Thermography in childhood reflex sympathetic dystrophy

Signs and symptoms in complex regional pain syndrome type I/reflex sympathetic dystrophy: judgment of the physician versus objective measurement

OBJECTIVE

To assess the relation between the subjectively assessed and objectively measured diagnostic signs and symptoms in complex regional pain syndrome type I (CRPS I) and to quantify their severity.

DESIGN

Diagnostic signs and symptoms were recorded in patients suffering from CRPS I of one upper extremity for less than 1 year. Independent assessors measured (a) pain by using four visual analog scales (VAS) and the McGill Questionnaire list of adjectives (MPQ), (b) edema with a hand volumeter, (c) skin temperature with an infrared thermometer, and (d) active range of motion (AROM) with goniometers.

SETTING

Two university hospitals.

PATIENTS

Ninety-five women and 40 men with CRPS I of one upper extremity.

RESULTS

Four signs and symptoms were diagnosed in 50 patients, and five in the remaining 85 patients. The mean score for present pain intensity was 31.5 mm and that for pain resulting from exertion of the affected extremity was 71.9 mm. A median of 11.5 words was chosen from the MPQ, with the highest number from its evaluative part. The difference in volume between both hands was 30.4 ml. The mean difference in temperature between the two hands was 0.78 degrees C dorsally and 0.66 degrees C palmarly. The largest decrease in mobility was seen in the wrist and fingers; the thumb was relatively less affected and the little finger relatively more affected than the other fingers.

CONCLUSIONS

Bedside evaluation of CRPS I with Veldman's criteria was in good accord with psychometric or laboratory testing of these criteria.

Reflex sympathetic dystrophy in children

Reflex sympathetic dystrophy is a syndrome characterized by pain in one or more extremities, usually associated with vasomotor changes. Its occurrence in childhood has long been thought to be rare. We describe six cases of pediatric reflex sympathetic dystrophy and suggest that this syndrome could be underdiagnosed in children and adolescents. Psychologic problems frequently play a role in this disorder, which often can be treated conservatively. We also point out that the diagnosis is mainly clinical. An early diagnosis can avoid unnecessary tests and potentially can improve response to treatment, and prognosis.

Reflex sympathetic dystrophy associated with deep peroneal nerve entrapment

Reflex sympathetic dystrophy (RSD or causalgia) has been rarely reported in children. We now report a 10-year-old boy with RSD in whom we performed extensive ancillary investigations including thermography, bone scintigraphy and dermo-echography. The clinical, laboratory and ancillary studies reported here highlight the profound focal acquired autonomic disturbance in this disorder. The patient presented a compression of the deep peroneal nerve at the inferior extensor retinaculum in the affected limb. Surgical decompression lead to rapid improvement of the patient's condition. Peripheral nerve decompression should be considered as a possible treatment of RSD in children, particularly those that are refractory to conservative maneuvers.

Stress infrared telethermography is useful in the diagnosis of complex regional pain syndrome, type I (formerly reflex sympathetic dystrophy)

OBJECTIVE

To assess the sensitivity, specificity, and predictive value (PV) of stress infrared telethermography (IRT) in the complex regional pain syndrome, type I (CRPS-I).

METHODS

One hundred eighty-five consecutive patients (47 men, 138 women) with 205 pairs of chronically painful limbs (upper, lower, or both) were examined by pain specialists in neurology, physiatry, and anesthesia, who then reached a consensus diagnosis. A clinical diagnosis of CRPS-I required at least two of the following observations: burning pain, vasomotor changes, diaphoresis, trophic changes, allodynia. Patients with only one criterion were classified as possible CRPS-I; those with none were judged not to have CRPS-I. Patients and 24 asymptomatic control subjects underwent stress IRT, which was considered positive for CRPS-I if it showed three of the following: quantitative thermal emission of > or = 1.00 degree C, abnormal distal thermal gradient patterns, presence of a "thermal marker," and abnormal response to functional cold water autonomic stress testing.

RESULTS

By clinical criteria, CRPS-I was diagnosed in 73 pairs of limbs; not CRPS-I was diagnosed in 70; and 62 pairs had possible CRPS-I. Excluding possible CRPS-I cases, there were 5 false-negative stress IRTs (sensitivity 93%) and 7 false-positive results (specificity 89%). Based on estimated 50% prior probability for our population, the positive PV is 90% and the negative PV 94%. None of the control subjects exhibited thermographic evidence of CRPS-I.

CONCLUSION

Stress IRT is a sensitive and specific indicator of CRPS-I.

Validation of thermography in the diagnosis of reflex sympathetic dystrophy

OBJECTIVES

To examine the validity of several thermogram-derived indices of autonomic functioning in the diagnosis of reflex sympathetic dystrophy (RSD).

DESIGN

A series of chronic pain patients were classified diagnostically based on thermogram results using discriminant function analysis, and validity measures (e.g., sensitivity, specificity) were used to determine the accuracy of computerized thermographic pixel analysis in discriminating RSD from other pathology.

SETTING

The study was conducted at the Rush Pain Center, a multidisciplinary outpatient pain clinic.

PATIENTS

A series of 46 chronic pain patients referred for suspected sympathetically mediated pain.

INTERVENTIONS

All patients underwent computerized thermographic examination under a baseline condition after acclimating to a climate-controlled room, immediately after a cold challenge was applied to the contralateral uninvolved extremity (4 degrees C for 90 s) and 20 min after the cold challenge.

OUTCOME MEASURES

Temperature during the three experimental periods, degree of temperature asymmetry between affected and nonaffected limbs during the three periods, response to cold challenge, and recovery following cold challenge were measured.

RESULTS

Temperature asymmetry accurately discriminated between RSD and non-RSD patients, with the most accurate asymmetry measures obtained at baseline. Responses to cold challenge and actual temperature values did not discriminate between RSD and non-RSD pain patients.

CONCLUSIONS

Thermography can be a useful component of RSD diagnosis. In situations where sensitivity and specificity are equally important, an asymmetry cutoff of 0.6 degree C appears optimal. If specificity (i.e., accurately ruling out non-RSD cases) is more important, a cutoff of 0.8 degree C or 1.0 degree C may be considered as well.

Regional hypothermia in response to minor injury

Minor injuries are sometimes followed by a potentially disabling syndrome of hyperalgesia, hyperesthesia, allodynia, and sudomotor disturbance as well as, eventually, weakness, muscle atrophy, trophic skin changes, and bone and joint abnormalities. Vasomotor changes frequently present as hypothermia or hyperthermia. Most of the literature refers to this syndrome as reflex sympathetic dystrophy (RSD). To observe possible early RSD changes, we studied 1000 military recruits before and during basic training. Evaluations consisted of lower limb clinical examinations and pain assessment. Infrared images were taken of anterior, posterior, medial, lateral legs, and plantar surface of the feet. If the clinical examination suggested a possible stress fracture, a bone scan was performed. Recruits were studied before training and again each time musculoskeletal complaints arose. The controls were recruits tested before the onset of training who had no musculoskeletal complaints. Two-hundred seven soldiers were injured. Regional hypothermia was noted in 8.6% of all thermograms, with 75% on the left and 25% on the right. The most common injuries causing this phenomenon were ankle pain/sprain and minor foot stress fractures, especially the left metatarsals. Hypothermia occurred within 24 to 48 h, usually beginning in the periphery and ascending proximally, lasting a few days to 6 wk (end of study). None of the recruits developed the full syndrome of RSD during the study period. Whether the continued training, even though modified, helped to prevent this complication or the observed post-traumatic hypothermia has no relationship to RSD needs to be determined.

Assessment of pain in patients with juvenile rheumatoid arthritis: relation between pain intensity and degree of joint inflammation

The relation between pain and joint inflammation in patients with juvenile rheumatoid arthritis has not previously been systematically evaluated. Eighteen patients with juvenile rheumatoid arthritis completed paediatric pain questionnaires and the joints affected were examined by thermography. Although significant correlations were shown between parent and doctor pain intensity ratings and joint temperature, correlations of patient pain intensity ratings and joint temperature were only significant in younger children. The degree of joint inflammation is only one factor of several contributing to the amount of subjective pain experienced by children with juvenile rheumatoid arthritis, indicating the need for a comprehensive assessment of the relatively independent variables of inflammation and pain in children with juvenile rheumatoid arthritis.

Reflex sympathetic dystrophy in children. A physical therapy approach

Children with reflex sympathetic dystrophy (RSD) almost always receive physical therapy as part of a multidisciplinary approach, but there is controversy about the efficacy of many alternative modalities. In a retrospective chart review of 24 females and 12 males with 49 episodes of RSD (mean age at onset, 13.4 years), the average time to correct diagnosis was 9.4 months (median, 4.2 months; range, 1-53 months). Sixteen ankles, 12 knees, eight wrists, two hips, and two shoulders were involved. Psychological assessments revealed significant abnormalities in 25 (83%) of 30 children evaluated. Thirty-four (94%) of 36 children received physical therapy including a wide variety of nonstandardized approaches. Children with one to two episodes of RSD averaged 4.0 physical therapy modalities; unresolved cases had 8.9 modalities attempted. Time from the first RSD episode to resolution averaged 9.0 months in 69% of children. Incorrect diagnoses prolonged many initial episodes; following correct diagnosis, symptom resolution occurred in 3.1 months. Recurrences are common, and 25% of children still exhibited RSD symptoms at last follow-up.

Post-herpetic neuralgia: the relation of pain complaint, sensory disturbance, and skin temperature

Twelve otherwise healthy patients with longstanding postherpetic neuralgia (PHN) were prospectively studied using clinical examination, infrared thermography and response to local anesthetic skin infiltration. All had at least 2 of 3 possible components to their PHN pain: continuous, neuralgic, or allodynic. In patients with allodynia, maximal reported pain and the location of maximal allodynia on sensory examination were largely overlapping and were often warm thermographically. Areas of dense sensory loss and skin scarring without allodynia were usually cool thermographically. Local anesthetic skin infiltration produced substantial pain relief in all 9 patients (essentially complete relief in 7) with allodynia: the 3 patients with predominantly continuous pain were not relieved. In 7 of 8 skin infiltration responders, the same dose of lidocaine i.m. in the deltoid muscle also produced significant, though less complete pain relief. These results suggest that PHN patients can be divided into at least 2 clinical groups: those with predominantly continuous pain localized to a region of significant sensory loss and those in whom allodynia is the most prominent sensory disturbance. The latter group has pain localized to areas with relatively preserved sensation. The differences in clinical features and response to lidocaine suggest that there are at least 2 different mechanisms contributing to the pain of PHN.

Pediatric rehabilitation. 6. Musculoskeletal and soft tissue disorders

This self-directed learning module highlights advances in evaluation and treatment of congenital and acquired musculoskeletal disorders in the child. It is a section of the chapter on pediatric rehabilitation for the Self-Directed Medical Knowledge Program Study Guide for practitioners and trainees in physical medicine and rehabilitation. This section contains information on alterations of limb structure and gait, scoliosis, torticollis, sports injuries and overuse syndromes, and unexplained pain in children.