Wrist
Carpal Tunnel Syndrome
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Carpal Tunnel Syndrome
, Median Neuropathy, Carpal Tunnel
See Also
Overuse Syndromes of the Hand and Wrist
Peripheral Nerve Injury
Epidemiology
Most common
Entrapment Neuropathy
of the arm
Incidence
: 3% of U.S. general population
Women outnumber men affected by 3 fold
Bilateral in 50% of cases
Associated with workplace repetitive hand activities
Hand
Paresthesia
s occur in 30% of computer users
Only 10% of these meet criteria for Carpal Tunnel
Only 3.5% of these have abnormal EMGs
Stevens (2001) Neurology 56:1568-70 [PubMed]
Pathophysiology
Compression of
Median Nerve
Occurs between transverse carpal ligament and underlying
Carpal Bone
s
Median Nerve
adjacent to 9 inflamed and enlarged synovial lining of flexor tendons
Sensory deficits predominate
Motor Nerve
s are much less susceptible than
Sensory Nerve
s to compression
Risk Factors
Repetitive motion of hand and wrist
Most common cause, and typically work related
More common if significant force applied or hand-operated vibratory tool
Local wrist or
Hand Trauma
Obesity
Many associated conditions (see below)
Associated Conditions
Hypothyroidism
Diabetes Mellitus
Acromegaly
Rheumatoid Arthritis
Gouty Arthritis
Lyme Disease
Amyloidosis
Multiple Myeloma
Edema
tous condition
Third trimester of Pregnancy
Symptoms subside after delivery
Congestive Heart Failure
Renal Failure
Aberrant or Anomalous
Muscle
s in wrist
Proximal lumbrical insertion
Distal extension of flexor superficialis
Muscle
Persistent thrombosed median artery
Abnormal palmaris longus tendon
Ganglion Cyst
Lipoma
Double-Crush Syndrome
Symptoms
Image:
Median Nerve
Sensory Innervation
Paresthesia
s along
Median Nerve
course (palmar surface)
Electrical
Sensation
or Dysesthesias
Commonly involves only palmar Index and Middle fingers
May affect palmar aspect of all
Median Nerve
innervated 3.5 fingers (thumb to fourth finger)
Pain in distal, palmar surface of wrist or arm
Distal radiation into thumb, index and middle finger
Radiation
Proximal radiation into
Forearm
(may rarely radiate proximally into
Shoulder
and neck)
May even present as
Chest Pain
(has resulted in ED
Chest Pain
cardiac work-ups)
Gradually increasing night pain (95% of patients)
Increase in wrist swelling with inactivity
Wrist
flexion at night (may awaken patient)
Numbness
Describes "poor circulation" and "Stiffness"
Despite which hand feels warm
Weakness and Clumsiness of hand
Decreased grip strength
Timing
Spontaneous onset
Provocative of Sensory and Motor Symptoms
Repetitive wrist flexion or hand elevation
Precipitated by Typing, holding phone, driving, painting, and wrist motion
Palliative
Shaking or moving hand
Allow hand to hang down
Flick Sign
Flicking wrist as if shaking down
Thermometer
(often after night-time awakening)
Test Sensitivity
93%,
Test Specificity
96%
Signs
Precautions
In addition to wrist and
Hand Exam
, also examine elbow,
Shoulder
and neck for referred pain source
Observation
Square-shaped wrist (depth dimensions approaches wrist width, esp in
Obesity
, OR 4.56)
Shiri (2015) Muscle Nerve 52(5): 709-13 [PubMed]
Modifying factors
Pain not worse with resisted motion
Flick Test
(see above)
Carpal Compression Test
(64-90% sensitive, 83-90% specific)
Direct pressure applied over the transverse carpal ligament for 30 seconds
Positive for sensory symptoms within first 30 seconds
Classic exam findings have individual poor predictive value (but combined 80% sensitivity, 92%
Specificity
)
Tinel's sign
(44-70% sensitive, 94% specific)
Phalen's Maneuver
(70-80% sensitive, 80% specific)
Hand elevation test
Hands raised overhead for one minute
Positive test if symptoms are reproduced in the first minute
Ahn (2001) Ann Plast Surg 46(2): 120-4 [PubMed]
Tourniquet
Test (not recommended as not sensitive and not specific)
Inflate
Blood Pressure
Cuff on upper arm above systolic
Blood Pressure
Positive if
Paresthesia
s and Numbness after inflation in first 60 seconds
Sensory deficit over
Median Nerve
Sensory deficit predominates as
Sensory Nerve
s are more susceptible to compression than
Motor Nerve
s
Hypalgesia in classic
Median Nerve
distribution has high
Likelihood Ratio
Patient draws areas of pain or numbness on hand diagram
Two Point Discrimination
<6 mm with caliper (33% Sensitive, 100% Specific)
Resolution of pain with persistent numbness suggests permanent sensory loss
Motor deficits (late finding in severe Median Neuropathy)
Weak thumb abduction and weakness
Weak on grasping items, opening jars, buttoning clothing
Thenar
Muscle
atrophy
Associated with decreased grip strength
Only present in severe, long-standing disease
Other hand and wrist neuropathies will cause this as well
Abductor pollicis brevis weakness
Abduct thumb perpendicular to palm against examiner's resistance
Findings suggestive of alternative diagnosis
Wrist
and hand with reduced range of motion (ROM should be unaffected in Carpal Tunnel)
Thenar eminence with reduced
Sensation
Innervated by
Median Nerve
's palmar cutaneous branch (origin is proximal to
Median Nerve
)
Suggests a
Median Nerve
injury in the neck or proximal arm
Diagnosis
Findings with highest predictive value
Classic hand symptoms in median distribution
Decreased
Pain Sensation
at index palmar surface
Weak thumb abduction
References
D'Arcy (2000) JAMA 283:3110-7 [PubMed]
Differential Diagnosis
Tenosynovitis
Flexor carpi radialis
Tenosynovitis
Extends from proximal 1st
Metacarpal
to medial epicondyle
De Quervain's Tenosynovitis
Affects extensor pollicis brevis, abductor pollicis longus
Other
Neuropathy
Cervical Radiculopathy
(C6 nerve)
Median Nerve
compression at elbow (
Pronator Syndrome
)
Ulnar Tunnel
(or
Cubital Tunnel
)
Peripheral Neuropathy
(e.g.
Diabetes Mellitus
)
Degenerative Joint Disease
Wrist
Osteoarthritis
Thumb carpometacarpal
Osteoarthritis
Vascular conditions
Raynaud Syndrome
Vibration white finger (occurs with vibratory hand tools)
Radiology
Wrist XRay
Evaluate for local bony abnormality
Diagnostics
Nerve Conduction Studies
(
Electromyography
, EMG)
Indicated in unclear cases or in pre-surgical assessment of severity
Delayed electrical conduction across wrist at the
Median Nerve
Efficacy: 56-85% sensitive, 94-99% specific
Normal in up to one third of patients with mild Carpal Tunnel
Ultrasound
See
Median Nerve Measurement on Ultrasound
Highest efficacy when wrist
Median Nerve
cross sectional area is compared with
Forearm
measurement
Noninvasive, painless test with high efficacy (for experienced operators) and evaluates other wrist structures
Other diagnostic studies (CT, MRI, XRay)
Not typically indicated
Consider
Wrist XRay
if bone or joint disorders are suspected
Management
Gene
ral Measures (Conservative)
Efficacy
Spontaneous resolution with
Placebo
: 50%
Goodyear-Smith (2004) Ann Fam Med 2:267-73 [PubMed]
Short-term: 80% respond
Long-term: 80% of responders recur after one year
Eliminate cause and modify work conditions
Avoid repetitive
Trauma
Avoid the extremes of wrist flexion or extension
Avoid vibratory tool use
Employ ergonomics (wrist rest, adjust chair/desk, voice recognition software)
Wrist Splint
or
Wrist
brace (neutral position)
Polypropylene occupational
Wrist Splint
Maintains wrist in neutral position
Avoid cock-up (hyperextension) brace
Most effective if started early (within 3 months)
Wear during both day and night (best results)
Burke (1994) Arch Phys Med Rehabil 75:1241-4 [PubMed]
Sevim (2004) Neurol Sci 25:48-52 [PubMed]
Wrist
and Hand
Exercise
s
Brief (1 minute)
Exercise
performed intermittently (e.g. during or after work)
May be taught by physical therapy, hand therapy or by online video
Nerve glide
Exercise
s (repeat each 10-15 repetitions)
May theoretically untether a compressed
Median Nerve
Hyperextend hand against wall
Wrist
rotation against wall
Repeat wrist rotation with neck lateral bending to either side
Alternate finger extension with clenched fist
https://www.youtube.com/watch?v=B5goXA9MqCA
Local or
Systemic Corticosteroid
Carpal Tunnel Steroid Injection
(preferred)
Risk of
Median Nerve
injury, tendon rupture
May repeat injection after 6 months
As effective as surgery with benefits lasting more than 10 weeks (often >1 year)
Ly-Pen (2005) Arthritis Rheum 52:612-9 [PubMed]
Consider
Systemic Corticosteroid
s
Less effective and more adverse effects than with local injection
First:
Prednisone
20 mg PO qd for 14 days
Next:
Prednisone
10 mg PO qd for 14 days
Chang (1998) Neurology 51:390-3 [PubMed]
Local
Ultrasound
Six weeks of therapy provides up to 6 months relief
Reference
Ebenbickler (1998) BMJ 316:731-5 [PubMed]
NSAID
s (e.g.
Ibuprofen
)
Variable efficacy (unlikely to offer benefit beyond transient pain relief)
Pyridoxine
may be indicated in pregnancy
Dose:
Pyridoxine
25-50 mg PO tid
Unproven benefit
Reference
(1993) Can Fam Physician, 39:2122-7 [PubMed]
Management
Surgical release transverse carpal ligament
Indications
Early surgery for moderate to severe
Median Nerve
injury
Persistent symptoms refractory to conservative therapy after 3-4 months
Progressive or persistent motor weakness (grip strength) or thenar
Muscle
atrophy
Efficacy
Results in prompt, permanent pain relief
Very effective in 66% of patients (some studies report 70-90% of cases)
May be effective even if EMG normal
Earlier return to work by 8 days with endoscopic repair (but equivalent longterm outcomes to open repair)
References
Katz (2001) Arthritis Rheum 44:1184-93 [PubMed]
Gerritsen (2001) Br J Surg 88:1285-95 [PubMed]
Course
Sensory, Motor function improvement may take months
Post-operative
Splinting
is not recommended
Results in increased stiffness and does not improve outcomes
Adverse affects
No
Disability
from sectioning transverse ligament
Residual discomfort may continue from
Tenosynovitis
Complications
Median Nerve
branch injury
Hypertrophic, painful scar
Superficial Palmar Arch
Laceration
Pillar pain adjacent to ligament release
References
D'Arcy (2000) JAMA 283(23): 3110-7 [PubMed]
Katz (1994) Am Fam Physician 49(6):1371-9 [PubMed]
Keith (2009) J Am Acad Orthop Surg 17(6): 389-96 [PubMed]
Keith (2009) J Am Acad Orthop Surg 17(6): 397-405 [PubMed]
LeBlanc (2011) Am Fam Physician 83(8): 952-8 [PubMed]
Silver (2021) Am Fam Physician 103(5): 275-85 [PubMed]
Viera (2003) Am Fam Physician 68(2):265-72 [PubMed]
Wipperman (2016) Am Fam Physician 94(12): 993-9 [PubMed]
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