Objective:To investigate the effect of oral capsaicin stimulation on the cerebral cortex hemodynamics of patients with post-stroke dysphagia (PSD).Methods:Thirty-four PSD patients were subjected to oral stimulation with either a saline or a capsaicin solution. Functional near-infrared spectroscopy (fNIRS) was used to document any changes in cortical oxyhemoglobin (HbO) concentrations and cortical activation. Functional connectivity (FC) and hemispheric lateralization were analyzed.Results:(1) Capsaicin stimulation significantly increased HbO concentration in the prefrontal and motor areas, producing significantly greater activation than saline stimulation and the resting state. (2) Both saline and capsaicin oral stimulation enhanced whole brain FC, with capsaicin producing a more pronounced increase between the bilateral prefrontal cortex and the right motor cortex. (3) Both saline and capsaicin stimulation induced a right-hemispheric lateralization trend in the whole brain and the prefrontal cortex, while the motor cortex maintained a left-lateralization pattern. Notably, the lateralization index under capsaicin oral stimulation was significantly higher than that under saline oral stimulation.Conclusions:Compared with the resting state and saline stimulation, capsaicin oral stimulation significantly enhances cortical activation above the resting state, and significantly more than saline stimulation. It increases FC between the prefrontal and motor cortices, and promotes adjustments in brain lateralization patterns in persons with PSD.

Objective:To investigate the effect of oral capsaicin stimulation on the cerebral cortex hemodynamics of patients with post-stroke dysphagia (PSD).Methods:Thirty-four PSD patients were subjected to oral stimulation with either a saline or a capsaicin solution. Functional near-infrared spectroscopy (fNIRS) was used to document any changes in cortical oxyhemoglobin (HbO) concentrations and cortical activation. Functional connectivity (FC) and hemispheric lateralization were analyzed.Results:(1) Capsaicin stimulation significantly increased HbO concentration in the prefrontal and motor areas, producing significantly greater activation than saline stimulation and the resting state. (2) Both saline and capsaicin oral stimulation enhanced whole brain FC, with capsaicin producing a more pronounced increase between the bilateral prefrontal cortex and the right motor cortex. (3) Both saline and capsaicin stimulation induced a right-hemispheric lateralization trend in the whole brain and the prefrontal cortex, while the motor cortex maintained a left-lateralization pattern. Notably, the lateralization index under capsaicin oral stimulation was significantly higher than that under saline oral stimulation.Conclusions:Compared with the resting state and saline stimulation, capsaicin oral stimulation significantly enhances cortical activation above the resting state, and significantly more than saline stimulation. It increases FC between the prefrontal and motor cortices, and promotes adjustments in brain lateralization patterns in persons with PSD.

Objective:To investigate the correlation between age and tongue pressure in healthy individuals using a newly-developed tongue pressure measuring device.Methods:A total of 154 healthy volunteers aged 20 to 97 years, without noticeable swallowing difficulties, were selected and divided into seven age groups: 20-29 years ( n=24), 30-39 years ( n=22), 40-49 years ( n=20), 50-59 years ( n=24), 60-69 years ( n=22), 70-79 years ( n=22), and 80 years or more ( n=20). Their maximum, minimum, average and initial pressures, work done, and coefficients of variation were measured using the newly designed tongue pressure measuring device in its intermittent and continuous measurement modes. The tongue pressures were correlated with age and gender. Results:The pressure data obtained using the new device were completely consistent with those from a manometer ( R=1). In the intermittent measurement mode, the readings showed that the maximum, minimum and average tongue pressures decreased significantly with age. In the continuous measurement mode, the initial tongue pressure, average pressure and work done also decreased significantly with age, while the coefficient of variation generally increased with age. There was a negative correlation between age and average tongue pressure ( R2=0.4). The relationship could be expressed as y=-0.8595x+ 103.3 (where x is age, and y is tongue pressure). However, no significant correlation was found between gender and tongue pressure. Conclusions:Tongue pressure and its stability are negatively correlated with age in healthy individuals without swallowing dysfunction, showing no significant correlation with gender.