Van Wyk A1, Eksteen CA2, Heinze B3, Van der Linde MJ4, Grimbeek RJ4
1University of Pretoria, Physiotherapy, Pretoria, South Africa, 2Sefako Magatho Health Sciences University, Physiotherapy, Pretoria, South Africa, 3University of Pretoria, Audiology, Pretoria, South Africa, 4MJSS (MJ Statistical Services), Pretoria, South Africa
Background: Vestibular dysfunction arising from central components of the vestibular system are associated with impaired balance and significantly increased risk of falls. Due to poor spontaneous recovery of the central vestibular system post-stroke, patients may develop maladaptive sensory strategies in the early months post-stroke in response to the absence of specific management to address vestibular dysfunction following a stroke. The researcher noticed that in clinical practice the assessment and management of central vestibular dysfunction are occasionally treated as a separate problem and not integrated into standard post-stroke rehabilitation.
Purpose: To determine the effect of vestibular rehabilitation therapy (VRT) on patients' diagnostic features of central vestibular dysfunction that includes;
(a) oculomotor function;
(b) reflexive control of gaze;
(c) saccule and inferior vestibular nerve function;
(d) utricle and superior vestibular nerve function;
(e) higher vestibular functions;
(f) anxiety and/or depression;
(g) impaired sensorimotor control of balance, mobility and gait; and
(h) impaired functional ability.
Methods: A single-blind cross-sectional RCT (n=60) which included male and female patients that suffered either an ischaemic or haemorrhagic stroke and presented with diagnostic features of central vestibular dysfunction post-stroke. Patients in the experimental group received VRT integrated with task-specific compared to patients in the control group who received task-specific activities alone. The duration of the intervention period was two (2) weeks.
Results: VRT integrated with task-specific activities resulted in statistically significantly improved
(i) oculomotor impairment: gain of smooth pursuit eye movements (p=0.0021);
(ii) oculomotor impairment: latency (p=0.0094), velocity (p=0.0131) and accuracy (p=0.0187) of saccadic eye movements;
(iii) oculomotor impairment: static visual acuity (p=0.0001);
(iv) impaired reflexive control of gaze: dynamic visual acuity (p=0.0005);
(v) higher vestibular functions: residual oculomotor visual performance (p=0.0007);
(vi) higher vestibular functions: visual-perceptual function (p=0.0000);
(vii) higher vestibular functions: cognitive function (p=0.0000);
(viii) anxiety (p=0.0001);
(ix) depression (p=0.0000);
(x) sensorimotor control of balance, mobility and gait: functional balance (p=0.0000);
(xi) sensorimotor control of balance, mobility and gait: ability to ability to modify gait in response to changing task demands (p=0.0000);
(xii) functional ability (p=0.0000) post-intervention.
Conclusion(s): Statistically significant improved functional capacity following VRT may be attributed to central compensation mechanisms due to active neuronal changes in the cerebellum and brainstem in response to sensory conflict produced by vestibular pathology. Statistically significantly improvement observed may also have occurred through the process of sensory substitution. Sensory substitution is the mechanism that involves the reweighting of extra-vestibular input facilitated by VRT. The activation of the combination of the superior rectus and inferior oblique extraocular muscles that have reflexogenic connections to the cerebellum may be associated with neural recovery and better functional outcomes post-stroke. Input from the visual system may compensate for the loss of vestibular information and is thus a substitute as a reference for Earth vertical in controlling posture and trunk stability resulting in improved functional balance.
Implications: VRT is a low cost and an effective complement to standard treatment and provide a functional application in the treatment of stroke.
Keywords: stroke, central vestibular dysfunction, vestibular rehabilitation therapy
Funding acknowledgements: National Research Foundation Innovation Doctoral scholarship (Reference SFH150729132539) and the South African Society of Physiotherapy's Research Foundation (VAN180).
Purpose: To determine the effect of vestibular rehabilitation therapy (VRT) on patients' diagnostic features of central vestibular dysfunction that includes;
(a) oculomotor function;
(b) reflexive control of gaze;
(c) saccule and inferior vestibular nerve function;
(d) utricle and superior vestibular nerve function;
(e) higher vestibular functions;
(f) anxiety and/or depression;
(g) impaired sensorimotor control of balance, mobility and gait; and
(h) impaired functional ability.
Methods: A single-blind cross-sectional RCT (n=60) which included male and female patients that suffered either an ischaemic or haemorrhagic stroke and presented with diagnostic features of central vestibular dysfunction post-stroke. Patients in the experimental group received VRT integrated with task-specific compared to patients in the control group who received task-specific activities alone. The duration of the intervention period was two (2) weeks.
Results: VRT integrated with task-specific activities resulted in statistically significantly improved
(i) oculomotor impairment: gain of smooth pursuit eye movements (p=0.0021);
(ii) oculomotor impairment: latency (p=0.0094), velocity (p=0.0131) and accuracy (p=0.0187) of saccadic eye movements;
(iii) oculomotor impairment: static visual acuity (p=0.0001);
(iv) impaired reflexive control of gaze: dynamic visual acuity (p=0.0005);
(v) higher vestibular functions: residual oculomotor visual performance (p=0.0007);
(vi) higher vestibular functions: visual-perceptual function (p=0.0000);
(vii) higher vestibular functions: cognitive function (p=0.0000);
(viii) anxiety (p=0.0001);
(ix) depression (p=0.0000);
(x) sensorimotor control of balance, mobility and gait: functional balance (p=0.0000);
(xi) sensorimotor control of balance, mobility and gait: ability to ability to modify gait in response to changing task demands (p=0.0000);
(xii) functional ability (p=0.0000) post-intervention.
Conclusion(s): Statistically significant improved functional capacity following VRT may be attributed to central compensation mechanisms due to active neuronal changes in the cerebellum and brainstem in response to sensory conflict produced by vestibular pathology. Statistically significantly improvement observed may also have occurred through the process of sensory substitution. Sensory substitution is the mechanism that involves the reweighting of extra-vestibular input facilitated by VRT. The activation of the combination of the superior rectus and inferior oblique extraocular muscles that have reflexogenic connections to the cerebellum may be associated with neural recovery and better functional outcomes post-stroke. Input from the visual system may compensate for the loss of vestibular information and is thus a substitute as a reference for Earth vertical in controlling posture and trunk stability resulting in improved functional balance.
Implications: VRT is a low cost and an effective complement to standard treatment and provide a functional application in the treatment of stroke.
Keywords: stroke, central vestibular dysfunction, vestibular rehabilitation therapy
Funding acknowledgements: National Research Foundation Innovation Doctoral scholarship (Reference SFH150729132539) and the South African Society of Physiotherapy's Research Foundation (VAN180).
Topic: Neurology: stroke; Disability & rehabilitation; Robotics & technology
Ethics approval required: Yes
Institution: University of Pretoria, Pretoria
Ethics committee: Faculty of Health Sciences Research Ethics Committee
Ethics number: 374/2015
All authors, affiliations and abstracts have been published as submitted.
