Abstract
Post-stroke sleep disorders (PSSDs), particularly insomnia, are common yet insufficiently recognized complications that can negatively affect recovery in stroke patients. Existing treatment options are often hindered by side effects, complex protocols, or cumbersome equipment. This short report introduces a smartphone-based biofeedback intervention designed to address insomnia by targeting autonomic nervous system (ANS) dysfunction. The intervention was tested on three subacute stroke in-patients unresponsive to pharmacological therapies. All patients demonstrated significant improvements in subjective sleep quality, assessed primarily with the Korean version of the Richards-Campbell Sleep Questionnaire (RCSQ) and secondarily with the Insomnia Severity Index (ISI-K) and Pittsburgh Sleep Quality Index (PSQI-K). RCSQ results indicated improvements in subjective sleep quality across all patients. ISI scores showed all three patients achieved remission thresholds for insomnia, with improvements exceeding the Minimal Clinically Important Difference (MCID). PSQI-K scores also improved in all cases, with two patients reaching threshold levels for insomnia. The intervention's efficacy was validated through an on-off-on design, as improvements were observed during intervention periods, diminished during washout phases, and resurfaced with reintroduction. Results highlight the potential of a fully non-invasive solution for managing insomnia in stroke patients, offering a practical and effective alternative to traditional treatments.