Criteria: Table 15-16 (496), others as directed (496)
Guidance: The 5th Edition methods for rating impairment due to causalgia, reflex sympathetic dystrophy (RSD), and complex regional pain syndromes (CRPS) differ from the approach found in previous editions. The 5th Edition methods for rating these conditions are found in four chapters: Chapter 13 The Central and Peripheral Nervous System, Chapter 16 The Upper Extremities, Chapter 17The Lower Extremities, and Chapter 18- Pain. Impairment can be based on anatomic or functional loss. The physical evaluation determines the anatomic impairment and is based on the history and a detailed examination of the person and the body part involved. The anatomic approach for evaluating impairment due to these conditions is appealing because the anatomic method bases impairment on objective findings a physician can identify during a standard examination and can demonstrate by standard clinical techniques. The functional evaluation measures the individual’s motor performance of activities of daily living or of a specific task within a set time frame. The functional approach for evaluating impairment due to these conditions is appealing because it is consistent with the Guides concept of impairment, namely, “Impairment percentages…are… estimates that reflect the severity of the medical condition and the degree to which the impairment decreases an individual’s ability to perform common activities of daily living.” (4) Chapter 13, The Central and Peripheral Nervous System considers causalgia and RSD in Section 13.8: Criteria for Rating Impairments Related to Chronic Pain, (343). The term chronic pain as it is used here has a specific connotation, namely, “Chronic pain in this section covers the diagnoses of causalgia, posttraumatic neuralgia, and reflex sympathetic dystrophy.” In contradistinction to Chapter 16, Chapter 17, and the Glossary, “The new term complex regional pain syndrome, type I and type II, is not used here”. A brief description of causalgia and RSD emphasizes the essential feature which distinguishes these conditions, namely, causalgia develops in a distal extremity following trauma to a peripheral nerve, while RSD occurs without known nerve lesions. The importance of correct diagnosis is stressed, To rate these conditions, diagnosis is key and is based on clinical criteria. The discussion of diagnosis describes symptoms, examination findings, and ancillary studies, but does not indicate how the diagnosis is established using the various criteria. Chapter 13 utilizes a functional approach for assessing impairment due to these conditions, using Table 13-22 Criteria for Rating Impairment Related to Chronic Pain in One Upper Extremity (343). Explaining their choice of using a functional approach, the authors note, “It is difficult to examine individuals who are experiencing these symptoms; therefore, once the criteria for the diagnosis have been met, the impact on ADL is determined.” No guidance is provided on how to determine the impact on ADL. Chapter 16 The Upper Extremities considers complex regional pain syndromes in Section 16.5e Complex Regional Pain Syndromes (CRPS), Reflex Sympathetic Dystrophy (CRPS I), and Causalgia (CRPS II) (495). Diagnostic criteria for CRPS are listed in Table 16-16 Objective Diagnostic Criteria for CRPS (RSD and causalgia) (496). Unlike Chapter 13, a method for arriving at a diagnosis based upon the criteria is provided, namely, “At least eight [of 11] of these findings must be present concurrently for a diagnosis of CRPS.” It is stressed that the criteria listed in Table 16-16 are signs not symptoms noting that, “Signs are objective evidence of disease perceptible to the examiner, as opposed to symptoms, which are subjective sensations of the individual.” Chapter 16 utilizes an anatomic approach for assessing impairment due to these conditions. The method is a variation of the 5th Edition’s scheme for rating upper extremity peripheral nerve disorders. Because CRPS I (RSD) occurs without a known nerve lesion, while CRPS II (causalgia) follows trauma to a peripheral nerve, the methods for rating these conditions differ. When evaluating CRPS I (RSD): (1) Rate the loss of motion of each joint involved using Section 16.4; (2) Rate the pain using Section 16.5b, Table 16-10a. The percent value selected represents the upper extremity impairment. A nerve value multiplier is not used because in CRPS I (RSD) there is no peripheral nerve injury; (3) Do not rate motor deficits or loss of power, because in CRPS I (RSD) there is no peripheral nerve injury; and (4) Combine the upper extremity impairments due to loss of motion and pain, then convert the upper extremity impairment to a whole person impairment. When evaluating CRPS II (causalgia): (1) Rate the loss of motion of each joint involved using Section 16.4; (2) Rate sensory deficits or pain using Section 16.5b, Table 16-10a. The percent value selected is used with a nerve value multiplier for the injured peripheral nerve involved; (3) Rate motor and loss of power deficits due to the injured peripheral nerve involved using Section 16.5b, Table 16-11a; and (4) Combine the upper extremity impairments due to loss of motion, sensory deficits or pain, and motor and loss of power deficits, then convert the upper extremity impairment to a whole person impairment. When rating these conditions using Section 16.5e: (1) No additional impairment is assigned for decreased pinch or grip strength; (2) The impairment rating method described for sensory deficits due to lesions of digital nerves is not applied; (3) In contrast to Chapter 13, impairment ratings are not adjusted for hand dominance. Chapter 18 Pain describes a qualitative method for evaluating permanent impairment due to chronic pain, an explication of which is beyond the scope of this review. The use of the term chronic pain in this chapter is different from the use of the term chronic pain in Chapter 13. In Chapter 13 the term chronic pain encompasses three diagnoses, causalgia, posttraumatic neuralgia and RSD. In Chapter 18, chronic pain refers to “an evolving process in which injury may produce one pathogenic mechanism, which in turn produces others, so that the cause(s) of pain change over time.” Chapter 18 does not provide a method for assessing impairment due to causalgia, RSD or CRPS per se, but CRPS Type I (RSD) is referenced in Table 18-1 Illustrative List of Well-Established Pain Syndromes Without Significant, Identifiable Organ Dysfunction to Explain the Pain, (571) and CRPS Type II (causalgia) is referenced in Table 18-2 Illustrative List of Associated Pain Syndromes, (571). Although the conditions are referenced in these tables, these tables are not rating tables. The evaluator can choose either the functional approach described in Chapter 13 or the anatomic approach described in Chapter 16. Alternatively, the evaluator can rate the impairment using each approach, describe the resulting impairments, and then choose the impairment value which best reflects the severity of the condition
