Cold-induced vasodilatation following traumatic median or ulnar nerve injury

Changes in Fingertip Cold-Induced Vasodilatation (Hunting Reaction) on Acute Exposure to Altitude

Fossati, Alexandre, and Aleid C. J. Ruijs. Changes in fingertip cold-induced vasodilatation (hunting reaction) on acute exposure to altitude. High Alt Med Biol. 00:000-000, 2024. Objective: Cold-induced vasodilation (CIVD) of the extremities is an interesting part of human physiology. Although the physiology of the CIVD reaction remains unknown, there are indications that hypoxia influences our CIVD reaction. The objective of this study is to measure the influence of acute hypoxia on the CIVD reaction of the fingertips. Methods: The CIVD reaction was measured using immersion of one hand in a water bath of 0°C in 12 healthy volunteers at low (1,235 m) and high (3,800 m) altitude during 35 minutes. High altitude was reached by a 20-minute cable car ride. Testing was performed indoors (room temperature, 22-25°C) at both altitudes. Data analysis was performed measuring the parameters of the CIVD reaction. Differences were found using the paired Student's t-test. Results: There was no significant difference in baseline finger temperature, onset time, peak time, and frequency of the CIVD reaction. However, at high altitude, maximum temperature and amplitude were significantly higher, slope was steeper, and minimum temperature was lower. Conclusion: We did not find evidence for a diminished CIVD reaction at high altitude due to hypoxia.

Microcirculatory response to cold stress test in the healthy hand

OBJECTIVE

Cold sensitivity of the fingers is common in several conditions. It has been linked to digital vasospasm, microvascular dysfunction, and neural mechanisms. This study aimed to investigate the normal digital microvascular response to a cold stress test in healthy individuals using Laser Speckle Contrast Imaging (LSCI).

METHODS

Twenty-six healthy individuals, mean age 31 (SD 9) years were included. Skin perfusion of digits II-V was measured using Laser Speckle Contrast Imaging before and after a standardized cold stress test. Changes in skin perfusion from baseline were analyzed between hands, digits, and sexes.

RESULTS

Skin perfusion was significantly (p < 0.0001) affected by cold provocation in both the cold exposed and the contralateral hands in all participants of the study. This effect was significantly different between the radial (digit II and III) and the ulnar (digit V) side of the hands (p < 0.001). There was a trend towards a larger decrease in perfusion in men (ns), and a faster recovery to baseline values in women (ns). A larger inter subject variability was seen in perfusion values in women.

CONCLUSIONS

The normal microvascular response to cold provocation may involve both centrally and regionally mediated processes. When exposing one hand to a cold stress test, the contralateral hand responds with simultaneous but smaller decreases in perfusion.

The Impact of Perceived Upper Extremity Severity and Prior Surgery on Patient-Reported Outcomes

Background: The recently validated Hand Questionnaire (HAND-Q) is a multifaceted patient-reported outcome measure (PROM) for hand/upper extremity (UE) pathology and treatment. Here, we conduct a pilot study utilising data collected as a participating site for the Phase II HAND-Q Pilot Multicenter International Validation Study. We hypothesised that self-reported hand functionality, symptom/disease severity, hand appearance, emotional dissatisfaction and treatment satisfaction would be worse in patients who perceived their disease severity to be more severe but would not differ between patients based on prior surgical history. Methods: Patients were prospectively enrolled for HAND-Q participation from September 2018 to August 2019. Patients were included in this analysis if they responded to the following scales of HAND-Q: Hand Functionality Satisfaction, Symptom Severity, Hand Appearance Satisfaction, Emotional Dissatisfaction and Treatment Satisfaction. Composite scores (CS) were created for each section. Surgical versus non-surgical CS and mild versus moderate/severe CS were compared with t-tests. Bi-variate comparisons of responses were performed between surgical and non-surgical groups, and between mild and moderate/severe groups. Results: HAND-Q individual question analysis revealed significant differences in functionality and symptom severity for patients with prior surgery (p < 0.047). CS analysis confirmed greater overall impairment in surgical patients, but no overall impact on symptom severity. Regarding disease severity HAND-Q individual question analysis, moderate/severe patients reported worse outcomes for specific aesthetic qualities and symptoms for almost all items (p < 0.05). CS analysis revealed significantly worse overall hand appearance satisfaction, hand functionality, emotional satisfaction and symptom severity for patients with moderate/severe hand conditions. Conclusions: HAND-Q revealed worsened outcomes for UE patients with self-reported moderate/severe conditions or previous surgical history. Understanding how previous surgery and disease severity may impact clinical outcomes is important for crafting appropriate treatment. Level of Evidence: Level II (Prognostic Study).

Duplex Ultrasound Studies Are Neither Necessary or Sufficient for the Diagnosis of Neurogenic Thoracic Outlet Syndrome

BACKGROUND

Duplex ultrasound (DU) is used in the diagnosis of neurogenic thoracic outlet syndrome (NTOS) to measure compression of the subclavian artery (SCA) which is thought to strengthen the NTOS diagnosis. However, the value of DU in NTOS remains unclear.

METHODS

A retrospective review of a prospectively acquired database from the TOS center of the Catharina Hospital Eindhoven was performed of patients referred between January 2017 and December 2019. Only "proven NTOS" patients, defined as a successful response to thoracic outlet decompression (TOD) surgery based on patient-reported outcomes (NRS pain scale, CBSQ and DASH score) were included to exclude wrongfully diagnosed NTOS patient. The presence of vascular symptoms (defined as discoloration, edema or temperature changes of the hand or fingers), results of provocative maneuvers, and outcome of DU was used for analysis. To assess the link between vascular symptoms and compression on DU, a chi-squared test was performed. Further, we looked for a correlation between vascular symptoms, compression on DU and clinical outcome using a repeated measures analysis of variance (ANOVA).

RESULTS

Vascular symptoms were seen in 49 of 133 patients (36.8%). In total, 51 of 133 patients (38.3%) had at least 50% variation in SCA peak systolic velocity (PSV) during DU at the level of SCA stenosis. SCA occlusion was seen in 11 patients (8.3%) during provocative maneuvers. The presence of clinical "arterial symptoms" was not significantly correlated with vascular laboratory findings, neither for alterations in PSV during DU (P = 0.245) nor for positional SCA occlusion (P = 0.540). No statistically significant correlations between the degree of SCA stenosis and postoperative outcomes, as measured with the DASH, CBSQ, or NRS scale for pain were found (P = 0.787).

CONCLUSIONS

The role of DU in the work-up of NTOS in patients with vascular complaints is questionable. Changes in flow velocities are seen in NTOS patients and do not correlate with "vascular symptoms" or clinical outcome.

Cold Susceptibility of Digit Stumps Resulting from Amputation After Freezing Cold Injury in Elite Alpinists

Gorjanc, Jurij, Shawnda A. Morrison, Rok Blagus, and Igor B. Mekjavic. Cold susceptibility of digit stumps resulting from amputation after freezing cold injury in elite alpinists. High Alt Med Biol. 19:185-192, 2018.

AIM

The aim of the study was to assess whether previous freezing cold injury in fingers and/or toes might predispose alpinists to greater risk of further freezing cold injury, primarily due to a greater vasoconstrictor response to cold, resulting in a lower perfusion, reflected in lower skin temperature.

METHODS

Ten elite alpinists (N = 10; 8 male and 2 female) with amputations after freezing cold injury participated in a cold-water (8°C) immersion stress test of the hands and feet. Digit skin temperatures of amputated digits, their noninjured counterparts, noninjured digits of the affected side and noninjured digits of the corresponding side were measured. The skin temperatures were compared during three consecutive phases of the cold stress test: prewarming, cold water immersion, and passive heating.

RESULTS

Amputated toes cooled much faster compared to their uninjured counterparts (n = 26, p < 0.001), and attained lower skin temperatures during the cold exposure test (n = 26, p < 0.001). Higher cooling rate was observed in all the toes on the injured limb compared with the toes on the uninjured limb (n = 40, p < 0.001). In contrast to the toes, the fingers on the injured limb after freezing cold injury were warmer during cooling phase compared to uninjured fingers (n = 15, p < 0.001).

CONCLUSIONS

The lower digit temperatures observed in affected toe stumps during the cold stress test compared to the nonamputated toes may indicate a heightened risk of future freezing cold injury with subsequent cold exposures, as a consequence of less perfusion, reflected in the lower skin temperature. This relationship was not confirmed in the fingers.

Correlation of volumetric flow rate and skin blood flow with cold intolerance in digital replantation

Cold intolerance is a common complication of digital replantation. The exact etiology is unclear, but it is considered to be multifactorial, including nonsurgical characteristics, vascular, and neurologic conditions. Blood flow may play a significant role in cold intolerance. This study was designed to evaluate the correlation of digital blood flow, including volumetric flow rate (VFR) and skin blood flow (SkBF), with cold intolerance in replanted fingers.A retrospective study was conducted among patients who underwent digital replantation between 2010 and 2013. Patients were selected into study cohort based on the inclusion criteria. Surgical data was collected on each patient, including age, sex, injury mechanism, amputation level, ischemia time, number of arteries repaired, and whether or not vascular crisis occurred. Patients were included as study cohort with both nerves repaired and without chronic disease. Cold intolerance was defined as a Cold Intolerance Symptom Severity (CISS) score over 30. The arterial flow velocity and caliber were measured by Color Doppler Ultrasound and the digital VFR was calculated. The SkBF was measured by Laser Speckle Imager. Both VFR and SkBF were calculated as a percentage of the contralateral fingers. Comparative study of surgical data and blood flow was performed between the patient with and without cold intolerance. Correlation between VFR and SkBF was also analyzed.A total of 93 patients met inclusion criteria for the study. Approximately, 42 patients were identified as having cold intolerance. Fingers that survived vascular crisis had a higher incidence of cold intolerance with a lower VFR and SkBF. The VFR was higher in 2-artery replantation, but the SkBF and incidence of cold intolerance did not differ significantly. No differences were found in age, sex, injury mechanism, amputation level, or ischemia time. Furthermore, no correlation was found between VFR and SkBF.Cold intolerance of digital replantation is associated with decreased SkBF and VFR in the replanted fingers, which survived vascular crisis. Further work will be focused on how vascular crisis cause the decreasing of SkBF and VFR and the increasing chance of cold intolerance.

Active skin perfusion and thermoregulatory response in the hand following nerve injury and repair in human upper extremities

Cutaneous vasoconstriction/vasodilatation occurs in response to whole body and local cooling/heating, and the vasomotor activities play a pivotal role in thermal control of the human body. The mechanisms underlying regulation of skin blood flow involve both neurogenic and humeral/local chemical influence, contributing to the initial response to thermal stimuli and the prolonged phase of response, respectively. Previous studies have suggested the impairment of cutaneous thermal regulation after nerve injury. However, the evidence regarding how the skin perfusion and thermoregulatory response evolve after nerve injury and repair remains limited. Here we observed, by utilizing laser-Doppler perfusion imaging, baseline skin perfusion and perfusion change in response to thermal stimuli after median and ulnar nerve injury, and the results showed that baseline perfusion in autonomous skin area profoundly decreased and active rewarming after clod stress dramatically diminished before sensory recovery of the skin became detectable. In addition, baseline cutaneous perfusion was recovered as the skin regained touch sensation, and exhibited positive correlation to touch sensibility of the skin. These data indicate that both active perfusion and thermoregulatory response of the skin are markedly compromised during skin denervation and can be recovered by re-innervation. This suggests the importance of timely repair of injured nerve, especially in the practice of replantation.

Finger and Toe Temperature Responses to Cold After Freezing Cold Injury in Elite Alpinists

OBJECTIVE

To assess whether previous freezing cold injuries (FCI) would affect digit skin temperatures and rewarming rates during a follow-up cold stress test protocol.

DESIGN

Nonrandomized control trial.

METHODS

Twenty elite alpinists participated; alpinists with previous FCI requiring digit amputations (injured, INJ: n = 10 total, n = 8 male) were compared with ability-matched, uninjured alpinists (control, CON: n = 10, all male). Digit skin temperature was measured using infrared thermography as an index of peripheral digit perfusion after a cold stress test, which consisted of 30 minutes of immersion in 8°C water.

RESULTS

The INJ alpinists' injured toes were warmer (approximately 6%) than their uninjured toes immediately after cold immersion (95% CI, 0.01°C to 1.00°C; P = .05); there were no differences between the rates of rewarming of injured and uninjured toes (INJ, 0.5° ± 0.1°C/min; CON, 0.7° ± 0.3°C/min; P = .16). Although the INJ alpinists had colder injured fingers immediately after the 35°C warm bath compared with their own uninjured fingers (32.2° ± 2.0°C vs 34.5° ± 0.5°C; P = .02), there were no differences observed between the rates of rewarming of injured and uninjured fingers after cold exposure (INJ, 1.1° ± 0.2°C/min; CON, 1.3° ± 0.5°C/min; P = .22).

CONCLUSIONS

Even after FCI that requires digit amputation, there is no evidence of different tissue rates of rewarming between the injured and uninjured fingers or toes of elite alpinists.

Responses of the hands and feet to cold exposure

An initial response to whole-body or local exposure of the extremities to cold is a strong vasoconstriction, leading to a rapid decrease in hand and foot temperature. This impairs tactile sensitivity, manual dexterity, and muscle contractile characteristics while increasing pain and sympathetic drive, decreasing gross motor function, occupational performance, and survival. A paradoxical and cyclical vasodilatation often occurs in the fingers, toes, and face, and this has been termed the hunting response or cold-induced vasodilatation (CIVD). Despite being described almost a century ago, the mechanisms of CIVD are still disputed; research in this area has remained largely descriptive in nature. Recent research into CIVD has brought increased standardization of methodology along with new knowledge about the impact of mediating factors such as hypoxia and physical fitness. Increasing mechanistic analysis of CIVD has also emerged along with improved modeling and prediction of CIVD responses. The present review will survey work conducted during this century on CIVD, its potential mechanisms and modeling, and also the broader context of manual function in cold conditions.

Cold intolerance assessment: A reappraisal

Introduction:

The cold intolerance symptom severity (CISS) questionnaire is frequently used for the assessment of cold intolerance (CI) in patients following hand trauma. Its practical and conceptual limitations prompted the development of a new cold intolerance questionnaire (CIQ). The CIQ assesses and gives equal weighting to five components of CI, severity, frequency, extent, duration and prevention. An optional impact score can be included as the CIQ+.

Method:

Data were collected over a five-month period from adult hand trauma patients. Each patient completed the CISS, CIQ and the Quick DASH questionnaires during their assessment. A total of 51 patients (34 men and 17 women) were examined at a median interval of 14 months (3–48) after injury. Their mean age was 42 years (SE = 2, range 18–81).

Results:

The median (range) scores were CIQ = 16 (0–27), CIQ + = 18 (0–33), CISS = 56 (0–89) and Quick DASH = 44 (2–86). The scores were significantly correlated. The majority of patients had symptoms localised to the digit or point of injury. All but one of the five selected components of the CIQ and the separate impact score were significantly correlated.

Conclusion:

The authors found the CIQ to be a simple scoring system that is suited to clinical use. The CIQ has value as a research tool as it provides a method of categorising patients and of identifying patients suited to certain treatment methods. Furthermore, it may be a more informative tool in monitoring treatment as it is able to assess changes in pattern as well as overall score.

Disordered conditioned pain modulation system in patients with posttraumatic cold intolerance

BACKGROUND

Conditioned pain modulation (CPM) is a phenomenon of 'pain inhibiting pain' that is important for understanding idiopathic pain syndromes. Because the pathophysiology of posttraumatic cold intolerance is still unknown but it could involve similar mechanisms as idiopathic pain syndromes, we evaluated the functioning of the CPM system in patients with posttraumatic cold intolerance compared to healthy controls.

METHODS

Fourteen healthy controls and 24 patients diagnosed with cold intolerance using the Cold Intolerance Symptom Severity questionnaire were included in the study. Of the 24 patients with cold intolerance, 11 had a nerve lesion and 13 an amputation of one or more digits. To quantify the CPM, pain threshold for mechanical pressure was measured at the affected region as a baseline measure. Then, the contralateral hand received a cold stimulus of ice water to evoke the noxious conditioning. After the cold stimulus, the pain threshold for mechanical pressure was determined again.

RESULTS

The absolute and relative changes in algometer pressure (CPM effect) between pre- and post-conditioning were significantly smaller in the cold intolerance group compared to the control group (absolute p = 0.019, relative p = 0.004). The CPM effect was significantly different between the control group and the subgroups of nerve lesion (p = 0.003) and amputation patients (p = 0.011).

CONCLUSIONS

In this study, we found a CPM effect after a cold stimulus in both controls and patients. A significant weaker CPM effect compared to the controls was found, as in other chronic pain conditions. The CPM system within patients with cold intolerance is altered.

Using the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) Statement to assess reporting of observational trials in hand surgery

PURPOSE

To use the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) statement checklist to critically evaluate the change in quality of observational trial reporting in the Journal of Hand Surgery American between 2005 and 2011.

METHODS

A cross-sectional analysis of observational studies published in the Journal of Hand Surgery American was designed to sample 2 6-month periods of publication (March 2005 to August 2005 and June 2011 to November 2011). Fifty-one items were extracted from the STROBE statement for evaluation. Overall STROBE compliance rates for articles and specific checklist items were determined. Final compliance percentages from each period were compared by Student t-testing. Changes in item compliance over time were quantified.

RESULTS

Overall compliance with the STROBE statement was 38% (range, 10%-54%) in 2005 and 58% (range, 39%-85%) for 2011 manuscripts representing a significant improvement. Seventy-five percent or greater of articles (2005/2011) provided the explicit reporting of background (100%/97%), follow-up time (85%/94%), overall interpretation of data (100%/94%), and results of similar studies (95%/89%). Twenty-five percent or less of articles provided the study design in the abstract (10%/20%), a clear description of the study's setting (10%/23%), the handling of missing data (0%/6%), the potential directions of bias (5%/11%), and the use of a power analysis (0%/17%). Eighty-six percent (44/51) of items were more frequently satisfied in 2011 articles than in 2005 publications. Absolute increases in compliance rates of 40% or greater were noted in 10 items (20%) with no worsening in compliance for an individual item over 6%.

CONCLUSIONS

The overall quality of the reporting of observational trials in the Journal of Hand Surgery American improved from 2005 to 2011. Current observational trials in hand surgery could still benefit from increased reporting of methodological details including the use of power analyses, the handling of missing data, and consideration of potential bias.

LEVEL OF EVIDENCE

Diagnostic III.

Cold-induced vasodilatation in cold-intolerant rats after nerve injury

PURPOSE

Cold-induced vasodilatation (CIVD) is a cyclic regulation of blood flow during prolonged cooling of protruding body parts. It is generally considered to be a protective mechanism against local cold injuries and cold intolerance after peripheral nerve injury. The aim of this study was to determine the role of the sympathetic system in initiating a CIVD response.

METHODS

Eight rats were operated according to the spared nerve injury (SNI) model, eight underwent a complete sciatic lesion (CSL) and six underwent a sham operation. Prior to operation, 3, 6 and 9 weeks postoperatively, both hind limbs were cooled and the skin temperature was recorded to evaluate the presence of CIVD reactions. Cold intolerance was determined using the cold plate test and mechanical hypersensitivity measured using the Von Frey test.

RESULTS

No significant difference in CIVD was found comparing the lateral operated hind limb for time (preoperatively and 3, 6 and 9 weeks postoperatively; p = 0.397) and for group (SNI, CSL and Sham; p = 0.695). SNI and CSL rats developed cold intolerance and mechanical hypersensitivity.

CONCLUSION

Our data show that the underlying mechanisms that initiate a CIVD reaction are not affected by damage to a peripheral nerve that includes the sympathetic fibres. We conclude that the sympathetic system does not play a major role in the initiation of CIVD in the hind limb of a rat.

CLINICAL RELEVANCE

No substantial changes in the CIVD reaction after peripheral nerve injury imply that the origin of cold intolerance after a traumatic nerve injury is initiated by local factors and has a more neurological cause. This is an important finding for future developing treatments for this common problem, as treatment focussing on vaso-regulation may not help diminish symptoms of cold-intolerant patients.