Ischaemic stroke: the ocular motor system as a sensitive marker for motor and cognitive recovery

Abstract

ObjectiveTo evaluate the sensitivity of measuring cognitive processing in the ocular motor system as a marker for recovery of deficit in post stroke patients.Methods15 patients (mean age 60.6 years, mean National Institutes of Health Stroke Scale (NIHSS) score 2.25) and 10 age matched control subjects (mean age 63.3 years) participated in the study. We included mildly affected acute stroke patients without a visual field defect or gaze palsy. Patients were examined at onset and at 1 month and 3 months post stroke by testing ocular motor function, NIHSS, modified Rankin Scale (mRS) and standard cognitive function assessments.ResultsSignificant differences were found in measures of ocular motor function between groups at stroke onset as well as between the first test and follow-up in patients. At 3 months, function had not returned to normal baseline. Ocular motor function was more sensitive in identifying cognitive dysfunction and improvement compared with NIHSS or mRS.ConclusionsStandard neurological assessments of stroke patients are weighted significantly towards motor and sensory function, underestimating cognitive deficits. Ocular motor assessment demonstrates cognitive effects of even mild stroke and may provide improved quantifiable measurements of cognitive recovery post stroke. We demonstrated abnormality in patients just after onset, extending beyond 3 months, when there was apparent full recovery of motor and sensory function, implying more widespread disruption of cognitive mechanisms, consistent with the subjective complaints received from patients. This may provide insight into cognitive rehabilitation strategies leading to improved functional outcomes.

Positive Effects of Post-ischemic Forced Treadmill Training on Sensorimotor and Learning Outcomes Following Transient Global Cerebral Ischemia

“…In an experimental study, occlusion of bilateral common carotid arteries led to progressive cognitive impairment and significant loss of cells in the hippocampal CA1 subfield (9). Ischemic stroke usually causes permanent damage to the brain tissue, which often leads to long-term decline in motor, sensory, and/or cognitive function, all of which significantly reduces the quality of life of patients (10,11). There is currently no approved method of improving brain recovery after stroke.…”

Auditory P300 as an Indicator in Effectiveness of Robot-Assisted Lower Limb Rehabilitation Training among Hemiplegic Patients after Ischemic Stroke

“…In addition to movement disorders, most patients with cerebral infarction had cognition dysfunction, manifesting as perception, attention, learning and memory and judgment ability disorder, and in turn, cognition dysfunction affected physical disability rehabilitation [9]. Recently, increasing evidences suggest that rehabilitation focusing on motor function could impact the individual's cognitive function and vice versa [10]. Event related potentials (ERP) P300 was discovered by Sutton in 1965, and it can reflect the changes of brain electrical physiological individual cognitive process.…”

Could saccadic function be a useful marker of stroke recovery?

“…Can saccade measures provide such a marker? Dong et al report that in a limited number of mild stroke patients, saccadic parameters that probe cognitive function, especially errors of inhibition during antisaccade and memory-guided paradigms, were abnormal immediately after stroke and improved over time but not to normal 1. These saccade measures appeared to be more sensitive than clinical assessment scales in reflecting initial cognitive impairment and recovery.…”