Face Cooling Research Articles

Blunted Cardiac Parasympathetic Activation in Student Athletes With a Remote History of Concussion: A Pilot Study.

Introduction: Blunted cardiac autonomic nervous system (ANS) responses, quantified using heart rate variability (HRV), have been reported after sport-related concussion (SRC). Research suggests this persists beyond clinical recovery. This study compared cardiac parasympathetic responses in student athletes with a remote history of SRC (> 1-year ago, Concussion History: CH) with those who reported no lifetime history of SRC (Concussion Naïve: CN).Design: Retrospective nested case-control.Setting: University laboratory.Patients or Other Participants: CH (n = 9, 18.3 ± 2 years, 44% male, median 2 years since injury) were student athletes with a remote history of concussion(s) from more than 1 year ago. CN (n = 21, 16.7 ± 3 years, 67% male) were student athletes with no lifetime history of concussion. Exclusion criteria included taking medications that could affect ANS function, history of concussion within the past year, persistent concussion symptoms, lifetime history of moderate to severe brain injury, and lifetime history of more than 3 concussions.Material and Methods: Participants performed the Face Cooling (FC) test for 3-min after 10-min of supine rest while wearing a 3-lead electrocardiogram in a controlled environment.Outcome Measures: Heart rate (HR), R-R interval (RRI), root mean square of the successive differences (RMSSD) of RRI, high frequency (HF) and low frequency to HF (LF:HF) ratios.Results: At baseline, CH had a lower resting HR than CN (62.3 ± 11 bpm vs. 72.9 ± 12, p = 0.034). CH had a different HR response to FC than CN (+8.9% change from baseline in CH vs. −7.5% in CN, p = 0.010). CH also had a smaller RMSSD increase to FC than CN (+31.8% change from baseline in CH vs. +121.8% in CN, p = 0.048). There were no significant group differences over time in RRI (p = 0.106), HF (p = 0.550) or LF:HF ratio (p = 0.053).Conclusion: Asymptomatic student athletes with a remote history of concussion had a blunted cardiac parasympathetic response to FC when compared with athletes with no lifetime history of concussion. These data suggest that an impaired autonomic response to a physiological stressor persists after clinical recovery from SRC for longer than previously reported.

Autonomic Activation During Face Cooling is Not Attenuated in Healthy Adults with a History of Concussion

Recent evidence indicates that physiological recovery from a concussion appears to take longer than clinical recovery. We have shown that symptomatic concussed patients have impaired cardiac parasympathetic activity and attenuated sympathetically‐mediated increases in blood pressure during face cooling (FC) vs. healthy controls. However, it is not known if the attenuated responses to FC persist in asymptomatic healthy adults who reported experiencing a concussion more than one year ago.PURPOSEWe tested the hypothesis that asymptomatic healthy active adults who experienced a concussion more than one year ago have diminished autonomic activation during FC vs. healthy active adults without a history of concussion.METHODSThirteen healthy adults without a history of concussion within one year of testing performed a FC test. Subjects were retrospectively grouped into those who reported experiencing a concussion more than a year ago (n=5, CH) and those without a history of concussion (n=8, NH). After 10 min of supine rest, a pliable plastic bag filled with ice water (~0° C) was placed on the forehead, eyes and cheeks for 3 min. Heart rate (HR, 3‐lead ECG), mean arterial pressure (MAP, finger photoplethysmography), systolic blood pressure (SBP), and diastolic blood pressure (DBP) were continuously recorded. Total peripheral resistance (TPR) was calculated as MAP/cardiac output. Root mean square of successive differences in R‐R interval (RMSSD) and high‐frequency power (HF) were calculated from spectral analysis of the R‐R interval (RRI) to estimate cardiac parasympathetic activity. Data were analyzed every 1 min and reported as the mean of the change from baseline (D) ± SD.RESULTSAt baseline, there were no differences between groups for HR (NH: 65±14; CH: 65±5 bpm, P=0.95), MAP (NH: 96± 7; CH: 94 ± 10 mmHg, P=0.67), SBP (NH: 130 ± 15; CH: 132 ± 13 mmHg, P=0.84), DBP (NH: 75 ± 5; CH: 74± 8 mmHg, P=0.77), TPR (NH: 17 ± 8; CH: 13± 1 mmHg, P=0.32), and RRI (NH: 990 ± 510; CH: 666 ± 407 ms, P=0.34). RMSSD (NH: 155 ± 85; CH: 50 ± 30 ms, P=0.05) and HF (NH: 3965 ± 1283; CH: 430± 550 ms2, P=0.01) were lower at baseline in CH. During FC, there were no main effects of group for DMAP (P=0.69), DSBP (P=0.86), DDBP (P=0.31), DTPR (P=0.22), DRMSSD (P=0.27), or DHF (P=0.97). During FC, DHR for NH was different vs. CH at Min 1 (NH: 5±4; CH: −4±7 bpm, P=0.01), Min 2 (NH: 1 ± 5; CH: −12 ± 9 bpm, P<0.01), and Min 3 (NH: 3 ± 9; CH: −9 ± 5 bpm, P<0.01). During FC, DRRI in NH was different vs. CH at Min 1 (NH: −68 ± 81; CH: 188 ± 240 ms, P=0.06), Min 2 (NH: −8 ± 130; CH: 253 ± 264 ms, P=0.06), and Min 3 (NH: −67 ± 210; CH: 31 ± 55 ms, P=0.06).CONCLUSIONThese preliminary data indicate that resting cardiac parasympathetic activity is lower in patients with a history of concussion. Despite a greater decrease in heart rate, there were no differences in markers of cardiac parasympathetic activity and sympathetically‐mediated increases in blood pressure during FC between individuals with a history of concussion vs. individuals with no history of concussion. More frequent assessments of the autonomic responses to FC are warranted to determine the normal progression of physiological recovery from concussion.Support or Funding InformationSupported by the National Center for Advancing Translational Sciences of the NIH Pilot Grants Award Program UL1TR001412

Heart Rate Variability during Face Cooling in Concussed Adolescents

ObjectiveWe measured heart rate variability (HRV) during physiological stimuli in acutely concussed adolescents (CX) and after clinical recovery, and compared with healthy controls (HC).BackgroundConcussion is associated with autonomic dysfunction. Face Cooling (FC) triggers the trigeminal nerve to evoke transient increases in cardiac parasympathetic (PNS) activity.Design/Methods11 CX (14.8 ± 0.9 years, 6 male, 7 days since injury) and 11 HC (16.1 ± 1.1 years, 9 male) participated. We calculated mean heart rate (HR), standard deviation of root mean square (RMSSD, measure of PNS tone) and low-frequency to high-frequency power ratio (LF/HF ratio, measure of sympathetic [SNS] tone) at rest and 3-minute FC test.ResultsCX at Visit 1 and 2 had significantly lesser increase in HR (p = 0.02) and RMSSD (p = 0.038) than HC on FC.ConclusionsThese data show that acutely concussed participants have an attenuated PNS response to physiological stimuli which continues after clinical recovery.

Face cooling exposes cardiac parasympathetic and sympathetic dysfunction in recently concussed college athletes.

We tested the hypothesis that concussed college athletes (CA) have attenuated parasympathetic and sympathetic responses to face cooling (FC). Eleven symptomatic CA (age: 20 ± 2 years, 5 women) who were within 10 days of concussion diagnosis and 10 healthy controls (HC; age: 24 ± 4 years, 5 women) participated. During FC, a plastic bag filled with ice water (~0°C) was placed on the forehead, eyes, and cheeks for 3 min. Heart rate (ECG) and blood pressure (photoplethysmography) were averaged at baseline and every 60 sec during FC. High‐frequency (HF) power was obtained from spectral analysis of the R‐R interval. Data are presented as a change from baseline. Baseline heart rate (HC: 61 ± 12, CA: 57 ± 12 bpm; P = 0.69), mean arterial pressure (MAP) (HC: 94 ± 10, CA: 96 ± 13 mmHg; P = 0.74), and HF (HC: 2294 ± 2314, CA: 2459 ± 2058 msec2; P = 0.86) were not different between groups. Heart rate in HC decreased at 2 min (−7 ± 11 bpm; P = 0.02) but did not change in CA (P > 0.43). MAP increased at 1 min (HC: 12 ± 6, CA: 6 ± 6 mmHg), 2 min (HC: 21 ± 7, CA: 11 ± 7 mmHg), and 3 min (HC: 20 ± 6, CA: 13 ± 7 mmHg) in both groups (P < 0.01 for all) but the increase was greater at each interval in HC (P < 0.02). HF increased at 1 min (12354 ± 11489 msec2; P < 0.01) and 2 min (5832 ± 8002 msec2; P = 0.02) in HC but did not change in CA (P > 0.58). The increase in HF at 1 min was greater in HC versus CA (P < 0.01). These data indicate that symptomatic concussed patients have impaired cardiac parasympathetic and sympathetic activation.

Face cooling increases blood pressure during central hypovolemia.

A reduction in central blood volume can lead to cardiovascular decompensation (i.e., failure to maintain blood pressure). Cooling the forehead and cheeks using ice water raises blood pressure. Therefore, face cooling (FC) could be used to mitigate decreases in blood pressure during central hypovolemia. We tested the hypothesis that FC during central hypovolemia induced by lower-body negative pressure (LBNP) would increase blood pressure. Ten healthy participants (22 ± 2 yr, three women, seven men) completed two randomized LBNP trials on separate days. Trials began with 30 mmHg of LBNP for 6 min. Then, a 2.5-liter plastic bag of ice water (0 ± 0°C) (LBNP+FC) or thermoneutral water (34 ± 1°C) (LBNP+Sham) was placed on the forehead, eyes, and cheeks during 15 min of LBNP at 30 mmHg. Forehead temperature was lower during LBNP+FC than LBNP+Sham, with the greatest difference at 21 min of LBNP (11.1 ± 1.6 vs. 33.9 ± 1.4°C, P < 0.001). Mean arterial pressure was greater during LBNP+FC than LBNP+Sham, with the greatest difference at 8 min of LBNP (98 ± 15 vs. 80 ± 8 mmHg, P < 0.001). Cardiac output was higher during LBNP+FC than LBNP+Sham with the greatest difference at 18 min of LBNP (5.9 ± 1.4 vs. 4.9 ± 1.0 liter/min, P = 0.005). Forearm cutaneous vascular resistance was greater during LBNP+FC than LBNP+Sham, with the greatest difference at 15 min of LBNP (7.2 ± 3.4 vs. 4.9 ± 2.7 mmHg/perfusion units (PU), P < 0.001). Face cooling during LBNP increases blood pressure through increases in cardiac output and vascular resistance.

The effects of face cooling on the prolactin response and subjective comfort during moderate passive heating in humans

The purpose of the present study was twofold: first, to determine the extent to which elevated skin temperature is responsible for the hormonal and perceptual responses to passive heating; and second, to determine to what extent face-cooling can override the effects of raised skin temperature. Sixteen recreationally active, non-heat-acclimated volunteers (12 male, 4 female; age, 29 +/- 9 years, [mean +/- S.D.]) underwent a passive heat exposure for 60 min in a sauna maintained at 58 degrees C (13% relative humidity), conditions under which sweating effectively maintains core temperature. Subjects were allocated to one of two experimental groups which were matched for sex, age, body mass index, body surface area and sweating response; one group received face cooling (FC) every 5 min, whilst the other control group (CON) received none. Mean skin temperatures were elevated by approximately 4 degrees C for the 60 min duration (CON, 36.5 +/- 0.1 degrees C; FC, 35.7 +/- 0.1 degrees C; P < 0.05) but core temperature rose by only approximately 0.25 degrees C with no difference between groups. Circulating prolactin remained stable and showed no increase for the FC group, whereas concentrations increased by 102 +/- 34% (P < 0.05) for the CON group. No differences were observed between groups for heart rate, but the sensation of heat was less (P < 0.05) with FC. We suggest that a significant component of the prolactin response to moderate passive heating is mediated by facial skin temperature, and selective cooling of the face is associated with improved perception of thermal comfort. These results indicate that the temperature of only a small part of the total skin area (approximately 10%) has a disproportionately large effect on the hormonal and perceptual responses to heat stress.