Interventions for people with perceptual disorders after stroke: the PIONEER scoping review, Cochrane systematic review and priority setting project
Authors: Hazelton Christine , Todhunter-Brown Alex , Campbell Pauline , Thomson Katie , Nicolson Donald J , McGill Kris , Chung Charlie SY , Dorris Liam , Gillespie David C , Hunter Susan M , Williams Linda J , Brady Marian C 
Published: November 2024

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

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

Methods
We undertook a scoping review and then Cochrane systematic review. Definitions, outcome prioritisation, data interpretation and research prioritisation were coproduced with people who had perceptual disorders post stroke and healthcare professionals.
We systematically searched electronic databases (including MEDLINE, EMBASE, inception to 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 the randomised controlled trial data, evaluated risk of bias (including randomisation, blinding, reporting) and meta-analysed intervention comparisons (vs. 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, mental health and psychological well-being perceptual functional and adverse event data were also extracted.

Results
Scoping review
We included 80 studies (n = 893): case studies (36/80) and randomised controlled trials (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) activities of daily living (22.5%, 18/80) or sensory function (15%, 12/80) outcomes.

Cochrane systematic review
We included 18 randomised controlled trials (n = 541) addressing tactile (3 randomised controlled trials; n = 70), somatosensory (7 randomised controlled trials; n = 196), visual (7 randomised controlled trials; n = 225) and mixed tactile-somatosensory (1 randomised controlled trial; n = 50) disorders. None addressed hearing, taste or smell disorders. One non-invasive brain stimulation, one compensation, 25 restitution and 4 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 randomised controlled trials); only 7 randomised controlled trials 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, coproducing 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.

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

Future work
Further research, including high-quality randomised controlled trials, to inform clinical practice are required.

Study registration
This study is registered as PROSPERO CRD42019160270.

Funding
This award was funded by the National Institute for Health and Care Research (NIHR) Health Technology Assessment programme (NIHR award ref: NIHR128829) and is published in full in Health Technology Assessment; Vol. 28, No. 69. See the NIHR Funding and Awards Website for further award information.