Disordered conditioned pain modulation system in patients with posttraumatic cold intolerance

Patient satisfaction after innervated digital artery perforator flap for fingertip injuries

OBJECTIVE

The aim of this study was to evaluate the results of the innervated digital artery perforator (IDAP) flap and to analyze the relationship between patient satisfaction and outcome measures.

METHODS

A total of 17 fingertips of 15 patients (14 men and one woman; mean age: 47.2 (26-62) years) were included in this retrospective study. Patients' injured finger and defect type were recorded. At the last follow-up, the static two-point discrimination (s2PD) test, Semmes Weinstein monofilament (SWM) test, and range of motion of the affected finger were analyzed. We interviewed patients to determine hand dominance, cold intolerance, and their satisfaction with the result. We performed correlation and logistic regression analyses between patient satisfaction and outcome measures.

RESULTS

The mean follow-up period was 13.8 (7-18) months. The mean range of motion was 77.3±3.5 (70-80) degrees for the distal interphalangeal joints of affected fingers. The mean s2PD was 6.4 (3-10) mm, and the SWM records ranged from 2.83 to 4.93 monofilament markings. Cold intolerance was noted in seven fingers (41%). Patient satisfaction was negatively correlated with cold intolerance, and cold intolerance decreased as the follow-up period extended.

CONCLUSION

IDAP flap satisfies both patient and surgeon, with the only significant problem being cold intolerance, regarding which patients must be informed. Although cold intolerance is hard to treat, fortunately, it generally improves with time.

LEVEL OF EVIDENCE

Level IV, Therapeutic study.

Ice therapy: cool, current and complicated

This is the fourth Capsule review article provided by the WSAVA Global Pain Council and which discusses the use of ice or cold therapy as a non-pharmacologic modality for pain control in small animal practice. The physiological effects of cold therapy on tissues, receptors and ion channels are discussed; as well as indications, recommendations for, and limitations of use.

Cold intolerance after nerve injury

Cold intolerance after nerve injury can be severe and has been associated with high levels of pain and disability. This article provides an overview of the assessment and nonoperative management of cold-induced symptoms after peripheral nerve injury. A comprehensive evaluation should include both objective measures such as skin temperatures and subjective tools to assess the patient's perspective and impact of the symptoms. Management of the patient with cold intolerance remains challenging and should include adaptive strategies, warming interventions, and desensitization conditioning programs to minimize cold-induced pain and hyperresponses.

Effect of Forearm Warming Compared to Hand Warming for Cold Intolerance Following Upper Extremity Trauma

PURPOSE

This study evaluated the effect of forearm or hand warming versus bare hand conditions to improve cold-induced symptoms and skin temperatures in hand trauma patients.

METHODS

Adults with symptoms of cold intolerance at least 3 months following hand trauma and age-/sex-matched controls were included. Testing sessions (bare hand, hand warming, forearm warming) were completed in a climate laboratory with continuous temperature monitoring. Outcomes included physical findings (skin temperature) and self-report symptoms (thermal comfort, pain).

RESULTS

Eighteen participants (9 hand trauma patients, 9 control subjects) underwent testing. More severe cold intolerance was associated with higher Disabilities of the Arm, Shoulder, and Hand scores. With bare hands, skin temperatures changed significantly from baseline to cold exposure and to rewarming. Hand trauma patients had the lowest skin temperatures with cold exposure in the injured digits (14.3°C ± 3.5°C) compared with the contralateral uninjured (16.9°C ± 4.1°C) digits. Compared with bare hands, wearing gloves significantly increased the minimum temperature during cold exposure and the maximum temperature after rewarming. Patients reported higher pain with cold exposure. All participants reported significantly more comfort with less coldness with forearm and hand warming.

CONCLUSIONS

There was cold response variability in hand trauma patients and control subjects. Hand trauma patients had greater changes in skin temperature during cold exposure that improved with glove warming. Continuous temperature monitoring identified subtle physiological changes associated with cold-induced pain and with warming interventions.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic III.

Small-to-moderate decreases in cold hypersensitivity up to 3 years after severe hand injuries: A prospective cohort study

BACKGROUND

The natural course and predictors for decreased cold hypersensitivity were studied in 85 patients with severe hand injuries involving nerve lesions.

METHODS

Questionnaires including the McCabe Cold Sensitivity Severity scale (CSS 0-400) were collected after injury, and at 6-month, 12-month, 2-year, and 3-year follow-ups.

RESULTS

Between the 12-month and 3-year follow-up, there was a small decrease in cold hypersensitivity as measured by the CSS (median = 24; Q1-Q3 = -11-75; n = 85). Five of the patients recovered from cold hypersensitivity, and ∼ 40% of the patients were less affected by cold hypersensitivity in daily life. Little or no pain early after injury and higher CSS-scores 12 months after primary surgery were weakly associated with the reduced CSS-scores (R(2) = 0.20) at the 3-year follow-up. Six patients had changed work or did not work due to cold hypersensitivity, but the majority of the patients had kept their cold-exposed work.

CONCLUSION

Cold-hypersensitive patients may have a reasonable chance for decreased cold sensitivity and cold-associated activity limitations over time, although the majority of the patients will experience persistent problems. Tools to predict improvement remain insufficient.

Relationship between blood- and cerebrospinal fluid-bound neurotransmitter concentrations and conditioned pain modulation in pain-free and chronic pain subjects

Descending pain inhibition is an endogenous pain control system thought to depend partially on the activation of bulbospinal monoaminergic pathways. Deficits in descending pain inhibition have been reported in numerous human chronic pain conditions, but there is currently no consensus regarding the neurochemical correlates responsible for this deficit. The aims of this study were to 1) assess the efficacy of descending pain inhibition in pain-free and chronic pain subjects, 2) screen for changes in centrally (ie, cerebrospinal fluid) and peripherally (ie, plasma) acting monoamine concentrations, and 3) explore the relationship between descending pain inhibition and monoamine neurotransmitter concentrations. Our results clearly show a deficit in pain inhibition, along with lower plasma norepinephrine and metanephrine concentrations in chronic pain subjects, compared to pain-free subjects. No differences were found in cerebrospinal fluid neurotransmitter concentrations. Finally, our results revealed a positive relationship between blood-bound norepinephrine and metanephrine concentrations and the efficacy of descending pain inhibition. Thus, basal monoamine levels in blood were related to descending pain inhibition. This finding supports the emerging idea that individual differences in descending pain inhibition may be linked to individual differences in peripheral processes, such as monoamines release in blood, which are possibly related to cardiovascular control.

PERSPECTIVES

This article presents psychophysical and neurochemical findings that indicate that the latent potential of descending pain inhibitory responses is associated with differential activity in peripheral processes governed by monoamine neurotransmitter release, bringing insights into the relationship between descending pain inhibition and cardiovascular control in humans.