1/43. The leaking labyrinthine lesion resulting from direct force through the auditory canal: report of five cases.The leaking labyrinthine lesion is treated by conservative methods or surgical procedures. With respect to the stapes, the surgical treatment is controversial. Five cases of middle ear injuries accompanying oval window rupture are reported herein. In each case, direct force through the auditory canal damaged not only the ossicular chain but also the oval window. Initial symptoms were sudden hearing loss with significant conductive disturbance and various degrees of unsteadiness. Spontaneous horizontal nystagmus directed toward the uninvolved ear was observed in each case. Tympanic cavities were promptly explored under general anesthesia and oval window injuries were confirmed. In each case, the damaged stapes was temporally removed from the oval window. Perilymphatic leakage was recognized in each case. Two patients had subluxation of the stapes with a paucity leakage. Three had complete luxation of the stapes with a relatively huge oval window fistula. Disrupted oval windows were repaired with temporalis muscle fascial grafts that were inserted under the middle ear mucosae surrounding the oval windows. The stapes were replaced in the repaired oval windows, and the ossicular chains were reconstructed without artificial grafts. Vestibular dysfunctions disappeared within 7 days, and satisfactory audiologic results were obtained in each case.- - - - - - - - - - ranking = 1keywords = nystagmus, horizontal (Clic here for more details about this article) |
2/43. Vestibular-evoked myogenic potentials in patients with dehiscence of the superior semicircular canal.Recently Minor and co-workers described patients with sound- and pressure-induced vertigo due to dehiscence of bone overlying the superior semicircular canal. Identifying patients with this "new" vestibular entity is important, not only because the symptoms can be very incapacitating, but also because they are surgically treatable. We present symptoms and findings for three such patients. On exposure to sounds, especially in the frequency range 0.5-1 kHz, they showed vertical/torsional eye movements analogous to a stimulation of the superior semicircular canal. They also showed abnormally large sound-induced vestibular-evoked myogenic potentials (VEMP), i.e. the short latency sternomastoid muscle response considered to be of saccular origin. The VEMP also had a low threshold, especially in the frequency range 0.5-1 kHz. However, in response to saccular stimulation by skull taps, i.e. when the middle ear route was bypassed, the VEMP were not enlarged. This suggests that the relation between the sound-induced and the skull tap-induced responses can differentiate a large but normal VEMP from an abnormally large response due to dehiscence of bone overlying the labyrinth, because only the latter would produce large sound-induced VEMP compared to those induced by skull taps.- - - - - - - - - - ranking = 4.9419260310815E-5keywords = vertical (Clic here for more details about this article) |
3/43. Rotational vertebral artery occlusion syndrome with vertigo due to "labyrinthine excitation".Leftward head rotations in a patient with a rotational vertebral artery occlusion syndrome elicited recurrent uniform attacks of severe rotatory vertigo and tinnitus in the right ear. These attacks were accompanied by a mixed clockwise torsional downbeat nystagmus with a horizontal component toward the right. A transient ischemia of the right labyrinth probably induced the attacks and led to a combined transient excitation of the right anterior and horizontal semicircular canals as well as the cochlea.- - - - - - - - - - ranking = 1.0016202486577keywords = nystagmus, horizontal (Clic here for more details about this article) |
4/43. Positional down beating nystagmus in 50 patients: cerebellar disorders and possible anterior semicircular canalithiasis.OBJECTIVES: To clarify the clinical significance of positional down beat nystagmus (pDBN). methods: A discussion of the neuro-otological findings in 50 consecutive patients with pDBN. RESULTS: In 38 patients there was evidence of CNS disease (central group) but in 12 there was not (idiopathic group). In the CNS group, presenting symptoms were gait, speech, and autonomic dysfunction whereas in the idiopathic group patients mostly reported positional vertigo. The main neurological and oculomotor signs in the CNS group were explained by cerebellar dysfunction, including 13 patients with multiple system atrophy. In patients with multiple system atrophy with a prominent extrapyramidal component, the presence of pDBN was helpful in the differential diagnosis of atypical parkinsonism. No patient with pDBN had the arnold-chiari malformation, a common cause of constant down beat nystagmus (DBN). In the idiopathic group, the pDBN had characteristics which suggested a peripheral labyrinthine disorder: vertigo, adaptation, and habituation. In six patients an additional torsional component was found (concurrently with the pDBN in three). Features unusual for peripheral disorder were: bilateral positive Dix-Hallpike manoeuvre in nine of 12 patients and selective provocation by the straight head-hanging manoeuvre in two. CONCLUSION: It is argued that some patients with idiopathic pDBN have benign paroxysmal positional vertigo (BPPV) with lithiasis of the anterior canal. The torsional component may be weak, because of the predominantly sagittal orientation of the anterior canal, and may not be readily seen clinically. Nystagmus provocation by bilateral Dix-Hallpike and straight head-hanging may be explained by the vertical upwards orientation of the ampullary segment of the anterior canal in the normal upright head position. Such orientation makes right-left specificity with the Dix-Hallpike manoeuvre less important than for posterior canal BPPV. This orientation requires a further downwards movement of the head, often achieved with the straight head-hanging position, to provoke migration of the canaliths. The straight head-hanging manoeuvre should be carried out in all patients with a history of positional vertigo and a negative Dix-Hallpike manoeuvre.- - - - - - - - - - ranking = 5.9903279273144keywords = nystagmus, vertical (Clic here for more details about this article) |
5/43. Inner ear pathologic features following mumps infection. Report of a case in an adult.temporal bone studies in an adult with a moderately severe, bilateral sensorineural hearing loss revealed bilateral cochlear changes 13 years after mumps infection. The organ of corti was completely absent in the greater part of the superior horizontal basal limbs, with occasional hair cell loss throughout the rest of the cochlea. The outer sulcus cell area was degenerated. The stria vascularis was normal, as was the tectorial membrane, except for small hyaline droplets. The number of nerve fibers was extremely decreased in the spiral bony lamina of the basal turns. Basophilic material, possibily representing degeneration of otoliths, was present in the saccule and utricle, bilaterally, with small amounts in all of the ampullae. This was considered to be either a possible result of cytotoxic cancerocidal therapy, or an incidental nonspecific change.- - - - - - - - - - ranking = 0.0016202486576588keywords = horizontal (Clic here for more details about this article) |
6/43. Caloric-eye tracking pattern test: I. Visual suppression and the possibility of simplified differential diagnosis between peripheral and central vertigo.During the examination of patients who complain of vertigo or who have equilibrium disorders, it is often difficult to determine the etiology of the disorders, that is, to determine whether it is dependent on a peripheral or central vestibular disorder. To attempt to guess the etiology in these cases, we devised a new method: the caloric eye-tracking pattern test. In normal subjects and in patients with peripheral disorders, as is well known, caloric nystagmus has little influence on the eye-tracking pattern. In contrast, in patients with central vestibular disorders, caloric nystagmus evoked abnormalities on the eye-tracking pattern, either superimposed or saccades, in spite of the fact that the eye-tracking pattern before the caloric stimulation is normal. These findings result from the visual suppression mechanism to the vestibular nystagmus. We can say that the visual suppression to the vestibular nystagmus is evoked more strongly bu pursuing a moving visual stimulus than by gazing at a stationary target. These results are interesting, not only form the physiological view point, but also from the clinical view point. There is a possibility of the differential diagnosis between peripheral and central vertigo.- - - - - - - - - - ranking = 3.9935190053694keywords = nystagmus (Clic here for more details about this article) |
7/43. Nodulus infarction mimicking acute peripheral vestibulopathy.The authors report two patients with cerebellar infarctions in the territory of the medial branch of the posterior inferior cerebellar artery who had vertigo, spontaneous ipsilesional nystagmus, and contralesional truncal lateropulsion. Although one of the two patients had slight dysmetria, overall signs closely mimicked those of acute peripheral vestibulopathy. The authors suggest that interruption of nodulouvular inhibitory projections to vestibular nuclei may account for the vestibular signs.- - - - - - - - - - ranking = 0.99837975134234keywords = nystagmus (Clic here for more details about this article) |
8/43. Superior semicircular canal dehiscence simulating otosclerosis.This is a report of a patient with an air-bone gap, thought 10 years ago to be a conductive hearing loss due to otosclerosis and treated with a stapedectomy. It now transpires that the patient actually had a conductive hearing gain due to superior semicircular canal dehiscence. In retrospect for as long as he could remember the patient had experienced cochlear hypersensitivity to bone-conducted sounds so that he could hear his own heart beat and joints move, as well as a tuning fork placed at his ankle. He also had vestibular hypersensitivity to air-conducted sounds with sound-induced eye movements (Tullio phenomenon), pressure-induced nystagmus and low-threshold, high-amplitude vestibular-evoked myogenic potentials. Furthermore some of his acoustic reflexes were preserved even after stapedectomy and two revisions. This case shows that if acoustic reflexes are preserved in a patient with an air-bone gap then the patient needs to be checked for sound- and pressure-induced nystagmus and needs to have vestibular-evoked myogenic potential testing. If there is sound- or pressure-induced nystagmus and if the vestibular-evoked myogenic potentials are also preserved, the problem is most likely in the floor of the middle fossa and not in the middle ear, and the patient needs a high-resolution spiral computed tomography (CT) of the temporal bones to show this.- - - - - - - - - - ranking = 2.995139254027keywords = nystagmus (Clic here for more details about this article) |
9/43. The canalith repositioning procedure: for treatment of benign paroxysmal positional vertigo.The Canalith Repositioning Procedure (CRP) is designed to treat benign paroxysmal positional vertigo (BPPV) through induced out-migration of free-moving pathological densities in the endolymph of a semicircular canal, using timed head maneuvers and applied vibration. This article describes the procedure and its rationale, and reports the results in 30 patients who exhibited the classic nystagmus of BPPV with Hallpike maneuvers. CRP obtained timely resolution of the nystagmus and positional vertigo in 100%. Of these, 10% continued to have atypical symptoms, suggesting concomitant pathology; 30% experienced one or more recurrences, but responded well to retreatment with CRP. These results also support an alternative theory that the densities that impart gravity-sensitivity to a semicircular canal in BPPV are free in the canal, rather than attached to the cupula. CRP offers significant advantages over invasive and other noninvasive treatment modalities in current use.- - - - - - - - - - ranking = 1.9967595026847keywords = nystagmus (Clic here for more details about this article) |
10/43. Rotatory nystagmus synchronous with heartbeat: a treatable form of nystagmus.PURPOSE: To describe a treatable form of nystagmus. methods: Two patients recently evaluated at the Mayo Clinic had experienced various forms of oscillopsia, imbalance, and worsening symptoms with a valsalva maneuver. Close inspection of the eye revealed a subtle rotatory nystagmus that was synchronous with the heartbeat. RESULTS: The two patients had surgical treatment for dehiscence of the superior semicircular canal; postoperatively, their symptoms completely resolved. This is a relatively newly discovered condition that has not been described on either slit-lamp or ophthalmoscopic examination. The cause is related to a dehiscence of the superior semicircular canal that permits communication of variable pressures between the intracranial cavity and the perilymphatic spaces of the semicircular canal. CONCLUSION: Being aware of this unusual form of nystagmus may permit physicians to diagnose it--one of the few treatable forms of nystagmus.- - - - - - - - - - ranking = 11.980557016108keywords = nystagmus (Clic here for more details about this article) |
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