MSK MIMICS

SWEDISH NEUROLOGY UPDATE 170922

Erik Ensrud, MD PM&R/EMG/Neurology/Neuromuscular Medicine Associate Professor Oregon Health Sciences University

1 MIMICS?

Henry Walter Bates English, ~1858 Brazil ? normal imitates noxious

German, ~1880 Lived in Brazil noxious+noxious

2 Neuromuscular Mimic-definition

A musculoskeletal condition that presents with pain or discomfort suggestive of a neuropathic or myopathic etiology.

3 Reasons to care about Neuromuscular Mimics

Common causes of limb pain Frequent reason for clinic/EMG referral ”Pain in limb-? radiculopathy, ? CTS” Treatable conditions

Neuro residency training programs (aka Neuro-ICU beatdowns) do not cover as not part of board exams. PM&R programs (aka Inpt Rehab beatdowns) usually have some coverage, although this can be quite variable.

4 THE BOOK OF PRESTON FIRST CHAPTER Verses 7 and 8 “In practice, EDX studies serve as an extension of the clinical examination and should always be considered as such. Accordingly, a directed physical examination should always be performed before EDX studies in order to establish a clinical diagnosis and establish a differential diagnosis.”

5 Blind men and an Elephant? Originated in the Indian subcontinent from where it has widely diffused into Jain, Buddhist, Sufi, and Hindu lore. It has been used to illustrate a range of truths and fallacies; broadly, the parable implies that one's subjective experience can be true, but that such experience is inherently limited by its failure to account for other truths or a totality of truth. AKA alt-truth or alternative facts?

6 Antibody?

Wet garbage HR +/-? bag? Late Positive response? sharp wave? NMJ?

Ethical?

Motor neuron?

Hanabusa Itcho

7 Are these really conditions I am going to see?

Need to look for and recognize to identify-they are very common i.e. one week in EMG lab-of 60 EMGs scheduled, 9 patients had neuromuscular mimics- identifying these mimics improved the diagnostic rate by over 15%

8 Musculoskeletal Exam Tests: Advantages

FAST/EASY/EFFECTIVE Ability to diagnose quickly at bedside or exam room with appropriate physical exam

Timesavers for the Provider (It’s All About You!)-keep up your clinic flow Fewer unnecessary MRIs ordered with time- consuming follow-up

9 Musculoskeletal Exam Tests: Pearls

Check bilateral limbs for side-to-side comparison: non-involved side first when possible Ask, “Is that the same pain you have been experiencing?” * Patients can have more than one condition- i.e. CTS and DeQuervain’s

10 Musculoskeletal Exam Tests Pearls: Wince sign

Look for the “Wince” sign for positive test

• Eye blink/face grimace

• Not just mild discomfort

11 Five Top Mimics Upper Extremity

Supraspinatus/rotator cuff tendonitis*

Biceps tendonitis

Lateral epicondylitis

De Quervain’s tendonitis

CMC joint arthritis

12 Supraspinatus/Rotator Cuff Tendonitis

13 Supraspinatus tendonitis mimics

Upper to mid-cervical radiculopathy*

14 Supraspinatus tendonitis Symptoms/risk factors Pain with arm movement, esp. overhead *Difficulty sleeping when lying on affected side Pain may radiate up towards neck and down arm, even beyond elbow Repetitive movements-esp. overhead, acromion anatomy (hooked) Especially in people with underlying neurologic disease, due to periscapular muscle imbalance leading to instability of glenohumeral joint

15 Supraspinatus Tendonitis: Hawkins Shoulder Test most sensitive at 92% Humerus flexed 90 deg Elbow flexed 90 deg Examiner’s hand stabilizes pt’s shoulder Examiner pulls down on pt’s forearm WITH RAPID JERK to internally rotate humerus Head of humerus pinches tendon under acromion  PAIN when inflamed

16 Supraspinatus tendonitis-Treatment NSAIDs PT-stretching, strengthening posterior muscles Steroid injection Confirm with MRI or US- need soft tissue visualization PT/PM&R/Rheum/Orthope dic referral

17 Biceps tendonitis-long head

18 Biceps tendonitis mimics

Upper cervical radiculopathy*

19 Biceps tendonitis symptoms/risk factors

Achy, poorly localized shoulder and upper arm pain Pain with lifting, esp. flexion and overhead

Repetitive arm movements-esp. overhead Shoulder arthritis Age Rapid increase in exercise

20 Yergason test for biceps tendonitis

21 Biceps tendonitis treatment

Ice-tid over area until numb (superficial) NSAIDs Avoid overuse Steroid injection-caution to avoid injecting tendon PT

22 Frozen paper cup for ice therapy

23 Lateral epicondylitis

24 Lateral epicondylitis mimics

Ulnar neuropathy*-pain around elbow

Lower cervical radiculopathy-pain can radiate distally along forearm/ulna

25 Lateral epicondylitis symptoms/risk factors Elbow pain, esp. lateral elbow pain Exacerbated by arm use, esp. wrist extension

Overuse of wrist extension/supination-any activity but tennis is esp. common

26 Lateral epicondylitis-exam test

• Palpate 0.5-1cm distal to the epicondyle (max . tenderness to palpation)

27 Lateral epicondylitis treatment

Ice-tid over area until numb Stretches NSAIDs Tennis elbow strap Steroid injection

28 Lateral epicondylitis Wrist extensor stretch

29 Lateral epicondylitis Elbow strap

Serves as partial proximal fixation

30 DeQuervain tendonitis

31 DeQuervain tendonitis mimics

Carpal tunnel syndrome “wrist pain”* C6 radiculopathy-pain along distal radius Superficial radial sensory neuropathy

32 De Quervain’s tendonitis symptoms/risk factors Pain with weight-bearing wrist extension, wrist turning, grasp Numbness(real!)-due to irritation of the superficial radial sensory nerve Pain with grasping/pinching Chronic overuse (aka “nursemaids”), arthritis, direct trauma

33 De Quervain’s tendonitis Finklestein’s test Have pt wrap fingers around thumb, “as if it were an egg”

(If they grasp too tightly they may splint the wrist and decrease test ROM, reducing sensitivity)

Ulnar deviate the wrist

34 De Quervain’s tendonitis- treatment

Ice-tid until numb NSAIDS Splint immobilization, avoiding repetitive movements Hand therapy-iontopheresis Steroid injection-avoid tendon

35 Carpometacarpal joint arthritis

36 CMC arthritis mimics

Carpal tunnel syndrome*

Lower cervical radiculopathy

37 CMC arthritis Symptoms/risk factors

Pain at the base of the thumb *Weakness of pinch/grasp, may give-way on APB testing

Women, esp. post-menopausal As much as 1/3 of women > 40yo have CMC changes on x-ray…may be secondary to hypermobile joints Arthritis, including OA, RA, and gout

38 CMC arthritis Exam test

• Compression of the CMC joint by grasping metacarpal and applying pressure to compress the CMC joint CMC

• Movement like a mortar and pestle or Atari joystick

39 CMC arthritis treatment

NSAIDs Thumb splint for stabilization Steroid injection Joint replacement

40 BEING HAPPY MADE LUDICROUSLY SIMPLE

41 4 Top Mimics Lower Extremity

Hip joint osteoarthritis

Greater trochanteric bursitis

Pes anserine bursitis

Plantar fasciitis

42 Hip osteoarthritis

43 Hip OA mimics

Upper lumbar radiculopathy*

Sciatica

Knee DJD*

44 Hip OA symptoms/risk factors Pain in anterior hip/groin/buttock/”back” which can radiate down thigh Worse with weight bearing and activity

Age (>65yo x-ray changes in 5%), increased BMI, hx weight-bearing sports including running, standing/lifting work, genetics- Icelandic deCODE work on collagen genes

45 Hip bedside exam-supine or seated Ext rotation:*Internal rotation

External Rotation Internal Rotation Pain free/min pain Elicits hip joint pain if OA changes present

46 Cheech and Chong

47 Hip OA test-X-ray: when joint OA present, internal rotation compresses joint causing **periosteum to periosteum contact PAIN

48 Hip OA treatment

Acetaminophen before NSAIDs due to likely long-term use (both effective in trials) PT helpful, esp. with gait Cane-use contralateral to OA hip Orthopedic surgery consultation

49 Greater trochanteric bursitis

50 Trochanteric bursitis mimics Upper lumbar radiculopathy*

Sciatica

if bilateral-neuropathy

51 52 Trochanteric bursitis symptoms/risk factors Thigh pain, esp. lateral. buttock pain Radiates to the knee-some pts report to the calf Can be worse with sleeping on affected side, walking (esp. up stairs)

Risks-hip trauma, hip OA, elderly, obesity

53 Trochanteric bursitis lying exam test

54 Trochanteric bursitis seated exam test *Patient seated, facing examiner *Examiner palpates along both lateral femurs until reach greater trochanters *Side-to-side differences? *Wince sign?

55 Trochanteric bursitis

treatment Injection-steroid/lidocaine VERY EFFECTIVE Pain may worsen 1-2 days before improving-ice to area (flexible frozen gel or frozen peas against lateral hip) Stretches

56 Trochanteric bursitis treatment Stretches-best after injection

57 Pes anserine bursitis

58 Pes anserine bursitis mimics

Lumbar radiculopathy, esp. L4*

59 Pes anserine bursitis symptoms/risk factors Leg pain Medial knee pain-esp. when ascending stairs/climbing Athletes-esp. in sports with side-to-side cutting activity such as tennis, soccer

60 Pes anserine bursitis-physical test is tenderness to palpation at bursae

61 Pes anserine bursitis- treatment Rest Ice-tid until numb NSAIDs PT Steroid injection Rarely surgery-athletes

62 Plantar fasciitis

63 Plantar fasciitis mimics Distal sensory neuropathy*

Small-fiber neuropathy (burning sensations)

L5/S1 radiculopathy-unilateral distal leg pain

64 Plantar fasciitis symptoms/risk factors

Foot pain-burning and gnawing in character Worse when standing/weightbearing, esp. in morning when get out of bed *In contrast with small-fiber neuropathy which is worse at night when off feet

Tight Achilles tendon (shortens plantar fascia), obesity are risk factors

65 Medial calcaneus palpation Test Palpate at the anterior-medial calcaneus (site of PF insertion)

66 Plantar fasciitis treatment Cold (frozen bottle) stretch tid until numb-see slide Achilles tendon stretches-why? NSAIDs Plantar fasciitis nighttime socks such as Strassburg sock Steroid injections

67 Cold stretch-use frozen soda can or plastic bottle tid until sole numb

68 Plantar fasciitis socks Strassberg sock

69 Why don’t we care more about Neuromuscular Mimics?

The IBW effect? See below…

You WILL see the above-learn how to manage them efficiently and effectively Dr. Scott Edwards

70 Neuromuscular Mimics: Summary

Hiding around your clinic and ward Making your NM pts miserable Diagnosis is relatively easy and quick-rewarding exam Increase your diagnostic yield, avoid unnecessary testing Enhance clinic flow

71 Musculoskeletal Exam Tests: Closing Pearls Check bilateral for side-to-side comparison, non-involved side first when possible Look for the “Wince” sign “Is that the same pain you have been experiencing?” Pts often have have more than one condition “True, True, and Unrelated”-Amato’s Law

72 THE END

Getting Hygge With It…

73