Medical Report Checklist: Upper Extremities Peripheral Nerve Disorders Impairments (PND)

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1 Craig Andrew Lange California Workers Compensation Certified AMA Guides Impairment & Disability Rating Specialists Voice: (415) / Fax: (415) Luis Pérez-Cordero [email protected] Medical Report Checklist: Upper Extremities Peripheral Nerve Disorders Impairments (PND) Only individuals with an objectively verifiable diagnosis should qualify for a permanent impairment rating. AMA Guides 5 th, pg. 493 In order to receive a permanent impairment, the complaints of pain and loss of sensation have to be consistent, reproducible, and in the defined anatomic pathway of the spinal nerve, brachial plexus or major peripheral nerve that is diseased. - AMA 5th, pg. 481 To Rate Impairment Neuropathy Examination Findings Must be Present at MMI Entrapment/compression neuropathies are rated when an objective verifiable diagnosis is present, supported by positive clinical findings and loss of function. The diagnosis should be documented by electromyography as well as sensory and nerve conduction studies. AMA Guides, 493 AMA Guides Section 16.5 & 16.5a, pg. 480: Accurate diagnosis of peripheral nerve disorders is based on a detailed history, a thorough physical examination with special emphasis on the nervous and vascular system, and appropriate diagnostic tests including a variety of electrical and imaging studies. The evaluation of permanent impairment resulting from peripheral nerve disorders is based on the anatomic distribution and severity of loss of function resulting from (1) sensory deficits or pain and (2) motor deficits or loss of power. AMA Guides requires that physicians, before estimating the extent of any impairment, establish an accurate diagnosis. The primary requirement is the confirmation of the presence or absence of specific pathology or loss of organ function. Neurodiagnostic studies are an integral part of this process. Neurodiagnostic testing is essential as an adjunct to the clinical examination in order to determine the diagnosis on which the impairment is based. Electrodiagnostic tests can be necessary to localize neurologic lesions affecting the peripheral nerves. The simple determination of a diagnosis is not sufficient to assess the level of impairment or disability. Electrodiagnostic Testing is necessary in order to document the degree of neurologic deficit. AMA Disability Evaluation- 2 nd Edition, pgs AMA Guides, pg.480. Nerve conduction and needle electromyography (EMG) studies help to determine which nerves are involved and their anatomic location. Skillful differentiation of peripheral neuropathy and neuromuscular disorders may also be possible. Expert neuromuscular knowledge and understanding of pathologic manifestations of disease processes are necessary for the appropriate application and performance of these tests, particularly the EMG. These tests are objective and require minimal cooperation from the individual being tested. They reflect pathology in the largest, fastest-conducting nerve fibers. The interpretation of these tests must be correlated with a detailed neurologic evaluation. Guides, pg 307

2 UE PND Report Checklist Page 2 MMI Medical Report Clinical Substantial Medical Evidence Checklist Upper Extremities Peripheral Nerve Disorders Impairments (PND) The pathology that affects the PNS produces signs and symptoms in the extremities that are specific to the level of area of injury. Only unequivocal and permanent sensory deficits are given permanent impairment ratings. Lesions of an individual nerve produce symptoms and signs in the distribution of the involved nerve. AMA 5 th Section 16.3 pgs. 445, 446; Section 16.5, pg. 480 & AMA Disability Evaluation 2 nd Edition, pg. 481 Guides pg. 488, Figure AMA Disability Evaluation 2 nd Edition, pg. 488, Figure 35-2:

3 UE PND Report Checklist Page 3 Diagnosis & Clinical Electrodiagnostic Testing MMI Medical Finding Testing Standards: Guides, pg. 10, 307, 493 & AMA Disability Evaluation 2 nd Edition, page Diagnosis: Confirmed by EMG Studies (needle & cutaneous) as well as sensory and motor NCS? 1.1. Testing Area has met required standards? 1.2. Upper Extremity Temperature at 32 C (89.6 F.) As required, stated within the Report? 1.3. Board Certified Technician? 2. Nerve Conduction Velocity Test (Nerve Conduction Study) measures how quickly electrical impulses move along a nerve. It is often done at the same time as an electromyogram, in order to exclude or detect muscle disorders Were motor and sensory latencies, conduction velocities, H reflex & F wave properly evaluated? 2.2. Level of Decreased Amplitudes? 2.3. Is Focal Demyelination Present? 2.4. CNAP & SNAP Responses? 2.5. Proximal & Distal Loss of Amplitude? 2.6. Results of Sensory NCS? 2.7. Results of Motor NCS? Longitudinal demyelination is typical of a generalized peripheral neuropathy. 3. Electromyogram (EMG) is a test that measures the electrical activity of a muscle. It detects any signs of blocking or slowing down of responses to nerve stimulation. The test provides information about the muscle itself and shows how well it receives stimulation from the nerve. (A nerve conduction velocity (NCV) test is often done at the same time as an EMG.) 3.1. Is EMG indicative of neuropathy? 3.2. Median Nerve 3.3. Ulnar Nerve 3.4. Radial Nerve 3.5. Findings Indicative of a Focal Neuropathy? 3.6. Findings Indicative of generalized neuropathy? 3.7. Findings Indicative of Multiple Focal Neuropathies? 3.8. Is the contralateral asymptomatic or symptomatic for median neuropathy? 3.9. Does the EMG provide objective evidence to support the symptoms and findings- confirmation of carpal tunnel syndrome? Degree of nerve involvement identified as per the electrodiagnostic studies? Is the injury to the nerve complete or partial? 4. Have both the Nerve Conduction Studies / EMG tests ruled out other pathologic nerve compression? 5. Has physician tested all the muscles of the upper extremities, tested sensation and reflexes? 6. With examination findings of motor weakness or sensory loss present, substantial amounts of conduction block (moderate neuropathy) and actual axon loss (severe neuropathy) or a combination of both is peseta as per the Nerve Conduction Studies.

4 UE PND Report Checklist Page 4 MMI Medical Finding LC Section 4663 Causation & Apportionment 7. Is the EMG indicative of non-vocational underlying polyneuropathy? 8. Are the findings of longitudinal demyelination typical of a generalized peripheral neuropathy? 9. Cervical radiculopathy? 10. Evaluator properly addressed (pre-existing) nonvocational causation factors? 11. Evaluator apportions to pre-existing/predisposing or associated conditions such as diabetes, arthritis, alcoholism, renal disease, hormonal changes, malnutrition, obesity, alcohol abuse, systematic neurologic disorders/diseases or hypothyroidism? Guides, pgs 480 & 491 MMI Medical Findings Physical Findings: Clinical Tests & Measurements at MMI MMI Neurological Evaluation and ancillary clinical testing have been correlated to the electromyographic studies? More than one test used to reproduce symptoms is positive? Tinel Sign? Phalen s Test? Median Nerve Compression Test? Two-Point Discrimination Testing: Median Nerve 12. Evaluation of 2-Point Discrimination Testing on the pulp of all the digits for both hands? Guides, pg Numbness, tingling, pain present on the palmar surface of the 3½ radial digits (thumb, index, middle and radial aspect of the ring finger; digits innervated by the median nerve? 14. Objective sensory deficit in a dermatomal distribution? 15. Physician addresses the type of sensory loss for other digits? 16. Type of sensory loss for innervated Median nerve digits - (See Table on Page 4 ) 17. Results: 18. Within Normal Range? 19. Fair Results 20. Poor Results 21. Protective Sensibility 22. Anesthetic

5 UE PND Report Checklist Page 5 MMI Medical Findings Physical Findings: Clinical Tests & Measurements at MMI Two-Point Discrimination Testing: Ulnar Nerve 23. Objective sensory deficit in a dermatomal distribution for the innervated ulnar nerve digits? 24. Type of sensory loss for innervated Ulnar nerve digits - (See Table on Page 4 ) 25. Results: 26. Within Normal Range? 27. Fair Results 28. Poor Results 29. Protective Sensibility 30. Anesthetic Two-Point Discrimination Testing: Radial Nerve 31. Deficit in a dermatomal distribution for the radial nerve: Sensory symptoms and signs are restricted to the lateral aspect of the dorsal surface of the hand? 32. Type of sensory loss for innervated Ulnar nerve digits - (See Table on Page 4 ) 33. Results: Semmes-Weinstein Touch Pressure Monofilament Testing: Median Nerve 34. Has physician considered diminished values for individuals older than 55 years of age? 35. Evaluator uses monofilaments to assess light touch in the median nerve distribution? 36. Results for Sensory Loss In The Median Nerve Distribution by Semmes-Weinstein Test Within Normal Range? Diminished Light Touch (Tactile Sensation)? Reduced Protective Sensation? Loss of Protective Sensation? Un-testable: No response, No Sensation 37. Objective sensory deficit in the distribution of the median nerve?

6 UE PND Report Checklist Page Yes No MMI Medical Finding Grading Sensory Deficits/Pain - AMA Guides, pg 482 Table Description of % Sensory Sensory Deficit or Pain Distorted superficial tactile sensibility with or without minimal abnormal sensations or pain that is forgotten during activity - Diminished Light Touch Testing, i.e., Semmes-Weinstein. % Of Sensory Deficit 1-25 % 38. Pain radiating into the palm and the thumb, index, middle and radial aspect of the ring finger? 39. Reasons provided for the specific % of deficit used? AMA Guides, pg. 22 Section 2.6ab Distorted superficial tactile sensibility with some abnormal sensations or slight pain, that 3 interferes with some activities - Diminished Light Touch And Two-Point Discrimination Test 40. If 3 Given, are both the Light Touch and 2- Point Discrimination Tests positive? 41. Other Tests? % 2 (Rare) Decreased superficial cutaneous pain and tactile sensibility with abnormal sensations or moderate pain that may prevent some activities. (Decreased Protective Sensibility) 61-80% 1 Deep cutaneous pain sensibility present; absent superficial pain and tactile sensibility with abnormal sensations or severe pain that prevents most activity. (Absent Protective Sensibility) 81-99% Absent sensibility, abnormal sensations, 100 or severe pain that prevents all activity 100% 0 b. Procedure 1. Identify t area of involvement using the cutaneous Innervation chart (Figure 16-48) or the dermatome chart (Figure 16-49). 2. Identify the nerve structure(s) that innervate the area(s) (Table and Figures 16-48, 16-49, and 16-50). 3. the severity of the sensory deficit or pain according to the classification given above (a). Use clinical judgment to select the appropriate percentage from the range of values shown for each severity grade. 4. Find the maximum upper extremity impairment value due to sensory deficit or pain for each nerve structure involved: major peripheral nerves (Table 16-15). 5. Multiply the severity of the sensory deficit by the Maximum upper extremity impairment value to obtain the upper extremity impairment for each nerve structure involved.

7 UE PND Report Checklist Page 7 MMI Medical Finding Grading Motor Loss & Power Deficits Guides Table 16-11, pg 484 Description of Muscle Function Deficit 5 Complete Active Range of Motion Against Gravity with full resistance 00% 4 Complete active range of motion against gravity with some resistance 1-25 % 3 Complete active range of motion against gravity only, without resistance 26-60% 2 Complete active range of motion against gravity with gravity eliminated 61-80% 1 Evidence of slight contractility; no joint movement 81-99% 0 Evidence of slight contractility; no joint movement 100% 42. Reasons provided for the specific % of deficit used? AMA Guides, pg. 22 Section 2.6ab 43. Evaluator examined all muscle groups, identifying which are weak if motor deficits or loss of power is present? 44. Is weakness neurogenic (EMG) or due to pain and/or decreased effort? 45. Do the EMG studies confirm motor function of a specific muscle or group of muscles? - AMA 5 th Ed, pg Does the motor examination reveal atrophy of abductors and adductors of the fingers (interrossei), abductor pollicis and ulnar lumbricales? 47. Is the clinical evidence supportive of physician s determination that the motor weakness is due to the loss of nerve function and not pain? AMA Guides, pg Late Stage Findings - Does the motor examination reveal atrophy of the thenar eminence muscles at the base of the thumb? 49. Weakness of the abductor pollicis brevis and opponents pollicis muscles? 50. Weakness of the extensor muscles of the wrist fingers and thumb? 51. Was the extensor digitorum brevis; examined? 52. Was pinch and grip properly evaluated? 53. Are circumferences of pertinent musculature provided? Radial Neuropathy 54. Weakness of the extensor muscles of the wrist fingers and thumb? b. Procedure 1. Identify the motion involved, such as flexion, extension, etc. 2. Identify the muscle(s) performing the motion and the motor nerve(s) involved. 3. the severity of motor deficit of individual muscles according to the classification given above. 4. Find the maximum impairment of the upper extremity due to motor deficit for each nerve structure involved: major peripheral nerves (Table ). 5 Multiply the severity of the motor deficit by the maximum impairment value to obtain the upper extremity impairment for each structure involved.

8 UE PND Report Checklist Page Tables & Charts Two-Point Discrimination Test (Most Specific for Nerve Lacerations) The quality of discriminative sensation determines the usefulness of the hand in ADL. The two-point discrimination test is the classic test for discriminative sensibility. Allows the patient to both feel and discern the difference between one or two points. The test is performed by fully supporting the patient s hand on the examining table while vision is occluded. Only the fingertips need to be tested, as they are the most important in active and tactile scanning of an object. Testing is begun with 5 mm of distance between the 2 points. One or two points are applied lightly to the fingertip in a random fashion in a longitudinal orientation perpendicular to the skin to the point of blanching. Seven of 10 responses must be accurate for scoring. If the responses are inaccurate, the distance between the ends is increased by increments of 1, 2, or 5 mm depending on the suspected severity of nerve injury. Testing is discontinued at 15mm if responses are inaccurate at that level. Interpretation of scores is based on the guidelines set by the American Society for Surgery of the Hand. Decreased Protective Sensibility - Defined as a conscious appreciation of pain, temperature or pressure before tissue damage results from the stimulus. 2-Point Discrimination Testing 1, 2 Test Criteria AMA 5 th, pg 446,483 & AMA 6 th, pg. 426 Table 16-10, AMA 5 th, pg. 482 Results Interpretation Classification 6mm Normal 5 (No Nerve Impairment) 6-10 mm Fair mm Poor 3-2 One Point Perceived Protective Sensibility 1 No Points Perceived Anesthetic 0 1 Static 2-Point Discrimination Testing: With vision occluded the points are applied longitudinally. 2 Moving 2-Point Discrimination Testing: Testing is carried out in a proximal to distal direction. Following nerve repair, return or moving two-point discrimination precedes static two-point discrimination by several months. Semmes-Weinstein Test - (More Sensitive in Neuropathy & Nerve Compression) o Semmes-Weinstein monofilament testing is a threshold test that seeks to determine the minimum stimulus that can be perceived by the patient. It provides information that isn t duplicated by any other test. When performed correctly, it is one of the few, if not the only, sensibility measuring instruments that approaches requirements for an objective test. o The instruments are used to assess the presence of touch sensibility. A set of 5 nylon monofilaments attached to a lucite rod are marked with a number that ranges from 2.83 to 6.65 that represent the logarithm of 10 times the force (in milligrams) required to bow the filament. They test along a continuum of touch sensibility from light touch, to moderate pressure to deep pressure. o The test is performed by fully supporting the patient s hand on the examining table while vision is occluded. Testing is begun with the 2.83 monofilament by applying a force perpendicular to the skin in the center of the selected zone until the monofilament bows. The stimulus is applied 3 times to each spot for 1 to 1.5 seconds. The patient is asked to respond when the stimulus is felt and a positive or negative response is documented on a hand grid. The stimulus must be perceived on 2 out of 3 times for a positive result.

9 UE PND Report Checklist Page 9 o Testing continues with progressively thicker filaments until a positive response has been achieved in the testing zone. Depending on the filament perceived, the zone is determined to have normal light touch, diminished light touch, diminished protective sensation, loss of protective sensation, or is unresponsive. AMA Guides Section 16.5: Semmes-Weinstein Touch Pressure Monofilament Test The use of the Semmes-Weinstein touch pressure threshold monofilaments test adjunct to the Two- Point Discrimination Test helps assess changes in light touch sensibility. - AMA Guides, Section 16.5b, pg. 482 &445 Monofilament Test Criteria AMA 6 th, p. 424 Table 16-10, AMA 5 th, pg. 482 Grams of Force Interpretation Classification 1.65 to 2.83 Normal to Light Touch to 3.61 Diminished Light Touch to 4.31 Diminished Protective Sensation to 6.65 Loss of Protective Sensation Un-testable: No response, No Sensation 0 SENSORY EXAMINATION OF THE UPPER EXTREMITIES - AMA Guides, pg. 489: Table Maximum UE Impairment Due to Unilateral Sensory or Motor Deficits of the Major Peripheral * Clinical Corroboration Nerve Root Sensory Pain Reflex Motor (R) (L) Musculocutaneous Nerve (very rarely damaged) Suprascapular Nerve (Direct blow to neck base) Axillary Nerve (dislocated shoulder, deep IM injection) Radial Nerve (Crutch Palsy) Median Nerve (Carpal Tunnel / Wrist Trauma) Ulnar Nerve (elbow: trauma, bed rest, # olecranon) (wrist: local trauma, ganglion of wrist joint) Lateral Forearm to Wrist Posterolateral Shoulder Over Deltoid (Small area) Lateral dorsal forearm Back of 1 st & 2 nd finger Lateral Palm & lateral fingers Medial Palm 5 th digit and medial half of 4 th *See Table 16-10a to grade sensory deficit or pain. See Table 16 11a to grade motor deficit. Lateral Forearm Posterolateral Shoulder & Periscapular Region Across Shoulder Tip Dorsum(back) of thumb & index finger 1 st, 2 nd and 3 rd digits Spreads up forearm Ulnar supplied fingers and palm distal to the wrist Biceps Jerk None Triceps & Supinator jerk Finger Jerks None Luis Pérez-Cordero & Craig Andrew Lange Certified, AMA Guides Impairment & California Disability Rating Specialists American College of Disability Medicine & Board of Independent Medical Examiners Sunday, February 02, 2014 (Revised) Elbow Flexion with elbow fully supinated (biceps & brachialis) Supraspinatus (Initiates Abduction) & Infraspinatus Muscle (externally rotates arm) Second 90 0 of shoulder abduction (deltoid) (teres minor cannot be evaluated) Elbow Extension (Triceps) Wrist Extension / Finger Extension Elbow Flexion, half supinated (brachioradialis) Wrist Flexors / Pronators of Forearm Long Finger Flexors (1 st, 2 nd & 3 rd ) Abductor Pollicis Brevis All small hand muscles except APB. However injury at elbow seems to preferentially affect first dorsal interosseous muscle flexor carpi ulnaris (clinical evidence of involvement unusual) Finger flexors (medial 2 fingers). Again clinical involvement unusual