Dosing and Deployment Trial: A Home-based Optokinetic Treatment

Dosing and Deployment Trial: A Home-based Optokinetic Treatment for Ipsilesional Gaze Deviation

Several interventions exist for remediation of spatial neglect, but they have mixed evidence. Optokinetic stimulation is a bottom-up intervention; in other words, it is a stimulus-driven process, with Level A (strongest) evidence, and is recommended in clinical practice guidelines such as the American Heart Association's stroke guidelines. The studies currently published all use varing doses (number of sessions a week), did not assess the impact on mobility and risk of falls, and have not been implemented in the home setting. It is imperative to understand how to successfully implement this intervention at home, and learn how it will impact mobility in order to better support a large population of individuals living with chronic spatial neglect and who face barriers to accessing care because they require caregiver support to leave the home. This will be done using both qualitative and quantitative methods.

Stroke is a leading cause of disability among adults in the United States (US) and increases the risk of falls. One factor associated with excess fall risk after stroke is spatial neglect, which occurs in 54% of right brain damaged stroke survivors. Spatial neglect is caused by damaged neural networks critical for spatial attention. A hallmark symptom of spatial neglect is ipsilesional gaze deviation (IGD) , which is a sustained horizontal gaze preference toward the affected brain hemisphere. Since IGD is a major predictor of poor recovery-adversely affecting daily activities and functional mobility, and extending hospital stays because of falls-intervention is necessary. And because of the challenges of the traditional rehabilitation paradigm (short length of stay), there is a significant need for an intervention, accessible to individuals living at home with SN, that will improve mobility and risk of falls.

Optokinetic stimulation is a treatment shown to induce brain neural plasticity and improve spatial exploration, in turn reduce spatial neglect symptoms, including IGD, experienced in daily life. Optokinetic stimulation requires the participant to follow one step command: "follow the targets with your eyes". The target is a small dot that moves across the computer screen. The literature shows variation in implementation because users (mostly therapists) were required to create their own optokinetic stimulation, until just recently when Eyemove was developed. Eyemove is computer-based intervention developed to standardize the way optokinetic stimulation is administered, via an inexpensive, commercially available software program.

Via a randomized clinical trial, the researchers plan to focus on dose and feasibility in the home setting to answer the specific aims.

The study will randomize stroke participants who meet all inclusion and exclusion criteria into two intervention dose groups. Group 1 will complete 3-sessions of Eyemove, and Group 2 will complete 5-sessions of Eyemove, all within 7-9 days. Outcomes will be measured at baseline, before and after the treated period. Screening and pre-treatment assessments will take approximately 2 hours, and the post assessments will take approximately 1 hour. The post-treatment assessments will be conducted 14 days after the pre-treatment assessments.

In the interest of feasibility and limiting unnecessary burden on participants, the study team will then conduct semi-structured interviews pre-treatment with at least the first 8 stroke participants who are randomized into each group. The study team will interview them again post-treatment and will also interview care partners of stroke survivors at time of screening and pre-treatment assessment, to participate in semi-structured interviews and two assessments. The researchers will also plan to conduct these with the first 8 care partners from each group, which will be determined after the stroke survivor is randomized.

Inclusion Criteria for stroke group:

1. first and unilateral right brain damage stroke, confirmed by medical records,
2. time post stroke >6 months,
3. moderate to severe SN, classified using the Catherine Bergego Scale (CBS) via the Kessler Foundation Neglect Assessment Process (KF-NAP),
4. over age of 60 years, and
5. IGD noted either on the KF-NAP or neuroimaging from medical records.

Exclusion Criteria for stroke group:

1. history of multiple strokes or neurological incidents (e.g., traumatic brain injury, seizures, or brain tumor),
2. unable to communicate through spoken English, screened using the Aphasia Rapid Test (ART), as instructions for treatment and assessment tasks will be provided verbally in English,
3. cognitive impairment as defined by the Blind-MoCA,
4. dependent in mobility- walking or wheelchair via medial chart,
5. legally blind per medical chart,
6. home located out of a 50-mile radius from Duke University, making it too costly for the frequent home visits, and
7. no IGD present.

Inclusion Criteria for caregiver group:

1. a current care partner (defined as someone providing care and assistance) of a stroke survivor living with SN,
2. English speaker,
3. the stroke survivor they are caring for has been enrolled into the study.

Exclusion Criteria for caregiver group:

1. not a care partner currently,
2. can't speak English,
3. the stroke survivor didn't consent