Carpal Tunnel Syndrome

Gershon Zinger MD MSHadassah Medical Organization

Jerusalem, Israel

Gershon Zinger MD MS

Grad School MIT – mechanical eng Medical School UCLA

Residency USC – orthopedic surgery Fellowship UCLA – hand & micro Work Private practice Denver, Colorado

Current Hadassah Medical OrganizationJerusalem, Israel

Definition

Carpal comes from the Greek word Karpos – means wrist !

Carpal tunnel syndrome means wrist tunnel syndrome

Syndrome – “A set of symptoms which occur together” (from Dorland’s Medical Dictionary) (AKA – we don’t really understand it !)

Anatomy

Wrist tunnel formed by bone on bottom and ligament on top

There are 9 tendons and one nerve in the tunnel

Analogous to 4 lanes of traffic going to 2 lanes then back to 4 !

Who Gets CTS

Women more often affected (ratio 3:1) Historically more common in retired people Associated with repetitive activity Can be associated with medical diseases

Diabetes Rheumatoid Arthritis Thyroid Disease

Diagnosis of CTS

History Physical Exam Nerve Conduction

Study/EMG

Nerve Exam

Sensory Motor Irritability

Nerve Exam - Sensory Pattern peripheral or radicular

Check for altered sensation, numbness on palmar and dorsal sides

Middle finger is median n. Small finger is ulnar n. First dorsal webspace is

radial nerve innervated

Median Nerve

The median nerve provides feeling to the thumb, index, middle and part of the ring fingers

Sometimes people complain of numbness in the little finger that may or may not be CTS

Nerve ExamSensory

Numbness over first dorsal web space may indicate cervical origin

Numbness glove-stocking may indicate general neuropathy

Numbness in non anatomic distribution may indicate trigger points

Nerve ExamSensory

2 point discrimination is an objective test of sensibility Use large, not small

paper clip As points get closer

together, it feels like one instead of two

6 mm or less is normal

Nerve ExamMotor – Carpal Tunnel

Look for atrophy of thenar muscles May be secondary to

thumb arthritis Test strength for

opposition (median)

Nerve ExamIrritability - Carpal Tunnel

Phalen Test (up to 60 seconds)

Local Compression

Tinel’s Sign

Other sources of nerve irritationCervical

Cervical testing Reproduction of

symptoms with extension+rotation

Numbness that extends to shoulder level very suspicious for proximal origin

Double-Crush Phenomenon

A compression point at one location may lower the threshold at another location

Other sources of nerve irritationThoracic Outlet Syndrome

90 degree abduction-external rotation test (AER) – neither too far forward nor too far back

Other sources of nerve irritationThoracic Outlet Syndrome

Examiner’s thumb over anterior scalene muscle

Other sources of nerve irritation Trigger Points

Palpation of parascapular trigger points may cause local pain but also reproduce tingling and numbness distal into hand Trapezius Rhomboid Latissimus Posterior arm

Nerve Conduction + EMG

Nerve Conduction Study Test speed of

signal down the nerve

EMG Needles into

muscles looking for defibrillation

Nerve anatomy

A nerve carries electricity in two directions

Axons in bundles or fascicles

Micro-circulation affected by pressure

Saltatory ConductionNode of Ranvier

Seddon Classification

Neuropraxia Interruption in

conduction Nerve elements normal Recovery full Recovery can take 6-8

weeks Axontmesis Neurotmesis

Seddon Classification Neuropraxia Axontmesis

Loss of axon continuity EMG 2-3 weeks later may

show denervation and fibrillation potentials

Epineurium preserved Axon may regenerate at

rate of 1mm/day Incomplete recovery Final result at one year

Neurotmesis

Seddon Classification Neuropraxia Axontmesis Neurotmesis

neurotmesis (neuro as in never as in fahgedaboutit)

Complete loss of nerve function

May include loss or scarring of all neural elements

Surgery can still help w/pain

Remember:

Nerve is brain tissue – limited ability to recover

Numbness may go away after 1 day, months, a year or never !

Numbness may be permanent if nerve already damaged beyond recovery

Treatment of CTS

JBJS 1980 – Steroid Injection + splint Prospective, one year, 50 hands Overall, only 22% of hands were sx-free In mild category, 40% hand were sx-free

J of Hand Surg 1994 – Steroid injection + splint Prospective, 76 hands, f/up 1 yr, avg age 38 yo, excluded

DM, thyroid dz, RA, preg and “severe dz” Overall only 13% of hands were sx-free

JAMA 2002 – surgery vs splint Prospective, 147 patients, excluded DM At 18 months, 90% success surgery group vs 37% for splint

group

Surgery - CTR

Under the skin lies palmar fascia

There are muscles on both sides – thenar and hypothenar consisting of 3 muscles each

Surgery - CTR

Under fascia lies the transverse carpal ligament

This ligament is cut and springs apart

Ligament later heals leaving the tunnel larger

Open versus endoscopic

Open theoretically safer

Endoscopic theoretically has faster recovery

Injuries

J of Hand Surgery* – May 1999 Survey of members of ASSH Endoscopic – 455 major injuries Open – 283 major injuries

* Palmer & Toivonen

Postoperative

Nurse visit at about 10 days for suture removal and nerve gliding exercise

Need to avoid heavy or repetitive for one month then gradual return to activities

Palm may be sore 2-4 months

Thank You !