Ganglion block

A ganglion block, sometimes known as a stellate ganglion block, is an injection of local anaesthetic into the front of the neck. A ganglion block can be either therapeutic, to deal with a problem, or diagnostic, to check on the existence and cause of one.

The sympathetic nervous system deals with the “fight or flight” reflex. If this becomes unbalanced it can lead to heart arrhythmia, to excessive sweating and problems with blood flow.

A solution to these problems can be to block the actions of the nerves causing them. It is also possible to have neuralgic pain, that caused by the nerves themselves being overactive in registering it. Again, a solution can be to block the excessive transmission by these nerves.

A ganglion is where a series of nerves meet, a junction. A substantial ganglion – the stellate or cervicothoracic is the other name – can be found just around the voice box or larynx. For certain problems inactivating this nerve junction with local anaesthetic can be helpful. The injection can be done from right or left dependent upon the precise location of the problem to be treated.

There are three potential outcomes from the procedure. One is that nothing much happens and that it wasn't done quite correctly. The second is that the problem being treated remains. This would indicate that the cause is something other than the assumed action of the nervous system itself.

The third is that the problem is diminished or fully treated for the effective time span of the anaesthetic. This indicates that the problem is in the sympathetic nervous system, in this portion of it, and is susceptible to the treatment. The ganglion block itself can therefore be repeated as needed.

A ganglion block is a treatment for pain in the head, arms, chest or neck that might be caused by a number of things. These include angina that is not reduced by other treatments, the pain of shingles (herpes zoster), injuries to nerves themselves (causalgia) and neuralgia – this is generalised pain being registered by the nerves with no direct other apparent cause. If any of these are present then a ganglion block might be indicated as the appropriate treatment.

There are also problems caused by circulation problems like Raynaud's Disease and limited scleroderma (CREST syndrome) which can be aided by a ganglion block. The influence of the sympathetic nervous system upon circulation – that fight or flight response – means that blocking it can treat such problems. Excessive and localised sweating can have the same cause and thus the same treatment.

If the first ganglion block is successful in – temporarily – treating the problem then a course of treatment will be advised. That is, a series of ganglion blocks, each one a week or two apart. The effect is cumulative, each further block will last for a longer period of time.

The treatment itself is the injection of local anaesthetic into the nerve junction – the ganglion – around the voice box or larynx. This temporarily reduces the activity along the nerves themselves. It does not require an overnight stay in hospital.

Your throat will be swabbed with antiseptic then the correct point or place identified by pressing upon it. The injection is made and the anaesthetic itself inserted through the needle. This will take 5 to 10 minutes. The needle is removed once the dose is completed.

You might be asked to stay still for it to take effect if the pain being treated is in your head. If it is lower in the body – say the arm – then you will be asked to sit up to allow the medicine to sink to that part of the body.

After the procedure itself you will be monitored for up to perhaps an hour. Blood pressure, pulse and temperature will be checked over this time. 

During the procedure it is important that you not cough, swallow or try to talk. Any of these will make the area the injection is aimed at move and significantly increase the difficulty.

A ganglion block is local anaesthetic so after the rest and observation period of up to an hour most normal activities can be resumed. You may not drive for the rest of the day. You must also be with a responsible adult who will either drive you or accompany you on your journey home.

The anaesthetic will affect your swallow reflex, so the instruction will be not to eat or drink for up to four hours after the procedure. It is possible that one eye will become droopy and that your sense of balance will be affected. Numbness in an arm is also a potential outcome – you should wear a sling until feeling returns. All of these will pass with the initial effects of the local anaesthetic, a few hours.

Regular eating and drinking can resume after your ability to safely swallow has returned. Any usual medications can also be restarted at this point. Assuming none of the unusual and rare complications  full recovery from a ganglion block is after these few hours, as the local anaesthetic wears off.

It is possible for there to be transient effects from a ganglion block. The inability to drive that day, a loss of balance, hoarseness, the pain of the injection itself. There will be some tenderness, possibly bruising, as a result of the injection.

There is a risk of seizure, this can occur if the injection is into a blood vessel. Pneumothorax – a collapsed lung – is also a rare possibility. A numb arm, known technically as brachial plexus block, on the side of the body the injection was on is more common.

This will last for the length of the anaesthetic, three or four hours, perhaps. A stuffy nose, droopy and bloodshot eye, and a temperature increase on the side of the injection are all to be expected. 

Damage to nerves not being targeted is possible. So is infection as with any injection. It is possible to be allergic to the medication used. 

The major restriction will be that you cannot drive until the day after the procedure.

It is important to understand that a ganglion block is a temporary treatment. A permanent severing or cauterisation of the nerves would be a sympathectomy and a much more significant decision and treatment.

It is this temporary nature that allows a block to be used as a diagnostic tool – does this cure the problem? If it does not then further investigation to uncover the specific cause then needs to be done.