Paralysis

When a conscious person is unable to voluntarily move, one or more, otherwise normal joints of the body, it is considered to be paralyzed. The inability to move may be limited to just one small joint of the hand or the whole hand or the elbow or the shoulder or one side of the body or the half of the lower body or the whole body. Thus, there can be a large spectrum of inability to move a body part. These are all considered to be paralyzed.

There can be many reasons for the paralysis.

How a normal joint moves ?

In the normal person, the brain initiates a signal for a conscious person to move a part of the body. This signal propagates through the spinal cord to a specific nerve followed by to a muscle and which in turn actuate a joint to move.

Why paralysis occurs?

The paralysis can be because of an injury to any part of the Brain- Nerve- Muscle-Tendon axis. For example, a sharp injury like a stab in the neck, can damage a set of nerves passing to the hand, resulting in paralysis of one or more muscles of the shoulder, or elbow or the hand.

A person may get head injury, injuring the part of the brain which controls the hand resulting in a paralysis of one side of the body.

A person may have a paralytic stroke, because of deranged blood supply to a very tiny but a very specific part of the brain leading to paralysis of one side of the body.

Paralysis can follow injury to the spinal cord.

Paralysis can occur if a motor cyclist falls off the motor bike and lands on the side of his head resulting in BRACHIAL PLEXUS injury. Only the shoulder and the elbow or the whole upper extremity may get paralyzed in the ensuing brachial plexus injury.

Following an injury to the radial nerve, one may get wrist drop. The person may not be able to extend the wrist, the fingers and the thumb This can also follow fracture of the humerus bone and injury to the radial nerve in the close vicinity.

One may present with a situation where only the terminal joint of the thumb cannot bend or straighten. This may not necessarily be because of any nerve injury but following tendon rupture.

The paralysis can follow, when the nerve is diseased, like a viral infection of a nerve. One of these conditions is Guillen Barre Syndrome. Infection like Poliomyelitis or Polio can also lead to a paralytic condition.

Motor neuron disease, Hirayama disease, Multiple sclerosis are some of the other conditions which present as some form of paralysis.

An abnormal lump or tumour can press a particular nerve and present as a paralytic condition affecting only the part where the nerve is affected.

At time a normal structure can press a nerve, leading to paralysis of a muscle. For example, in a condition called carpal tunnel syndrome, the thickened flexor retinaculum may press on the median nerve. Synovitis of the flexor tendons may compromise the dimensions of the carpal tunnel, causing median nerve dysfunction. This manifests as tingling and numbness in the hand. There may be a lump in the carpal tunnel leading to carpal tunnel syndrome.

So how do we treat them ?

Surgery can help alleviate numerus paralytic conditions and improve the quality of life. The surgery may involve nerve repair, nerve grafting, nerve transfer or tendon transfer, removal of the offending space occupying structure or some type of joint surgery like arthrodesis.

Nerve Repair: If the nerve is damaged, it is repaired under microscope. An appropriately repaired nerve regrows over a period of time under suitable conditions in young patients.

Nerve Grafting: If there is large gap between the two ends of the nerve to be reconnected, the gap is bridged using a nerve graft. The nerve graft is usually obtained from the leg. The most common source of nerve graft is sural nerve.

Nerve transfer: A nerve gives out multiple branches, exactly like a tree trunk gives out multiple branches. One of these branches is rerouted in such a way that it connects the recipient nerve through the transferred nerve to the headquarters, that is the brain. This rerouting of the nerve will restore the function of the targeted muscle.

Tendon transfer: The other method to restore function of a paralyzed joint is called tendon transfer. Almost 80 percent of the liver is spare. One can live normal life with a single kidney. This kind of spare capacity exists in many parts of the body including the heart, brain and muscles. The spare muscle is relocated to function in place of one which is more important but is paralyzed.

Arthrodesis or joint fusion: Multiple joints work in unison. Function of one joint affects the function of other joints. If one joint is adversely positioned, the other joints also get adversely positioned. Hence at times, one of the joints is immobilized in such a way, that the function of other joints is enhanced significantly.

On other occasions, fusing the joint can spare a few muscles for transferring to other joints for augmentation of overall hand function.

Prerequisite:

The patient with a paralytic condition may seek treatment after a significant delay. The nerve surgery may not be feasible after a significant delay. With a delay, the treatment option may get limited and directed at the tendons and the muscle. For tendon surgery, the target joints should be soft, supple and passively mobile. The patient may need a prolonged period of dynamic splinting to mobilize the joints or may need surgery to make the joints passively mobile and prepare for tendon transfer surgery.