The clinical course of vestibular neuritis from the point of view of the ocular vestibular evoked myogenic potential.

BACKGROUND: Studying otolith functions after unilateral vestibular neuritis using ocular vestibular-evoked myogenic potentials and subjective visual vertical tests could give different results. METHOD: A total of 39 patients underwent a vestibular assessment that included the Dizziness Handicap Inventory and horizontal and vertical semicircular canal function testing with video head impulse testing, ocular vestibular-evoked myogenic potential testing, cervical vestibular-evoked myogenic potentials and subjective visual vertical testing. RESULTS: All patients showed a significant alteration (asymmetry ratio more than 40 per cent) for ocular vestibular-evoked myogenic potentials as well as for subjective visual vertical testing (more than -2° to more than +2°) during the acute phase, whereas after 72 hours from the acute vertigo attack normal values (asymmetry ratio less than 40 per cent) were found in 6 out of 39 patients for ocular vestibular-evoked myogenic potentials and 36 out of 39 for the subjective visual vertical (less than -2° to less than +2°). CONCLUSION: Ocular vestibular-evoked myogenic potentials are the most suitable test to evaluate otolith functions in patients with unilateral vestibular neuritis in the acute and sub-acute phase.

Binocular cyclotorsion in superior vestibular neuritis.

SUMMARY: Conjugated cyclotorsion of the eyes toward the affected side can commonly be observed in vestibular neuritis. The aim of this study was to assess the differences in cyclotorsion between the ipsi- and contralesional eye during selective involvement of the superior branch of the vestibular nerve. We studied binocular cyclotorsion through ocular fundus photographs in 10 patients affected by acute superior vestibular neuritis (SVN). Cyclotorsion was also studied in 20 normal subjects. All SVN patients showed an ipsilesional cycloversion of the eyes. Normal subjects exhibited a constant mild excyclovergence (6.42 ± 2.34°). In SVN patients, contralateral incyclotorsion (8.4 ± 8.14°) was lower and not normally distributed compared to ipsilateral eye excyclotorsion (17.9 ± 4.36°) with no correlation between them. The interocular difference in cyclodeviation could be related to the starting physiological excyclovergence, to different tonic effects on the extraocular muscles of the two eyes and to the different influence of spontaneous nystagmus on cyclodeviation in the two eyes. We recommend referring only to ipsilateral excyclotorsion in the evaluation of utricular function during SVN and its subsequent compensation. Further studies are required to determine the binocular cyclotorsion in the case of other kinds of selective involvement of the vestibular nerve.

Subclinical vestibular dysfunction in migraineurs without vertigo: A Clinical study.

OBJECTIVES: This observational study aimed to investigate the presence of potential vestibular system subclinical dysfunction among migraineurs without a history of vertigo and dizziness compared with healthy controls. METHODS: Patients diagnosed with episodic migraine with and without aura were enrolled. All patients and healthy controls underwent vestibular examination using the following conventional tests: sitting position, Pagnini-McClure's, Dix-Hallpike's, head hanging, video head impulse, subjective visual vertical, Romberg, Fukuda, and caloric vestibular stimulation by Fitzgerald-Hallpike's tests. Nystagmus and angular velocity of the slow phase during culmination phase was analyzed by video-nystagmography. RESULTS: Overall, 33 patients (76% female, 7 with aura and 26 without aura; mean age (mean ± SD): 29.1 ± 4.3 years) and 22 controls (33% female, mean age: 30.8 ± 9.4 years) were enrolled. There were no statistically significant differences in demographic features between patients and controls. Caloric vestibular stimulation test results were found to differ among patients and controls. In particular, right and left angular velocity (AV) were highly correlated one another (r = 0.88, P < .001). Right AV (53.0 ± 6.7 vs 44.0 ± 9.6) and left AV (54.3 ± 5.3 vs 43.3 ± 9.0) were statistically higher in migraineurs as compared to controls (P < .001). Also right V-HIT (1.1 ± 0.1 vs 0.8 ± 0.4) and left V-HIT (1.1 ± 0.1 vs 0.7 ± 0.2) were statistically higher in migraineurs compared to controls (P < .001). CONCLUSION: Our findings suggest a subclinical alteration of vestibular pathway in migraineurs who have never complained vertigo or postural imbalance. This finding supports the hypothesis of a vestibular-cerebellar dysfunction in migraineurs, particularly among those with aura.

Asymmetric vestibular stimulation reveals persistent disruption of motion perception in unilateral vestibular lesions.

Self-motion perception was studied in patients with unilateral vestibular lesions (UVL) due to acute vestibular neuritis at 1 wk and 4, 8, and 12 mo after the acute episode. We assessed vestibularly mediated self-motion perception by measuring the error in reproducing the position of a remembered visual target at the end of four cycles of asymmetric whole-body rotation. The oscillatory stimulus consists of a slow (0.09 Hz) and a fast (0.38 Hz) half cycle. A large error was present in UVL patients when the slow half cycle was delivered toward the lesion side, but minimal toward the healthy side. This asymmetry diminished over time, but it remained abnormally large at 12 mo. In contrast, vestibulo-ocular reflex responses showed a large direction-dependent error only initially, then they normalized. Normalization also occurred for conventional reflex vestibular measures (caloric tests, subjective visual vertical, and head shaking nystagmus) and for perceptual function during symmetric rotation. Vestibular-related handicap, measured with the Dizziness Handicap Inventory (DHI) at 12 mo correlated with self-motion perception asymmetry but not with abnormalities in vestibulo-ocular function. We conclude that 1) a persistent self-motion perceptual bias is revealed by asymmetric rotation in UVLs despite vestibulo-ocular function becoming symmetric over time, 2) this dissociation is caused by differential perceptual-reflex adaptation to high- and low-frequency rotations when these are combined as with our asymmetric stimulus, 3) the findings imply differential central compensation for vestibuloperceptual and vestibulo-ocular reflex functions, and 4) self-motion perception disruption may mediate long-term vestibular-related handicap in UVL patients.NEW & NOTEWORTHY A novel vestibular stimulus, combining asymmetric slow and fast sinusoidal half cycles, revealed persistent vestibuloperceptual dysfunction in unilateral vestibular lesion (UVL) patients. The compensation of motion perception after UVL was slower than that of vestibulo-ocular reflex. Perceptual but not vestibulo-ocular reflex deficits correlated with dizziness-related handicap.

Balance control impairment induced after OKS in patients with vestibular migraine: an intercritical marker.

The aim of the study was to assess the effects of optokinetic stimulation (OKS) on vestibular postural control in migraine patients with recurrent vertigo. 15 patients with vestibular migraine (VM) were enrolled in a posturographic study in eyes open (OE) and eyes closed (CE) condition. The tests were performed between attacks of headache and vertigo at three different time: before, during, and 60 min after OKS. Data of patients with VM were compared with those obtained from two control groups matched for sex and age (15 for each group): (a) normal subjects not suffering from migraine without history of recurrent vertigo (N group); (b) subjects suffering from migraine with no history of recurrent vertigo (M group). Mean sway path velocity and sway area were analyzed. OKS increased the instability in all groups during the stimulus, and both the velocity and area values were higher in M and VM group. However, there was not significant difference between these two groups when stability was examined in OE condition before, during and after OKS stimulation. Conversely, in CE condition a significant greater instability was induced after OKS stimulation only in VM. In particular, post-stimulus values were significantly higher than the pre-stimulus one only in this group, while no significant difference was observed in other groups. A spatial analysis of the sway area evidenced that the instability induced by the OKS in VM group occurred along the direction of OKS. We suggest that this enhanced instability observed after OKS during the intercritical period may be considered an useful marker to support the diagnostic definition of VM in the absence of other vestibular signs.

Benign paroxysmal positional vertigo and migraine: analysis of 186 cases.

OBJECTIVE: This retrospective study assessed several clinical, case history and functional parameters to investigate benign paroxysmal positional vertigo (BPPV) in patients with migraine. METHODS: Two groups of patients were compared: those affected by BPPV and migraine (group A), as defined by International Headache Society criteria, and those with BPPV without migraine or with another form of headache (group B). The following parameters were investigated: onset of BPPV, recovery time, residual dizziness, recurrence of BPPV, atypical eye movement patterns and Meniere-like vertigo in the inter-critical BPPV period. RESULTS: Mean age at BPPV onset was 39 years +/- 9.2 in Group A and 53 years +/- 7.3 in Group B (p = 0.00). No significant difference emerged in the number of manoeuvres needed to achieve recovery (Group A: 1.7 +/- 0.94; Group B: 1.9 +/- 0.89; p > 0.05). Highly recurrent BPPV (at least 4 documented episodes) was observed in 15 patients from group A (19.4%) and in 8 patients from group B (7.3%). Atypical eyes movements and Meniere-like vertigo were more frequent in migraineurs with highly recurrent BPPV (Chi square = 5.76; p < 0.016). CONCLUSIONS: A high prevalence of BPPV and earlier onset in migraine are the main findings of this study. There is a higher incidence of a range of neurotological patterns in the intervals between BPPV episodes in migraineurs with recurrent vertigo. No direct pathophysiological link between migraine and BPPV has yet been established; comorbidity seems to affect clinical features in a sub-population of patients and make BPPV more debilitating.

Prolonged asymmetric vestibular stimulation induces opposite, long-term effects on self-motion perception and ocular responses.

Self-motion perception and the vestibulo-ocular reflex (VOR) were investigated in healthy subjects during asymmetric whole body yaw plane oscillations while standing on a platform in the dark. Platform oscillation consisted of two half-sinusoidal cycles of the same amplitude (40°) but different duration, featuring a fast (FHC) and a slow half-cycle (SHC). Rotation consisted of four or 20 consecutive cycles to probe adaptation further with the longer duration protocol. Self-motion perception was estimated by subjects tracking with a pointer the remembered position of an earth-fixed visual target. VOR was measured by electro-oculography. The asymmetric stimulation pattern consistently induced a progressive increase of asymmetry in motion perception, whereby the gain of the tracking response gradually increased during FHCs and decreased during SHCs. The effect was observed already during the first few cycles and further increased during 20 cycles, leading to a totally distorted location of the initial straight-ahead. In contrast, after some initial interindividual variability, the gain of the slow phase VOR became symmetric, decreasing for FHCs and increasing for SHCs. These oppositely directed adaptive effects in motion perception and VOR persisted for nearly an hour. Control conditions using prolonged but symmetrical stimuli produced no adaptive effects on either motion perception or VOR. These findings show that prolonged asymmetric activation of the vestibular system leads to opposite patterns of adaptation of self-motion perception and VOR. The results provide strong evidence that semicircular canal inputs are processed centrally by independent mechanisms for perception of body motion and eye movement control. These divergent adaptation mechanisms enhance awareness of movement toward the faster body rotation, while improving the eye stabilizing properties of the VOR.

Results and complications of the Baha system (bone-anchored hearing aid).

The aim of this work is to reexamine our experience with the treatment of conductive and mixed hearing loss using the Baha system. The system was implanted in 47 patients (16 adults and 31 children under the age of 14), bilaterally in two cases. The causes of hypoacusis were bilateral congenital aural atresia (31 patients), bilateral chronic otitis media or outcomes of middle-ear surgery (Gillett et al. in J laryngol Otol 120:537-542, 2006), and otosclerosis (Pazzaglia et al. in Acta Orthop Scand 54:574-579, 1983). The following parameters were assessed: mean preoperative air- and bone-conduction thresholds for the frequencies of 500, 1,000, 2,000 and 4,000 Hz; mean postoperative threshold with the Baha; hearing improvement calculated by subtracting the postoperative threshold with the Baha from the preoperative threshold for air conduction in the better ear; speech audiometry test; improvement in the quality of life, calculated using the Glasgow Benefit Inventory for the adult patients and the Glasgow Children's Benefit Inventory for paediatric patients; frequency and type of surgical complications. Follow-up ranged from 6 to 38 months. The audiological results were satisfactory, with air-bone gap closure in 85.1% of cases. In terms of quality of life, assessment using the Glasgow Benefit Inventory showed a clear-cut improvement in health for all the 45 patients that answered to the questionnaires in our study. Out of the 49 operations that were performed, complications were reported in 3 cases (6.1%): 2 cases of skin regrowth around the titanium screw and one in which the abutment was not osseointegrated. The data from this study show that the Baha system offers a high percentage of success, which can significantly improve the patient's quality of life, and a low rate of complications.

Influence of extero- and proprioceptive afferents of the plantar surface in determining subjective visual vertical in patients with unilateral vestibular dysfunction.

Subjective visual vertical refers to an individual's ability to indicate what, in his or her opinion, is a perfectly vertical line in specific experimental conditions. Although the otolith organs play a key role in the perception of verticality, the contribution of other sensory systems, e.g. the visual and proprioceptive systems, cannot be overlooked. The aim of this study was to test the hypothesis that extero- and proprioceptive afferent signals, particularly from the plantar surface of the foot, can influence the temporal evolution of altered subjective visual vertical following unilateral acute vestibular dysfunction. Subjective visual vertical was studied in 40 consecutive patients: 19 females and 21 males (mean age 46.4 years). It was first measured at diagnosis (1-2 days after onset of symptoms). For this measurement, a baseline test was performed (patient standing in direct contact with the floor), followed by a provocation test with a soft support between the patient's feet and the floor. Based on a comparison between the baseline and provocation tests, the patients were divided into three groups: Group A--patients showing a significant increase (p < 0.05) in subjective visual vertical(0 )values in the provocation test compared to baseline values; Group B--patients showing a significant decrease (p < 0.05) in subjective visual vertical(0 )values in the provocation test compared to baseline values; Group C--patients showing no significant changes (p < 0.05) in subjective visual vertical(0 )values in the provocation test compared to baseline values. The baseline test was repeated at 30, 90 and 180 days. At the end of the follow-up, a persistent change in subjective visual vertical was noted in 87% of the patients from Group B, 31% of the patients from Group C but none of the patients from Group A, all of whom were able to correct the perception error during the second examination. The study demonstrates that normalisation of subjective visual vertical in subjects with unilateral vestibular lesions seems to be influenced by the possibility of exploiting extra-vestibular sensory information, particularly extero- and proprioceptive information from the plantar surface.

Paroxysmal positional vertigo: the role of age as a prognostic factor.

Aim of this study was to examine possible relationships between several clinical aspects of paroxysmal positional vertigo and factors better defined as "intrinsic" to the patient, above all age. The disorder can affect essentially all age groups; nevertheless, the onset of age-linked degenerative processes, such as vascular damage, can have a negative influence--at least in theory--on the pathogenic mechanisms of cupulolithiasis or canalolithiasis. The study was based on the review of 566 patients with the typical form of paroxysmal positional vertigo. Based on age, the patients were divided into two groups, respectively < or =50 years and > 50 years. For the purposes of this study, a series of clinical-laboratory conditions associated with the risk of, or clear, vascular damage were also considered. The results indicate that if there are no clinical or case-history elements that can be attributed to an aetiological hypothesis, the clinical behaviour of paroxysmal positional vertigo is not affected by the age factor. However, the existence of generic vascular damage, hypothesised by the presence of the above-mentioned conditions, influences certain clinical aspects of the disorder, particularly recovery time, the trend of the active phase and the number of relapses. In conclusion, paroxysmal positional vertigo with a presumed vascular aetiology, the incidence of which increases with age, presents a worse prognosis, not only with respect to the "idiopathic" form in childhood but also the "idiopathic" type in the elderly. The lithiasic model responds well to pathogenic interpretation requirements, which envisage macular degeneration with a vascular component. However, the observation, via imaging, of diffuse ischaemic lesions in critical areas of the brainstem and the cerebellum in many "vascular" patients, does not exclude the possibility of alternative pathogenic mechanisms that, in the final analysis, can lead to compromised VOR on a central level.

Balance disorders in headache patients: evaluation by computerized static stabilometry.

OBJECTIVES: The aim of the study was to investigate the occurrence of equilibrium disturbances in headache patients, during the interictal period, by computerized static stabilometry. MATERIALS AND METHODS: Sixty-seven patients were studied: 35 with migraine without aura (MwoA), 12 with tension-type headache (TTH) in the episodic form (ETTH) + MwoA, and 20 with only TTH [10 ETTH + 10 chronic (CTTH)]. The stabilometric parameters considered were: statokinesigram length (L) and surface (S) in open (EO) and closed (EC) eyes conditions with/without occlusal bite, EC with head retroflexion (ECR), and optokinetic stimulation (OKN). RESULTS: The alteration of at least one of the stabilometric parameters was observed in 45 patients (67.2%): 21 MwoA, 8 ETTH + MwoA, and 16 TTH (8 ETTH + 8 CTTH). CONCLUSION: In TTH patients (ETTH, CTTH, ETTH + MwoA), the stabilometric findings show a proprioceptive alteration induced by cervicofacial muscle contraction, which was peripheral in origin. In MwoA patients the alterations appear under OKN and support a control impairment in involuntary oculomotility of central origin.

Retrospective study on precancerous laryngeal lesions: long-term follow-up.

The classification and the most appropriate treatment of dysplastic lesions of the larynx continue to be controversial issues. Aim of present study was to evaluate the incidence of precancerous lesions of larynx, their potential to evolve in relation to grade of dysplasia, and the most appropriate treatment. The study is based on the review of a series of 207 patients (157 (75.9%) male, 50 (24%) female) with keratosis of the laryngeal epithelium, with or without dysplasia. Patients were divided into four groups, according to Friedmann's classification (1986), based on presence and grade of any dysplasia. The follow-up period ranged from approximately 7 to 16 years. With regard to progression of the disease, 159 of the 185 patients considered were cured following initial treatment (85.9%), whereas 26 (14.1%) had recurrences. Of the latter, 19 had a single recurrence and 7 had multiple recurrences. Progression to carcinoma occurred in a total of 12 cases, above all in patients with the highest grades of dysplasia. Results emerging from this study confirm not only that dysplastic lesions of the larynx have the potential to evolve into frankly malignant lesions, but also that this capacity to evolve is significantly correlated with grade of dysplasia of the covering epithelium. Therefore, the histological classification of precancerous lesions of the larynx, based on the presence or absence of atypical cells and on their severity, is clearly valid from a clinical standpoint, representing, above all, an important prognostic factor. As far as treatment is concerned, mucosal stripping at site of the lesion is considered to be the treatment of choice for precancerous lesions of the larynx. Nevertheless, in patients presenting keratosis with a higher grade of dysplasia, it is mandatory to consider more aggressive treatment.