Median Nerve injuries

Prof Nabil Khalil Suez canal university

CONSIDERING Anatomy

Entrapment of Median nerve Can Occur at :

1)Course in the arm supracondylar process

* may form accessory origin for PT MU , thru ligament of Struthers

2) At the elbow

3) in the forearm-lacertus fibrosus

-pronator teres

- sublimis bridge

4) at the wrist

5) In the hand

paralysis of the muscles supplied by it

deformity of the hand

loss of sensation

(1) Paralysis of all muscles supplied .

(2) loss of pronation of the forearm .

(3) weak flexion of the wrist .

(4) loss of the flexion & opposition of the thumb.

Above The ElbowMotor Affection

(1) hyper-extended thumb .

(2) adduction .

(3) flat thenar eminence .

- lat. 2/3 of the palm of the hand .

- lat. 3 ½ fingers anteriorly & their distal halves posteriorly.

Deformity: Ape Hand Deformity

Sensory Loss

- lat. 2/3 of the palm of the hand .

-lat. 3 ½ fingers anteriorly & their distal halves posteriorly.

-Paralysis of the 5 hand muscles supplied by the nerve.

-The forearm muscles escape the injury as they are supplied at elbow.

Below The ElbowMotor Affection :

Deformity : Ape Hand Deformity

Sensory Loss :

Clinical Features

•Inability to flex IP joint of thumb

•Ape thumb deformity

•Oppones palsy

•Sensory signs

Carpal Tunnel Syndrome

Definition

It’s a Clinical Diagnose Of peripheral neuropathy, results from compression of the median nerve at the wrist

epidemiology

•Affects an estimated 3 percent of adult Americans

•Three times more common in women than in men

•High prevalence rates have been reported in persons who perform certain repetitive wrist motions (frequent computer users)

Clinical FeaturesPainNumbnessTinglingSymptoms are usually worse at night and can

awaken patients from sleep.difficulty in holding on to a glass or cup

securelyTo relieve the symptoms, patients often “flick”

their wrist as if shaking down a thermometer (Flick Sign).

Clinical Features Cont.

Pain and paresthesias may radiate to the forearm, elbow, and shoulder.

Decreased grip strength may result in loss of dexterity, and thenar muscle atrophy may develop if the syndrome is severe.

Atrophy

Physical Examination

i. Phalen’s maneuverii. Tinel’s signiii. two-point discrimination

Phalen’s Maneuver

Tinel’s Sign

Diagnostics

History Physical examination Nerve Conduction Study

Differential DiagnosesTendonitisTenosynovitisDiabetic neuropathyKienbock's diseaseCompression of the Median nerve at the elbow

Treatment•CONSERVATIVE TREATMENTS

General measuresWrist splintsOral medicationsLocal injectionPredicting the Outcome of Conservative Treatment

•SURGERY

ORAL MEDICATIONS

•Diuretics•Nonsteroidal anti-inflammatory drugs (NSAIDs)

•pyridoxine (vitamin B6)•Orally administered corticosteroids

▫Prednisolone▫20 mg per day for two weeks▫followed by 10 mg per day for two weeks

DO NOT WORK !!!

SURGERY•Should be considered in patients with symptoms that do not respond to conservative measures and in patients with severe nerve entrapment as evidenced by nerve conduction studies,thenar atrophy, or motor weakness.

•It is important to note that surgery may be effective even if a patient has normal nerve conduction studies

Complications of surgery

•Injury to the palmar cutaneous or recurrent motor branch of the median nerve

•Hypertrophic scarring•laceration of the superficial palmar arch•tendon adhesion•Postoperative infection•Hematoma•arterial injury•stiffness

Pronator Syndrome

- Proximal Forearm Compression - Because Of :-ligament of Struthers, lacertus fibrosus, pronator teres muscle

Same Symptoms As C.T.S But Could Be Differentiated By :

• include the distribution of the palmar cutaneous nerve

•The Tinel sign is positive at the forearm level

•The Phalen maneuver does not provoke symptoms

•Patients may experience pain with resistance to contraction of the pronator teres or flexor digitorum superficialis

Anterior Interosseous Syndrome

Clinical Findingsinability to flex either the thumb interphalangeal joint or the index-finger distal interphalangeal joint .

In contrast to those with pronator syndrome, these patients do not complain of numbness or pain . WHY ?

Thank You !

QQUUEESSTTIIOONNSS??