| A 30-year-old man presented with sudden left deafness and vertigo. CT showed an osteolytic retrolabyrinthine tumour of the left temporal bone. High signal from the tumour and labyrinth was seen on fat-suppressed T 1-weighted images. At surgery, a haemorrhagic papillary-cystic adenocarcinoma of the endolymphatic sac was found. ( info) |
12/511. Superior semicircular canal dehiscence: a new cause of vertigo. There are many known causes of vertigo, but many cases remain unexplained. sound-induced, pressure-induced, or positional vertigo caused by bony dehiscence of the superior semicircular canal into the middle cranial fossa is a newly described etiology of vertigo. Three case studies of patients with CT evidence and surgical confirmation of bony dehiscence of the superior semicircular canal with variable presentations are described. The history, symptoms, CT findings, vestibular studies, and method of surgical repair are presented. Two patients had disabling vertigo and one had no vestibular symptoms. All underwent exploration via a middle cranial fossa approach with repair of the dehiscence. The bony dehiscence of the superior semicircular canal of the asymptomatic patient was identified and closed at the time of an encephalocele repair procedure. All patients did well postoperatively and both patients with vertigo improved. Bony dehiscence of the superior semicircular canal may cause vertigo or be asymptomatic and should be added to the differential diagnosis of vertigo. ( info) |
13/511. Silicone prosthesis prevents vertigo due to the defect at the mastoid process after mastoidectomy: a clinical report. This clinical report describes a 64-year-old woman with a bony defect in the mastoid process after mastoidectomy and who experienced vertigo on cold and windy days during winter. The patient noticed that packing a piece of paper or cotton into the defect prevented the vertigo. The patient refused surgical repair, so a silicone prosthesis was fabricated to fill the defect completely. electronystagmography confirmed the effectiveness of the prosthesis to prevent nystagmus. Although surgical repair is ideal, prosthesis repair of the defect may prove to be effective in some patients. ( info) |
14/511. Electron microscopic observations of the utricle and ampullae in a case of dizziness of suspected saccular origin. Electron microscopic observation was reported on the utricle and ampullae of a case, a 36-year-old male, with dizziness attack due to suspected saccular origin. After the removal of the utricle and ampullae, the dizziness recurred, and finally the saccular nerve section relieved the dizziness attack of this case. So the actual lesion was localized in the saccule and was not in the specimens obtained at the first surgery. Though most of hair cells appeared normal, there were a few with many vacuoles or shrinkage of the cytoplasm distributing sparsely throughout the sensory epithelia. The distribution of the pathological hair cells in the utricle was more general than in the ampullae. The sensory hair cells without pathology and the presynaptic structures were similar to those found in the experimental animals. Nerve and nerve endings showed normal structures. The findings may be physiological at this age group or an extension of the pathology of the dizziness-causing lesion. ( info) |
15/511. Lumbomuscular proprioceptive reflexes in body equilibrium. To evaluate the role of reflexes related to the lumbar proprioceptors in maintenance of body equilibrium, changes in equilibrium function of the eyes and body were observed after unilateral procainization of the lumbar erector muscles. Observations were made on normal subjects and vertigo cases with lumbar pain after whiplash injury using various equilibrium tests. The results obtained were as follows: (1) On unilateral procainization of the lumbar erector muscles of normal subjects, eye nystagmus and disturbances of the righting reflex developed. Simultaneously, changes in drift reactions of the lower limbs were detected by the stepping test. Namely, in many of the subjects examined the direction of stepping deviation became quite different from that before procainization, and stepping after procainization tended to show slight or moderate ataxic features, associated with a sensation of unsteadiness. (2) When procaine was injected unilaterally into tender spots in the lumbar erector muscles of traumatic vertigo cases, spontaneous eye nystagmus and disturbances of the righting reflex decreased. Simultaneously, significant changes in the drift reactions of the lower limbs were observed in many of the cases examined. Namely, the direction of deviation became the opposite of that before procainization and ataxia in walking almost disappeared with reduction in vertigo. The following conclusions were drawn from these findings: (1) The effects of procaine on equilibrium of normal subjects are in sharp contrast to its effects on equilibrium of traumatic vertigo cases. Findings in the former might be due to increased imbalance between the activities of the right and left lumbar proprioceptors, while those in the latter might be due to decreased imbalance between the two. (2) These findings support the view that from the standpoint of body equilibrium, there are two phases of the proprioceptive reflex, and that Fukuda's concept of "two phases of the labyrinthine reflex, i.e., a stage of disturbance and a stage of coordination", can be applied to interpretation of the proprioceptive reflex of lumbar origin. ( info) |
| A patient with acute vertigo, and normal findings on neurologic examination, was found to have vertebral artery dissection (VAD). This case shows that the clinical picture of VAD can mimic vertigo of labyrinthine (i.e, peripheral) origin. ( info) |
| We compared auditory and vestibular function between a patient with typical Cogan's syndrome and a patient with atypical Cogan's syndrome. Repeat audiograms demonstrated fluctuating sensorineural hearing loss in the affected ear. Brainstem auditory evoked response testing revealed no abnormalities. Hallpike caloric testing showed a decreased response in the affected ear in the typical case and responses within normal limits in the atypical case. Sinusoidal harmonic acceleration was normal in the typical case, and there was an abnormal phase at 0.01 Hz in the atypical case. endolymphatic hydrops was investigated by electrocochleography. In both patients, there was an enhancement of the summating potential, with an increased ratio of summating potential to action potential amplitude. This finding is consistent with endolymphatic hydrops. ( info) |
18/511. Superior canal dehiscence syndrome. OBJECTIVE: To present the symptoms, signs, and findings on diagnostic tests of patients with the superior canal dehiscence syndrome and to describe the surgical procedures used to treat the dehiscence in five patients. DESIGN AND SETTING: Prospective study of a series of patients identified as having this syndrome at a tertiary care referral center. patients AND RESULTS: Seventeen patients with vertigo, oscillopsia, or both evoked by intense sounds or stimuli that caused changes in middle ear and/or intracranial pressure were identified over a 4-year period. The evoked eye movements had vertical and torsional components, with the direction corresponding to the effect of the stimuli in causing excitation (Valsalva against pinched nostrils, tragal compression, sounds) or inhibition (Valsalva against a closed glottis or jugular venous compression) of the affected superior semicircular canal. Thirteen (76%) of these patients also experienced chronic dysequilibrium that was often the most debilitating symptom. Dehiscence of bone overlying the superior semicircular canal on the affected side was confirmed with computed tomographic scans in each case. Surgical procedures through the middle fossa approach to plug or resurface the superior canal were performed in five patients (canal plugging in three cases and resurfacing of the dehiscence without plugging in two). The debilitating symptoms resolved or improved after the procedures. Signs of vestibular hypofunction, without loss of hearing, were noted in one patient after plugging of the superior canal and in one other patient after resurfacing of the canal. CONCLUSIONS: The superior canal dehiscence syndrome is identified based on characteristic symptoms, signs, and computed tomographic findings. The clinical presentation and findings can be understood in terms of the effect of the dehiscence on the physiology of the labyrinth. The syndrome is a treatable cause of vestibular disturbance. ( info) |
19/511. An unusual complication of cochlear implant: benign paroxysmal positional vertigo. Three days after the initial fitting of the cochlear device a 40-year-old woman complained of severe rotational vertigo following head movements associated with neurovegetative symptoms. Otoneurological evaluation revealed a horizontal paroxysmal positional nystagmus beating towards the lowermost ear, induced by rolling the patient's head from supine both to the right or to the left lateral position suggesting the diagnosis of benign paroxysmal positional vertigo of the left horizontal semicircular canal. The nystagmus characteristics were the same whether the cochlear device was switched on or off. The hypothesis of an otolith dislodging due to the electrical stimulation during the initial fitting is discussed. ( info) |
| The relationship of vascular disease of the vertebrobasilar artery system to isolated vertigo was examined by magnetic resonance imaging and angiography. Eighty-nine individuals complaining of vertigo were evaluated by standard otoneurologic investigations, and the data were correlated with the vascular patterns of the cervical region and posterior fossa. The age distribution extended from the fourth decade to the ninth decade; the peak occurrence was observed in the eighth. Approximately 85% of the group experienced numerous episodes of vestibular dysfunction from months to years before examination; the remaining segment was examined following the first episode due to severity or persistence of symptoms. The criteria for vascular abnormality proposed by the authors are based upon comparison with previous normal findings. Approximately 52% of the cohort demonstrated abnormal configurations or evidence of diminished flow within the vertebrobasilar artery system. Of this segment, a vertebral artery was most frequently abnormal, in 76%; the basilar artery was judged pathological in 32%, and combined disease of several arteries was evident in 20%. ( info) |