Cardiac autonomic status is associated with spasticity in post-stroke patients

Abstract

BACKGROUND: Whether post-stroke spasticity is associated with autonomic status is unclear. The purpose of our study was to determine whether spasticity in post-stroke patients is associated with heart rate variability (HRV), an indicator of sympathetic and parasympathetic regulation. OBJECTIVE: To determine whether HRV is associated with spasticity in post-stroke patients. METHODS: Our cross-sectional observational study included 21 post-stroke patients with varying degrees of knee spasticity. We measured patients' heart rate variability (HRV) during the morning and afternoon of the same day using the modified Ashworth assessment and the pendulum test. The relationship between HRV and the spasticity parameters was evaluated based on the Pearson correlation coefficient (r). RESULTS:The data for the morning measurements showed that the relaxation index negatively correlated with the high frequency (HF) power of HRV (r = −0.47, P < 0.05), and positively correlated with the low frequency (LF) power of HRV(r = 0.47, P < 0.05) and the LF/HF power ratio (r = 0.55, P < 0.05). Similar correlations were observed between the diurnal differences of HRV and the relaxation index. No correlation was observed among the data for the afternoon measurements. CONCLUSIONS: Higher parasympathetic tone and lower sympathetic tone are associated with a higher degree of knee spasticity in post-stroke patients. Further studies are warranted to confirm our findings and investigate the pathological mechanisms involved.

Heart rate variability alterations in infants with spontaneous hypertonia

“…29,30 Finally, entropy analysis of HR also has prognostic value in both animal models and human heart disease patients. 6,31 All these indicators of HRV analysis, strongly suggest that infant with hypertonia displayed autonomic control impairment to the heart. However, something interesting to note is that the parasympathetic withdrawal in infants with hypertonia was a consistent observation, independent of the type of HRV analysis used to assess autonomic balance (i.e., linear vs. non-linear).…”

“…4 In addition to abnormal control of movement, several studies suggest that hypertonia is associated with abnormal function of the autonomic nervous system. 5,6 Indeed, abnormal autonomic function is observed in clinically distinct hypertonia populations. 5,6 Treatment for hypertonia typically focuses on the recovery of skeletal muscle function, however it has been proposed that abnormal cardiac autonomic control, mostly associated to parasympathetic modulation, in adult hypertonic patients with concomitant cerebral palsy, is an important risk factor that contributed to the development of cardiovascular diseases and could contribute to the progression of the overall pathophysiological state.…”

“…5,6 Indeed, abnormal autonomic function is observed in clinically distinct hypertonia populations. 5,6 Treatment for hypertonia typically focuses on the recovery of skeletal muscle function, however it has been proposed that abnormal cardiac autonomic control, mostly associated to parasympathetic modulation, in adult hypertonic patients with concomitant cerebral palsy, is an important risk factor that contributed to the development of cardiovascular diseases and could contribute to the progression of the overall pathophysiological state. 5 Indeed, parasympathetic withdrawal is associated to increase mortality events in patients with cardiovascular dysfunction.…”

Exploring the Utility of Autonomic Nervous System Evaluation for Stroke Prognosis

“…Damage to the sensorimotor cortex and corticospinal cord pathway after stroke may impair vagus nerve function and lower heart rate. Hence, HRV is a proximal biomarker of the integrity of cortical pathways associated with motor impairments of the affected upper and lower limbs, and stroke survivors with high HRV generally require less assistance in performing ADL [ 23 , 27 , 28 , 29 , 30 ].…”