van Wyk A.1, Eksteen C.A.1, Heinze B.M.2
1University of Pretoria, School of Health Care Sciences, Department of Physiotherapy, Pretoria, South Africa, 2University of Pretoria, Department of Speech-Language Pathology and Audiology, Pretoria, South Africa
Background: A recent Cochrane review of interventions for eye movement disorders in post stroke patients concluded that eye movement disorders may affect over 70% of stroke patients. Eye movement disorders may result in difficulty moving the eyes appropriately. Difficulty with spontaneous and voluntary movement of the eyes during functional activities may include impairment of smooth pursuit eye movements (SPEM) (slow movement of the eyes (1°-30°/ sec) that serve to keep gaze on a moving visual object of interest when the head is stationary. Smooth pursuit eye movement velocity (gain) should match the velocity of the moving object. Performing smooth pursuit eye movements accurately requires the integration of visual, vestibular and cervical (neck proprioceptive) information.
Clinical observations of patients with smooth pursuit eye movements dysfunction following a stroke may include the following: (1) closing or covering one eye during conversations and/or activities due to blurred vision or double-vision; (2) bumping into walls or objects during walking or when manoeuvring in a wheelchair; (3) not seeing people or objects approaching suddenly from one side; (4) increased postural sway during challenging stance positions; and (5) decreased stability whilst following moving targets during locomotion or perturbed stance.
Clinical observations of patients with smooth pursuit eye movements dysfunction following a stroke may include the following: (1) closing or covering one eye during conversations and/or activities due to blurred vision or double-vision; (2) bumping into walls or objects during walking or when manoeuvring in a wheelchair; (3) not seeing people or objects approaching suddenly from one side; (4) increased postural sway during challenging stance positions; and (5) decreased stability whilst following moving targets during locomotion or perturbed stance.
Purpose: To determine the prevalence of eye movement disorder specifically smooth pursuit eye movements and central vestibular dysfunction in patients who are in the sub-acute phase post-stroke.
Methods: A cross-sectional survey (n = 70) was conducted to determine the prevalence of smooth pursuit eye movement disorder and vestibular dysfunction in patients that sustained a stroke. An independent physiotherapist assessed smooth pursuit eye movements with Video Nystagmography (VNG) to quantify smooth pursuit eye movements and completed the Berg Balance Scale.
Results: All stroke patients assessed presented with impaired smooth pursuit eye movements on SPEM left eye left visual field (mean ± SD: 62.0±23.83 gain), SPEM left eye right visual field (mean ± SD: 57.9±25.65 gain), SPEM right eye left visual field (mean ± SD: 61.3±23.99 gain) and SPEM right eye right visual field (mean ± SD: 58.6±26.46 gain). Pearson correlations (1% significant level) between SPEM and Berg Balance Scale were SPEM left eye left visual field (r = 0.28254; p = 0.0178), SPEM left eye right visual field (r = 0.26278; p = 0.0280), SPEM right eye left visual field (r = 0.34073; p = 0.0039) and SPEM right eye right visual field (r = 0.34084; p = 0.0039).
Conclusion(s): The prevalence of eye movement disorders specifically smooth pursuit eye movement impairment was higher than previously reported. Eye movements interact with the postural control system and movement therefore smooth pursuit eye movement dysfunction may result in increased functional dependence during ADL and disability.
Implications: The study contributes to the diagnosis strategy that should be implemented in the rehabilitation of visual- and vestibular system dysfunction to optimise post-stroke rehabilitation, to improve functional outcome post-stroke and improve the provision of evidence based post-stroke care.
Funding acknowledgements: National Research Foundation Innovation Doctoral scholarship for 2016 (Reference SFH150729132539) and the South African Society of Physiotherapy's Research Foundation (VAN180).
Topic: Neurology: stroke
Ethics approval: Ethics approval was obtained from the Ethics Committee of Faculty of Health Sciences at the University of Pretoria (UP) (374/2015).
All authors, affiliations and abstracts have been published as submitted.
