Heart Rate Variability And Mild Traumatic Brain Injury: Case Study And Review Of Literature
Sports-related mild traumatic brain injury (MTBI) is estimated to affect 3.8 million people in the United States. Identifying quantitative measures of recovery has become a point of interest in treatment. Heart Rate Variability (HRV), the average fluctuation in the interval between heartbeats, shows promise as a noninvasive biomarker.
A 15-year-old Caucasian male cross-country runner hit the back of his head during a soccer game suffering an MTBI. The patient rested from activity for 1 week then returned to training. Two months after the injury the patient complained of persistent shortness of breath, fatigue, and increased heart rate while running. His average BPM while running prior to the injury was in the 160s and has since jumped to the 180s. The patient was monitored, and training was adjusted to avoid symptoms. Patient's condition improved gradually with return to baseline activity in 4 months.
Current MTBI treatment guidelines depend on the presentation of the injury, however, return to play guidelines for athletes remain dependent on self-reported symptoms. In this case, symptoms correlated with HRV and persisted for 4 months post-concussion. Returning an athlete to play prematurely may prolong the recovery process and cause symptoms to re-emerge. There is limited evidence demonstrating a diminished HRV during exercise exists in athletes recovering from MTBI compared to controls. HRV may also be a useful marker for recovering athletes to manage their symptoms during recovery.
HRV is a promising point of investigation for management of post-concussive symptoms. Further research is necessary to elucidate the effects.