J Korean Neuropsychiatr Assoc.  2010 Jul;49(4):374-382.

Assessment of Autonomic Function in Post-Acute Ambulatory Patients with Mild or Moderate Traumatic Brain Injury Using the Analysis of Heart Rate Variability

• Ann JH
• Lee J
• Kim JH

Abstract

OBJECTIVES
Autonomic nerve system dysfunction has been reported in patients following traumatic brain injury (TBI). However, studies providing direct evidence of a link between the two have been scarce. The purpose of the present study was to evaluate cardiac autonomic modulation in post-acute ambulatory outpatients with TBI using an analysis of heart rate variability (HRV).
METHODS
Twenty-one patients with TBI and 21 age- and gender-matched normal controls were evaluated. The HRV assessments were performed using conventional time and frequency domain analyses as well as non-linear complexity analysis.
RESULTS
In the patient group, standard deviation values of the RR intervals (SDNN), the square root of the mean squared differences of successive normal sinus intervals (RMSSD), total successive RR interval difference (TSRD), and the very low frequency (VLF) power spectral parameter were significantly lower than in the control group. The patients with moderate severity of TBI exhibited a significantly lower value of VLF than those with mild severity. The severity of anxiety symptoms had a tendency to be correlated with the mean heart rate and the ratio of low-to-high frequency spectral power.
CONCLUSION
The results of the present study provide evidence that TBI is associated with reduced HRV, suggesting the critical involvement of central autonomic structures in the pathogenesis of TBI. The HRV measures may serve as an index for monitoring aspects of autonomic function in patients with TBI.

Keyword

Traumatic brain injuries; Autonomic nervous system; Heart rate variability

MeSH Terms

Aluminum Hydroxide
Anxiety
Autonomic Nervous System
Autonomic Pathways
Brain Injuries
Carbonates
Heart
Heart Rate
Humans
Outpatients
Aluminum Hydroxide
Carbonates