UL Peripheral Nerve Injury

Question 1

Axillary Nerve injury

Answer 1

Sensory:
Numbness at Lat. Sh

Motor:
-Deltoid–>weak Sh Abd/F/Ext
-Teres minor–>weakn Sh ER

Deformities:
-Deltoid wasting
-Sh: in Add+IR position

Question 2

Musculocutaneous Nerve

Answer 2

Sensory:
Numbness at Lat. forearm

Motor:
-BBC–>very weak elbow flexion & supination

Deformity:
-Ant. arm waiting
-Elbow: in Ext+Pron

Question 3

Radial nerve in Axilla

Answer 3

Sensory:
Numbness at Post. arm+foerarm, radial distribution of hand

Motor:
-Triceps–>lose elbow Ext
- Post. compartment of forearm–>lose wrist+thumb Ext, finger MCPJ Ext

Deformity:
- Wasting of triceps+post. compartment of forearm
- Wrist drop at rest

Question 4

Radial nerve in Spiral groove

Answer 4

Sensory:
Numbness at radial distribution of hand (only superficial branch)

Motor:
-Weakned triceps only
- Post. compartment of forearm–>lose wrist+thumb Ext, finger MCPJ Ext

Deformity:
- Wrist drop at rest

Question 5

Radial nerve in Forearm

Answer 5

Sensory:
Numbness at radial distribution of hand (only superficial branch)

Motor:
- Majority of post. compartment of forearm–>lose thumb Ext, finger MCPJ Ext
- ECRL not affected–>wrist Ext still possible but weak

Deformity:
- No wrist drop

Question 6

Median Nerve at elbow

Answer 6

Sensory:
Numbness at thenar eminence & lat. 2/3 of palm and 3&1/2 fingers

Motor:
- Weak wrist Flex (will have UD due to FCU & medial 1/2 of FDP)
- No Pron
- No IPJ Flex of I/F, M/F
- No Thumb Flex/Oppo
- Weak pincer grip & overall grip

Deformity:
- Wasting of Ant. compartment of forearm
- Ape hand
- Hand of benediction when trying finger Flex

Question 7

Median Nerve at Forearm

Answer 7

Sensory:
No disturbance (Ant. interosseus nerve only motor)

Motor:
- Loss of Lat. 1/2 of FDP & FPL–>loss of pincer grip with thumb&I/F
Pinch sign/OK sign

Question 8

Median nerve at wrist

Answer 8

Sensory:
Numbness at 3&1/2 fingers only
(intact palmar cutaneous)

Motor:
- Lat 2 lumbricals=weak MCPJ Flex+ IPJ Ext
- thenar eminence=loss thumb Oppo, Weak pincer grip&grip strength, weak thumb flexion

Deformity:
Ape hand deformity

Question 9

Ulnar nerve at elbow

Answer 9

Sensory:
Numbness at ulnar distribution of hand

Motor:
- Weak wrist flexion (still have FCR->accompanied by RD)
- No R/F,L/F DIPJ Flex
- No finger Abd/Add, med 2 lumbrical, hypothenar affected
- No adductor pollicis
+ve Froment’s sign

Deformity:
- Wasting of hypothenar & intrinsic hand muscles
- Ulnar Claw hand at rest & finger Ext (less pronounced vs wrist injury)

Total Claw–>Klumpke’s palsy

Question 10

Ulnar nerve at wrist

Answer 10

Sensory:
- Ant. wrist laceration:
Palmar & superficial branch
–> med 1/3 palm & ant. portion of medial 1&1/2 finger
- Compression at Guyon’s tunnel:
superficial branch
–>ant. portion of medial 1&1/2 finger only

Motor:
- No finger Abd/Add, med 2 lumbrical, hypothenar affected
- No adductor pollicis
+ve Froment’s sign

Deformity:
- Wasting of hypothenar & intrinsic hand muscles
- Pronounced Ulnar Claw hand at rest & finger Ext