Adult Brachial plexus injuries

                           Adult Brachial Plexus Injuries

Adult brachial plexus injuries are becoming increasingly common. In adults most common cause is motor cycle accidents, other notably causes are tumors, radiotherapy and iatrogenic.

brachial plexus is a plexus of nerves which arise out of lower cervical (C5-C8) and first thoracic T1 spinal nerves.Anterior primary rami which are motor in function participate in plexus formation. They supply motor and sensory innervation to upper limbs from shoulder to hand. In the C5 and C6 forms upper trunk just after exiting scalene triangle,C7 continue as middle trunk and lower two(C8&T1) joined as lower trunk. They gives rise to cords which are below clavicle and followed by terminal branches. All posterior division arising from trunks forms posterior cord which gives arise to terminal branches, anterior division of upper trunk give arise to lateral cord and medial cord comes from anterior division of middle trunk. Terminal branches comes after that which supply the muscles.
injury can happen at any areas of brachial plexus from cervical spine to terminal branches.If connection from cervical cord of peripheral nerve is snapped out it is known as avulsion. Term rupture is used when nerves damaged  along the course.

 Clinical examination reveal the site of injury , management and prognosis. MRI is usually done at three weeks of injury and repeated at three months,EMG also helps in diagnosis and follow up of recovering patients.
Clinical picture consist of paralysis of muscles of upper limb in various combination and associated symptoms. Pain is also important symptom associated with root avulsion.
Treatment of brachial plexus depends upon severity of injury , time since of injury and  and associated injuries.
Usually sometime around three months is given before planning any surgical intervention, This time allow associated injuries to he al, allow any recovery to take place. Best time to do surgery is 3 to 9 months post injury, after this recovery is delayed . Initial assessment after three months gives clinical picture and surgery to be planned.MRI and nerve conduction studies help in delineating extent of injury. 

Surgery of brachial plexus injury is of wide spectrum. Exploration of brachial plexus is done to confirm diagnosis, to know extent of injury, to dissect nerve for repair or transfer.

Primary repair is possible only in sharp cut early injury. Repair with nerve graft is possible in delay setting with localized neuroma. Paediatric brachial plexus palsy is usually ameable to neuroma exision and nerve grafting.In adults injury is wide spread at multiple levels so nerve transfer is usually done. avulsion injuries are managed by extra plexal or intra plexal nerve transfer, short rupture injuries can be nerve grafted.
Now days distal nerve transfer is preferred whenever feasible. In primary nerve surgery nerve transfer is done for shoulder abduction and elbow flexion. Surgery for hand function is usually done after recovery from first surgery, usually two years after first surgery. It entails free functioning muscle transfer for finger flexion. Supplemental procedure for wrist arthrodesis and tendon transfer are also needed. Whole management and treatment is spread over five years. Patient can expect to gain useful function and can be rehabilitated in society and job.