Interventions for people with perceptual disorders after stroke: the PIONEER scoping review, Cochrane systematic review and priority setting project

Background
Stroke often affects recognition and interpretation of information from our senses, resulting in perceptual disorders. Evidence to inform treatment is unclear.

Objectives
To determine the breadth and effectiveness of interventions for stroke-related perceptual disorders and identify priority research questions.

Methods
We undertook a scoping review then Cochrane systematic review. Definitions, outcome prioritisation, data interpretation and research prioritisation were co-produced with people who had perceptual disorders post-stroke and healthcare professionals. We systematically searched electronic databases (including MEDLINE, Embase, inception-August 2021) and grey literature. We included studies (any design) of interventions for people with hearing, smell, somatosensation, taste, touch, or visual perception disorders following stroke. Abstracts and full texts were independently dual reviewed. Data were tabulated, synthesised narratively, and mapped by availability, sense and interventions. Research quality was not evaluated. Our Cochrane review synthesised randomised controlled trial (RCT) data, evaluated risk of bias (including randomisation, blinding, reporting), and meta-analysed intervention comparisons (versus controls or no treatment) using RevMan 5.4. We judged certainty of evidence using Grading of Recommendations, Assessment, Development and Evaluation. Activities of daily living after treatment was our primary outcome. Extended activities of daily living, quality of life, psychological wellbeing and mental health, functional, and adverse event data were also extracted.

Results
Scoping review: We included 80 studies (n=893); case studies (36/80), RCTs (22/80). No stroke survivor or family stakeholder involvement was reported. Studies addressed visual (42.5%, 34/80), somatosensation (35%, 28/80), auditory (8.7%, 7/80) and tactile (7.5%, 6/80) perceptual disorders; some studies focused on “mixed perceptual disorders” (6.2%, 5/80 such as taste-smell disorders). We identified 93 pharmacological, non-invasive brain stimulation or rehabilitation (restitution, substitution, compensation, or mixed) interventions. Details were limited. Studies commonly measured perceptual (75%, 60/80), motor-sensorimotor (40%, 32/80) ADL (22.5%, 18/80), or sensory function (15%, 12/80) outcomes.

Cochrane systematic review: We included 18 RCTs (n=541) addressing tactile (3 RCTs;n=70), somatosensory (7 RCTs;n=196), visual (7 RCTs;n=225) and mixed tactile-somatosensory (1 RCT;n=50) disorders. None addressed hearing, taste, or smell disorders. One non-invasive brain stimulation, one compensation, 25 restitution and four mixed interventions were described. Risk of bias was low for random sequence generation (13/18), attrition (14/18) and outcome reporting (16/18). Perception was the most commonly measured outcome (11 RCTs); only 7 RCTs measured activities of daily living. Limited data provided insufficient evidence to determine the effectiveness of any intervention. Confidence in the evidence was low-very low.

Our clinical (n=4) and lived experience (n=5) experts contributed throughout the project, co-producing a list of clinical implications and research priorities. Top research priorities included exploring the impact of, assessment of, and interventions for post-stroke perceptual disorders.

Limitations
Results are limited by the small number of studies identified and the small sample sizes, with a high proportion of single-participant studies. There was limited description of the perceptual disorders and intervention(s) evaluated. Few studies measured outcomes relating to functional impacts. There was limited investigation of hearing, smell, taste and touch perception disorders.

Conclusions
Evidence informing interventions for perceptual disorders after stroke is limited for all senses.

Future work
Further research, including high quality RCTs, to inform clinical practice are required.

Study Registrations
PROSPERO: CRD42019160270