A series of recent articles on the nature and management of CRPS unanimously concluded that "functional restoration is the necessary and often sufficient condition "to restore health; other treatments serve primarily to facilitate this.2 We consider that CRPS type 2 is easier to diagnose, given the presence of overt nerve injury that can be documented electrophysiologically or during surgical exploration. CRPS type 1 seems, however, to be surrounded by controversy.
On the basis of the most recent concept that CRPS in general is a multifaceted disorder, its care must indeed be multidimensional.4 Mobilization of the involved limb as early as possible is the cornerstone of treatment to avoid permanent changes in the peripheral nervous system and CNS. This should include range of movement and stress-loading techniques. At the same time, pain control (oral and via sympathetic blocks, if the patient responds to them) is of paramount importance to allow for mobilization.2
Although combined approaches seem more effective than single modality treatments for all forms of chronic noncancer pain, including CRPS, interdisciplinary pain rehabilitation programs may be required for patients with intractable pain. These treatments typically provide education; reconditioning physical/occupational therapy; a pharmacological approach; biofeedback/relaxation training; operant conditioning; psychotherapy (personal and family); treatment of psychiatric comorbidity; and interventional approaches, such as nerve blocks, spinal cord stimulation, and intraspinal analgesia.
In pharmacological approaches, the only evidence-based preventive strategy for CRPS is the use of vitamin C (200 mg/d) in patients who have sustained wrist fractures.9 For therapy in established CRPS, the literature suggests the following therapeutic approaches:
• A short course of oral corticosteroids can be of value, such as 30 mg/d of oral prednisone(Drug information on prednisone)(Drug information on prednisone), until a clinical remission occurs or for a maximum of 12 weeks.10 In our program, we prefer a "crash course" that starts with 50 to 60 mg/d and decreases thereafter by 5 mg every 2 days to completion.
• Gabapentin(Drug information on gabapentin)(Drug information on gabapentin) (starting as low as 100 mg tid in sensitive or low-weight patients and titrated to a maximum of 3600 mg/d in 3 to 4 divided doses).11 Pregabalin(Drug information on pregabalin)(Drug information on pregabalin) and tricyclic antidepressants (TCAs) used in other models of neuropathic pain can also be of value in CRPS.12 We suggest that pregabalin be started at low doses of 25 to 50 mg/d (particularly in sensitive or low-weight patients) and titrated up to 300 mg bid within a 10- to 14-day period.
For TCAs, the safest strategy is to start at 10 to 25 mg at bedtime ("start low and go slow" in sensitive or low-weight patients) and titrate upward every 5 days to a maximum dose (for analgesia) of 75 to 100 mg.12 Some prefer to go as high as 150 mg at bedtime, but by that time one reaches antidepressant doses. There currently is no evidence to support the use of one TCA over another, but patients may prefer TCAs with lesser anticholinergic effects, such as desipramine and nortriptyline(Drug information on nortriptyline)(Drug information on nortriptyline).
• Bisphosphonates such as intravenous pamidronate(Drug information on pamidronate)(Drug information on pamidronate) (a single dose of 60 mg) and oral alendronate (40 mg/d for 8 weeks) have been shown to be effective in CRPS, particularly in the early phases.10
• Topical lidocaine(Drug information on lidocaine)(Drug information on lidocaine) may be useful in the early phases of CRPS.13
• Opioid analgesics can be used to facilitate mobilization of the extremity during physical therapy. Their long-term use may be necessary in refractory cases. However, the clinician must use them wisely given their addiction potential and both short- and long-term adverse effects. The best evidence for opioid efficacy in CRPS is an add-on study of morphine(Drug information on morphine)(Drug information on morphine) in patients already treated with spinal cord stimulators.14
• Intranasal (200 to 400 IU/d for 8 weeks) or intramuscular (100 to 300 IU/d for 4 weeks) calcitonin has been shown to have a slight benefit in ameliorating CRPS.10 However, the collective results of 6 randomized controlled trials reported in the literature show that this benefit is comparable with the pain relief obtained by other therapies (eg, physical therapy combined with analgesics).10
• In extreme cases in which patients did not respond to all known interventions, very few have been treated with "ketamine coma."10 The treatment is very aggressive, necessitates intensive care, and remains totally experimental. However, benefit from ketamine(Drug information on ketamine)(Drug information on ketamine) in CRPS and other intractable neuropathic pain syndromes has been reported in a number of cases.15
In particular, CRPS type 1 symptoms and signs are the result of derangement of the peripheral nervous system and CNS (what in our view constitutes true CRPS) associated with musculoskeletal, endocrinological, and vascular compromise. However, similar presentations can be seen in profound immobilization because of fear of pain and movement; disease imitators (eg, inflammation, tumor, and vascular events), and self-inflicted disorders.20 In the latter case, failing to recognize the self-induced nature of the presentation risks major iatrogenic complications as part of unnecessary and even harmful treatments. Given the complexity and variability of symptoms and signs, every effort should be made to appropriately diagnose the condition as such by using both symptoms and observed signs, as well as inclusion and exclusion criteria.
The prognosis of CRPS 1 and 2 can be variable, depending on a multiplicity of factors, such as magnitude and duration of symptoms/signs, degree of limb guarding or immobility, the presence of CNS changes (in the form of central sensitization or, to the contrary, the presence of expanding sensory hypoesthesia), the degree/intensity of therapeutic interventions, and patient coping factors and psychological/ psychosocial status.
Although science has not yet succeeded in providing full understanding or in reversing the mechanisms that underlie CRPS, most cases are treated successfully by a combination of functional restoration techniques in conjunction with medical and behavioral management.2 Even patients who experience substantial residual symptoms often can regain satisfactory function and good quality of life.