The minimal clinically important difference for gait speed in significant unilateral vestibular hypofunction after vestibular rehabilitation

Gait speed is a valid measure of both physical function and vestibular health.Vestibular rehabilitation is useful to improve gait speed for patients with vestibular hypofunction,yet there is little data to indicate how changes in gait speed reflect changes in patient-reported health outcomes.We determined the minimal clinically important difference in the gait speed of patients with unilateral vestibular hypofunction,mostly due to deafferentation surgery,as anchored to the Dizziness Handicap Index and the Activities Balance Confidence scale,validated using regression analysis,change difference,receiveroperator characteristic curve,and average change methods.After six weeks of vestibular rehabilitation,a change in gait speed from 0.20 to 0.34 m/s with 95%confidence was required for the patients to perceive a significant reduction in perception of dizziness and improved balance confidence.

Repeated video head impulse testing in patients is a stable measure of the passive vestibulo-ocular reflex

Objectives The video head impulse test(vHIT)is used as a measure of compensation yet it’s stability in patients with vestibular pathology is unknown.Methods 144 patients(n=72 female,mean 54.46±15.8 years)were grouped into one of three primary diagnoses(Peripheral,Central,or Mixed).Subjects were further categorized based on sex(male versus female),ear(left versus right;ipsilesional versus contralesional),age(six groups ranging from 19 to 84 years),and duration between visits(five groups,mean 191.46±SE 29.42 days,median 55.5 days).The gain of the VOR during passive head rotation was measured for each semicircular canal(horizontal,anterior,posterior).Results There was no difference in the VOR gain within any semicircular canal between the two visits(horizontal:p=0.179;anterior:p=0.628;posterior:p=0.613).However,the VOR gain from the horizontal canals was higher than the vertical canals for each visit(p<0.001).Patients diagnosed with peripheral vestibular pathology had significantly lower(p≤0.001)horizontal semicircular canal gains at each visit.There was no difference in VOR gain between sex(p=0.215)or age groupings(p=0.331).Test-retest reliability of vHIT in patient subjects is good(ICC=0.801)and the VOR gain values across two separate visits were significant and positively correlated(r=0.67)regardless of sex,ear,age,or duration between visits.Conclusion The vHIT is a stable measure of VOR gain over two different times across a variety of vestibular patients with no influence of age or sex.

Complex nystagmus in traumatic benign paroxysmal positional vertigo:A case study on the critical value of knowing semicircular canal excitation and inhibition patterns

A 73-year-old female presented to the emergency department with chief complaint of dizziness after sustaining a fall one month prior to dizziness onset.Although careful examination of eye movement patterns during positional testing was attempted at varying stages of her inpatient admission,her complex nystagmus patterns as a result of traumatic benign paroxysmal vertigo were difficult to manage.In particular,the nystagmus pattern from this case suggests the BPPV was variable and affecting either 1)left posterior semicircular canal(pSCC)exclusively 2)left pSCC and right anterior semicircular canal,3)left and right pSCC canal.This case illustrates the importance of two critical details;positional testing should include observing nystagmus with fixation removed and an experienced clinician should be involved as early as possible.