Improvement of Gait in Patients with Stroke Using Rhythmic Sensory Stimulation: A Case-Control Study

Association Between Lower Limb Strength Asymmetry and Gait Asymmetry: Implications for Gait Variability in Stroke Survivors

Background: Gait disturbances characterized by asymmetries in lower limb strength and gait patterns are frequently observed in stroke patients, which increases gait variability and fall risk. However, the extent to which lower limb strength asymmetry influences gait asymmetry and variability in this population remains unclear. Methods: This cross-sectional study included 84 participants, comprising stroke survivors and age- and sex-matched healthy older adults. A portable dynamometer was used to assess lower limb strength, and inertial measurement units to analyze gait parameters. Asymmetry indices were used to quantify strength and gait asymmetries. Statistical analyses included Pearson correlations and stepwise regression to examine the relationships among lower limb strength asymmetry, gait asymmetry, and gait variability. Results: Stroke survivors exhibited significantly greater lower limb strength and gait asymmetries than healthy older adults (p < 0.001). Knee extension (KE) strength asymmetry was a significant predictor of increased gait variability in stroke survivors (R2 = 0.448, p < 0.001) but not in healthy controls. Moreover, longer poststroke duration was associated with greater asymmetry in KE strength (r = 0.42, p < 0.05) and double support time (r = 0.45, p < 0.05). Conclusions: Lower limb strength asymmetry, specifically in knee extensors, is a critical determinant of gait asymmetry and variability in stroke survivors. The association between poststroke duration and increased asymmetry indicates the progressive nature of these impairments. These findings emphasize the importance of targeted interventions to reduce strength asymmetry and address chronic impairments in poststroke rehabilitation to improve gait stability and reduce fall risk.

Therapeutic potential of gamma entrainment using sensory stimulation for cognitive symptoms associated with schizophrenia

Schizophrenia is a complex neuropsychiatric disorder with significant morbidity. Treatment options that address the spectrum of symptoms are limited, highlighting the need for innovative therapeutic approaches. Gamma Entrainment Using Sensory Stimulation (GENUS) is an emerging treatment for neuropsychiatric disorders that uses sensory stimulation to entrain impaired oscillatory network activity and restore brain function. Aberrant oscillatory activity often underlies the symptoms experienced by patients with schizophrenia. We propose that GENUS has therapeutic potential for schizophrenia. This paper reviews the current status of schizophrenia treatment and explores the use of sensory stimulation as an adjunctive treatment, specifically through gamma entrainment. Impaired gamma frequency entrainment is observed in patients, particularly in response to auditory and visual stimuli. Thus, sensory stimulation, such as music listening, may have therapeutic potential for individuals with schizophrenia. GENUS holds novel therapeutic potential to improve the lives of individuals with schizophrenia, but further research is required to determine the efficacy of GENUS, optimize its delivery and therapeutic window, and develop strategies for its implementation in specific patient populations.

The Effect of Rhythmic Audio-Visual Stimulation on Inhibitory Control: An ERP Study

Inhibitory control, as an essential cognitive ability, affects the development of higher cognitive functions. Rhythmic perceptual stimulation has been used to improve cognitive abilities. It is unclear, however, whether it can be used to improve inhibitory control. This study used the Go/NoGo task and the Stroop task to assess various levels of inhibitory control using rhythmic audio-visual stimuli as the stimulus mode. Sixty subjects were randomly divided into three groups to receive 6 Hz, 10 Hz, and white noise stimulation for 30 min. Two tasks were completed by each subject both before and after the stimulus. Before and after the task, closed-eye resting EEG data were collected. The results showed no differences in behavioral and EEG measures of the Go/NoGo task among the three groups. While both 6 Hz and 10 Hz audio-visual stimulation reduced the conflict effect in the Stroop task, only 6 Hz audio-visual stimulation improved the amplitude of the N2 component and decreased the conflict score. Although rhythmic audio-visual stimulation did not enhance response inhibition, it improved conflict inhibition.

The contribution of walking speed versus recent stroke to temporospatial gait variability

BACKGROUND

Inconsistent results have been reported for temporospatial gait variability after stroke. Given the large differences in gait speed across stroke subjects and relative to healthy controls, it is not clear which changes in temporospatial gait variability can be ascribed to the walking speed during gait evaluation versus the consequences of stroke.

RESEARCH QUESTIONS

Does temporospatial gait variability differ between (1) stroke subjects grouped in clinically-relevant functional ambulation classes, (2) the paretic and non-paretic legs within each class, and (3) stroke and healthy subjects after controlling for gait speed?

METHODS

Stroke subjects were evaluated at their comfortable speed < 2 months post-onset and classified into the household (<40 cm/s, n = 38), limited-community (40-80 cm/s, n = 35), and full-community (>80 cm/s, n = 14) walkers. Coefficients of variation (CVs) for paretic and non-paretic stance, initial double-support, and single-support times, step length, step cadence, and step width were compared across the stroke ambulation classes and between the two legs. For the parameters with significantly different CVs between stroke subjects and 33 age-matched controls walking at very-slow and free speeds, a 1-way ANCOVA was used with the gait speed as a covariate.

RESULTS

For most step parameters, CVs were greater in slower stroke ambulation classes except for the smaller step width CV. The differences between the paretic and non-paretic legs emerged in slower walkers only. After controlling for the gait speed, CVs of stroke subjects no longer significantly differed from controls walking at very-slow speed. With controls walking at free speed, however, CVs for the paretic and non-paretic single-support times and the non-paretic step time remained significantly different.

SIGNIFICANCE

Gait is more variable at slower speeds both in stroke subjects and healthy controls. After accounting for the free gait speed, the increased variability of only a few temporal parameters may be attributed to a recent stroke.

Potential Benefits of Music Therapy on Stroke Rehabilitation

Stroke is associated with a high rate of disability and mortality, and survivors are usually accompanied with dysphagia, aphasia, motor dysfunction, cognitive impairment, depression, and other complications. In the past decades, many studies have been conducted to reveal the pathogenesis and pathological mechanisms of stroke. Furthermore, treatment methods have been developed that contribute to the elevated survival rate of stroke patients. Early rehabilitation poststroke is starting to be recognized as important and has been receiving increasing attention in order to further improve the quality of life of the patients. As an emerging method of poststroke rehabilitation, music therapy can help attenuate dysphagia and aphasia, improve cognition and motor function, alleviate negative moods, and accelerate neurological recovery in stroke patients. This review helps summarize the recent progress that has been made using music therapy in stroke rehabilitation and is aimed at providing clinical evidence for the treatment of stroke patients.