Successful therapy of complex regional pain syndrome after hip arthroscopy for femoroacetabular impingement syndrome: a case report

BACKGROUND

Complex regional pain syndrome is a neuropathic pain disorder associated with ongoing pain that persists beyond the usual expected tissue healing time and that is disproportionate to the degree of tissue injury present. Complex regional pain syndrome after hip arthroscopy has not been reported before. Hip arthroscopy is a fast-growing domain that could lead to an increasing number of complex regional pain syndrome cases, probably owing to the high traction forces that are necessary.

CASE PRESENTATION

We report the case of a 30-year-old German female semiprofessional tennis player who presented with complex regional pain syndrome type I in the lower leg 3 weeks after hip arthroscopy for femoroacetabular impingement syndrome with suture anchor labral repair and femoroplasty. After 2 months of immediate multimodal conservative therapy including administration of gabapentin, prompt full weight-bearing, and intensified physiotherapy, complete recovery was achieved.

CONCLUSION

Complex regional pain syndrome does occur after elective hip arthroscopy. Disproportionate postoperative pain or other symptoms raising suspicion of complex regional pain syndrome should be promptly evaluated and treated through a multimodal approach. Postless hip arthroscopy may be advantageous.

Safety and Efficacy of Intravenous ExoFlo in the Treatment of Complex Regional Pain Syndrome

BACKGROUND

Complex regional pain syndrome (CRPS) is an extremely painful disorder driven primarily by inflammation.

OBJECTIVES

We hypothesized that the immunomodulatory biologic, ExoFloTM, composed of bone marrow mesenchymal stem cell-derived extracellular vesicles, could be safely administered to CRPS patients and alleviate symptoms.

STUDY DESIGN

Ten patients received 2 intravenous (IV) infusions, each containing 15 mL ExoFlo, on day one and day 4. A series of tests were performed at baseline (day 0, prior to infusion), week one, and months one, 3, and 6 after the second infusion.

SETTING

All patients were treated in one of 2 outpatient pain management clinics in Orange County, CA.

METHODS

Testing for clinical improvement included: visual analog scale of pain, brief pain inventory, 36-item short-form questionnaire, range of motion analysis, and jamar dynamometer testing.

RESULTS

No serious adverse events related to ExoFlo treatment occurred. Statistically significant improvements in pain and motion assessments occurred across the patient pool.

LIMITATIONS

This study was limited by its patient number enrolled (10), it lacked a control arm, and one patient who dropped out of the study.

CONCLUSIONS

IV delivery of ExoFlo appears safe in patients with CRPS. In addition, ExoFlo exhibited efficacy in addressing CRPS symptoms. Given the lack of effective and safe treatments available to CRPS patients, these results suggest that further studies are warranted to explore and validate this potential treatment for CRPS.

Differences in incidence rate and onset timing of undiagnosed finger symptom among shoulder surgeries related to complex regional pain syndrome

The purpose of this study was to clarify the difference in onset timing and incidence of undiagnosed finger symptom (UDFS) between various shoulder surgical procedures. In this study, UDFS symptoms included the following four symptoms in the fingers;edema, limited range-of-motion, skin color changes, and abnormal sensations. UDFS cases were defined as those presenting with at least one UDFS. In result, the incidence rate of UDFS cases was 7.1% overall (58/816 shoulders), 7.4% (32/432) in arthroscopic rotator cuff repair (ARCR), 9.0% (11/122) in open rotator cuff repair (ORCR), 1.4% (2/145) in arthroscopic subacromial decompression (ASD), 13.2% (5/38) in open reduction and internal fixation (ORIF), 11.1% (3/27) in humeral head replacement, 4.8% (1/21) in anatomical total shoulder arthroplasty, and 12.9% (4/31) in reverse total shoulder arthroplasty cases. The Rate was significantly higher with ARCR compared to ASD (p<.01). About onset timing in weeks postoperatively, the ORIF group had a statistically earlier symptom onset than the Rotator cuff repair (ARCR + ORCR) group (2.4 weeks vs. 6.0 weeks, p<.01). When classifying the onset timing into before and after the removal of the abduction pillow, the ORIF group showed a statistically higher rate of onset before brace removal than the Rotator cuff repair groups (p<.01). Differences in UDFS among shoulder surgeries were demonstrated in this study. J. Med. Invest. 70 : 415-422, August, 2023.

Complex Regional Pain Syndrome: A Comprehensive Review

Complex regional pain syndrome (CRPS) is a chronic pain condition often involving hyperalgesia and allodynia of the extremities. CRPS is divided into CRPS-I and CRPS-II. Type I occurs when there is no confirmed nerve injury. Type II is when there is known associated nerve injury. Female gender is a risk factor for developing CRPS. Other risk factors include fibromyalgia and rheumatoid arthritis. Unfortunately, the pathogenesis of CRPS is not yet clarified. Some studies have demonstrated different potential pathways. Neuropathic inflammation, specifically activation of peripheral nociceptors of C-fibers, has been shown to play a critical role in developing CRPS. The autonomic nervous system (ANS) is involved. Depending on whether it is acute or chronic CRPS, norepinephrine levels are either decreased or increased, respectively. Some studies have suggested the importance of genetics in developing CRPS. More consideration is being given to the role of psychological factors. Some association between a history of depression and/or post-traumatic stress disorder (PTSD) and the diagnosis of CRPS has been demonstrated. Treatment modalities available range from physical therapy, pharmacotherapy, and interventional techniques. Physical and occupational therapies include mirror therapy and graded motor imagery. Medical management with non-steroidal anti-inflammatory drugs (NSAIDs) has not shown significant improvement. There have been supporting findings in the use of short-course steroids, bisphosphonates, gabapentin, and ketamine. Antioxidant treatment has also shown some promise. Other pharmacotherapies include low-dose naltrexone and Botulinum toxin A (BTX-A). Sympathetic blocks are routinely used, even if their short- and long-term effects are not clear. Finally, spinal cord stimulation (SCS) has been used for decades. In conclusion, CRPS is a multifactorial condition that still requires further studying to better understand its pathogenesis, epidemiology, genetic involvement, psychological implications, and treatment options. Future studies are warranted to better understand this syndrome. This will provide an opportunity for better prevention, diagnosis, and treatment of CRPS.

Complex regional pain syndrome in a patient with neuroendocrine tumour under treatment with everolimus

Everolimus is an immunosuppressant agent used in organ transplantation and, more recently, in cancer therapy. It has demonstrated beneficial effects in breast cancer, renal cancer, and neuroendocrine tumours. However, the treatment is not without side effects, some of which are still little known. We report the case of a 56 year-old man with a diagnosis of neuroendocrine tumour who developed a complex regional pain syndrome (CRPS) secondary to treatment with everolimus. CRPS has been linked to treatments with everolimus in renal and breast cancer patients as well as in renal transplant patients. To our knowledge, this is the first case of CRPS in a neuroendocrine tumour patient on everolimus treatment.

Chronic pain-related cortical neural activity in patients with complex regional pain syndrome

Quantitative objective measurement of chronic pain is important. We elucidated chronic pain-related cortical neural activity and neural connectivity among pain-related brain regions in complex regional pain syndrome (CRPS). Resting-state magnetoencephalography recordings were performed. Cortical current density and neural connectivity, revealed by amplitude envelope correlation (AEC), were estimated on standardized brain magnetic resonance imaging. Intra-experiment pain was assessed subjectively using a visual analogue scale (VAS). The correlation between current density and VAS scores was calculated for the occipital areas and pain-related cortices. Current density in the primary (SI) and secondary (SII) somatosensory cortex and precuneus in both hemispheres was negatively correlated with the pain VAS score. The AEC and VAS values were significantly correlated for the SII and the precuneus and for the SII and insular cortex in the alpha frequency band in the right hemisphere. In the theta frequency band, the AEC and VAS values correlated for the SII and posterior cingulate cortex in the right hemisphere. Our results suggested that disruption of pain processes and functions in the default mode network occurs in CRPS. Our method targeting the neural mechanism of pain has the potential to offer a clinically objective means of evaluating it.

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Chronic pain can be objectively evaluated with magnetoencephalography.

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Neural connectivity of pain-related cortices was reduced in complex regional pain syndrome.

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Default mode network is disrupted in complex regional pain syndrome patients.

Interventional Radiofrequency Treatment for the Sympathetic Nervous System: A Review Article

Introduction

Interventional techniques such as radiofrequency (RF) treatment can be used to interrupt pain signals transmitted through the sympathetic nervous system (SNS). RF treatments including the pulsed (PRF) and continuous (CRF) modalities show enhanced control over lesion size and enhanced ability to confirm accurate positioning compared to other interventional methods. PRF also acts to reduce the area of the lesion. In this article, we characterize the currently available evidence supporting the use and efficacy of RF treatments in sympathetically mediated pain (SMP) conditions.

Study Design

A comprehensive literature review.

Methods

A PubMed and Cochrane Library database search was performed for human studies applying RF treatment at sympathetic sites (sphenopalatine ganglion, stellate ganglion, cervical, thoracic, or lumbar sympathetic ganglia, celiac plexus, splanchnic nerves, superior hypogastric plexus, and ganglion impar) between January 1970 to May 2020. Data were extracted, summarized into tables, and qualitatively analyzed.

Results

PRF and CRF both show promise in relieving SMP conditions, such as complex regional pain syndrome (CRPS), pain in the perineal region, headache and facial pain, and oncologic and non-oncologic abdominal pain, in addition to other types of pain, with minimal complications. Furthermore, in most comparative studies, outcomes using RF treatments exceeded other interventional techniques, such as anesthetic block and chemical neurolysis.

Conclusions

RF treatments can be effective in carefully selected patients who are refractory to conservative management. However, further randomized controlled studies are needed prior to implementing it into common practice.

Pain reduction by inducing sensory-motor adaptation in Complex Regional Pain Syndrome (CRPS PRISMA): protocol for a double-blind randomized controlled trial

BACKGROUND

Complex Regional Pain Syndrome (CRPS) presents as chronic, continuous pain and sensory, autonomic, and motor abnormalities affecting one or more extremities. People with CRPS can also show changes in their perception of and attention to the affected body part and sensory information in the affected side of space. Prism Adaptation (PA) is a behavioural intervention targeted at reducing attention deficits in post-stroke hemispatial neglect. PA also appears to reduce pain and other CRPS symptoms; however, these therapeutic effects have been demonstrated only in small unblinded studies. This paper describes the protocol for an ongoing double-blind, randomized, sham-controlled clinical trial that will evaluate the efficacy of PA treatment for CRPS. The secondary aims of the study are to examine the relationships between neuropsychological changes (such as spatial attention, space and body representation, and motor spatial performance) and clinical manifestations of CRPS, as well as symptom improvement.

METHODS

Forty-two participants with upper-limb CRPS type I will undergo 2 weeks of twice-daily PA treatment or sham treatment. The primary outcome measures are current pain intensity and CRPS severity score, measured immediately before and after the treatment period. Secondary outcome measures include the results of self-report questionnaires about pain, movement, symptoms interference, and body representation; clinical assessments of sensory, motor, and autonomic functions; and computer-based psychophysical tests of neuropsychological functions. Data are collected in four research visits: 4 weeks and 1 day before treatment, and 1 day and 4 weeks after the end of treatment. Additional follow-up through postal questionnaires is conducted 3 and 6 months post-treatment.

DISCUSSION

It is hypothesised that participants undergoing PA treatment, compared to those receiving sham treatment, will show greater reduction in pain and CRPS severity score, and improvements on other clinical and neuropsychological measures. Also, more pronounced neuropsychological symptoms are predicted to correlate with more severe clinical CRPS symptoms. This study will provide the first randomized double-blind evaluation of the therapeutic effects of PA that could be implemented as a rehabilitation method for CRPS, and will contribute to the understanding of how neuropsychological changes in body representation and attention pertain to the manifestation and treatment of CRPS.

TRIAL REGISTRATION

(27/03/2017): ISRCTN46828292 (ISRCTN - ISRCTN46828292: Treatment of complex regional pain syndrome (CRPS) with sensory-motor adaptation).

Complex regional pain syndrome type 1 in the medico-legal setting: High rates of somatoform disorders, opiate use and diagnostic uncertainty

Objective The aim of this study was to review demographic and clinical characteristics of patients with complex regional pain syndrome type 1 (CRPS) seen in a UK medico-legal setting - particularly the relationship between CRPS and somatoform disorders. Methods Fifty consecutive cases of CRPS (interviewed 2005-2016) undergoing psychiatric assessment were reviewed. A systematic assessment of mental states was conducted via interview and examination of medical/psychiatric records. Thirty patients also completed the Brief Illness Perception Questionnaire (BIPQ). Results Sixty per cent of patients ( n = 30) were female, and the mean age was 43 years. Twenty-two per cent ( n = 11) were employed, and 60% ( n = 30) received disability benefits. Symptoms were reported in the upper limb (62%; n = 31), lower limb (30%; n = 15), both (6%; n = 3) or elsewhere (2%; n = 1). Eighty-four per cent ( n = 42) satisfied DSM-5 criteria for current somatoform disorder. A history of more than two pain-related functional somatic syndromes (e.g. non-cardiac chest pain) was found in 42% ( n = 21) and functional neurological symptoms (e.g. 'claw-hand') in 42% ( n = 21). BIPQ scores resembled those associated with somatoform disorders and disorders mediated by psychological factors (e.g. irritable bowel syndrome). In 38% ( n = 19), the CRPS diagnosis was disputed among experts. A history of depression was noted in 60% ( n = 30), panic attacks in 20% ( n = 10) and alcohol/substance misuse in 18% ( n = 9). Opiates were prescribed to 64% ( n = 32). Conclusions Patients diagnosed with CRPS involved in litigation have high rates of prior psychopathology (mainly somatoform disorders) and pain-related disability for which opiate use is common. They risk an adverse reaction to limb pain 'shaped' by maladaptive illness beliefs. The CRPS diagnosis lacks reliability in medico-legal settings and may cause iatrogenic harm.

Advancing Transcranial Magnetic Stimulation Methods for Complex Regional Pain Syndrome: An Open-Label Study of Paired Theta Burst and High-Frequency Stimulation

INTRODUCTION

Complex Regional Pain Syndrome (CRPS), a rare and severe chronic pain condition, often responds poorly to existing treatments. Previous studies demonstrated Transcranial Magnetic Stimulation (TMS) provided short-term pain relief for upper extremity CRPS.

METHODS

Building on previous methodologies, we employed a TMS protocol that may lead to significant pain relief for upper and lower extremity CRPS in a nonrandomized open label pilot trial involving 21 participants. We individualized TMS coil positioning over motor cortex of somatic pain location, and administered intermittent theta-burst stimulation followed by 10 Hz high-frequency stimulation using a deeper targeting coil. We assessed response (≥30% pain reduction) from a single session (n = 5) and five consecutive daily sessions (n = 12) and compared change in pain from baseline, after one treatment and one-week posttreatment between groups using a mixed ANVOA.

RESULTS

Both groups demonstrated significant pain reduction after one session and one-week posttreatment; however, no group differences were present. From a single session, 60% of participants responded at Week 1. From five sessions, 58% and 50% of participants responded at Weeks 1 and 2, respectively. Two from each group achieved >50% pain reduction beyond six to eight weeks. No serious adverse events occurred. Though headache and nausea were the most common side-effects, we urge careful monitoring to prevent seizures with this protocol.

CONCLUSIONS

We used a TMS protocol that, for the first time, led to significant pain relief in upper and lower extremity CRPS, and will soon examine our protocol in a larger, controlled trial.

[Complex regional pain syndrome following distal fractures of the radius : Epidemiology, pathophysiological models, diagnostics and therapy]

The complex regional pain syndrome (CRPS) still represents an incompletely etiologically understood complication following fractures of the distal radius. The incidence of CRPS following fractures of the distal radius varies between 1 % and 37 %. Pathophysiologically, a complex interaction of inflammatory, somatosensory, motor and autonomic changes is suspected, leading to a persistent maladaptive response and sensitization of the central and peripheral nervous systems with development of the corresponding symptoms. Decisive for the diagnostics are a detailed patient medical history and a clinical hand surgical, neurological and pain-related examination with confirmation of the Budapest criteria. Among the types of apparatus used for diagnostics, 3‑phase bone scintigraphy and temperature measurement have a certain importance. A multimodal therapy started as early as possible is the most promising approach for successful treatment. As part of a multimodal rehabilitation the main focus of therapy lies on pain relief and functional aspects.

Complex regional pain syndrome type I following pacemaker implantation

A 70-year-old woman presented with burning pain and swelling over dorsum of right hand and small joints of the fingers, associated with redness, feeling of warmth, and stiffness of the fingers, with inability to bend the fingers since 2 months. The symptoms were progressively increasing in intensity for the past 1 month. There was no history of fever or trauma to the hand. Two months before her symptoms started, she had permanent pacemaker implanted for complete heart block with syncope. She was hypertensive and was on regular medication. Her X-ray of right hand showed decreased bone density (demineralisation), suggestive of osteopenia. A diagnosis of reflex sympathetic dystrophy syndrome or complex regional pain syndrome type I induced by pacemaker insertion was made. She was treated with amitriptyline and steroids, after which her symptoms improved dramatically.

Complex regional pain syndrome in a 15-year-old girl successfully treated with continuous epidural anesthesia

A 15-year-old girl developed severe pain in her right upper limb within a few days after she experienced an astatic epileptic seizure accompanied by falling on her right side. She was treated with fluid infusion through a cannula into her right hand. Swelling, mild flaring, and muscle weakness of the right arm subsequently appeared. Pharmacotherapy and stellate ganglion block were ineffective, and continuous epidural anesthesia was commenced 14 days after the falling event. The pain and accompanying symptoms completely disappeared within 5 days. Early treatment with continuous epidural anesthesia may be a promising option for the management of complex regional pain syndrome during childhood.

Development and validation of a sensitive LC-MS/MS method for the determination of D-serine in human plasma

A validated LC-MS/MS method was developed for the determination of d -Serine in human plasma. The method was fully validated for use with human plasma samples and was linear from 0.19 nmol/ml to 25 nmol/ml. The coefficient of variation was ≤5% for the high QC standards and ≤8% for the low QC standards in plasma. d -Serine and l -serine were resolved by pre-column derivatization using (R)-1-Boc-2-piperidine carbonyl chloride as the derivatizating agent. The method was used to determine the concentration of d-serine in plasma samples obtained in patients receiving a continuous 5-day intravenous infusion of (R,S)-ketamine. The changes in d-Ser levels varied in the six patients, with circulating d-Ser levels increasing as much as 35% in a patient, while decreasing 20% in a patient. While only preliminary data, the results suggests the potential importance in determining the d-Ser levels in plasma and their potential role in physiological response.