What is thalamotomy?
Thalamotomy is a minimally-invasive neurosurgical technique which involves
permanently inactivating a small but specific part of the brain. This
area is deep within the brain, in an important structure called the
thalamus. The thalamus is an important part of the brain involved in
tremor production.
The goal of thalamotomy is to improve or relieve tremor.
Which conditions is it used to treat?
Thalamotomy may be used to treat certain individuals with the following
conditions:
What are the reasons for surgery?
When medications and other treatments are no longer working well or their
side effects are to severe, thalamotomy may be of value.
What are the alternatives to surgery?
A number of medications may be useful for tremor, and these will be prescribed
by your neurologist. The other surgical procedure that can be performed
to treat tremor is deep brain 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
Before your admission to hospital
Before you are selected for thalamotomy, you will undergo an extensive
series of assessments and investigations. Most of these are performed
as an outpatient (no hospital admission required). You will be reviewed
by a neurologist with specific training and expertise in this area,
and also by your neurosurgeon.
As an outpatient, before surgery you will also have:
- An MRI scan. This helps us to map your brain for the surgery so
we can clearly see the areas to target during the operation.
- A Neuropsychology assessment. This will include an assessment of
your suitability for this operation.
- A Clinical Psychology assessment. This will include an assessment
of any potential depression or anxiety (both of which also may require
treatment), as well as your suitability for this operation.
Special precautions
It is important that you stop certain drugs before surgery, especially
ones that thin your blood. If you are taking aspirin, warfarin, other
blood-thinning agents, or herbal products, it is very important that
you contact us two weeks before your admission so that we can discuss
stopping them with you. If you are taking warfarin we may need to admit
you earlier but each case varies, so it is important that you phone
and we can discuss the plan for you.
What are the specific risks of this type of surgery?
As with all types of surgery, there is a small chance of complications.
- 1-5% chance of stroke or haemorrhage (higher in MS tremor)
- small risk of infection (1%)
- risk of death is extremely small (1 in 1000)
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 does the operation involve?
Thalamotomy is done under local anaesthesia and sedation (ie. you will
be awake). Your admission will be for approximately 2-3 days.
You will be given a sedative first and then areas of your scalp will
be numbed with local anaesthetic. With your scalp numb a metal frame
will be securely attached. You will then have a CT scan which will be
fused with your MRI using an advanced computer program. The frame must
stay on for the surgery, but will be removed as soon as it is over. You
will be awake for the surgery so that we can use changes in your tremor
to guide the final position of the electrode, and to minimise the risk
of side effects.
Your head will be shaved and cleaned with antiseptic. A small area
of your scalp will be injected with local anaesthetic. You should not
feel any pain in your head. Your neurosurgeon makes a small hole in your
skull which allows him to place an electrode (wire) into your brain.
A small electrical current will be passed down this electrode, and its
position will be adjusted to obtain maximal tremor reduction. Microelectrode
recording is also performed, in order to increase the accuracy of the
lesion. Once we are happy with the position of the electrode tip, the
neurosurgeon will inactivate that area by heating the electrode tip to
70-80 degrees for around 60-70 seconds. Once this is done, we will close
the incision and take the frame off. You will have an MRI scan a day
or two later and will be discharged after that. Your neurologist will
adjust your medications over a few months after surgery.
The procedure will take approximately 1-2 hours but does vary from
patient to patient.
What are the success rates?
Thalamotomy helps over 70% of the patients treated. This effect is frequently
dramatic.
In some patients the beneficial effect may wear off over a year or two,
but these patients almost always benefit from a repeat procedure, in
which a larger area is inactivated.
What happens when you go home?
You will need to take it easy for 6 weeks. You should do an
hour of gentle exercise such as walking, every day or two.
Your GP should check your wound 4 days after discharge. You should
not sign or witness any legal documents until you have been seen by your
GP. You will be given instructions about when the staples need to be
removed (either by your GP or by the Precision Neurosurgery Practice
Nurse).
You will be reviewed after several weeks by your neurologist and neurosurgeon.
You should not drive a motor vehicle or operate heavy machinery until
they give you the go ahead.
What should you notify your doctor of after surgery?
- Increasing headache
- Fever
- Swelling or infection of the wounds
- Leakage of fluid from the wound
- Fitting (seizures)
- Abnormal sensations or movements in your face, arms or legs
- Weakness or numbness
- Drowsiness
- 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. |