The successful use of pamidronate in an 11-year-old girl with complex regional pain syndrome: response to treatment demonstrated by serial peripheral quantitative computerised tomographic scans

Use of bisphosphonates in a retrospective case series of children and adolescents with complex regional pain syndrome

BACKGROUND

There is increasing evidence for the use of bisphosphonates to treat Complex Regional Pain Syndrome in adults. However, there are scarce data for their use in children with Complex Regional Pain Syndrome.

AIM

This retrospective case series aimed to analyze the effects of intravenous bisphosphonate use in children and adolescents with Complex Regional Pain Syndrome enrolled in a multidimensional pain treatment program.

METHODS

We analyzed the data of 16 patients (15 females and 1 male, mean age 14 ± 3 years) who received infusions of zoledronic acid (0.015 ± 0.0044mg/kg), pamidronate (0.72 ± 0.17mg/kg), or both depending on their initial response between October 2014 and December 2019. The primary endpoint of the study was the patient's global impression of change. Secondary outcomes included pain intensity, physical function, role function (school attendance), need for pain medications, and adverse effects.

RESULTS

Nine of 16 patients reported meaningful improvements (global impressions of change of 84% or higher) at a median follow-up time of 16 (8-21) months after their last infusion of bisphosphonates. There were also meaningful reductions in pain intensity and the need for pain medications. There was an increase in the proportion of patients with minimal or without physical disability, and almost all patients normalized their school activities. Thirteen patients (81%) reported adverse effects, mostly flu-like symptoms, for a few days after the infusion.

CONCLUSION

The use of bisphosphonate infusions may represent an effective treatment option for children with Complex Regional Pain Syndrome, not responding to multidisciplinary pain treatment programs.

Bone microstructure is significantly altered in CRPS-affected distal tibiae as detected by HR-pQCT: a retrospective cross-sectional study

In the course of complex regional pain syndrome (CRPS), local osteopenia in the subchondral/subcortical areas of the affected limb represents a central manifestation. Mechanistic aspects of CRPS-associated pathologies remain unclear, and knowledge about bone morphology in CRPS-affected areas is rare. The aim of this study was to assess trabecular and cortical bone microstructure in patients with CRPS of the distal tibiae. We retrospectively analysed 14 women diagnosed with unilateral CRPS type I of the lower limb whose affected and unaffected distal tibiae were examined by high-resolution peripheral quantitative computed tomography (HR-pQCT). Laboratory tests included serum levels of calcium, phosphate, 25-hydroxyvitamin D, bone alkaline phosphatase, parathyroid hormone, osteocalcin and urinary levels of deoxypyridinoline (DPD). Bone mineral density was measured by dual-energy X-ray absorptiometry (DXA) at the lumbar spine and both proximal femurs. Average urinary DPD levels, a biochemical marker of bone resorption, were elevated in the examined patient cohort (7.1 ± 1.9 nmol/mmol, reference 3.0-7.0 nmol/mmol). According to HR-pQCT, CRPS-affected distal tibiae showed significantly lower values of cortical BMD and cortical thickness compared to the unaffected contralateral side. Also, bone volume relative to total volume was significantly lower. Trabecular number and trabecular thickness tended to be lower in the affected tibiae. CRPS is associated with significant alterations in bone microstructure of the affected tibiae. Increased bone resorption seems to play a crucial role within a multifactorial process of CRPS-mediated bone atrophy. HR-pQCT could possibly serve as a diagnostic tool in specific CRPS therapy.

Complex regional pain syndrome type I in children: What is new?

Complex regional pain syndrome type I (CRPS-I), although first described by the French surgeon Ambroise Paré as far back as the 16th century, nevertheless remains shrouded in mystery. The most common symptoms are pain in an entire hand or foot, allodynia, functional impairment induced by the pain, local oedema and skin color changes and transient sweating abnormalities. Most cases occur after a minor injury (i.e., a sprain or fracture), although there may be no identifiable triggering event, particularly in children. Primarily cold CRPS-I is by far the most common variant in children. Development of the Budapest criteria has benefited the diagnosis. These criteria are clinical and no specific diagnostic investigation is available. In vitro and in vivo studies have established that several pathogenic mechanisms can be involved concomitantly. However, there is no satisfactory explanation to the full clinical spectrum. Blood tests and imaging studies are useful for ruling out other diagnoses then monitoring the course of the condition, which may involve the development of demineralisation or osteopenia. High-resolution peripheral quantitative computed tomography may be helpful, as it provides quantitative assessments of the cortical and trabecular bone. CRPS-I has several specific characteristics in children compared to adults and whether the condition is the same entity in these two age groups is a legitimate question. The optimal management involves an early diagnosis followed by a multidisciplinary management programme of functional rehabilitation therapy and cognitive behavioral therapy. Analgesics are useful only during the phase of acute pain and to facilitate physical therapy. Studies in adults showed that bisphosphonates were effective within the first 12 months after symptom onset and calcitonin in longer-lasting cases. No high-quality clinical research studies into the aetiopathogenesis and treatment of CRPS-I in children and adolescents are available to date.

Intravenous Therapies for Complex Regional Pain Syndrome: A Systematic Review

Complex regional pain syndrome (CRPS) remains a challenging clinical pain condition. Multidisciplinary approaches have been advocated for managing CRPS. Compared with spinal cord stimulation and intrathecal targeted therapy, IV treatments are less invasive and less costly. We aimed to systemically review the literature on IV therapies and determine the level of evidence to guide the management of CRPS. We searched PubMed, Embase, Scopus, and the Cochrane databases for articles published on IV therapies of CRPS up through February 2015. The search yielded 299 articles, of which 101 were deemed relevant by reading the titles and 63 by reading abstracts. All these 63 articles were retrieved for analysis and discussion. We evaluated the relevant studies and provided recommendations according to the level of evidence. We conclude that there is evidence to support the use of IV bisphosphonates, immunoglobulin, ketamine, or lidocaine as valuable interventions in selected patients with CRPS. However, high-quality studies are required to further evaluate the safety, efficacy, and cost-effectiveness of IV therapies for CRPS.

Treatment of complex regional pain syndrome

Complex Regional Pain Syndrome (CRPS) is a multifactorial and disabling disorder with complex etiology and pathogenesis. Goals of therapy in CRPS should be pain relief, functional restoration, and psychological stabilization, but early interventions are needed in order to achieve these objectives. Several drugs have been used to reduce pain and to improve functional status in CRPS, despite the lack of scientific evidence supporting their use in this scenario. They include anti-inflammatory drugs, analgesics, anesthetics, anticonvulsants, antidepressants, oral muscle relaxants, corticosteroids, calcitonin, bisphosphonates, calcium channel blockers and topical agents. NSAIDs showed no value in treating CRPS. Glucocorticoids are the only anti-inflammatory drugs for which there is direct clinical trial evidence in early stage of CRPS. Opioids are a reasonable second or third-line treatment option, but tolerance and long term toxicity are unresolved issues. The use of anticonvulsants and tricyclic antidepressants has not been well investigated for pain management in CRPS. During the last years, bisphosphonates have been the mostly studied pharmacologic agents in CRPS treatment and there are good evidence to support their use in this condition. Recently, the efficacy of intravenous (IV) administration of neridronate has been reported in a randomized controlled trial. Significant improvements in VAS score and other indices of pain and quality of life in patients who received four 100 mg IV doses of neridronate versus placebo were reported. These findings were confirmed in the open-extension phase of the study, when patients formerly enrolled in the placebo group received neridronate at the same dosage, and these results were maintained at 1 year follow-up. The current literature concerning sympathetic blocks and sympathectomy techniques lacks evidence of efficacy. Low evidence was recorded for a free radical scavenger, dimethylsulphoxide (DMSO) cream (50%). The same level of efficacy was noted for vitamin C (500 mg per day for 50 days) in prevention of CRPS in patients affected by wrist fracture. In conclusion, the best available therapeutic approach to CRPS is multimodal and is based on the use of several classes of drugs, associated to early physiotherapy. Neridronate at appropriate doses is associated with clinically relevant and persistent benefits in CRPS patients.

[Please don't hurt me!: a plea against invasive procedures in children and adolescents with complex regional pain syndrome (CRPS)]

BACKGROUND

Complex regional pain syndrome (CRPS; formerly known as Morbus Sudeck/reflex dystrophy) is diagnosed in children and adolescents, but the clinical presentation is often atypical. Unfortunately, potentially harmful, invasive treatments are used in pediatric patients.

PATIENTS AND METHODS

A retrospective chart study of pediatric chronic pain patients with CRPS was performed.

RESULTS

Over the course of 6 years, 37 (35 girls) children and adolescents took part in a multidisciplinary chronic pain inpatient program. At admission, patients took on average 4.4 (range 1-10) different medications and 29 different pharmaceuticals were used overall. Prior to admission, invasive pain treatments were performed without success in 16 of the children (43%). At least 13 children received two or more invasive treatments. Although sympathetic blocks were most prevalent, operations and regional anesthesia were also used.

CONCLUSION

Despite a lack of evidence for invasive procedures, these continue to be used in children and adolescents with CRPS, who later respond positively to conventional treatment. The English full-text version of this article is available at SpringerLink (under "Supplemental").

Bisphosphonates: focus on inflammation and bone loss

Bisphosphonates are pharmacological compounds that have been used for the prevention and treatment of several pathological conditions including osteoporosis, primary hyperparathyroidism, osteogenesis imperfecta, and other conditions characterized by bone fragility. Many studies have been performed to date to analyze their effects on inflammation and bone remodelling and related pathologies. The aim of this review is, starting from a background on inflammatory processes and bone remodelling, to give an update on the use of bisphosphonates, outlining the possible side effects and proposing new trends for the future. Starting from a brief introduction on inflammation and bone remodelling, we collect and analyze studies involving the use of bisphosphonates for treatment of inflammatory conditions and pathologies characterized by bone loss. Selected articles, including reviews, published between 1976 and 2011, were chosen from Pubmed/Medline on the basis of their content. Bisphosphonates exert a selective activity on inflammation and bone remodelling and related pathologies, which are characterized by an excess in bone resorption. They improve not only skeletal defects, but also general symptoms. Bisphosphonates have found clinical application preventing and treating osteoporosis, osteitis deformans (Paget's disease of bone), bone metastasis (with or without hypercalcaemia), multiple myeloma, primary hyperparathyroidism, osteogenesis imperfecta, and other conditions that feature bone fragility. Further clinical studies involving larger cohorts are needed to optimize the dosage and length of therapy for each of these agents in each clinical field in order to be able to maximize their properties concerning modulation of inflammation and bone remodelling. In the near future, although "old" bisphosphonates will reach the end of their patent life, "new" bisphosphonates will be designed to specifically target a pathological condition.