Somatosensory Stimulation for Unilateral Neglect Post Stroke (SSUN)

MTS is a module of current routine therapy for the treatment of the contralesional Upper Limb (UL) after a stroke. It involves hands-on physical therapy techniques that provide somatosensory stimulation (specifically touch and proprioception) of the hand and forearm: joint mobilization (passive movements, accessory movements through anatomical range); massage and soft tissue mobilisation/stretch; specific sensory input (e.g. compression, touch including textures); and isolated / selective joint movement including placing the hand.

MTS is commonly used to treat UL complications after stroke such as limitation or loss of range of motion, and loss of sensation. MTS has also been reported to be used in the treatment of perceptual problems such as unilateral neglect (UN), which is defined as cognitive disorder that affects the ability to attend and respond to stimuli, including visual, somatosensory, and auditory stimuli, presented in the contralesional hemispace following brain lesion, like stroke, following stroke. However, UN was not formally assessed with a valid and reliable outcome measure but was based on the therapist's subjective assessment and observation of ADL and communication. As a result, research evaluating the effect of MTS on UN after stroke using valid and reliable tests of UN is warranted.

The design of this study will be a mixed methods feasibility study involving quasi-experimental, single- system (n=1) studies with A-B-A design and qualitative semi- structured interview or group interview, where appropriate . In the A-B-A design, the first A phase represents the baseline phase for comparison with subsequent phases (e.g., no intervention). Initial outcome measures are recorded at regular intervals in this phase and the participant's performance should be stable. The B phase acts as the intervention phase, and the final A phase is the withdrawal phase (i.e., no intervention). Throughout all the phases, outcome measurements are recorded regularly. In the B (intervention) phase, the researcher will deliver the MTS intervention to the participants' hemiparetic UL for 45-60 minutes daily, on five days per week, for six weeks. This dose was chosen because an average daily MTS dose of between 37 and 66 minutes was found to be suitable for subsequent evaluation in a dose-response MTS study, and this is the evidence-based dose used in previous MTS studies. The researcher will deliver MTS to the participant at their home or in an appropriate hospital-based room if this was more convenient for the participant and the content and duration of each session will be noted on a treatment schedule.

The single system ABA design selected is believed to be the most appropriate design for many reasons. Firstly, it allows detailed examination of individual responses to the intervention as well as offering distinctive perspectives on treatment responses that might not be visible in a group study. Additionally, using single system design studies is especially helpful in modelling early therapy evaluation, and assessing complex behaviour, such as those found following stroke. It is especially useful for therapists when assessing or investigating the effectiveness of a treatment. Some disorders are not suitable for evaluation through RCTs due to the difficulty in finding a large, homogeneous sample of patients. In such cases, a single-system design is appropriate. It is known that UN is characterised by heterogeneous symptoms and patients may present with different types of UN. Given the heterogeneity of the syndrome and the difficulties in recruiting a large homogeneous sample, the study of UN behaviour in patients with stroke and their response to the intervention lends itself to evaluation by a single-system design study. Finally, this design has been adopted successfully in the other literature exploring effects of limb activation on UN treatment.

In the semi-structured or group interviews, which will be conducted by a member of the research team, participants and carers will be asked to provide their feedback and opinion on various topics including: the intervention (MTS), challenges they faced, changes they noticed and acceptability of carer-collected outcome measures. If the participants or carers do not want to take part in a group interview, or there are no other participants available at that time, a separate interview will be arranged.

Topics of discussion with the participants in an interview will specifically include:

• Acceptability of the intervention: dose/frequency/comfort.
• Acceptability of the therapist coming to their home daily.
• Challenges/ barriers to completion they faced during the research study.
• Changes observed (perceived benefits).

Topics of discussion with the carers in an interview will include:

• Acceptability of carer-collected outcome measures: daily collection/ training
• Challenges/ barriers experienced in outcome measure's daily collection
• Acceptability of the frequency of MTS.
• Changes observed in participants. The interview will take place shortly after completion of the ABA study with each participant. If two participants begin and end the study at the same time, a group interviews will be offered and conducted including two participants and two carers (i.e. one group interview with two participants, and one group interview with two carers); however, if there is only one participant (and, if appropriate, the carer), a single semi structured interview will be conducted with the participant and, if appropriate,the carer The semi-structured interview or group interviews (if appropriate) will be conducted either in person or online depending on participants/ carers preference.

The design of the qualitative part of the study was chosen as a semi-structured interview for a number of reasons. Firstly, interviews are known to be a useful means of gathering people's opinions and experiences, which is one of the secondary aims of this research study. Both open and close ended questions will be asked to participants and carers on topics related to MTS dose (intensity, frequency, and duration), and comfort and outcome measure to ultimately assess the feasibility and acceptability of MTS, which emphasises the use of a semi-structured interview as a method of data collection.

Inclusion criteria

• Adult (≥18 years of age) who is an Adult stroke survivors (≥18 years of age) with a clinical diagnosis of UN, in the subacute-chronic phase of stroke (≥20 weeks post stroke)
• Ability to consent to participate in the study, assessed by their understanding of the study when it is explained to them.
• Sufficient cognitive and physical ability to allow inclusion in this study, assessed by the ability to follow a simple one-stage command with the non-paretic limb.
• Able and willing to receive and engage with regular therapy (MTS) (e.g. at home).

Exclusion criteria

• Stroke survivor with major communication problems (e.g receptive aphasia) that affect their understanding of the treatment, their ability to follow instruction, or ability to consent to participate.
• Participants who do not speak/understand English and who do not have access to an interpreter.