Pain is the first sensation to return.
Numbness, paresthesia, or muscle weakness in the related area.
MRI confirms the diagnosis of nerve injury.
Elbow or upper forearm.
Traction lesions (traumatic hip dislocations and with pelvic fractures) and iatrogenic lesions (posterior approach in total hip replacement).
Numbness of the ulnar one and a half fingers, claw hand deformity, weak finger abduction and thumb adduction, hypothenar and interosseous wasting, positive Froment’s sign.
A painful fibrous tissue mass around the nerve ending formed by regenerating axons, Schwann cells, and fibroblasts.
In low lesions, the flexor digitorum profundus is working and causes flexion, leading to claw hand. In high lesions, both muscles are affected, resulting in less clawing.
Tendon transfer or arthrodesis if tendon transfer is not available.
Only the epineurium is intact, severe internal damage, unlikely recovery, requiring excision and repair or grafting.
A reversible physiological nerve conduction block with loss of sensation and muscle power, followed by spontaneous recovery.
Crutch palsy, Saturday night palsy, tourniquet palsy, compartment syndrome, carpal tunnel syndrome, distal humerus fracture, and posterior hip dislocation.
Elbow fractures or dislocations.
High up in the forearm.
Oligodendrocytes.
Motor recovery is slower than sensory recovery.
A process where axons are still intact but there is a dent in the myelin sheath/Schwann cells, with no damage to the nerve.
Wrist extension.
Damage at the level of the fibular neck.
Paralysis of the triceps (loss of elbow extension) and absence of the triceps reflex.
The posterior cord.
A positive 'OK' sign indicates high lesions of the median nerve.
Epineurium.
It is particularly strong to provide protection.
Ischemia, compression, traction, laceration, or burning.
Transient ischemia is caused by acute nerve compression, leading to numbness and tingling within 15 minutes.
It measures innervation density.
Signs of abnormal posture (wrist/foot drop, claw hand, high-stepping gait), weakness, and changes in sensibility.
No more than 2-2:30 hours; if needed longer, remove it every 2 hours and reapply after 1 hour.
Humerus (around spiral groove).
Cuts on shattered glass or injury at the level of the forearm due to compression.
Axilla or shoulder.
Inability to hold a paper using the thumb, compensating by using flexor pollicis longus due to loss of thumb adductor pollicis.
Nerve exploration and primary repair or grafting as soon as possible.
Compression or entrapment of the nerve in the medial epicondylar (cubital) tunnel.
Endoneurium.
Tinel’s Sign is a test where peripheral tingling (paresthesia) or dysesthesia occurs upon percussing over the nerve. It is positive in axonotmesis and negative in neurapraxia.
Disruption of the endoneurium with intact perineurium, good chances of axon regeneration but limited by fibrosis and crossed connections.
Neurotmesis, such as a knife cut of the forearm leading to drop wrist.
Fractures of the humerus or prolonged tourniquet pressure.
A more severe form of nerve injury involving axonal interruption, with loss of conduction but the nerve is in continuity.
Inability to plantar-flex the ankle or toes, absent sensation over the sole of the foot and part of the calf, and minimal clawing due to involvement of both long flexors and intrinsic muscles.
Forearm fractures or elbow dislocation.
Axon covered by myelin and Schwann cells.
A positive 'Pucker sign' indicates high lesions of the median nerve.
Transient ischemia, as it involves no damage to the myelin.
Low energy injuries have a high chance of recovery, while high energy injuries (like MVA or fall from height) are not a good sign for the patient.
Transient ischemia and neurapraxia, which is reversible.
Mechanical pressure causing segmental demyelination, with the axon itself still intact.
Cuts in front of the wrist or by carpal, lunate dislocations.
Severe traction when the knee is forced into varus, fractures around the knee, operative correction of gross valgus deformities, pressure from a splint or plaster cast, and lying with the leg externally rotated.
Trauma or operations around the shoulder, chronic compression in the axilla (Saturday night palsy or crutch palsy).
The division of the nerve trunk, often due to high energy trauma, where regenerating axons cannot reach the end organ, leading to permanent dysfunction.
Because the ulnar half of FDP (Flexor Digitorum Profundus) is paralyzed, causing less clawing of the fingers.
Observation, splinting, physiotherapy, and sending the patient for EMG/NCS.
Loss of pain sensibility.
Usually after 6 weeks, then at 3 months, 6 months, and 12 months.
Axonal degeneration with preserved endoneurium, allowing for complete or near-complete recovery without intervention.
The nerve is divided and the epineurium is injured, requiring repair.
Near the wrist.
Foot-drop (inability to dorsiflex or evert the foot), high-stepping gait, and loss of sensation over the front and outer half of the leg and the dorsum of the foot.
Wallerian degeneration occurs distal to the lesion, and axonal regeneration starts within hours at a speed of 1-2 mm per day.
The long flexors to the thumb, index and middle fingers, the radial wrist flexors, the forearm pronator muscles.
Teres minor and deltoid muscle.
Prolonged pressure on the elbows in anesthetized or bedridden patients.
Durkan test (carpal compression test).
Avoiding injury to the anterior branch of the axillary nerve, which curls around the surgical neck of the humerus at 5 cm below the tip of the acromion.
Compare the shoulder contour of both sides.
Tests of muscle power and sensitivity to light touch and pin-prick.
To check if the patient has a good degree of nerve sensitivity.
Denervation potentials appear by the third week, indicating nerve injury.
Fractures or dislocations at the elbow and iatrogenic lesions of the posterior interosseous nerve.
Paralysis of the hamstrings and all muscles below the knee, absent ankle jerk, loss of sensation below the knee except on the medial side of the leg, foot-drop, and high-stepping gait.
Wrist drop.
Unable to abduct the thumb, loss of thumb opposition, sensation loss over the radial three and a half digits, thenar eminence wasting and trophic changes, carpal tunnel syndrome.
Schwann cells.
High lesions of the median nerve.
Abduction of the shoulder.
Perineurium.
It is richly supplied by blood vessels that run longitudinally.
A patch of skin over the deltoid muscle at the proximal lateral arm.
Similar to high lesions but without any sensory loss, usually caused by brachial neuritis (Parsonage–Turner syndrome).
Numbness and tingling within 15 minutes, loss of pain sensibility after 30 minutes, muscle weakness after 45 minutes.
Entrapment of the ulnar nerve as it passes through Guyon’s canal at the ulnar border of the wrist, commonly caused by a ganglion or ulnar artery aneurysm.
Shoulder weakness, rapid deltoid wasting, numbness over the deltoid, and a high recovery rate with 80% of cases recovering spontaneously.
MRI will diagnose the ganglion, which is the most common cause.
Shoulder dislocation or fractures of the humeral neck, and lateral deltoid-splitting incisions.
Intense paresthesia for 5 minutes, feeling restored within 30 seconds, and full muscle power after about 10 minutes.
