Botulinum Toxin A (Botox) for Treatment of Proximal Myofascial Pain in Complex Regional Pain Syndrome: Two Cases

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1 Botulinum Toxin A (Botox) for Treatment of Proximal Myofascial Pain in Complex Regional Pain Syndrome: Two Cases Delaram Safarpour, MD, Bahman Jabbari, MD

2 Pain Medicine 2010; 11: Wiley Periodicals, Inc. Case Report Botulinum Toxin A (Botox) for Treatment of Proximal Myofascial Pain in Complex Regional Pain Syndrome: Two Casespme_ Delaram Safarpour, MD, and Bahman Jabbari, MD Department of Neurology, Yale University School of Medicine, New Haven, Connecticut, USA Reprint requests to: Delaram Safarpour MD, 40 Temple Street, 6C Neurology clinic, New Haven, CT 06510, USA. Tel: ; Fax: ; delaram.safarpour@yale.edu2. Disclosures: Dr Delaram Safarpour reports no disclosures. Dr Bahman Jabbari receives educational and research grants and serves in the advisory board of Allergen Inc. Abstract Objectives. To describe development of myofascial pain syndrome (MFPS) with trigger points in the proximal muscles of the patients with complex regional pain syndrome (CRPS1) and improvement of distal symptoms of CRPS 1 after successful treatment of proximal MFPS. Setting and Design. In our practice, we frequently encounter patients in whom a proximal myofascial pain syndrome develops ipsilateral to the distal limb of CRPS1 patients. We describe two such patients in detail with their treatment. Patient 1. A 48-year-old woman experienced severe allodynia, swelling and autonomic changes in the right hand after surgery for carpal tunnel syndrome. Over the succeeding months, she developed painful trigger points in the right trapezius and upper back muscles which was treated with administration of botulinum toxin A (BoNT-A) into the trigger points (20 unit/point). Patient 2. A 41-year-old woman following a traumatic forearm injury suffered from CRPS1 affecting the left hand and forearm. Proximal MFPS gradually developed on the same side over 12 months and was treated with administration of BoNT-A into the trapezius, splenius capitis, and rhomboid muscle trigger points. Results. In both patients treatment with BoNT-A improved the proximal pain of MFPS and the distal symptoms of CRPS1. Conclusion. proximal MFPS develops ipsilateral to the distal painful limb in patients with CRPS1. Administration of BoNT-A into the affected proximal muscles may alleviate both MFPS and the distal allodynia, discoloration and, tissue swelling of CRPS. Key Words. Complex Regional Pain Syndrome (CRPS); Botulinum toxin type A; BoNT-A; Myofascial pain syndrome; Reflex Sympathetic Dystrophy (RSD) Introduction Complex Regional Pain Syndrome (CPRS) is characterized by chronic and relapsing burning pain, edema, temperature asymmetry, abnormal skin perfusion and excessive sweating in an injured limb. Chronicity and frequent relapses in the course of CRPS often lead to disability [1]. The more common of the two CRPS variants, type 1 (reflex sympathetic dystrophy) has a prevalence of 21/100,000 and more often affects females (ratio 2:1 to 4:1) [2]. Myofascial pain syndrome (MFPS) is characterized by the presence of trigger points, palpable muscle abnormality (fibrocystic nodule) and referred pain distal to the trigger point. It is a common dysfunction with lifetime prevalence of up to 85% in general population [3]. Most of the treatment methods for MFPS are aimed to reduce the pain in trigger points and reduce the muscle spasm. Two previous publications described the association between CRPS1 and development of MFPS in the proximal muscles without detail description of the patients. In a retrospective chart review of 41 consecutive patients with CRPS1, Rashiq et al. described proximal myofascial dysfunction (MD) in 61% of the patients [4]. Their criteria for myofascial dysfunction are identical to what is currently accepted for MFPS. Upper limbs and lower limbs were affected in 70% and 46% of the patients, respectively. The authors recommended careful examination of proximal 1415

3 Safarpour and Jabbari muscles in all patients with CRPS4. Proximal muscle treatment in some patients improved the outcome of CRPS [5]. More recently, in a review paper, Argoff briefly described 11 patients with CRPS1 and proximal MFPS in whom intramuscular injection of botulium toxin type A (BoNT-A) (deltoid, trapezius, splenius, rhomboid, suprand infraspiniti) relieved myofascial pain and revered distal symptoms (pain, swelling, tissue discoloration) of CRPS1. He used units/muscle with a total dose of 300 units. Patients continued the treatment with consistent relief of their symptoms for approximately 4 years [5]. In our practice, we frequently encounter patients in whom a proximal myofascial pain syndrome develops ipsilateral to the distal limb of CRPS1 patients. In this communication, we present two of these patients in details. Case Reports Patient 1 A 48-year-old, right handed woman was referred to the clinic for the evaluation of pain in the right upper limb for 4 years. Pain and swelling of the right hand began shortly after a second carpal tunnel surgery of that hand. It gradually worsened, spread to the forearm and shoulder, with wrist, and hand and fingers assuming a dystonic flexed posture. Examination and Findings 1. Marked skin hypersensitivity at the right wrist and the lateral aspect of the lower right forearm. Touching this area caused intense burning pain (allodynia). 2. Annoying deep pain affecting the whole right upper limb. 3. Significant right neck and shoulder pain with many tender and trigger points over left trapezius and upper back muscles (developed gradually, months after development of allodynia on the same side). 4. Intermittent painful flexor spasms of the three middle fingers of the right hand. There was also intermittent discoloration and coldness of the right hand and forearm in examination. She had failed a number of medications including nonsteroidal analgesics and narcotics (e.g., Percocet), Lidoderm and Flector patches, steroid injections and nerve block (partial relief). She rated her average pain as 8 and worst pain as 10 on a pain scale of 1 10 (visual analog scale [VAS]) [6]. Treatment BoNT-A was prepared by reconstituting vacuum-dried toxin with preservative free 0.9% saline to 50 units/ml concentrations. The following muscles were injected into the trigger points on the right side: Right trapezius: 60 units, rhomboid 60 units, levator scapulae 40 units and right flexor digitrum superfecialis: 40 units. Each trigger point was injected with 20 units of the neurotoxin. Treatment Response and Outcome After a week, she reported 90% reduction of her neck and upper back pain, 60 70% reduction of her right arm pain and 80% reduction in right finger flexion spasms. She noted marked improvement in her quality of life and considered her response very satisfactory (on the scale of: worsened, neutral, mildly satisfactory and very satisfactory). She was able to swim again, move her head to the sides without pain, and enjoy her social life. Following treatment, she rated her pain intensity as a 2 (out of 10) on the VAS. Three years later, she reported continuous relief of MFPS with quarterly BoNT-A treatments. Painful finger flexions disappeared after the third treatment. Examination of the affected hand showed less swelling and marked improvement of allodynia and discoloration. Patient 2 A 41-year-old female suffered from severe pain in the left hand and forearm after her hand got stuck in a closing door of a bus. The hand gradually became swollen, changed color and the finger movements became weak and painful. Over the next 2 years, she developed pain in the left shoulder, base of the neck and periscapular region. She tried a large number of medications including nonsteroidal analgesics, baclofen, Neurontin, and oxycodone but none offered satisfactory relief. MRI studies of the neck and both shoulders disclosed no significant abnormality. Examination and Findings 1. The left hand was swollen, with marked allodynia over the dorsum of the hand and wrist. 2. The affected hand was cooler than the other side and the skin had a bluish/white color. 3. All finger movements were limited due to pain and swelling. 4. There were several tender areas and trigger points over the left trapezius, left side of the neck and upper rhomboid muscles. In pressing these points a tight muscle band was felt under the finger and the pain referred to distant areas from the pressure point. Treatment BoNT-A was injected into the trigger points of trapezius, splenius capitis and rhomboid muscles. The numbers of injected trigger points were 4, 3, and 5 for the aforementioned muscles, respectively. Each trigger point was injected with 20 units. At 1 month, patient reported her level of satisfaction as very satisfactory. Treatment Response and Outcome Following treatment, level of pain reduced from 9 to 4 (out of 10) on the VAS. After second treatment, daily activities were improved (e.g., driving, doing laundry). She reported 1416

4 no side effect from treatment and was able to reduce the dose of her pain medications gradually. An examination 18 months after initiating neurotoxin therapy, no longer showed any trigger points in the rhomboid region. The overall pain score for the proximal muscles was 3 (out of 10) on the VAS. The left fingers were no longer clinched and had near normal movements. The hand swelling reduced considerably. The skin color came back with near normal temperature. The area of allodynia shrunk to 1/3 of its size with the remaining area still scoring 9 out of 10 on the VAS (significant pain). Discussion Occurrence of trigger points in reflex sympathetic dystrophy (CPRS1) has been reported in 1946 in 59% of 32 patients with RSD[7]. The distribution of trigger points was not mentioned in this communication. Our patients had distinct MFPS with trigger points in the proximal muscles ipsilateral to the distal CRPS1 symptoms. Two other reports in the past described this association [4,5] without individual patient descriptions. Treatments of MFPS consist of physical therapy, oral medications and trigger point injections. Some of the most commonly used oral medications are: nonsteroidal antiinflammatory drugs, tricyclic antidepressants, muscle spasmolytics, opioid analgesics, neuropathic analgesics and antidepressants. Among non-needling therapies, mechanical pressure to the trigger points or stretching of the affected muscle are also used [8]. Needling treatments include injection of local anesthetics, corticosteroids, neurolytic agents and botulinum toxins into the trigger points [9 11]. Few reports provide adequately controlled clinical comparisons between these injectable treatments for MFPS. Three studies have compared the therapeutic effects of dry needling into trigger points with anesthetic agents: Procaine, Lidocaine [12,13] and Lidocaine plus steroid, acupuncture, and vapocoolant spray with acupressure [14]. These studies showed no difference between dry needling and lidocaine/procaine injection treatment and suggest that improvement was the result of needle s mechanical effect. In one study however, dry needling cause significantly more post-injection soreness compared to lidocaine/procaine injection (100% vs 40%) [14]. Other studies have compared the effect of anesthetics (lidocaine) vs BoNT-A injection [15,16]. They show that injection in trigger points with either of the two gives the same amount of pain relief. Considering the cost of BoNT-A, authors recommended using anesthetics as the first line of treatment. In one of these two studies botulinum toxin and anesthetics were also compared with dry needling. In this particular study BoNT-A and lidocain were superior to dry needling in terms of reducing the pain scores (VAS) and improving the quality of life [16]. Porta et al. compared the effect of methyl prednisolone with botulinum toxin type A injected into trigger point of 40 PMPS in Complex Regional Pain Syndrome patients with MFPS [17]. The reduction in pain score at 30 days compared to baseline was greater with botulinum toxin A than methyl prednisolone (P = 0.06). Furthermore pain reduction at 60 days was greater than 30 days for BoNT-A (-5.5 vs -3.9) whereas the effect of methyl prednisolone had begun to wane. Double-blind studies of sizeable number of patients comparing BoNT-A with placebo in MFPS however, produced contradictory results [10,11,18,19] with efficacy depicted in the studies that provided higher number of trigger point injections (>10) [11,19]. In conclusion, our observation indicates that a proximal MFPS can develop in patients with CRPS1 ipsilateral to the distal painful limb. Successful treatment of this proximal MFPS may improve, over time, pain and swelling of the distal part of the limb in CRPS1. Our patients responded well to BoNT-A treatment. A prospective study is needed to discern the incidence of proximal MFPS in CRPS1 and the role of BoNTs as an effective therapeutic agent. References 1 Tran De QH, Duong S, Bertini P, Finlayson RJ. Treatment of complex regional pain syndrome: A review of reference. Can J Anesth 2010;57: Borenstein DG, Wiesel SW, Boden SD. Neurologica and psychiatric disorders of the spine. In: Borenstein DG, Wiesel SW, Boden SD, eds. Low Back and Neck Pain, Comprehensive Diagnosis and Management. Philadelphia, PA: Saunders; 2004: Fleckenstein J, Zaps D, Ruger LJ, et al. 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