Work-related Carpal Tunnel Syndrome

1
Work-related Carpal Tunnel Syndrome

• ??? MD.PhD
• ?????

2
Case - M/48

• ?xx
• CC referral here under the impression of work
  related carpal tunnel syndrome.

3
????????

1. ?????
2. ???????
3. ?????
4. ?????????????
5. ???????????

4
?????

1. Symptoms
2. Signs
3. Tests

5
SYMPTOMS

• Numbness,
• Tingling pain in the volar aspects of hands
• Weakness in left hand gripping
• Especially noted after work or at night
• Shaking hands to relieve the pains
• No sleep disturbance yet

6
(No Transcript)
7
Signs

• Tinel's sign (/-) tapping over the median
  nerve at the wrist causes paresthesias or pain
  radiating from the wrist to the thumb and the
  index, the middle and half the ring fingers.
• Phalens test (/-) bending the wrist forward
  all the way for 60 seconds results in numbness,
  tingling, or weakness in a median nerve
  distribution
• Atrophy of the thenar muscles (-)

8
(No Transcript)
9
Present illness

1. Numbness, tingling pain and weakness of hands for
   3 years
2. Pain could temporarily relieved by the
   analgesics, traditional massages, herb medicines
   and local steroid injection.
3. Carpal tunnel syndrome was diagnosed at the??
   hospital on 2011/01/07.
4. Referral under the impression of work related
   disease.

10
Motor Nerve Conduction Study

1. Normal amplitude
2. Delayed distal latencies of bilateral median
   nerves.
3. Prolong F latencies of bilateral median nerves in
   F wave study
4. Normal results of ulnar, peroneal and tibial
   nerves.

11
(No Transcript)
12
F wave study

• Supra-maximal stimulation
• Ortho-dromic stimulus ? M wave muscle
  contraction.
• Anti-dromic stimulus ? the motor neuron cell
  bodies ? backfire down towards the muscle ? small
  F wave.

13
F-wave study

• D the length from the stimulation (wrist
  crease) to the spine (C7) (for median nerve) .
• F-M the latency difference between mean F and M
  
• Delay 1 millisecond
• Conduction velocity 2D/(F-M-1).

14
Sensory Conduction Study

1. Slowing in the palm-wrist conduction of bilateral
   median nerves
2. Normal results of ulnar and sural nerves.

15
(No Transcript)
16
(No Transcript)
17
Nerve Conduction Study (NCS)

• Motor NCS
• Sensory NCS
• F-wave study (initially recorded in the foot
  muscles)
• H(Hoffmann)-reflex study

18
F-wave study vs. Motor and Sensory coduction
studies

• The F-wave latency can be used to derive the
  conduction velocity of nerve between the limb and
  spine,
• whereas the motor and sensory nerve conduction
  studies evaluate conduction in the segment of the
  limb.
• F-wave study is not a reflex.

19
H reflex

• monosynaptic reflex
• electrically stimulating the tibial nerve (Ia
  afferents from muscle spindles), generally in the
  popliteal fossa,
• recording from the gastrocnemius-soleus muscle
• similar to the Achilles reflex, except that the
  neuromuscular spindles are bypassed.

20
Hoffmann reflex

1. Square-wave current of short duration and small
   amplitude
2. Early response on EMG M-wave
3. Later responses H-wave (reflected).
4. As the stimulus increases, the M-wave increases
   and the H-wave decreases.
5. At supramaximal stimulus, alpha fibers involved,
   the H-wave disappears and the F-wave appears.

21
NCV Reports

• Slowing at wrist conduction of bilateral median
  nerves.
• Diagnosis carpal tunnel syndrome (CTS)

22
(No Transcript)
23
Tests

• Nerve conduction velocity positive
• Therapeutic and diagnostic challenge test
  possibly positive.
• Wrist X-rays negative
• Electromyography nil.

24
Electromyography (EMG)

• surface EMG
• intramuscular (needle and fine-wire) EMG.
• Resting and contracting

25
Occupational CTS (OCTS)
26
????????

1. ?????
2. ???????
3. ?????
4. ?????????????
5. ???????????

27
???1

• 1980-1984 ??????????
• 1988-1992 ??????????
• ???, ??????????????????
• ??????????????,??????????????(5??)?????????.
  ??????20???,????8???

28
???-2

• 1992-2001 ?????????
• 2001-now ??????????
• ????,??,??,??,??????.
• ????????20-30?????????????,?6-7??.
• ?????????6??,?1-2?????.

29
?????

• ????????????,???????????,???????????????????????.
• ??????
• ????????????.
• ?????????????

30

31
(No Transcript)
32
????????

1. ?????
2. ???????
3. ?????
4. ?????????????
5. ???????????

33
???

• 1980-1992 ????
• 1992now????,??,??,????,??,??????????
• ?2008??????????????????

34
????????

1. ?????
2. ???????
3. ?????
4. ?????????????
5. ???????????

35
Reviews

1. The median nerve is formed from parts of the
   medial and lateral cords of the brachial plexus.
2. It continues down the arm to enter the forearm
   with the brachial artery.
3. It originates from the brachial plexus with roots
   from C5, C6, C7, C8, T1.

36
(No Transcript)
37
Carpal Tunnel Syndrome

1. Median nerve compression at the wrist is the most
   common peripheral nerve entrapment disorder.
2. Constellation of specific symptoms and signs,
   described as CTS.
3. Annual incidence in the general population
   1/1000

38
Epidemiology of CTS

1. most often in people 30 to 60 years old
2. more common in women than men.
3. common in people who perform repetitive motions
   of the hand and wrist.

39
Repetitive motions of the hand and wrist

• Typing on a computer keyboard
• Sewing
• Driving
• Assembly line work
• Painting
• Writing
• Use of hand tools that vibrate
• Sports such as racquetball or handball
• Playing some musical instruments

40
Work-related CTS

• most often associated with activities requiring
  extensive, forceful, repeated, or prolonged use
  of the hands and wrists,
• (NIOSH Publication no. 97141.US Department of
  Health and Human Services, 1997)
• (Palmer KT et al.Occup Environ Med 2007
  575766)?

41
?????????

• ???,????
• ???????,
• ????????????????,
• ??????????????
• ??????????
• ??????????????,
• ???????????????????.

42
Occupational Carpal Tunnel Syndrome (OCTS)

1. Forceful hand use, particularly if repeated for
   prolonged periods
2. Constant firm gripping of objects
3. Moving or using the hand and wrist against
   resistance or with force
4. Exposing the hand and wrist to strong regular
   vibrations
5. Regular or intermittent pressure on the wrist

43
Work Exposures and the Probability of
Work-Relatedness
Exposure Examples of types of jobs Probability of work-relatedness
Combinations of high force with high repetition and awkward posture regular strong vibrations Seafood, fruit, or meat processing or canning, carpentry, roofing, dry-wall installation, boat building, book binding High, Relative risk gt 4
Medium-high force, high repetition or awkward posture alone, on a nearly continuous basis Dental hygienists, wood products production Medium, Relative risk 2-4
Low force or medium-low repetition alone, on an intermittent basis Computer or keyboard use Low, Relative risk lt 2
44
????????

1. ?????
2. ???????
3. ?????
4. ?????????????
5. ???????????

45
????

1. ??????????????????????????????????????????????????
   ????
2. 2011???????,????,???????

46
Risk factors for CTS

1. inflammatory or non-inflammatory arthropathies,
2. recent or remote wrist trauma or fractures,
3. diabetes mellitus,
4. obesity,
5. hypothyroidism,
6. pregnancy,
7. genetic factors.

47
Medical problems associated with CTS

• Fracturesand arthritis of the wrist
• Acromegaly
• Diabetes
• Alcoholism
• Hypothyroidism
• Kidney failure and dialysis
• Pregnancy
• Infections
• Obesity
• Rheumatoid arthritis, systemic lupus
  erythematosus (SLE), and slceroderma

48
OCUPATIONAL DISEASE

• on a more probably than not basis (greater than
  50) that the workplace activities (exposure) in
  an individual case contributed to the development
  or worsening of the condition (outcome).

49
Summary

• Dx???????????????????????????
• Exposure???????(repeated and forceful
  works),?????????????????
• Time sequence 1980???30?,?2008??????????,???????,
  ????????,?????????
• ??????????????????????????
• Thus, ??????????????50??

50
????

• ???????????3.4?????????????????????
• ??work related carpal tunnel syndrome, bilateral
  (???????????)

51
????

• ?????????,?????????.
• ??
• ????
• ??
• ??

52
Education

1. Avoid sleeping on wrists.
2. Hot and cold compresses
3. Take frequent breaks when typing and always stop
   if tingling or pain.
4. Avoid or reduce the number of repetitive wrist
   movements whenever possible.

53
Occupational Therapy

1. Wearing a neutral position wrist splint at night
   
2. Wearing a splint intermittently during work
3. Ergonomic aids, such as split keyboards, keyboard
   drawers, cushioned mouse pads, and wrist braces.
   
4. Job modification
5. Forearm/wrist stretching home exercise
6. Referral to an occupational therapist

54
MEDICATIONS

• Cyclo-oxygenase (COX) inhibitors
• Nonselective ibuprofen or naproxen.
• COX-2 selective celecoxib
• Local steroid injections into the carpal tunnel
  for short term relief.

55
Prognosis

• Symptoms often improve with treatment,
• but more than 50 of cases eventually require
  surgery.
• Surgery is often successful, but full healing can
  take months

56
SURGERY

• Carpal tunnel release
• Release of the transverse carpal ligament
• Open or endoscopic approach
• Decompression of the median nerve at the wrist
• Revision after 6 months if worsening

57
(No Transcript)
58
(No Transcript)
59
Possible Complications

• If untreated, the nerve can be damaged, causing
  permanent weakness, numbness, and tingling.

60
The END
61
(No Transcript)