Management of complex regional pain syndrome

Abstract

Complex regional pain syndrome (CRPS) is a relatively rare, chronic, and debilitating condition that significantly impacts the patient's quality of life. There is an overall paucity of literature addressing the management of CRPS in immunocompromised patients. We define features of CRPS, outline its treatment options, and describe a course of CRPS management for a 35-year-old patient who had heart transplantation requiring immunosuppressive medications.

Complex regional pain syndrome (CRPS) is a relatively rare (1), chronic, and debilitating condition that significantly decreases a patient's quality of life. In this report, we describe the management of CRPS in a patient who was initially on therapeutic anticoagulation for an in situ ventricular assist device and was subsequently immunosuppressed after heart transplantation. The estimated 10 million immunocompromised individuals in the United States (2) deserve special consideration in various disease processes and their associated management options due to their increased susceptibility to infection and complications.

CASE REPORT

A 35-year-old man had idiopathic dilated cardiomyopathy with heart failure, cardiorenal syndrome, congestive hepatopathy, hepatosplenomegaly, obesity, obstructive sleep apnea, hypothyroidism, cholelithiasis, a left ventricular assist device, and heart transplantation. The patient suffered viral cardiomyopathy and congestive heart failure with multiple associated admissions and interventions. During an intra-aortic balloon pump placement, he suffered an injury to the neurovascular structures supplying the right lower extremity, necessitating vascular exploration and repair. The patient subsequently developed lateral ankle pain radiating to the foot, as well as edema and decreased ankle range of motion. His symptoms were not relieved by physical therapy, gabapentin 600 mg three times a day, and hydrocodone-acetaminophen 10–325 mg (Norco 10) four times a day.

The patient was seen by our pain clinic 6 months after the onset of right lower extremity symptoms. He reported severe 10 out of 10 pain, now extending 2 inches proximal to the lateral malleolus radiating distal to all toes. The pain was exacerbated by light touch and weight bearing. On exam, he had severe pain to light touch, leg edema, and decreased right ankle range of motion compared to the contralateral ankle, consistent with the diagnosis of CRPS by the Budapest criteria (3). A lumbar sympathetic block was ruled out since the patient was on warfarin for his ventricular assist device. Instead, an ankle ring block was performed with a 10 mL mixture of 80 mg triamcinolone with 8 mL 0.25% bupivacaine with 30 days of significant pain relief. The gabapentin and Norco were continued. The patient subsequently received two ankle ring blocks prior to his heart transplantation, which provided 10 days and then 3 days of significant pain relief, respectively.

The patient was off warfarin after his heart transplant. Due to lack of symptom relief from extended conservative and medical management, a lumbar sympathetic block was performed. With fluoroscopic guidance, contrast was injected with the nerve block needle tip at the anterolateral edge of the L3 vertebral body. After visualization of appropriate contrast spread to the anterolateral aspect of the L2 to L4 vertebral bodies, where the sympathetic ganglia are commonly located (4), a 20 mL mixture consisting of 10 mg dexamethasone, 9 mL 1% lidocaine, and 10 mL 0.25% bupivacaine was injected in 3 mL aliquots. The block provided near complete pain relief for 3 weeks with a gradual return of pain. The patient had three subsequent lumbar sympathetic blocks performed at 1-month intervals with similar efficacy before lumbar sympathetic radiofrequency ablation (RFA) for longer duration of symptom relief. The patient reported that RFA (Figure) provided better relief of his pain than other interventions, with a 90% reduction in symptoms that lasted for almost 3 months. The gabapentin and Norco were continued. He reported taking the Norco towards the end of the third month when the effects of the lumbar sympathetic RFA had waned. With initiation of lumbar sympathetic blocks and RFA, the patient reported that he was able to perform activities such as hiking, rock climbing, and fishing with his son. The lumbar sympathetic RFAs were repeated every 3 months for the past 4 years with continued excellent control of symptoms.

Figure.

(a). Anteroposterior fluoroscopy of L2–L4 lumbar spine with injection of contrast to verify needle placement for radiofrequency ablation of lumbar sympathetic chain. Sensory and motor stimulation were performed up to 1V and 2V, respectively, to ensure no involvement of the genitofemoral nerve, paresthesia, and motor stimulation of the lower extremity at any level. Each level was treated with pulsed radiofrequency ablation at 42°C for 120 seconds. Each level was then treated with thermal radiofrequency thermocoagulation at 80°C for 60 seconds. The thermocoagulation treatment was repeated at each level after the needles were withdrawn approximately 1 cm. (b) Posterior fluoroscopy of L2–L4 lumbar spine with injection of contrast to verify needle placement for radiofrequency ablation of lumbar sympathetic chain.

DISCUSSION

CRPS is a chronic pain condition with uncertain pathophysiology and variable clinical course. It is characterized by pain disproportionate to the inciting event with associated autonomic and inflammatory symptoms. Such symptoms may include sensory (allodynia and/or hyperalgesia), vasomotor (temperature and/or skin color changes), edema, sweating, motor (weakness and/or range of motion deficits), and/or trophic (hair, nail, skin) changes. The condition is diagnosed based on history and clinical findings and is ultimately a diagnosis of exclusion in which no other conditions better account for the symptomology (5).

CRPS is currently divided into type I and type II based on the absence and presence, respectively, of peripheral nerve injury. It has an overall incidence of 26.2 per 100,000 person-years; it is 3.4 times more common in women, peaks in the 6th decade of age, more frequently affects the upper extremity (vs. the lower extremity), and is most commonly precipitated by fractures (44%) (1).

The initial treatment of CRPS should include physical and occupational therapy (such as graded motor imagery [6] and mirror therapy [7]) in combination with symptom-oriented pharmacological treatments. Neuropathic pain is a primary component of CRPS, and mainstay therapy consists of gabapentin (8), tricyclic antidepressants (9), and/or carba-mazepine (10). Inflammatory features/symptoms of CRPS may be responsive to oral corticosteroids (11). However, prolonged treatment with steroids is not favorable because of various complications associated with long-term steroid treatment. For patients with dystonia/myoclonus and/or vasomotor symptoms, baclofen and/or calcium channel blockers, respectively, may be of benefit (12, 13).

For patients who fail to obtain adequate symptom relief with conservative management, interventional pain procedures such as sympathetic (stellate ganglion and lumbar sympathetic) blocks and spinal or peripheral nerve stimulation may be considered. Stellate ganglion blocks for upper extremities and lumbar sympathetic blocks for lower extremities have been shown in trials to provide symptomatic and functional benefits (14, 15). In patients responsive to sympathetic blocks, RFA or phenol neurolysis may provide longer-term symptom control (16, 17). RFA may be preferred to phenol based on reports of neuropathic pain symptoms secondary to phenol neurolysis (18). If patients fail to obtain adequate symptom control with the aforementioned treatment, spinal cord/peripheral nerve stimulation or an implantable drug delivery system may be considered (19–21).