Carpal Tunnel

Carpal Tunnel

associated with the median nerve

- concave “tunnel” at the anterior aspect of the wrist

How is the carpal tunnel created?

• the flexor retinaculum/transverse carpal ligament creates a “roof” over the anterior/flexor side of the wrist, which creates a “carpal tunnel”

• TCL is attached to carpals

What is located within the carpal tunnel?

(9 tendons)

1. 4 tendons of FDS (flexor digitorum superficialis muscle)

2. 4 tendons of FDP (flexor digitorum profundus muscle)

3. the ulnar bursa (the common synovial sheath that surrounds FDS & FDP

tendons)

4. 1 tendon of FPL (flexor pollicis longus m.)

5. median nerve

Are the radial artery, ulnar artery, & ulnar nerve in the carpal tunnel?

NO they have nothing to do with it

Carpal Tunnel Syndrome

compression of the median nerve within the carpal tunnel

- this is due to inflammation of the ulnar bursa, secondary to overuse

Where would Carpal Tunnel Syndrome hurt the hand at?

The lateral side of the hand (thumb side)

Where is Carpal Tunnel Syndrome seen?

Wakes people up from sleep (n. pain will do this)

Dropping object

Median n. MOTOR to:

wrist flexion & most of digital flexion

- motor to the “thenar compartment” of the hand

- involved in grip strength

Median n. SENSORY to

- skin on the lateral surface of the palm

- palmar surface of the first 3 ½ digits plus their dorsal tips

Signs & Symptoms of CTS

• atrophy of muscles controlling the thumb (the “thenar compartment”)

• paresthesia or dysesthesia of skin on the lateral side of the palm, and into the palmar surface of the first three ½ digits plus their dorsal tips

• grip strength weakness

Tunnel of Guyón/Canal of Guyón

associated with the ulnar nerve

- fibro-osseous tunnel on the medial side of the wrist

- passageway for the ulnar nerve & artery to get into the hand

Passes between the pisiform and hook of the hamate

“Guyón canal/tunnel syndrome”

As the ulnar n. crosses the wrist it may become compressed against the medially located carpals and ligaments

“Guyón canal/tunnel syndrome” injury

Mibodel younger or OA. Changes in the hamate and pisiform

Signs & Symptoms of Guyón canal syndrome:

• atrophy of muscles everywhere in the hand except for the thenar compartment

• paresthesia or dysthesia over the medial surface of the palm and dorsum of hand, and the last 1 ½ digits

• grip strength weakness

What is the differential diagnosis of CTS vs. Guyón canal syndrome?

• LOCATION of pain

Feature	Carpal Tunnel Syndrome	Guyon's Canal Syndrome
Nerve Involved	Median Nerve	Ulnar Nerve
Lateral Hand (Thumb, Index, Middle)	Affected (Pain, numbness, tingling)	Normal
Medial Hand (Pinky, half of Ring)	Normal	Affected (Pain, numbness, tingling)