Test-retest reliability of heart-rate variability metrics in individuals with aphasia

Individuals with aphasia may have impairments in cognition, higher incidences of depression, and a variety of post-stroke functional impairments. However, evaluating these issues is challenging since most assessments require some degree of linguistic processing and task instructions are often verbal. Heart rate variability has shown to be an objective marker for cognitive functioning in neurologically healthy individuals, depression and post-stroke depression, and post-stroke functional impairments. However, before the utility of heart rate variability is established in persons with aphasia, its test-retest reliability needs to be established. The purpose of this study was to assess test-retest reliability of heart rate variability metrics in persons with aphasia. Heart rate variability was recorded at rest while in a sitting position in twenty-one persons with aphasia at two time points. Heart rate variability metrics were mostly moderately reliable. The majority of participants had resting heart rate variability parasympathetic and sympathetic indexes similar to those of neurologically healthy individuals. Further research is needed to establish the test-retest reliability of heart rate variability metrics in different postures and breathing conditions in persons with aphasia.

[The efficacy of the anti-acidemic agent dimephosphone at the first rehabilitation stage in patients in the acute period of carotid-related ischemic stroke]

OBJECTIVE

To evaluate the efficacy of the intravenous form of dimephosphon at the first stage of rehabilitation in patients with ischemic stroke in the carotid system.

MATERIAL AND METHODS

The article presents the results of examination of 60 patients in the acute period of ischemic stroke in the carotid system (30 patients were treated with dimephosphon and 30 patients were in the comparison group). The dynamics of the clinical picture (according to the NIHSS), functional dependence in self-service (according to the modified Rankin scale), state of autonomic response using spectral analysis of heart rate variability, cerebrovascular reactivity using functional tests were assessed during the treatment.

RESULTS

A significant decrease in NIHSS points was recorded (on average by 60% from the initial level) in the main group, relative to the comparison group (on average by 33% from the initial points). On the 10th day of therapy, there was a significantly more improvement in cerebrovascular reactivity to hypercapnic and hypocapnic loads, the index of vasomotor reactivity, as well as the state of cerebral blood flow autoregulation in the main group compared with the comparison group. In addition, by the 10th day of therapy relative to the initial values in the main group, a statistically significant increase (by 30%) was revealed in the number of patients with adaptive sympathicotonic type of autonomic regulation with a decrease in the number of patients with hypersympathetic and asymptomatic types of autonomic regulation after orthostatic test (by 10% and 20%, respectively). By the 10th day of hospitalization, there were more patients with no or mild signs of disability (0-2 points according to the modified Rankin scale) in the main group (83%) compared with the comparison group (60%).

CONCLUSION

The use of the multimodal drug dimephosphon in complex therapy in patients in the acute period of ischemic stroke in the carotid system contributes to the normalization of the regulatory mechanisms of cerebral circulation and autonomic regulation. This helps to improve functional recovery and enhance the rehabilitation potential of patients.

The impact of breathing rate on the cardiac autonomic dynamics among children with cerebral palsy compared to typically developed controls

PURPOSE

To describe the immediate effect of breathing rate on heart rate (HR) and heart rate variability (HRV) in children with cerebral palsy (CP) and a control group of typically developed (TD) age and gender-matched children.

METHODS

Twenty children with CP at gross motor function classification system levels I-III and 20 TD children aged 6-11 participated in the study. HR was monitored at rest and during paced breathing with biofeedback. Respiratory measures were assessed by KoKo spirometry.

RESULTS

Children with CP have lower spirometry and HRV values at rest compared to TD children. The mean reduction of breathing rate during paced breathing among children with CP was significantly smaller. Nonetheless, while practicing paced breathing, both groups reduced their breathing rate and increased their HRV.

CONCLUSIONS

The results of the current work present the immediate effect of paced breathing on HRV parameters in CP and TD children. Further studies are needed to investigate the effect of long-term treatment focusing on paced breathing for children with CP.

Interactions between autonomic cardiovascular regulation and cortical activity: a CNV study

The study investigated interactions between autonomic cardiovascular regulation and cortical activity. In 54 healthy subjects, baroreflex sensitivity (BRS) and respiratory sinus arrhythmia (RSA) were assessed at resting conditions. As an EEG indicator of cortical excitability, the contingent negative variation (CNV) was induced using a constant foreperiod reaction time task. At bivariate level, only RSA showed a moderate positive correlation with the CNV recorded at frontal electrodes. However, when common variance of BRS and RSA was controlled for in multiple regression analysis, an inverse association between BRS and the frontal CNV also arose. The inverse association between BRS and the CNV is discussed as reflecting bottom-up modulation of cortical excitability by baroreceptor afferents. The positive correlation between RSA and the CNV may relate to the interplay between prefrontal processing and cardiac vagal tone.