Polanowska 2009.
| Methods | RCT. Single site and double‐blinded Setting: Poland | |
| Participants | 40 participants with first ever stroke and hemineglect Experimental: n = 20. control: n = 20 Adequacy of matching at baseline? No, although age, sex, BI, MMSE are well balanced the baseline, accuracy on neglect tests seems lower in the experimental versus control group Number lost to follow‐up: authors confirm no losses to follow‐up Mean age (mean (SD)): experimental 61.6 (8.3), control 58.3 (12.9) years Sex (male/female): experimental 11/9, control 14/6 Side of damage: right Method of diagnosing stroke: confirmed by neuroimaging and neurological exam (CT) Method of diagnosing neglect: confirmed by neuropsychological exam as fulfilling 2 of 3 criteria: at least 4 omissions of left‐sided targets in subtest A of Balloons Test; marked rightward bias (cut‐off score 7) on line bisection; spontaneous behaviours specific to neglect e.g. ipsilesional deviation of head, eyes, trunk; attending to ipsilesional side; neglect dyslexia and dysgraphia with tendency to initiate search on right of stimulus sheet Time post‐onset: experimental 44.4 (27.3), control 46.6 (26.2) days Inclusion criteria: first right hemisphere stroke, left visuospatial neglect, recruited from single rehabilitation unit, 2 to 12 weeks post‐stroke, right‐handed, 25 to 75 years, informed consent obtained Reasons for exclusion: if electrical stimulation contraindicated, history of dementia, neurological or psychiatric disorders, if communication or other problems meant were unable to co‐operate Visual sensory deficit: 'visual sensory deficit': experimental 13/20, control 13/20; and 'hemianopia': experimental 6/20, control 9/20 as assessed by "standard neurological assessment" |
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| Interventions | Electrical somatosensory stimulation of the left hand combined with conventional visual scanning training, 1 month duration of 20 session of 45 minutes duration each, 5 days per week. This stimulation lasted for the first 30 of the 45 minutes. Electrical stimulation was provided by 2 electrodes on the hand giving a maximum intensity of 15 mA. Visual scanning used 2 programs from RehaCom computerised system to get active purposeful exploration of visual field (1. saccadic training ‐ seek stimuli within detailed background, 2. attention and concentration ‐ detected and identify stimuli then seek their counterpart on the opposite side within a detailed background). Visual scanning also used some paper and pencil tasks to improve scanning when reading and writing; drawing and copying; analysing form and content of complex visual stimuli. Verbal and visual cues and instructions given as was feedback on achievements and errors versus visual scanning training as above, with placebo stimulation where electrodes were applied to the hand but without "current intensity" The visuospatial scanning training was conducted by a neuropsychologist and electrostimulation was supervised by a neurologist For this review we classified this as a comparison of one cognitive rehabilitation approach to another cognitive rehabilitation approach. For analyses; visual scanning training plus electrical somatosensory stimulation was classed as Approach 1 and the visual scanning training plus placebo stimulation as Approach 2. For analysis of bottom‐up and top‐down rehabilitation approaches this review coded the experimental condition as bottom‐up, but combined with top‐down visual scanning training |
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| Outcomes |
Also measured after only 1 day of stimulation but excluded those results in favour of the more meaningful 1 month results which are immediate post‐rehabilitation – so no maintenance/follow‐up outcomes were measured |
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| Notes | Postulated mechanism of action: visual scanning training aims to remind and motivate participants to scan to the left to build the habit of voluntarily scanning their neglected space. Requires awareness by the participant which is not always present. Hence the use of passive (non‐volitional) physiological approaches such as sensory stimulation. Assumes manipulated sensory inputs are linked to auto levels of orientation behaviour. But effects seem transitory so this study attempts to combine active training of visual scanning with passive stimulation to enhance activation of right hemisphere attention system and improve visual exploration of extra‐personal space All participants received visual scanning training ‐ the only difference was the electrical stimulation Authors state in the paper that 11 participants reported a tingling sensation during a trial electrostimulation period. During the study itself, however, only 1 participant noted such a sensation; afterwards it was noted this person was in the sham group |
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| Risk of bias | ||
| Bias | Authors' judgement | Support for judgement |
| Allocation concealment (selection bias) | Low risk | "Blocked randomisation was performed by 1 person unblinded to group allocations and was based on random number tables. For each 10 subjects, numbers 1‐5 meant that patients would be in group E, the numbers 6‐10 meant that patients would be in Group C with the constraint that in each block of 10 there would be 5 in group E and 5 in group C. Allocations were stored in sealed, numbered envelopes that were opened only at the time of recruitment and the author has confirmed all envelopes were prepared before recruitment began by someone other than the recruiter." |
| Blinding of outcome assessment (detection bias) All outcomes | Low risk | States outcome assessor blinded |
| Incomplete outcome data (attrition bias) All outcomes | Low risk | Authors advise that all randomised participants were followed up on all variables and there were no post‐randomisation exclusions |
| Free of systematic differences in baseline characteristics of groups compared? | High risk | The control group had significantly better scanning accuracy at baseline |
| Did authors adjust for baseline differences in their analyses? | High risk | No adjustment made for differences is scanning accuracy |