients were treated with a liberatory maneuver based on the hypothesis that the syndrome is caused by the presence of free-floating dense particles inside the endolymph of the posterior arm of the semicircular horizontal canal. The maneuver favors their outmigration into the utricle. patients were reexamined immediately after the treatment and again 2 days later. MAIN OUTCOME MEASURE: The treatment outcome was considered as responsive when, after one or more liberatory maneuvers, the clinical signs of PPV disappeared at the end of physical therapy. RESULTS: The liberatory maneuver resulted in a complete remission of the positioning vertigo and nystagmus in all patients after the first session. CONCLUSIONS: This approach represents a simple and effective approach to the management of the geotropic form of HC-PPV.- - - - - - - - - - ranking = 6keywords = canal (Clic here for more details about this article) |
9/65. perilymph fistula associated with pulse-synchronous eye oscillations.Three-dimensional eye movements (scleral search coil system) were recorded in a patient with a surgically acquired perilymph fistula of the left horizontal semicircular canal. Spontaneous horizontal pendular nystagmus was found to be related to the heart rate and may be caused by pressure transfer of blood pulses to the labyrinth. In addition, a contralesional horizontal jerk nystagmus was elicited by valsalva maneuver, indicating that Ewald's first law may not only be valid for excitation but also for inhibition.- - - - - - - - - - ranking = 1keywords = canal (Clic here for more details about this article) |
10/65. Periodic alternating nystagmus associated with arnold-chiari malformation.The arnold-chiari malformation type I is a rare congenital condition characterized by herniation of the cerebellar tonsils into the upper cervical spinal tract. Various otoneurological manifestations occur in patients with the disease, which has usually been associated with a downbeat type of nystagmus. In this paper a case with this condition is reported presenting with periodic alternating nystagmus (PAN), which is a rare type of nystagmus observed in diseases of the central nervous system of different pathologies. The patient had a complete otoneurological examination and vestibular function testing. diagnosis was established by using magnetic resonance imaging (MRI).- - - - - - - - - - ranking = 0.0013605566564631keywords = spinal (Clic here for more details about this article) |
| | Next -> |