Reflex sympathetic imbalance. Response to epidural blockade

Complex Regional Pain Syndrome in Athletes: Scoping Review

Background and Objectives: Complex regional pain syndrome (CRPS) is a chronic condition characterized by disproportionate regional pain, usually affecting distal limbs, that follows trauma or surgery. Athletes may develop CRPS because of exposure to traumatic or overuse injuries. The aim of the present study is to review the available literature about CRPS type 1 in athletes. Materials and Methods: We searched two online databases (PubMed and Web of Science), selecting papers aiming at investigating CRPS type 1 (algodystrophy) in athletes. The analysis of databases was made considering original articles published until 30 June 2021, written in English. Results: Fifteen papers (12 case reports, 3 case series) were selected for a total of 20 clinical cases (15 females, 5 males), aged between 10 and 46 years (mean age 18.4 ± 9.8 standard deviation years). Patients included practiced different types of sport (soccer, athletics, gymnastics, basketball). The most involved anatomical sites were lower limbs, and time to diagnosis ranged from 2 days to 4 years. The most used treatments were pharmacological and physical therapies, but sometimes invasive approaches, as regional nerve, or lumbar sympathetic blocks, were provided. The main assessed outcomes were return to activity and pain. Conclusions: Our review suggests a higher prevalence of CRPS type 1 in younger people and in lower limbs than in general population but confirms the higher prevalence in females. However, the number of studies addressing CRPS in athletes is limited, as well as the number of involved patients, considering that only few and heterogeneous case reports were published about this topic. Moreover, the high prevalence of old studies (only 5 available studies in the last 10 years) might have influenced the choice of both assessment tools and management strategies. Despite these limitations, athletes showing disproportionate pain after sport-related injury should be promptly evaluated and treated through a multidimensional approach to avoid long-term consequences of algodystrophy.

Osteoid osteoma: percutaneous laser ablation and follow-up in 114 patients

PURPOSE

To retrospectively evaluate the effectiveness of interstitial laser ablation (ILA) as a curative treatment of osteoid osteoma.

MATERIALS AND METHODS

Ethical review board approval was obtained for the retrospective study. Informed consent was waived. From June 1994 to June 2004, 114 patients (mean age, 22.3 years) suspected of having osteoid osteoma underwent ILA with a diode laser (805 nm). An optical fiber was introduced into the nidus of the osteoid osteoma, and 400-3000 J of energy was delivered, depending on the size and location of the nidus. Twelve spinal osteoid osteomas were treated; in five of these cases, the nidus was located fewer than 8 mm from the adjacent nerve roots, and slow epidural or periradicular infusion of normal saline was used to avoid thermal damage to neurologic structures. Pain was evaluated with a visual analog scale (VAS) and medication. ILA was considered successful (score, 0) when complete pain relief was achieved (VAS score, <1) without medication.

RESULTS

One week after ILA, 112 patients had a score of 0. One week after ILA, one patient had pain that persisted for 2 months because of reflex sympathetic dystrophy. At follow-up (mean, 58.5 months; range, 13-130 months), six patients had recurrence of pain from 6 weeks to 27 months after the initial ILA. These recurrences were treated successfully with a second ILA. Only one unsuccessful treatment was encountered.

CONCLUSION

Percutaneous ILA is an effective treatment for osteoid osteoma.

Management of Pediatric Patients With Complex Regional Pain Syndrome

This review summarizes current information about diagnosis and treatment of complex regional pain syndrome (CRPS) in children. Although it has been widely held that CRPS in children is intrinsically different from adults, there appear to be relatively few differences. However, there is a marked preponderance of lower extremity cases in children. Historically, psychological factors have been invoked to explain the genesis and persistence of CRPS in children, but the evidence is not compelling. Treatment outcome studies are limited but indicate that children generally respond to a primary focus on physical therapy. Multidisciplinary treatment reports are particularly encouraging. The general perception that children have a milder course may relate to the potentially greater willingness of children to actively participate in appropriately targeted treatment rather than to innate differences in the disease process itself. Recurrence rates appear higher than in adults, but response to reinitiation of treatment seems to proceed efficiently. Clinical judgment dictates the extent of medication or interventional therapy added to the treatment to facilitate rehabilitation. In many ways, the approach to the treatment of children mirrors that of adults, with perhaps greater restraint in the use of medications and invasive procedures. The rehabilitation of children with CRPS, like that of adults with CRPS, needs further rigorous investigation.

Epidural Infusion of Opiates and Local Anesthetics for Complex Regional Pain Syndrome

Complex Regional Pain Syndrome Type-I (CRPS-I) is a neuropathic pain syndrome resulting from complex pain mechanisms that involve several levels and components of the nervous system. CRPS-I consists of multiple signs, including autonomic dysfunction, in the form of edema, vasomotor changes, motor dysfunctions, muscle spasms, tremors and dystonia, as well as burning pain, hypersensitivity and allodynia that could present in any combination. The treatment is progressive physical therapy rehabilitation program. Multiple analgesic modalities have been used to facilitate the rehabilitation program with varying rates of success. The most successful treatment is a multi-disciplinary comprehensive approach, where initial pain control allows for physical and psychological interventions that are believed to be the basis for successful treatment.(1) The pain in CRPS-I may be mediated through the sympathetic nervous system, sympathetic maintained pain (SMP) or sympathetic independent pain (SIP)(2).

Intravenous regional anesthesia with clonidine in the management of complex regional pain syndrome of the knee

STUDY OBJECTIVE

To evaluate the safety and efficacy of administering intravenous regional anesthesia (IVRA) with clonidine in the management of complex regional pain syndrome (CRPS) of the knee.

DESIGN

Prospective, non-blinded study.

SETTING

University-affiliated pain management center.

PATIENTS

7 patients with the diagnosis of CRPS of the knee. The diagnosis of CRPS was made if a) patients had at least four of these symptoms: allodynia, hyperesthesia, edema, vasomotor changes, pain with a burning quality, sudomotor changes, joint stiffness, or temperature differences between extremities; b) patients had significant pain relief (>75%) after a lumbar sympathetic block.

INTERVENTIONS

Each patient received IVRA with a solution containing clonidine 1 microg/kg in a total volume of 50 mL 0.5% lidocaine. IVRA clonidine (IVRA-C) was performed on each patient up to six times (maximum of once a week for six weeks). MEASUREMETNS: Pain was assessed using a verbal pain scale (VPS) between 0 and 10 before each IVRA-C treatment. Duration of pain relief was defined as the time during which the patients experienced no pain (VPS = 0). Continuous electrocardiogram (ECG) and pulse oximetry (SpO2) were monitored and blood pressure was recorded every 5 minutes for the first 60 minutes after tourniquet deflation.

MAIN RESULTS

Five patients received complete pain relief with 4 to 6 IVRA-C blocks. The two remaining patients reached a therapeutic plateau from IVRA-C, but had persistent anatomic lesions contributing to the recurrence of their CRPS. No patient experienced hypotension (mean arterial pressure < or = 20% baseline), hypoxemia (SpO2 < or = 90%), bradycardia (heart rate < or =H 60 beats/min), or excessive sedation.

CONCLUSIONS

IVRA-C is a useful treatment modality in the management of CRPS of the knee. Clonidine doses of 1 microg/kg appear to be well tolerated without significant side effects.

Pain dysfunction syndrome of the knee

Pain dysfunction syndrome is a descriptive term recommended by Amadio to describe patients whose pain is excessive, nonanatomic, and out of proportion to their injury. This retrospective review reports the effectiveness of a differential epidural block in the evaluation of these patients. Four patterns of response were identified with the block: 1) reflex sympathetic dystrophy (RSD) (14%), 2) somatic (9%), 3) mixed sympathetic and somatic (27%), and 4) central (50%). The inciting injury in 70% of the patients was a minor strain, sprain, or contusion. Despite accurate diagnosis, the results in compensation cases with pain dysfunction syndrome are exceedingly poor.

Reflex Sympathetic Dystrophy of the Knee

Reflex sympathetic dystrophy (RSD) of the knee frequently does not present with the classic combination of signs and symptoms seen in the upper extremity. Pain out of proportion to the initial injury is the hallmark symptom. Symptom relief by sympathetic block is the current standard for confirmation of the diagnosis. Because invasive diagnostic procedures, such as arthroscopy, are likely to increase symptoms, evaluation with a noninvasive diagnostic modality, such as magnetic resonance imaging, is preferred. Generally, RSD should be treated before surgical intervention to correct any underlying intra-articular pathologic condition. However, surgery may sometimes be necessary before RSD symptoms resolve; in these cases, use of intra- and postoperative continuous epidural block can be successful. The initial treatment of RSD of short duration should be conservative; physical therapy modalities, including exercise and contrast baths, and non-steroidal anti-inflammatory drugs are indicated. In the authors' experience, an indwelling epidural block using bupivacaine for several days followed by use of a narcotic agent, combined with functional rehabilitation, is the most effective management when noninvasive treatment has failed. Surgical sympathectomy can be successful, but should be reserved until repeated lumbar sympathetic block or more than one trial of inpatient epidural block has failed. Early diagnosis and early institution of treatment (prior to 6 months) are the most favorable prognostic indicators in the management of RSD.

Posttraumatic reflex sympathetic dystrophy: Mechanisms and medical management

Reflex sympathetic dystrophy (RSD) refers to a symptom complex of posttraumatic pain associated with a wide and varying spectrum of vasomotor and neurologic changes. The diagnosis of reflex sympathetic dystrophy is made almost entirely on clinical grounds, and is often confirmed by observation of the results of diagnostic local anesthetic nerve blocks. Laboratory and radiographic investigations are useful adjuncts to diagnosis. The key to successful management is early recognition, as delays in treatment are associated with worse outcome. A multimodal approach to treatment is recommended that may include nerve blocks, rehabilitation, and pharmacologic and behavioral pain management. The role of other modalities including surgery and electrical stimulation remains controversial.