Overview of peripheral nerve injury and entrapment

Nerve entrapment in the upper and lower extremities can be temporary or long-standing. Conditions such as obesity and pregnancy where there is increase fluid or body weight on nerves can interfere with nerve gliding. Surgical interventions and subsequent scar formation can also entrap nerves, resulting in chronic nerve symptoms, pain, and loss of function.

In some cases, patients consent to surgery to release the nerve or to transfer nerves to restore function in affected sensory and motor areas.

 

Upper Extremity Peripheral Nerve Injuries

Upper extremity nerve injuries are more common than lower extremity. Compression and traction (stretching) forces to components of the brachial plexus can result in pain, loss of sensation, and loss of motor function. Note how the brachial plexus originates from C5-T1 and then forms a series of overlapping trunks, divisions, and cords, before branching into peripheral nerves. Proximal compression can result in significant neurovascular syndromes, which may requires surgical releases to preserve nerve function and circulation. Neal and Fields (2010) noted, "risk factors include a superficial position, a long course through an area at high risk for trauma, and a narrow path through a bony canal"

https://commons.wikimedia.org/wiki/File:Brachial_plexus_anterior_view_nerves.JPG;

https://commons.wikimedia.org/wiki/File:Wikipedia_medical_illustration_thoracic_outlet_syndrome_brachial_plexus_anatomy_with_labels.jpg

 

Upper Extremity Nerve Injury Signs and Symptoms

Nerve

Injury Risk

Presentation

Axillary

Stretch during abduction; glenohumeral dislocation; compression in axilla (e.g. misuse of crutches)

Weakness in teres minor and deltoid

Long Thoracic

Sudden upper extremity traction; shoulder depression with contralateral lateral cervical flexion, sustained compression ("Backpacker's syndrome)

scapular winging

Suprascapular

Throwing athletes, trauma, clavicle fracture

supraspinatus weakness, atrophy and tenderness, pain with horizontal adduction,

Median

Elbow, forearm, and wrist overuse or injury

weak and painful grip; sensory changes in hand

Musculocutaneous

Shoulder dislocation; biceps injury; hypertrophy of coracobrachialis

shoulder and elbow flexion weakness

Radial

Proximal humerus fracture; elbow fracture or dislocation; "Saturday Night Palsy" when passing out from alcohol use results in prolonged compression on chair or bar

weakness in elbow flexion and wrist extension

Ulnar

Elbow dislocation or prolonged posterior elbow compression; repetitive throwing

weakness in the ulnar side of the hand and interossei

 

Lower Extremity Nerve Entrapment Signs and Symptoms

Nerve

Injury Risk

Presentation

ilioinguinal (T12-L1)

 

Lower abdominal surgery; orthopedic surgery (iliac bone harvesting for bone graft), pregnancy

 

pain in groin and medial inner thigh, may radiate to genital areas

lateral femoral cutaneous nerve (L1-L3)

tight clothing (e.g. jeans), pregnancy, trauma to ASIS

also known as "meralgia paresthetica"

burning, coldness, or lightning like pain on lateral thigh

 

femoral nerve (L2-4)

trauma (surgical or other), pelvic fracture, acute hyperextension of hip, diabetes (neuropathy), tumors

numbness, tingling and burning in the thigh, quadriceps weakness; difficulty managing stairs, feeling like knee will buckle

sciatic nerve (L4-S1)

 

 

hypertrophy of piriformis, direct trauma to SI or gluteals, hip flexion contracture, excessive hamstring exercise

 

also known as "piriformis syndrome"

Numbness, tingling, and weakness in the posterior hip and extend down posteriorly to the toes

tibial nerve

 

Rheumatoid arthritis, Baker's cyst (posterior knee), diabetes, tight-fitting shoes, pronation or pes planus

 

also known as "tarsal tunnel syndrome" when involves the posterior tibial nerve

sensation changes and weakness to the bottom of the foot and toes; weakness in plantar flexion and eversion; pain with weight bearing

 

 

https://en.wikipedia.org/wiki/Piriformis_syndrome