Thalamotomy

In thalamotomy a surgeon destroys a small portion of thalamus called nucleus ventralis intermedius that controls some of the involuntary body movements. The procedure is done to control tremors.

Tremors are a symptom of various conditions that cause rhythmic, involuntary shaking of one or more body parts. They most commonly affect the hands; however, they can also affect the head, arms, torso, vocal cords, and legs. Tremors can be either continuous or intermittent, and they can occur on their own or as a result of an underlying condition. Although tremors are not life-threatening, they can make it difficult for you to perform even the most mundane daily activities.

The left side of the brain controls the right side of the body and vice versa. Therefore, if tremors are present on the right side of your body, surgery will be performed on the left side of the brain. The procedure can also be performed on both sides of the brain; however, the risk of speech, memory, and reasoning disability increases following such a surgery.

This surgery may be recommended for the treatment of severe tremors on either the right or left side of the body, especially for tremors in legs and arms. The surgery is rarely performed today; instead, deep brain stimulation or pallidotomy may be performed if they are more suitable. Individuals with the following conditions can have tremors:

• Parkinson’s disease
• Essential tremor disorder
• Stroke
• Brain injury
• Multiple sclerosis

The symptoms of tremors include:

• Shaky voice
• Rhythmic shaking of head, torso, arms, hands or legs
• Difficulty holding things like spoon, utensils, and pencil

A surgeon may not perform this procedure in individuals with any of the following conditions:

• Brain tumours
• Severe high blood pressure
• Conditions that cause abnormal bleeding, such as Von Willebrand disease and haemophilia 
• Treatment with warfarin, aspirin, or other antiplatelet and anticoagulant medications within 10 days prior to the procedure
• Unwillingness or the inability of the person to lie on their back for long periods during the procedure
• History of stroke or bleeding inside the brain within six months before surgery
• History of seizures in the year prior to the surgery
• Claustrophobia
• Ineligible to undergo magnetic resonance imaging (MRI) scan due to the presence of metal implants such as pacemaker or ear implants

The surgeon will ask you to visit the hospital for a preoperative assessment wherein the medical team will perform some tests to assess your condition, including:

• Physical examination to assess your symptoms
• Video recordings to study your tremors while performing different activities
• Magnetic resonance imaging to identify the area in the brain to be operated
• Neuropsychological assessment to study your mood, memory, and thought process

The assessment helps the surgeon decide whether you are a suitable candidate for the surgery. If you are able to undergo the surgery, the surgeon will explain the procedure to you along with the risks and benefits and tell you to sign a consent form.

In the days leading to your surgery, the surgeon will give you certain instructions to prepare yourself for the operation, such as: 

• You may be asked to discontinue medications including aspirin, ibuprofen, warfarin or any other blood thinning medications and painkillers two weeks before the surgery:
• Inform the surgeon if you develop any new symptoms or conditions (such as an infection or fever) prior to the surgery.
• Use a medicated soap to shower with, the night before the surgery, to prevent infection after the procedure.
• If you have Parkinson’s disease (a neurodegenerative disorder that affects the part of the brain), you will need to discontinue taking medications for the condition 12 hours prior to the surgery.
• You will be asked to stop taking any medications for tremors on the morning of the surgery.

After you arrive at the hospital on the day of the surgery, the hospital staff will tell you to wear a hospital gown. You will be given special stockings to wear before the surgery to help prevent the formation of blood clots in your legs. An anaesthetist (a medical professional who administers anaesthesia) will visit you before the surgery to discuss the anaesthesia to be used in operation. A doctor will start an intravenous (IV) line in your arm to provide you with fluids during the procedure. The surgery will be done as follows:

• The hospital staff will take you to the X-ray department.
• You will be given local anaesthesia, a medicine that will be injected at four sites on your scalp to numb the area of surgery.
• The surgeon will then insert four pins at these sites a few millimetres deep into your skull. You will experience a slight burning or pricking sensation during this process.
• A stereotactic frame will be fitted over the pins to hold your skull in a fixed position throughout the procedure. You will experience a squeezing sensation as the frame takes hold of your head. The sensation will subside within a few minutes.
• An MRI scan will then be performed.
• After this, you will then be moved to the operating theatre where you will be placed on the operating table with the frame supporting your skull.
• Someone from the surgical team will shave a small patch of your hair on one side of your skull (the area that will be operated). He/she will clean the area with an antiseptic solution.
• You will be given local anaesthesia again to numb some more area on your scalp.
• Once the area gets numb, the surgeon will make a small cut and drill an approximately three mm wide hole in your skull. The drilling process is loud but not painful.
• Next, the surgeon will inset an electrode through this hole to test the targeted area in your brain and check if it controls tremors without causing side effects like tightness in the face or hands or slurred speech. If the test does not control the tremors, the surgery will be stopped.
• If the tremors are controlled, the surgeon will pass an electric current through the electrode to destroy the target area.
• After this, he/she will remove the electrode, the frame, and finally, the pins from your skull, suture the area and place a bandage on your head.

The procedure takes about two hours, after which you will be transferred to the recovery room where a nurse will constantly monitor your heart rate and the surgical wound. You may require hospitalisation for about two to three days to recover from the surgery. You can expect the following during the hospitalisation period:

• You will have a catheter placed in your vein (IV drip) to administer essential fluids and medicines.
• An MRI will be performed on the day after the surgery to ensure the success of the procedure.
• You will be asked to frequently change your position in bed, preferably every two to three hours, to prevent prolonged pressure on any body part.
• Once your health is stable enough, he/she will check your level of consciousness by asking questions such as your name and current date. 
• They will also test your ability to perform movements by asking you to perform certain activities, including squeezing your fingers, pushing back and forth with your feet, and wiggling your toes.

You will be discharged once the surgeon feels that you can perform simple daily chores or activities and look after yourself.

The surgeon will give you certain instructions to take care of yourself after the surgery. These may include the following:

• Avoid exhausting or demanding physical activities for at least six weeks after surgery.
• It is common to experience swelling in the eyelid on the operated side and temporary weakness on the side of the body opposite to the surgical area. These symptoms subside within a week.
• Avoid touching the operated area or your stitches until they are removed. The drill holes in your skin will reform over time.

You will be advised to rest for four to six weeks before resuming work and avoid driving for about six months after the surgery.

Most individuals recover completely within six weeks. The surgery helps improve the severity of tremors and the well-being of the person. A majority of the people achieve about 80% to 90% improvement in their tremors. However, this surgery does not treat the underlying condition; neither does it provide relief from other symptoms of the condition.

When to see the doctor?

Inform a doctor immediately if you experience any of the following signs and symptoms after surgery:

• Stiffness in the neck
• A general feeling of being unwell
• Blurred vision
• Douuble vision
• Severe headache
• Swelling, redness, or pain in the thigh or calf
• Memory problems
• Confusion
• Difficulty walking 
• Sensitivity to light
• Fever
• Persistent vomiting

The potential risks or complications associated with the procedure include:

• Epilepsy (low chance)
• Stroke, the most severe complication
• Infection
• Lack of the desired improvement in tremors
• Weakness
• Slurred speech

You will be asked to visit the hospital a week after the surgery to get your stitches removed. A follow-up appointment will be scheduled for six to eight weeks after the surgery to check your progress.

Disclaimer: The above information is provided purely from an educational point of view and is in no way a substitute for medical advice by a qualified doctor.