What is Occipital Nerve Stimulation?
You have probably had many treatments for your headaches, most
of which will have been of little or no help. This surgical procedure
works by targeting one or more of the occipital nerves (greater,
lesser, and third occipital nerves) which are transmitting most
of the pain. In certain headache syndromes, other nerves may
be targeted (for example the supraorbital and supratrochlear
nerves). We introduce a small amount of electrical current to
these nerves, which helps to mask the pain that you are feeling.
This procedure is ordinarily non-destructive and reversible.
Who might be suitable for occipital nerve stimulation?
A number of painful conditions can be treated using occipital nerve
stimulation. Patients with the following conditions who have
failed all standard medical therapies may benefit:
- Occipital neuralgia
- Whiplash-related headaches
- Other neck-related or ‘cervicogenic’ headaches
- Nerve injuries (from trauma or previous surgery)
- Occasionally cluster headaches
What are the reasons for surgery?
When medications and other treatments are no longer working well
or their side effects are to severe, surgery may be of value.
What are the alternatives to surgery?
A number of medications may be useful for pain. These include the
standard opioid and non-opioid analgesic agents, anti-inflammatory
medications, membrane-stabilising agents and anticonvulsants,
as well as the most recent agent to be released- Pregabalin.
Special medical treatments such as Ketamine infusions, local
nerve and joint blocks, as well as other surgical options such
as spinal cord stimulation should also be considered. It is critical
that you have been assessed by a pain specialist before contemplating
peripheral nerve stimulation.
What do you need to tell the doctor before surgery?
It is important that you tell your surgeon if you:
- Have blood clotting or bleeding problems
- Have ever had blood clots in your legs (DVT or deep venous
thrombosis) or lungs (pulmonary emboli)
- Are taking aspirin, warfarin, or anything else (even some
herbal supplements) that might thin your blood
- Have high blood pressure
- Have any allergies
- Have any other health problems
What happens before surgery?
We will send you pain charts to fill in. These are important in
planning your surgery and monitoring your response.
The first chart is a body map. You should shade in the areas
of your body and head that are affected with pain.
The second chart is a pain diary. Fill this in over a period
of a week or so. If your pain varies over the day, do a few scores
per day, but if your pain tends to stay the same over the day a
daily score will be enough.
The third chart is called McGill Questionnaire. This chart does
not rely on numbers but helps you to describe your pain to us.
As it states on the form, not every group of words may apply to
you. Pick the words that best describe your pain.
Who will perform surgery? Who else will be involved?
Surgery will be carried out by your Precision Neurosurgery surgeon.
A surgical assistant will be present and an experienced anaesthetist
will be responsible for your anaesthetic or sedation.
What are the aims and potential benefits of surgery?
The goals and potential benefits of surgery include:
- Pain reduction
- Reduced medication requirements
The chance of obtaining a significant benefit from surgery depends
upon a wide variety of factors. Your neurosurgeon will give you
an indication of the likelihood of success in your specific case.
What are the possible outcomes if treatment is not undertaken?
Potential outcomes of not treating your condition include:
- Ongoing pain
- Reduced quality of life
How is occipital nerve stimulation performed?
This is usually done in 2 stages, several weeks apart.
Trial Stimulation
This is usually done with local anaesthetic and is not too bothersome.
You will be taken to the operating theatre and your skin cleaned
with antiseptic. Local anaesthetic will be injected and you
will be lightly sedated. An electrode (wire) will be placed
over the relevant nerve or nerves at the back of your head.
These will be brought out through the skin, and secured in
place. You will then be transferred back to the ward after
a brief period of time in the recovery room.
These electrodes will be attached to a small external stimulator,
and the effects of stimulation on your pain will be tested for
at least several days. Throughout your admission you will frequently
be asked to score and describe your pain. This will allow us
to know if the treatment is working or not. It also gives time
for you to decide whether or not you are happy with the amount
of pain relief you are getting. At the completion of the trial,
the wires will be removed (this is quick and easy, and is not
painful) and you will be discharged home.
Implantation of Permanent
System
If you are happy with the amount of pain relief obtained from
the trial, your neurosurgeon will carry out the full implantation
several weeks later. The reason for this delay is to minimize
the risk of infection.
This is performed under general anaesthetic (ie. you will be
asleep). An incision is made and permanent wires are inserted.
These electrodes connected to a battery which is normally implanted
under the skin in your chest, back, or abdomen. Your battery
will be programmed over the following days and weeks so that
the stimulation you receive will be best for you.
What happens next (after implantation of the permanent
system)?
You should be ready for discharge from hospital 1-2 days after
your operation. Your GP should check your wounds 4 days after discharge.
We will advise you when to have your stitches removed at your GP's
surgery or by the Precision Neurosurgery Practice Nurse.
You will need to take it easy for 6 weeks after your surgery.
You should do an hour of gentle exercise, such as walking, every
day. You should not sign or witness any legal documents until you
have been seen by your GP.
You will be reviewed after 6-8 weeks by your neurosurgeon. You
can drive a motor vehicle after a few weeks if you do not have
too much discomfort.
You will also be given some detailed information about things
you must avoid, such as metal detectors at airports. It is critical
that you read such information thoroughly. There may be some other
restrictions on what you can and cannot do, and these will be discussed
with you before discharge from hospital.
How successful is occipital nerve stimulation for headaches?
Occipitall nerve stimulation helps up to 70% of the patients selected
for treatment. The rate of reduction in pain varies from patient
to patient. On average, pain scores are reduced by around 50%.
For example if a patient had a pain score of 10/10 we would be
able to reduce it to 5/10.
Some patients who suffer from severe headaches, particularly
those with occipital neuralgia and cervicogenic headaches, respond
extremely well to this procedure.
What are the specific risks of this type of surgery?
As with all types of surgery, there is a small chance of complications.
- There is a small risk of infection (3%)
- There could be movement of the electrode, and it may need
to be replaced in a separate procedure
- Failure of the stimulator
- Small risk of bleeding
- The chance of making your pain worse, rather than better is
less than 1%
- The risk of death is extremely small (less than 1 in 30,000)
What are the risks of anaesthesia and the general risks
of surgery?
- Significant scarring (‘keloid’)
- Wound breakdown
- Drug allergies
- DVT (‘economy class syndrome’)
- Pulmonary embolism (blood clot in lungs)
- Chest and urinary tract infections
- Pressure injuries to nerves in arms and legs
- Eye or teeth injuries
- Myocardial infarction (‘heart attack’)
- Stroke
- Loss of life
- Other rare complications
What happens down the track?
We will keep in close contact with you after your discharge from
hospital. You will probably require repeated programming adjustments
over the first few months to optimise your pain relief. Your
pain medications can be reduced as tolerated.
The battery life will vary depending on your stimulation settings
(on average the rechargeable batteries used will last at least
5 or 10 years). We will need to see you at least once a year to
check the battery and ensure you have continued pain relief.
How long will the benefits last?
This will vary from patient to patient. Typically, patients obtain
a benefit for several years or longer. The benefit may gradually
decreases with time and so the stimulator settings may be increased
to compensate for this. A small proportion of patients may benefit
from repeat surgery if the benefits drop off.
What should you notify your doctor of after surgery?
- Fever
- Swelling or infection of the wounds
- Weakness or numbness
- Any other concerns
What are the costs of surgery?
Private patients undergoing surgery will generally have some out-of-pocket
expenses.
A quotation for surgery will be issued, however this is an estimate
only. The final amount charged may vary with the eventual procedure
undertaken, operative findings, technical issues etc. Patients
are advised to consult with their Private Health Insurance provider
and Medicare to determine the extent of out-of-pocket expenses.
Separate accounts will be rendered by the anaesthetist and sometimes
the assistant, and hospital bed excess charges may apply. Medical
expenses may be tax deductible (you should ask your accountant).
You should fully understand the costs involved with surgery before
going ahead, and should discuss any queries with your surgeon.
What is the consent process?
You will be asked to sign a consent form before surgery. This form
confirms that you understand all of the treatment options, as
well as the risks and potential benefits of surgery. If you are
unsure, you should ask for further information and only sign
the form when you are completely satisfied. |
