compression neuropathies neuropathies • spinal accessory nerve • upper/lower trunk plexopathy...

Compression Neuropathies

Andrew Martin DO, MBA, CAQSMOMED 2013

Compression Neuropathies

• Spinal Accessory Nerve

• Upper/Lower Trunk Plexopathy

• Long Thoracic Nerve

• Axillary Nerve

• Suprascapular Nerve

• Musculocutaneous Nerve

• Guyon Canal Syndrome

• Cubital Tunnel Syndrome

• Ulnar Nerve Interdigital Neuroma

• Tibial Nerve

• Plantar Nerve

• Common Peroneal Nerve

• Superficial Peroneal Nerve

• Deep Peroneal Nerve

• Medial Calcaneal Nerve

• Sural Nerve

• Saphenous Nerve

• Obturator Nerve

• Interdigital

• Lat. Femoral Cutaneous Nerve

• Medial Hallucal Nerve

• Carpal Tunnel Syndrome• Cubital Tunnel Syndrome

Objectives

• Upper Extremity Compression Neuropathies

• Lower Extremity Compression Neuropathies

• Ultrasound and Compression Neuropathies

Pathophysiology

Pathophysiology

Vasa Nervorum

Nerve Axons ≠ Action Potentials

Pathophysiology

Seddon Classification of Peripheral Nerve Damage

NeuropraxiaCompression Axonotemisis Neurotemsis

Treatments

• Surgery

• Physical Therapy

• OMM

• Injections

• Bracing

• NSAIDS, Muscle Relaxers, Oral Steroids, Narcotics, Antidepressants

Entrapments of the Upper Extremity

• Cervical Radiculopathy

• Spinal Accessory Nerve Compression

• Suprascapular Nerve Syndrome

• Quadrilateral Space Syndrome

• Radial Nerve Compression

• Ulnar Nerve Compression

• Median Nerve Compression

Cervical Radiculopathy

• Posterolateral Disc Herniation

• Facet Degeneration

• C7 > C6 > C8

Etiology


• Pain, Paresthesia, and Weakness

• Atrophy

• Reflex Sympathetic Dystrophy

Signs and Symptoms


• Sensory, Muscle, and Reflex testing

• Spurling Test

• MRI

Evaluation


Axial View T2 Weighted

Spinal Accessory Nerve Compression

Posterior Triangle

• Equipment (backpacks/shoulder pads)

• Blows to the Shoulder

Etiology


• Shoulder Syndrome

• Pain over trapezius, heaviness

• Abnormal Scapular Rotation

• Adhesive Capsulitis

Signs and Symptoms


• Test Trapezius

• Test Sternocleidomastoid

• Abnormal Scapular Rotation

Evaluation

Suprascapular Nerve Syndrome

• Suprascapular notch

• Spinoglenoid notch

• Thickened Transverse Scapular Ligament

• Extrinsic compression by a space-occupying lesion (ganglion cysts or soft tissue tumor)

Etiology


• Poorly localized pain and discomfort at the back of the shoulder

• Weakness when raising the arm.

Signs and Symptoms


Sagittal oblique T2 fat-saturated Sagittal oblique T1 weighted

42 yo swimmer with clinical and EMG evidence of right supraspinatus and infraspinatus muscle denervation at the suprascapular notch. Mild muscle atrophy with fatty infiltration.


Axial T2 fat-saturated image

28-year-old patient High Grade Sarcoma withMRI appearances indicating a right suprascapular nerve entrapment

Coronal postcontrast T1 image

Axillary Nerve CompressionQuadrilateral Space Syndrome

• Axillary Nerve enters the quadrilateral space w/ circumflex artery

• Supplies the teres minor and deltoid muscles and the overlying skin of the shoulder

• Compression from abduction and external rotation of the shoulder joint

• Hypertrophy of the adjacent musculature

• Space-occupying lesions

Etiology

Axillary NerveQuadrilateral Space Syndrome

• Poorly localized shoulder pain and paresthesias in the affected arm in a nondermatomal distribution.

• Weakness/Atrophy of the Deltoid and Teres Minor

• Confused with rotator cuff pathology or other shoulder joint-related abnormalities

Signs and Symptoms

Axillary Nerve CompressionQuadrilateral Space Syndrome

Oblique Coronal T2-fat saturated

26 year old Baseball Pitcher presented with Right Shoulder pain. Had clinical and EMG evidence of quadrilateral space syndrome.

Severe fatty atrophy of the teres minor muscle

Axillary NerveQuadrilateral Space Syndrome

Oblique Sagittal T2-fat saturated Oblique Sagittal T1-weighted

Severe fatty atrophy of the teres minor muscle

Radial Nerve Compression

• Spiral Groove of the Humerus

• Radial Tunnel

• First Dorsal Wrist Compartment

Etiology

Radial Nerve CompressionSpiral Groove Syndrome

• Saturday Night Palsy

• Humerus Fractures

• Deep puncture wounds

Etiology

Radial Nerve CompressionSpiral Groove Syndrome

• Triceps Weakness

• Wrist drop

• Patient unable to extend wrist or fingers

• Arm/Forearm/Hand/ Numbness

Signs and Symptoms

Posterior Interosseous Nerve Compression(Radial Tunnel Syndrome)

• Formed by the superficial layer of the Supinator Muscle (arcade of Frohse)

• Radiocapitellar joint ganglions

• Synovitis

• Congenital tightness of Arcade of Frohse

• Prominent radial recurrent artery (RRA)

• Radial Head Dislocations

Etiology

• Tenderness more over the Arcade of Frohse

• Painless weakness of the wrist and finger extensors

• No Sensory Deficits

Signs and Symptoms

Posterior Interosseous Nerve CompressionRadial Tunnel Syndrome

Posterior Interosseous Nerve Entrapment

Axial T2 fat-saturated Axial T1-weighted

An 18-year-old Tennis Player with clinical and EMG evidence of PIN entrapment. Level of right distal humerus show thickening and high T2 signal of the radial nerve.

Posterior Interosseous Nerve Entrapment

Axial T2 fat-saturated

An 18-year-old Tennis Player with clinical and EMG evidence of PIN entrapment. Supinator muscle edema

Superficial Branch Radial Nerve CompressionWartenberg's Syndrome

• Compression of the superficial branch radial nerve (SRN)

• Compressed by scissoring action of Brachioradialis and Extensor Carpi Radialis Longus Tendons during forearm pronation.

Etiology

Superficial Branch Radial Nerve CompressionWartenberg's Syndrome

• Ill-defined pain and Paresthesia over dorsoradial hand

• Aggravation by motions involving repetitive wrist flexion, ulnar deviation and pronation

• No motor weakness

Signs and Symptoms

Ulnar Nerve Compression

• Cubital Tunnel

• Guyon’s Canal

Etiology

Ulnar Nerve CompressionCubital Tunnel Syndrome

• Cubital Tunnel is formed by the Arcuate Ligament

• Caused by abnormal fascial bands, subluxation, or dislocation of the ulnar nerve over the medial epicondyle

• Trauma

• Direct compression by soft tissue masses.

Etiology


• Sensory abnormality of the ulnar hand

• Weakness of the flexor carpi muscle group of the 4th and 5th fingers

Signs and Symptoms


Axial T2 fat-saturated (Normal-Distal) Axial T2 fat-saturated (Abnormal-Cubital Tunnel)

A 17-year-old Baseball Pitcher with right cubital tunnel syndrome.

Ulnar Nerve CompressionGuyon’s Canal Syndrome

• Formed by the flexor retinaculum and the palmar carpal ligament

• Ulnar nerve divides into the superficial sensory and deep motor branches at the level of the hamate


• Trauma

• Ulnar artery aneurysms.

Etiology

Level of the Pisiform

Level of the Hamate

http://en.wikipedia.org/wiki/Flexor_retinaculum

http://en.wikipedia.org/wiki/Flexor_retinaculum

http://en.wikipedia.org/wiki/Palmar_carpal_ligament

http://en.wikipedia.org/wiki/Palmar_carpal_ligament


• Motor and sensory findings

• Depends of position of bifurcation to the superficial (sensory) and deep (motor) branches

• Types I, II, III

Signs and Symptoms


Axial T2 fat-saturatedAxial T1 - weighted

A 57-year-old Cyclist with clinical evidence of right ulnar nerve compression at wrist. Crowded Guyon’s Canal compressed by a tortuous ulnar artery.


MR Angiography Using Sensitivity Encoding (SENSE)

Median Nerve Compression

• Pronator Teres

• Flexor Digitorum Superficialis

• Carpal Tunnel

Etiology

Median Nerve CompressionPronator Syndrome

• Between the ulnar and humeral heads of the pronator teres muscle

• Trauma

• Congenital abnormalities

• Pronator teres hypertrophy

Etiology

Median Nerve CompressionPronator Syndrome

• Pain and numbness of the volar aspect of the elbow, forearm, and wrist

Signs and Symptoms

Median Nerve CompressionAnterior Interosseous Syndrome

• Entrapment of the Anterior Interosseous Nerve in the proximal forearm by the Flexor Digitorum Superficialis

• Direct nerve trauma

• Compression from a hematoma or mass

Etiology

Median Nerve CompressionAnterior Interosseous Syndrome

• Patients may present clinically with pain and muscle weakness in the volar forearm

• Flexor digitorum profundus

• Flexor pollicis longus

• Pronator quadratus

Signs and Symptoms

Median Nerve CompressionCarpal Tunnel Syndrome

• Most common cause of compressive/entrapment neuropathy

• Repetitive trauma

• Conditions related to metabolic and hormonal changes

• Ganglion cysts

Etiology

Median Nerve CompressionCarpal Tunnel Syndrome

• Burning wrist pain

• Paresthesia or numbness in the 1st through 3rd fingers, and the radial aspect of the 4th finger.

Signs and Symptoms

Carpal Tunnel Syndrome

Axial T1 - weighted Axial T2 fat-saturated

48-year-old patient with surgically proven right carpal tunnel syndrome. There is thickening and increased signal intensity of the median nerve.

Carpal Tunnel Syndrome

Axial T1 - weighted Axial T2 fat-saturated

Bowing of the flexor retinaculum with a flattened median nerve at the level of hamate.

Entrapments of the Lower Extremity

• Sciatic Nerve

• Common Peroneal Nerve

• Tibial Nerve

• Interdigital Nerve

Sciatic Nerve Compression

• Occurs in the hip region and less commonly in the thigh

• Fibrous or Muscular Type entrapment

• Vascular compression

• Scarring related to trauma or radiation

• Tumors

Etiology


• Pain, weakness, parasthesia, or numbness in the leg.

• Clinical presentations are based upon the level of injury

Signs and Symptoms


Axial T1 - weighted Sagittal T2-weighted fat-saturated

54 year old patient after a water skiing injury which resulted in an extensive tear of the left hamstring at the muscle origin with sciatic nerve scarring.


Axial T2-weighted fat-saturated Sagittal T1-weighted postcontrast

Surgically proven neurofibroma of the left sciatic nerve in a 33-year-old patient.

• Level of fibular head due to its superficial location, or as it travels deep to the origin of the peroneus longus

• Idiopathic mononeuritis

• Space-occupying lesions including (intraneural ganglion cyst)

• Traumatic injury

• Tumors

Etiology

Common Peroneal Nerve Compression

• Experience paresthesia and pain at the site of entrapment with foot drop

• Slapping gait

Signs and Symptoms



MCG Emergency Department


Sagittal T2-weighted fat-saturatedSagittal T2-weighted fat-saturated

44-year-old patient with a 6-month history of right foot drop, Intraneural ganglion cyst multilobulated structure compressing the adjacent common peroneal nerve.

Patchy high signal in tibialis anterior and extensor digitorum longus muscles

Tibial Nerve CompressionTarsal Tunnel Syndrome

• Formed by the flexor retinaculum medial malleolus and calaneous

• Posttraumatic fibrosis due to fracture

• Tenosynovitis / Bursitis


• Dilated or tortuous veins

Etiology

Tibial Nerve CompressionTarsal Tunnel Syndrome

• Burning pain and paresthesia along the plantar foot and toes

Signs and Symptoms

Tarsal Tunnel Syndrome

Axial T1-weighted Axial T2-weighted fat-saturated

Tarsal tunnel syndrome caused by a ganglion cyst in a 32-year-old patient. Multilobulated cystic structure within the right tarsal tunnel, adjacent tibial nerve.

Interdigital Nerve CompressionMorton’s Neuroma

• Most frequently occurs in the second and third intermetatarsal spaces

• Repetitive mechanical stress with subsequent perineural fibrosis

• Compression of the nerve by an inflamed intermetatarsal bursa

Etiology

Interdigital Nerve CompressionMorton Neuroma

• Standing on a pebble in your shoe

• A burning pain in the ball of the foot

• Paresthesia or numbness in the toes

Signs and Symptoms

Morton Neuroma

Coronal T1-weighted Coronal T2-weighted with fat saturation

Morton neuroma in a 38-year-old patient. Tear-drop-shaped soft tissue mass in the third intermetatarsal space. A small amount of fluid is noted within the

intermetatarsal bursa dorsal to the neuroma.

Ultrasound Carpal Tunnel Syndrome

Short Axis (cross sectional area) Long Axis

Hydrodisection of Median NerveCarpal Tunnel

Annual Meeting 2014

compression neuropathies neuropathies • spinal accessory nerve • upper/lower trunk plexopathy...

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