Clinical dynamic visual acuity in patients with cerebellar ataxia and vestibulopathy

Abstract

Deterioration of dynamic visual acuity (DVA) as a result of impaired vestibulo-ocular reflex (VOR) has been well described in peripheral vestibulopathies, however, changes in DVA in patients with degenerative cerebellar ataxias (CA) and its relation to VOR impairment in these patients has not yet been evaluated. Our aim was to assess the alterations of DVA in CA and to evaluate its relation to vestibular function. 32 patients with CA and 3 control groups: 13 patients with unilateral and 13 with bilateral vestibulopathy and 21 age matched healthy volunteers were examined by clinical DVA test, VOR was assessed by video Head Impulse Test and caloric irrigation. The severity of ataxia in CA was assessed by Scale for the assessment and rating of ataxia (SARA). Relationship between DVA and vestibular function in CA patients was examined by linear regressions. DVA impairment was highly prevalent in CA patients (84%) and its severity did not differ between CA and bilateral vestibulopathy patients. The severity of DVA impairment in CA was linked mainly to VOR impairment and only marginally to the degree of ataxia. However, DVA impairment was present also in CA patients without significant vestibular lesion showing that central mechanisms such as impairment of central adaptation of VOR are involved. We suggest that the evaluation of DVA should be a standard part of clinical evaluation in patients with progressive CA, as this information can help to target vestibular and oculomotor rehabilitation.

Effectiveness and cost of integrated cognitive and balance training for balance and falls in cerebellar ataxia: a blinded two-arm parallel group RCT

“…In addition, the sensitivity of the LOS to identify subtle changes in dual-tasking may have been superior when compared to the BBS. Lastly, previous studies report the impairment in vestibular-ocular reflex (46), visual influence and dependence (47,48) during dynamic tasks in this population. The findings of our study demonstrate a decrease in visual scores of the SOT post-intervention suggestive of a reduction in visual dependence during the dynamic balance task.…”

Visual oculomotor abnormalities and vestibulo‑ocular reflex dynamics in polyglutamine spinocerebellar ataxias (Review)

“…To the best of our knowledge, few studies have measured vestibular function in SCA2 mutation carriers, and the preservation of VOR function has been described in these studies (34,35,57). A recent study demonstrated that prominent dynamic visual acuity impairment is highly prevalent even in patients with normal vestibular function and has a statistically significant correlation with VOR deficits (57).…”

“…(15,16,27,29,32,34,35,(50)(51)(52)(53)(54)(55)(56)(57))(9,12,15,16,27,30-32,35,64-80) nuclei, basal ganglia, abnormalities, SWJs, saccadic intrusions/ VOR and VORr gain, DBN, downbeat nystagmus; pHSN, perverted head-shaking nystagmus; GEN, gaze-evoked nystagmus; OKN, optokinetic nystagmus; PAN, periodic alternating nystagmus; SHIMP, suppression head impulse test; SWJs, square wave jerks; VOR, vestibulo-ocular reflex; VVOR, visually enhanced VOR; SCAs, spinocerebellar ataxias; ATXN, ataxin; VORr, regression of VOR; CACNA1A, calcium voltage-gated channel subunit α1 A; TBP, TATA-binding protein.…”