Clinical dynamic visual acuity in patients with cerebellar ataxia and vestibulopathy.

Michaela Dankova,Rudolf Cerny,Alena Zumrova,Dylan J Jester,Jaroslav Jerabek,Silvia Kmetonyova,Martin Vyhnalek,Jaroslava Paulasova Schwabova,Eric R Anson

doi:10.1371/journal.pone.0255299

Michaela Dankova, Rudolf Cerny + Show 7 more

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https://doi.org/10.1371/journal.pone.0255299

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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.

Highlights

Dynamic visual acuity (DVA) is an ability to maintain clear vision during head movement
The presence of oscillopsia using screening question was reported by both subgroups of patients with cerebellar ataxias (CA) as well as both vestibular control groups but not by healthy control (56.2% of CA: 58.3% of CA-V and 55% of CA-NV patients reported the presence of oscillopsia compared to 53.8% unilateral chronic vestibulopathy (UV), 76.9% bilateral chronic vestibulopathy (BV) and 0% healthy controls (HC))
The impairment of DVA is very common in CA patients, which corresponds well with the high prevalence of subjectively reported oscillopsia

Summary

Introduction

Dynamic visual acuity (DVA) is an ability to maintain clear vision during head movement. DVA is mediated mainly by vestibulo-ocular reflex (VOR) which enables gaze stabilization during high-velocity head movements by producing compensatory eye movements with a very short latency. Impairment of DVA manifests as oscillopsia—a false sensation of movement of the visual surround during head movements [1, 2]. These symptoms have been well described in bilateral vestibulopathy [3, 4], vestibulopathy is not the only cause of DVA impairment.

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