Lars Ödkvist

Usher syndrome: An otoneurologic study

Usher syndrome is an autosomal recessive disorder characterized by severe hearing loss or deafness and retinitis pigmentosa. Eleven families with 25 affected members were studied. The test battery included genetic studies, clinical examination, audiological, ophthalmologic, and otoneurological tests, and magnetic resonance imaging. Sixteen affected persons had profound hearing loss or were considered anacusic, with absent bilateral vestibular responses. These patients had varying degrees of retinitis pigmentosa. These 16 patients were considered to have type I Usher syndrome. Nine persons were diagnosed as Usher type II with a moderate to profound hearing loss, normal vestibular function, and retinitis pigmentosa of varying degree. Magnetic resonance imaging was normal in all cases. Otoneurological tests indicated no central nervous system disturbances. The conclusion is that hearing loss and balance problems in Usher syndrome are due to inner ear damage with no evidence of central nervous system disturbances. Furthermore, the ataxia seen in Usher type I is due to a combination of retinitis pigmentosa and bilateral peripheral vestibular deficiency.

Postural stability using different neck positions in normal subjects and patients with neck trauma

Subjects with neck problems, such as whiplash injuries, often complain of disturbed equilibrium and, in some instances, provocation of the neck position can elicit such problems. The importance of neck proprioceptors for maintaining balance is gaining increased interest, moreover the function or malfunction of the otoliths may disturb equilibrium in certain head positions. The aim of the study was to create a reference material for postural control and its dependence on head position in healthy subjects and to compare this with a set of patients with known neck problems and associated vertiginous problems. A total of 32 healthy subjects (16 men, 16 women; age range 21-58 years) as well as 10 patients age range 27-62 years (mean 44 years) with neck problems and associated balance problems since a whiplash injury were tested for postural control using the EquiTest dynamic posturographic model. The normal subjects were initially split into four age groups in order to estimate the effects of age on performance. The postural stability was evaluated for dependence of support surface conditions (stable or sway-referenced), visual input (eyes open or closed) and head position (neutral, left rotated, right rotated, extended backwards or flexed forward) using analysis of variance (ANOVA) with Tukeys post hoc test in case of a significant factor effect. As expected, visual cues as well as stable support surface improve postural stability (p<0.001). Postural stability is statistically different in the head extended backwards condition compared with the other four head positions (p<0.001 in all cases) in both patients and controls. Eliminating this test condition from the analysis, only a slight (p<0.05) difference between head forwards and head turned left remained. This pattern of results remained if the normal subjects were only split into two age groups instead of four. Finally, the patient group exhibited significantly lower postural performance than all the groups of normal subjects (p<0.01), but none of the normal groups differed significantly from each other. It is concluded that the postural control system is significantly challenged in the head extended backwards condition in both normal subjects and patients with previous whiplash injury and persistent neck problems. The patient group differed statistically from all groups of normal subjects. This suggests that neck problems impair postural control, and that the head extended position is a more challenging task for the postural system to adapt to. Whether this is due to utricular malpositioning, central integrative functions or cervical proprioceptive afferents is not within the scope of this study to answer.Subjects with neck problems, such as whiplash injuries, often complain of disturbed equilibrium and, in some instances, provocation of the neck position can elicit such problems. The importance of neck proprioceptors for maintaining balance is gaining increased interest, moreover the function or malfunction of the otoliths may disturb equilibrium in certain head positions. The aim of the study was to create a reference material for postural control and its dependence on head position in healthy subjects and to compare this with a set of patients with known neck problems and associated vertiginous problems. A total of 32 healthy subjects (16 men, 16 women, age range 21-58 years) as well as 10 patients age range 27-62 years (mean 44 years) with neck problems and associated balance problems since a whiplash injury were tested for postural control using the EquiTest dynamic posturographic model. The normal subjects were initially split into four age groups in order to estimate the effects of age on performance. The postural stability was evaluated for dependence of support surface conditions (stable or sway-referenced), visual input (eyes open or closed) and head position (neutral, left rotated, right rotated, extended backwards or flexed forward) using analysis of variance (ANOVA) with Tukeys post hoc test in case of a significant factor effect. As expected, visual cues as well as stable support surface improve postural stability (p < 0.001). Postural stability is statistically different in the head extended backwards condition compared with the other four head positions (p < 0.001 in all cases) in both patients and controls. Eliminating this test condition from the analysis, only a slight (p < 0.05) difference between head forwards and head turned left remained. This pattern of results remained if the normal subjects were only split into two age groups instead of four. Finally, the patient group exhibited significantly lower postural performance than all the groups of normal subjects (p <0.01), but none of the normal groups differed significantly from each other. It is concluded that the postural control system is significantly challenged in the head extended backwards condition in both normal subjects and patients with previous whiplash injury and persistent neck problems. The patient group differed statistically from all groups of normal subjects. This suggests that neck problems impair postural control, and that the head extended position is a more challenging task for the postural system to adapt to. Whether this is due to utricular malpositioning, central integrative functions or cervical proprioceptive afferents is not within the scope of this study to answer.

Audiological and Vestibulo-Oculomotor Findings in Workers Exposed to Solvents and Jet Fuel

Three groups of subjects with long-term (5-41 years) occupational exposure to industrial solvents have been evaluated with extensive audiological and vestibular test batteries. Group A comprised 16 subjects with a confirmed diagnosis of psycho-organic syndrome (POS), while group B consisted of 7 subjects with suspected POS. Both groups had been exposed to mixtures of aliphatic and aromatic solvents. Eight subjects with long-term exposure to jet fuel constituted group C. In the audiological test battery, discrimination of interrupted speech and evoked cortical potentials in response to frequency glides were the tests that yielded significantly abnormal results. In the vestibular test battery, considerable pathology was seen in electronystagmography, and in addition, visual suppression test and saccade test indicated CNS disturbance. In general, when a test yielded pathological results, the incidence of pathology was highest in group A and lowest in group C.

Effects of middle ear pressure changes on clinical symptoms in patients with Ménière's disease--a clinical multicentre placebo-controlled study.

Different medical and surgical methods have been tried in attempting to reduce endolymphatic pressure in Ménières disease. Pressure treatment has a role on the treatment staircase, after pharmacological treatment and before destructive methods. Pressure chamber treatment has shown that some patients respond well to the treatment with diminishing inner ear symptoms and also some hearing improvement. Earlier studies have shown that electrocochlear measurements improve after local pressure treatment in the ear. The present study was a prospective randomized placebo controlled, multicentre clinical trial. 56 patients with active Ménières disease, age 20-65 years, with a hearing loss of 20-65 dB PTA participated. A total of 31 patients completed 2 weeks use with an active apparatus (Meniett) and 25 patients completed the 2 weeks with the placebo gadget. Both machines were produced by Pascal Medical, Halmstad, Sweden. Two weeks before the start of treatment a grommet was placed in the tympanic membrane. A significant improvement concerning frequency and intensity of vertigo, dizziness, aural pressure and tinnitus was reported by the active group on the visual analogue scales (VAS) questionnaire. In the placebo group no change was the most common finding, followed by worsening of the symptoms and a few improvements. The function in professional and family life improved during active treatment and did not during placebo treatment. Pure-tone audiometry did not improve after placebo treatment, but improved at the frequencies 500 Hz and 1,000 Hz after active treatment. The study showed an improvement in the inner ear symptoms after Meniett treatment. The mechanism may be explained by the influence on the round window membrane pressure receptors or an endolymphatic flow out through the pressure release points, such as the endolymphatic duct and sac, thus activating the longitudinal flow. Other mechanisms are also possible.Different medical and surgical methods have been tried in attempting to reduce endolymphatic pressure in Ménières disease. Pressure treatment has a role on the treatment staircase, after pharmacological treatment and before destructive methods. Pressure chamber treatment has shown that some patients respond well to the treatment with diminishing inner ear symptoms and also some hearing improvement. Earlier studies have shown that electrocochlear measurements improve after local pressure treatment in the ear. The present study was a prospective randomized placebo controlled, multicentre clinical trial. 56 patients with active Ménières disease, age 20-65 years, with a hearing loss of 20-65 dB PTA participated. A total of 31 patients completed 2 weeks use with an active apparatus (Meniett) and 25 patients completed the 2 weeks with the placebo gadget. Both machines were produced by Pascal Medical, Halmstad, Sweden. Two weeks before the start of treatment a grommet was placed in the tympanic membrane. A significant improvement concerning frequency and intensity of vertigo, dizziness, aural pressure and tinnitus was reported by the active group on the visual analogue scales (VAS) questionnaire. In the placebo group no change was the most common finding, followed by worsening of the symptoms and a few improvements. The function in professional and family life improved during active treatment and did not during placebo treatment. Pure-tone audiometry did not improve after placebo treatment, but improved at the frequencies 500 Hz and 1,000 Hz after active treatment. The study showed an improvement in the inner ear symptoms after Meniett treatment. The mechanism may be explained by the influence on the round window membrane pressure receptors or an endolymphatic flow out through the pressure release points, such as the endolymphatic duct and sac, thus activating the longitudinal flow. Other mechanisms are also possible.

Local Overpressure Treatment Reduces Vestibular Symptoms in Patients with Ménière's Disease: A Clinical, Randomized, Multicenter, Double-Blind, Placebo-Controlled Study

Objectives: To evaluate the efficacy of a new device, the Meniett, in the treatment of Ménières disease. The device delivers pressure pulses to the middle ear through a ventilating tube in the tympanic membrane at a frequency of 6 Hz for 0.6 second. After rising to a pressure level of 1.2 kPa, the pressure oscillates between 0.4 and 1.2 kPa. It is believed that the pressure changes are conveyed to the inner ear, inducing a transport of fluids via the pressure outlets and thus reducing the endolymphatic hydrops. Study Design: A clinical, randomized, multicenter, double-blind, placebo-controlled study. A total of 40 patients were included that had active Ménières disease according to American Academy of Otolaryngology-Head and Neck Surgery criteria, aged between 20 and 65 years, with a history of at least eight attacks during the past year. After insertion of the ventilation tube, the patients should have had attacks of vertigo for 2 months before entering the study. Outcome Measures: Primary study endpoints were change in frequency of vertigo, change of functionality profile, and change in patient perception of vertigo (visual analogue scale); secondary endpoints were perception of tinnitus, aural pressure, and hearing, as well as an audiologic evaluation of hearing before and after the treatment period. Results: The functionality level improved statistically significantly in the active group compared with the placebo group (p = 0.0014), as did the visual analogue scale evaluation of vertigo (p = 0.005). There was a trend toward a reduction of the frequency of vertiginous attacks that was not significant (p = 0.090). With regard to the secondary endpoints, there was no statistical difference between active and placebo groups. Conclusion: Local overpressure treatment is a novel treatment that is noninvasive, nondestructive, and safe. It significantly reduces vestibular symptoms in patients with Ménières disease. The Meniett was cleared by the Food and Drug Administration in 2000.

Benign Paroxysmal Vertigo in Childhood: A Long-term Follow-up

Benign paroxysmal vertigo in children is characterized by sudden attacks of vertigo lasting seconds or minutes. During the attack, the child has nystagmus and is unable to stand without support. Initially, the attacks are frequent, later slowly disappearing. Nineteen children who were diagnosed in 1975–1981 participated in a follow‐up study. Sixteen of them were examined with audiometry and electronystagmography. Age at onset was from 5 months to 8 years, and the symptoms disappeared after 3 months to 8 years. The follow‐up was performed 13 to 20 years after diagnosis. Twenty‐one percent developed migraine which is somewhat more than in a normal population of this age. Thirty‐nine percent had a family history of migraine which is a figure considerably lower than in a migraine population. None still had vertigo or a balance disorder. Our conclusion is that benign paroxysmal vertigo has a favorable outcome, and it is not a general precursor of migraine.

Vestibular and somatosensory inflow to the vestibular projection area in the post cruciate dimple region of the gat cerebral cortex

SummaryIn anesthetized cats 251 cells within the cortical vestibular projection area, adjacent to the post-cruciate dimple, were analyzed as to their input characteristics employing extracellular recording techniques. The post cruciate dimple vestibular field, which is located in area 3a, has a high degree of convergence between vestibular and peripheral somatosensory input. The latter is not restricted to muscle afferents but includes cutaneous modalities. The functional significance of this vestibular cortical projection field is discussed.

Projection of thalamic neurons to cat primary vestibular cortical fields studied by means of retrograde axonal transport of horseradish peroxidase.

SummaryThe two vestibular cortical projection areas in the anterior suprasylvian sulcus and post-cruciate dimple regions were defined by evoked potential technique in anaesthetized cats. The thalamic location of neurons with axon terminals in these fields was determined using the method of retrograde axonal transport of horseradish peroxidase. The ascending vestibular pathway appeared to be separated also at the thalamic level, where cells in the ventro-posterolateral nucleus were found to project to the post cruciate dimple and cells in the posterior nuclear group to the anterior suprasylvian vestibular cortical fields.

Effects of home training and additional physical therapy on recovery after acute unilateral vestibular loss- a randomized study

Objective: To evaluate the effects of additional physical therapy on recovery after acute unilateral vestibular loss given to patients receiving home training. Design: Randomized controlled trial. Setting: Ear, nose and throat departments in three hospitals. Subjects: Fifty-four patients (mean age 52 years) with acute unilateral vestibular loss within the last week confirmed with electronystagmography testing were included. Patients with central neurologic or auditory symptoms or other vertigo disease were excluded. Interventions: Home training with or without additional physical therapy 12 times during 10 weeks. Main measures: Electronystagmography testing was performed before and after the training period. Clinical static (Romberg?s test, sharpened Romberg?s test, standing on foam and standing on one leg) and dynamic (walking forward and backward on a line) balance tests and subjective ratings of vertigo and balance problems on a visual analogue scale were done one week, 10 weeks and six months after the start of training. Results: Similar changes were seen in the two training groups. Conclusions: No significant differences in outcome regarding balance function or perceived symptoms were found between home training with or without additional physical therapy.

Middle Ear Ototoxic Treatment for Inner Ear Disease

Twenty-nine patients seriously disabled by Menieres disease due to frequent attacks were treated with Gentamicin administered in the middle ear once daily until first sign of an inner ear disturbance, usually a spontaneous nystagmus and a sensation of unsteadiness. All patients except one were relieved from their vertiginous attacks and returned to normal activities. Tinnitus was usually diminished or absent, as was the feeling of pressure in the ear. The hearing was slightly improved in 5 patients, worse in 9 patients and two treated ears became deaf. The indication for an intratympanal treatment with Gentamicin should be a disabling form of Menieres disease not responding to medical treatment. The risk for the cochlea increases after 6 days of treatment. The advantage versus intracranial surgery is the absence of the surgical risks for complications. The mode of action exerted by the ototoxic drug is a destruction of the vestibular sensory epithelium and the endolymph producing cells.