Clinical Cases Of The Upper Limb Flashcards
Discuss damage to the upper brachial plexus
Occurs at C5, C6 (C7)
Damage to upper parts of brachial plexus (roots &/or trunks)
Most common presentation- Erb’s palsy
Arm adducted and internally rotated, forearm extended and pronated
Sensory loss along lateral border of limb (C5,C6, +/-C7) dermatomes)
What are the clinically involved nerves in the upper brachial plexus (damage)?
Suprascapular: inability to initiate abduction and loss of external rotation
Axillary: loss of abduction to 90 degrees and external rotation
Musculocutaneous- loss of forearm flexion and weakened forearm supination
Discuss lower brachial plexus damage
C8/T1
Klumpke’s (Klempe-dejerne) palsy
- damage to lower parts of brachial plexus (trunks or median cord)
- loss of flexor carpi ulnaris (FCU) and medial 1/2 of flexor digitirum profundus (FDP)
- Loss of all intrinsic hand muscles (both ulnar and median)
- SENSORY LOSS ALONG MEDIAL BORDER OF HAND AND FOREARM AND ARM (C8 & T1 DERMATOMES)
What is the origin of the radial nerve?
From posterior cord
What is the course of the radial nerve?
- Spiral (radial) groove of humerus
- Crisses elbow anterior to lateral to lateral epicondyle
Ends by splitting into superficial (Sensory only) and deep (motor only) just distal to the elbow
- deep pierces the supinator and exits becoming the posterior interroseus nerve
- Superficial comes off in the forearm but is carrying sensation from the hand
What is the motor supply of the radial nerve?
Supplies extensors of the forearm, wrist and digits (via the radial nerve, deep nerve and posterior interosseous nerve)
What is the Sensory supply of the radial nerve ?
Arm- posterior and. Lower lateral
Forearm-posterior
Hand-dorsum of hand/ lateral 2 1/2 digits (proximal part of these digits)
What are the 3 common radial nerve injuries?
- Injury in the Axilla (Saturday night palsy)
- Injury in the arm eg midshaft fracture of the humerus
- Injury in the forearm eg posterior interosseous nerve syndrome (motor only)
Explain depth injury in axilla
Radial nerve injury
- loss of ability to extend the elbow joint
- Wrist drop
- Impaired grip strength
Sensory loss:
- Arm: posterior and lower lateral
- Forearm: posterior
- Hand- dorsum of hand- lateral 2 1/2 digits (proximal part if these digits)
Explain injury at the midshaft of the humerus
Radial nerve injury
Retain ability to extend the elbow joint
Wrist drop
-Impaired grip strength
Sensory loss: -Arm- variable -Forearm- posterior -Hand-dorsum of hand- lateral 2 1/2 digits (Proximal part of these digits)
What is the origin of the m3dian nerve?
From lateral & medial cords
What is the course of the median nerve?
Crosses anterior to elbow through cubital fossa
-supplies all muscles in superficial and intermediate flexor compartment of firearm except FCU
- Just distal to elbow, gives off the anterior interroseus
- Supplies the deep flexor compartment except ulnar half of FDP
Through carpal tunnel into the hand
- motor innervation:
- palmar digital branches-2 lumbricals (1st and 2nd)
- recurrent branch -OAF muscles
Sensory innervation
-palmar digital branches-lateral 3 1/2 fingers palmar side and their distal phalanx on the dorsal side
-palmar cutaneous branch- mid-palm (comes off median in firearm and doesn’t pass through carpal tunnel
What are the common median nerve injuries?
- At/above the elbow eg supracondylar fracture
- Injury to the anterior interroseus nerve (AIN) only e.g. entrapment of the AIN between the two heads of pronator teres
- At the level of the wrist e.g. carpal tunnel syndrome, lunate dislocation, suicide attempt
- Injury to the palm e.g. laceration to the base of the thumb
What are the effects of median nerve injury at or above the elbow ?
Injury at or above elbow
Benediction hand
Weakened wrist flexion
-Thenar wasting: thenar eminence is flatted due to atrophy of thumb OAF muscles
- Ulnar deviation (FCU unopposed)
- Loss of flexion of index and middle fingers at DIP & PIP joints (FDP and FDS)
- Loss of pronation
- Loss of opposition of thumb
- Loss of flexion of thumb
- Weakened abduction of thumb
Sensiry: palmar aspects of thumb, index, middle, and half of ring finger up to the DIP on the dorsal aspect
Identify Sensory effects in median nerve injury at or above elbow
Palmar aspects of thumb, index, middle, and half of ring finger up to the DIP on the dorsal aspect
What is benediction hand?
Injury at or above elbow
Benediction hand- when patient attempts to make a fist.
The index and middle fingers stay straight (both FDS and FDP to these digits is intact-Ulnar)
Thumb remains in plane of palm - flexor pollicis longus and brevis have lost innervation but adductor pollicis is intact- Ulnar
What are the motor effects of median nerve injury at the wrist?
- Flexor muscles in firearm are NOT paralyzed so no benediction hand
- Wrist flexion, forearm pronation and long flexor of thumb all intact
- LLOAF muscles of intrinsic hand are paralyzed:
- Atrophy of thenar muscles:
- Loss of opposition of thumb
- Weakened abduction and flexion of thumb
- Atrophy of thenar muscles:
What are the sensory effects of median nerve injury at the wrist?
Same as previous
Palmar aspects of thumb, index, middle, and half of ring finger up to the DIP on the dorsal aspect
What is Carole tunnel syndrome?
Entrapment syndrome causing increased pressure in the carpal tunnel
-Compresses the median nerve
What are the sensory deficits of carpal tunnel syndrome?
Paresthesia in median nerve distribution in the hand (except central palm which is supplied by the palmar cutaneous branch), nocturnal pain common
What is the motor deficit of carpal tunnel syndrome?
Loss of function to muscles supplied by median nerve in the hand
How can we test medial nerve Sensory functions, fir example, fir carpel tunnel syndrome ?
Provocative tests for median nerve function in the hand
A) A positive Tinel sign refers to distally radiating pain and/or parasthesia elicited by precussing a superficial peripheral nerve, in this case the median.
B) the Phalen maneuver is performed by apposing the wrists in goo of flexion. Parasthesia in the hand within 60 seconds is considered a positive test
Explain the effects of injury to median nerve in the proximal palm
Injury in proximal palm : laceration to the base of the thumb
- recurrent branch
- Motor only nerve
- Flexor muscles in forearm are NOT paralyzed
- OAF muscles of intrinsic hand are paralyzed
- Atrophy of thenar muscles, loss of opposition, weakened flexion and abduction of thumb
- No sensory loss
What is the origin of the ulnar nerve?
From medial cord
