Neuro Disorders: Brachial Plexopathy

Brachial Plexopathy means injury, damage or pathology involving the brachial plexus, a structure in the nervous system in the lower neck & shoulder area from which all the upper extremity nerves arise.

Brachial plexus is formed by the ventral division of c5 to c8 spinal roots (cervical spinal roots corresponding to neck area). C4 and T1 spinal roots too may contribute with a twig sometimes. The spinal roots unite to form the trunks and the divisions of the trunks unite to form the cords of the brachial plexus.

The c5 & c6 roots unite to form upper trunk, c7 continues as middle trunk, c7 & c8 unite to form the lower trunk. Each trunk divides into anterior and posterior divisions; the anterior divisions of the upper two trunks unite to form the lateral cord, the anterior division of the lower truck continues as medial cord and the posterior divisions of all three trunks unite to form the posterior cord.

Individual nerves arise from different segments of the brachial plexus (from the roots, trunks, cords) but most of them arise from the cords of the brachial plexus. All nerves supplying the upper extremities are derived from the brachial plexus. Nerves supplying muscles in the scapular area and few muscles of the neck and chest also arise from this plexus.

There are myriad causes including;

• Traumas (e.g. birth traumas, falls etc)
• Infections e.g. viral
• Post infectious/ immunologic
• Inflammatory/immunological
• Tumor infiltration(e.g. lung cancer or breast cancer)
• Shoulder dislocations
• Surgical procedures
• Radiation injury etc

These are the usual presentations;

• Shoulder pain
• Muscle weakness in the arm, forearm hand, fingers etc
• Muscle thinning (atrophy)
• Decreased or absent deep tendon reflexes
• Fasciculation (twitching)
• Loss of sensation
• Tingling (pins & needles)
• Numbness etc.

In the acute stage the muscle atrophy is not seen as it takes some time for muscles to loose their bulk.

An EMG/NCS (electromyography & nerve conduction study) is highly useful to confirm the diagnosis. An MRI of the brachial plexus may help sometimes. A bunch of blood tests may be necessary depeding upon what we are suspecting.

It would depend upon what caused this condition. In idiopathic (parsonage Turner syndrome), thought to be a type of immune mediated condition a course of oral steroid like prednisolone can be tried.

The symptomatic therapy includes pain killers, nerve pain pills like gabapentin, pregabalin; physical therapy, occupational therapy etc.

A neurologist is commonly involved in the treatment of brachial plexopathy patients.