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Carpal Tunnel Syndrome
Carpal tunnel syndrome (CTS) is a common disorder with symptoms involving the median nerve. The median nerve is vulnerable to compression and injury in the palm and at the wrist, where it is bounded by the wrist (carpal) bones and the transverse carpal ligament. CTS is a combination of finger, hand and arm distress with symptoms that reflect sensory or motor compromise. It most commonly occurs in adults over age 30, particularly in women.
A detailed history considering work and non-work activities is essential and should include duration, evolution and anatomic location of all symptoms.
A history of suspected CTS should elicit the following details:
1. Character of symptoms: Tingling, swelling, numbness, pain (dull, aching discomfort), hand weakness.
2. Frequency: Episodic or constant, nocturnal.
3. Duration: Days, weeks, months.
4. Location: Anatomic correlation, unilateral or bilateral.
5. Association with hand positions or activity: Repetitive forceful wrist motions, vibrating/oscillating tools, static postures with extremes of wrist flexion or extension.
6. Onset: Relation to specific work and/or non-work activities.
7. Relief: Shaking the hand, vacation (time away from work and/or aggravating non-work activities), hanging the hand over the edge of the bed.
8. Review of systems: CTS can be associated with other medical conditions including, but not limited to: endocrine disorders (diabetes, thyroid disease), pregnancy, obesity, rheumatologic conditions (arthritis), trauma, multiple sclerosis.
9. Work and non-work activities: Type of work, length of time in this particular job, recent changes in work or unaccustomed work, relationship between work and onset of symptoms, relief with vacation, other work (second job, self-employment), hobbies (biking, crocheting).
A patient-completed hand diagram (copy attached) describing the location and quality of sensory symptoms is recommended.
Carpal tunnel syndrome represents a clinical diagnosis that can be confirmed with diagnostic testing.
1. Electrodiagnostic Testing (EDT): Includes nerve conduction studies (NCS) and electromyography (EMG)
a. Indications for Testing:
* Patients who do not improve with 1-4 weeks of conservative treatment.
* When surgery is being considered.
* To rule out other nerve entrapment or radiculopathy.
Nerve Conduction Studies (NCS):
* May localize source of CTS symptoms/signs and confirm the clinical diagnosis.
* May be normal in small percentage of actual CTS cases.
* If NCS are normal, the diagnosis of CTS must be supported by accurate history and physical findings.
Expected Findings in CTS:
* Abnormalities of the median distal sensory and/or motor latencies or conduction through the carpal tunnel region.
* Electromyographic changes in the thenar eminence in the absence of proximal abnormalities (less common).
* Guidelines to upper limits of normal latencies:
- Median distal motor latency 4.2 msec/8 cm
- Median distal sensory latency (wrist-digit) 3.5 msec/14 cm
- Median intrapalmar latency (palm-wrist) 2.2 msec/8 cm
- Median segmental difference (cm-cm, "inching") .04 msec/cm
Note: Hand temperature should be controlled (86-93 degrees F/30-34 decrees C). Colder temperatures may prolong latencies and/or slow nerve conduction velocities.
Electromyographers may use different distances and/or latency values; normative data should be available from these laboratories to establish the criteria for CTS.
Non-Operative Treatment (may include concurrent use of the following)
1. Splinting of the Wrist:
* Neutral position or slight extension.
* Should fit appropriately and comfortably without significant compression of the wrist or limitation of hand function.
* Specific instructions must be provided to the patient about when and how the splint is to be worn.
* May be more useful at night.
* If a rigid splint is used initially, the patients should be weaned to a soft splint after 2-4 weeks.
* Reassessment is indicated if no improvement after 3-4 weeks.
* Document/verify patient compliance.
Time to produce effects 3-4 weeks
Frequency of treatment continuous, at night, task related
Optimum duration 4-8 weeks
Maximum duration 12 weeks
2. Modification of Activities:
* Provider must evaluate the patient's current job description (including specific job tasks).
* Worksite and/or ergonomic evaluation may be indicated.
* Evaluation of both work and non-work activities should address repetitive, forceful wrist motions and extremes of flexion/extension; consider all the following activities: lifting, pushing, pulling, awkward and/or sustained postures, hot and cold environments, repetitive motions tasks, sustained hand grip, tool usage, and exposure to vibration.
* Provider should document all recommended job/activity modifications in detail for patient and/or employer.
Consistent with accepted medical practice, consultation with other health-care providers may be initiated at any time by the attending physician.
If the worker is not improving and/or has a documented, well defined clinical and electro-physiological carpal tunnel syndrome, the attending physician should refer the worker for surgical consideration.
Surgical intervention should be considered only if the worker has a positive history and physical exam and abnormal nerve conduction studies and failure of conservative management.
1. Criteria for surgical decompression of the median nerve at the carpal tunnel might include:
a. Severe compression of the median nerve as documented by motor and sensory nerve dysfunction associated with electrodiagnostic signs of denervation of thenar muscles.
b. Persistence of pain, numbness or dysesthesia in the median nerve distribution with accompanying sensory or motor signs despite appropriate conservative treatment.
c. Repeated improvements of symptoms/signs with conservative treatment followed by flare-ups with return to full-work status; this may be an indication for a permanent change in work rather than an indication for surgery.
2. There are two accepted techniques of surgical release: open or endoscopic. These can be performed under local, regional, or general anesthesia. Exploration and decompression of the median nerve is the most commonly performed surgery. Additional surgical procedures such as tenosynovectomy, opponensplasty, simultaneous Guyon's canal exploration, and neurolysis are seldom indicated in initial onset carpel tunnel syndrome. Indications for any of these additional procedures must be completely documented.
* If surgery is contemplated in a patient with normal nerve conduction studies, a second opinion should be obtained prior to the surgery.
* The majority of carpal tunnel surgeries take place in an outpatient setting; however, under certain circumstances an inpatient setting may be appropriate.
Please draw on the hand diagram the areas of each hand where pain, numbness, tingling, or other types of discomfort have occurred in a typical day during the past two (2) weeks.
Key: xxxx - pain
//// - numbness/tingling
0000 - other discomfort (please describe)
For Physician Use
Rating System for Hand Diagrams:
1) Classic - tingling, numbness, or decreased sensation with or without pain in at least two of the digits 1, 2, or 3. Palm and dorsum of the hand excluded; wrist pain or radiation proximal to the wrist allowed.
2) Probable - same as for classic, except palmar symptoms allowed unless confined solely to ulnar aspect.
3) Possible - tingling, numbness, decreased sensation and/or pain in at least one of digits 1, 2, or 3.
4) Unlikely - no symptoms in digits 1, 2, or 3.
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