[Effects of steroid therapy on long-term canal prognosis and activity in the daily life of vestibular neuronitis patients]

Glucocorticoids improve acute dizziness symptoms following acute unilateral vestibulopathy

Acute unilateral vestibulopathy (AUV) is characterized by acute vertigo, nausea, and imbalance without neurological deficits or auditory symptomatology. Here, we explore the effect of glucocorticoid treatment on the degree of canal paresis in patients with AUV, and critically, establish its relationship with dizziness symptom recovery. We recruited consecutive patients who were retrospectively assigned to one of the two groups according to whether they received glucocorticoid treatment (n = 32) or not (n = 44). All patients underwent pure-tone audiometry, bithermal caloric testing, MRI brain imaging, and were asked to complete a dizziness handicap inventory on admission to hospital and just prior to hospital discharge. In the treatment group, the canal paresis at discharge was significantly lower than in the control group (mean ± SD % 38.04 ± 21.57 versus 82.79 ± 21.51, p < 0.001). We also observed a significant reduction in the intensity of nystagmus in patients receiving glucocorticoid treatment compared to the non-treatment group (p = 0.03). DHI test score was significantly lower at discharge in the treatment group (mean ± SD % 23.15 ± 12.40 versus 64.07 ± 12.87, p < 0.001), as was the length of hospital stay (2.18 ± 1.5 days versus 3.6 ± 1.7 days, p = 0.002). Glucocorticoid treatment leads to acute symptomatic improvement, with a reduced hospital stay and reduction in the intensity of acute nystagmus. Our findings suggest that glucocorticoids may accelerate vestibular compensation via a restoration of peripheral vestibular function, and therefore has important clinical implications for the treatment of AUV.

Insufficient evidence for the effect of corticosteroid treatment on recovery of vestibular neuritis

The authors studied the effect of corticosteroid treatment on clinical recovery and recovery of vestibular function in patients with vestibular neuritis. The comprehensive search (March 29, 2012) yielded 496 original papers, of which 5 (including 199 patients) during full-text screening satisfied our eligibility criteria. Methods assessment showed that 1 study (30 patients) provided direct evidence and carried low risk of bias. Two studies properly reported on their random and concealed allocation of treatment. In 1 study, patients were not randomly allocated to treatment. Blinding of outcomes was lacking in 2 studies, whereas outcome data were clearly incomplete for 2 studies. Given the wide variety in outcome measures and scales and follow-up duration, the meaning of the size of reported effects is not clear. Therefore, the reported effects cannot simply be compared between studies, and this precludes pooling of study results. Still, there are large differences between studies in the size of the reported absolute effects after the placebo treatment. Moreover, the difference in effects between treatments is rather small and does not always favor corticosteroids. The moderate to high risk of bias of studies precludes firm conclusions, whereas the reported short-term effects on symptom recovery and improvement of peripheral vestibular function are too small to be clinically important. No long-term effect on symptom recovery has been shown. Recommendations or decisions for corticosteroid treatment in patients with vestibular neuritis cannot be based on current best evidence and therefore should be discussed with the patient.

Corticosteroids for the treatment of idiopathic acute vestibular dysfunction (vestibular neuritis)

BACKGROUND

Idiopathic acute vestibular dysfunction (vestibular neuritis) is the second most common cause of peripheral vertigo after benign paroxysmal positional vertigo (BPPV) and accounts for 7% of the patients who present at outpatient clinics specialising in the treatment of dizziness. The exact aetiology of the condition is unknown and the effects of corticosteroids on the condition and its recovery are uncertain.

OBJECTIVES

To assess the effectiveness of corticosteroids in the management of patients with idiopathic acute vestibular dysfunction (vestibular neuritis).

SEARCH STRATEGY

We searched the Cochrane ENT Group Trials Register; CENTRAL; PubMed; EMBASE; CINAHL; Web of Science; BIOSIS Previews; Cambridge Scientific Abstracts; ICTRP and additional sources for published and unpublished trials. The date of the most recent search was 28 December 2010.

SELECTION CRITERIA

Randomised controlled trials comparing corticosteroids with placebo, no treatment or other active treatments, for adults diagnosed with idiopathic acute vestibular dysfunction.

DATA COLLECTION AND ANALYSIS

Two authors independently selected studies from the search results and extracted data. Three authors independently assessed risk of bias.

MAIN RESULTS

Four trials, involving a total of 149 participants, compared the effectiveness of oral corticosteroids against placebo. All the trials were small and of low methodological quality. Although there was an overall significant effect of corticosteroids compared with placebo medication on complete caloric recovery at one month (risk ratio (RR) of 2.81; 95% confidence interval (CI) 1.32 to 6.00, P = 0.007), no significant effect was seen on complete caloric recovery at 12 months (RR 1.58; 95% CI 0.45 to 5.62, P = 0.48), or on the extent of caloric recovery at either one month (mean difference (MD) 9.60%; 95% CI -20.66 to 39.86, P = 0.53) or at 12 months (MD 6.83%; 95% CI -27.69 to 41.36, P = 0.70). In addition, there was no significant difference between corticosteroids and placebo medication in the symptomatic recovery of vestibular function following idiopathic acute vestibular dysfunction with respect to vertigo at 24 hours (RR 0.39; 95% CI 0.04 to 3.57, P = 0.40) and use of the Dizziness Handicap Inventory score at one, three, six and 12 months.

AUTHORS' CONCLUSIONS

Overall, there is currently insufficient evidence from these trials to support the administration of corticosteroids to patients with idiopathic acute vestibular dysfunction. We found no trials with a low risk of methodological bias that used the highest level of diagnostic criteria and outcome measures. We recommend that future studies should include health-related quality of life and symptom-based outcome measures, in addition to objective measures of vestibular improvement, such as caloric testing and electronystagmography.

[Dynamic vestibular compensation in vestibular peripheral diseases]

Vestibular compensation, or neuronal plasticity in the central vestibular system, is quite an important process in patients with acute unilateral peripheral vestibular disease, allowing them to lead a comfortable daily life when medical treatments fail to cure the peripheral vestibular function. Is the residual unilateral vestibular input from damaged vestibular endo-organs a positive or negative factor for the development of dynamic vestibular compensation in the central nervous system? To elucidate the true mechanism of vestibular compensation, we examined the ENG findings and dizziness handicap inventory questionnaire in patients with vestibular neuronitis (VN), sudden deafness with vertigo (SDV), Meniere's disease (MD) and acoustic tumor (AT) during remission of the vertigo attacks. We obtained neuro-otological findings from caloric tests and head shaking after nystagmus using ENG and information on motion-evoked dizziness in daily life using the questionnaire. There were no significant differences in the sex, age or canal paresis % (CP%) among the four groups. The results of the present study showed that dynamic vestibular compensation processes developed progressively in the order of patients with SDV, VN, MD and AT (Kruskal-Wallis : p < 0.05). This finding suggests that processes of dynamic vestibular compensation could be accelerated in patients with fixed vestibular lesions caused by SDV and VN more than in those with fluctuating vestibular functions caused by MD and AT. In patients with fixed vestibular lesions caused by SDV and VN, patients with lower CP% showed dynamic vestibular compensation (i.e. disappearance of head shaking after nystagmus (chi-square: p < 0.05) and motion-evoked dizziness (Mann-Whitney: p < 0.0005)) more rapidly than those with higher CP%. In patients with fluctuating vestibular functions caused by MD and AT, patients with lower CP% did not always develop dynamic vestibular compensation more smoothly than those with higher CP%.

Steroid effects on vestibular compensation in human

Vestibular neuritis (VN) rapidly damages unilateral vestibular periphery, inducing severe balance disorders. In most cases, such vestibular imbalance is gradually restored to within the normal level after clinical therapies. This successive clinical recovery occurs due to regeneration of vestibular periphery and/or accomplishment of central vestibular compensation. We experienced 36 patients with VN treated at our hospital, including cases in our previous preliminary report. To elucidate effects of steroid therapy both on the recovery of peripheral function and on the adaptation of central vestibular compensation, we examined caloric test and several questionnaires with two randomly divided groups, 18 steroid-treated and 18 nonsteroid-treated patients, over two years after the onset. These examinations revealed that steroid-treated patients had a tendency of better canal improvements (13/18, 72%) than nonsteroid-treated ones (10/18, 55.6%). However, there was no significant difference between these two groups. In cases with persistent canal paresis, steroid-treated patients (n = 5) reduced handicaps in their everyday life due to the dizziness induced by head and/or body movements and the disturbance of their mood, more effectively than those with nonsteroid therapy (n = 8). These findings suggest that steroid therapy with VN could be effective on not only vestibular periphery but central vestibular system, to restore the balance.