Surgeries

This information is designed to help patients talk with their surgeon about this operation.   The results and complications will vary between centres especially because this operation has become quite rare.

The stereotactic mesencephalotomy operation is designed to destroy the pain pathways coming from the head and neck before they reach their target in the brain.  This can be ideal for patients with pain on one side of their head or neck due to cancer.  We have recently published our results in the peer reviewed British Journal of Neurosurgery.

Download a copy of our paper: Mesencephalotomy BrJNSx 2016

Cancer pain is most often due to a tumour destroying the normal tissue around it.  Pain from the body is carried up to the brain through a well known pathway in the spinal cord called the spinothalamic tract.  If the spniothalamic tract is deliberately cut (or burned) by a neurosurgeon, then no pain from that part of the body can be transmitted to the brain. This operation is called a cordotomy and is described elsewhere. It is ideal for unilateral pain below the shoulder (i.e. from the body).

For cancer pain from the head and/or neck (i.e. above the shoulder), we use the stereotactic mesencephalotomy operation. This operation blocks the pain pathway higher up – while it is passing through the midbrain.

This can be a wonderful benefit to patients with severe cancer pain if:

1. their medications can not block the pain, or

2. the high dosage of the medications required to block their pain is causing intolerable side effects (e.g. sedation)

The operation at our centre is performed with local anesthesia and a brief bolus of sedation.  The procedure begins with a stereotactic head frame attached to the head with local anesthesia. An MRI is then done to visualize the target area within the brain. The patient is then transferred to the operating room and the procedure takes about an hour. The top of the head is shaved and cleaned (3 cm) and then frozen with local anesthetic. A small (2 cm) incision is made in the scalp and a small hole (1 cm) drilled in the skull. An electrode is then lowered down to the brain target (patients can not feel this as there are no pain sensors in this part of the brain). When the electrode is at the correct anatomical location, we confirm with physiologic testing. Small pulses of electricity are released from the tip of the electrode and the patient is asked what they feel. If the electrode is in the correct physiologic target, the patient will feel warmth or pain in the desired region (i.e. where their cancer pain is located). A small sedative is given and the pain pathway is then destroyed by heating. After the lesion, the patient will no longer feel pain from the desired region of their body.

The benefits and risks of this procedure must be discussed directly with your neurosurgical team.

The benefit of this operation

is elimination of cancer pain on one side of the head or neck. As a side effect, the patient will not be able to sense temperature (hot or cold) in the same area but this usually has no significance for the patient. Interestingly, the patient is still able to feel touch – they are not numb and do not describe ‘pins and needles’ – they just lose the ability to feel pain within the targeted area. The benefit has been reported to typically last a year and therefore patients are usually selected for this operation if their expected lifespan is less than a year.

The risks of this operation

include but are not limited to incomplete or temporary pain relief, numbness in the head or body, double vision, and a rare but devastating stroke causing weakness, paralysis or death.

After the operation, the palliative care team typically aggressively reduces the pain medications (e.g. morphine).  Occasionally all these medication are stopped but usually some is still given by mouth.

Introduction

Patients should speak directly with their neurosurgeon to fully understand the benefits and risks of this surgery.

This information is designed to help patients discuss their operation with their neurosurgeon.  The specific benefits and risks of the operation must be reviewed directly with their surgeon.

These pumps contain a refillable reservoir of Baclofen (anti-spasticity medication) and are connected to a small tube which delivers the drug to the space around the spinal cord. The pump is about the size of a hockey puck and sits under the skin of the lower abdomen. The drug is delivered directly to where it is needed (around the spinal cord) and therefore has less systemic sedative side-effects. There is an approximately 4 to 1 concentration difference between the spinal cord (where the drug is needed) and the brain (where the drug causes side-effects) when the pump is used.

Candidates for this surgery should have lower limb spasticity that is interfering with their quality of life.  They should either i) not be able to control their spasticity with their oral medications, or ii) not be able to tolerate the side-effects of the medications required to control their spasticity.

All patients considering surgery will have a test dose organized by the Baclofen Pump Clinic.  This will be a small injection of Baclofen into their back through a lumbar puncture needle.  This will place a dose of Baclofen into the fluid around the spinal cord and will be a very good indication of what it would be like to have the effects of a Baclofen Pump.

If patients get a good response from the test dose then they should consider surgery.  If they do not get a good response from the test dose, they should avoid surgery.

The operation is performed under a general anesthetic at Vancouver General Hospital.  Patients typically leave the hospital the next day.

Once the pump is in place under the skin of the abdomen, it holds about 6 months worth of Baclofen.  The pump can be refilled as necessary by the Baclofen Pump Nurse.  A small needle is used to go through the skin and into the pump and then refill the reservoir of medication.  The dosage of medication released by the pump can be controlled with a computer in the Baclofen Pump Clinic.  If you need more Baclofen it can be adjusted up or if you are have some side-effects, it can be adjusted down.

Benefits

Baclofen will reduce the spasticity in your lower limbs.  If your quality of life is reduced because of symptoms due to your spasticity, then the Baclofen pump will help you.  Some symptoms that can be helped include the following:

1. difficulty sitting, transferring, toiletting, or cleaning because of extensor spasms,

2. painful spasms or spasms that interfere with walking

Baclofen will not make you stronger or improve your sensation.  Occasionally patients use their spasticity to help transfer if their legs are weak.  In those patients, Baclofen can actually worsen their transfers because they can no longer use their stiff, spastic legs as a brace to help transfer.

Risks

The two most common complications are infection and technical malfunction.  Any wound infection must be treated with antibiotics (to cure it if possible) but also to prevent the infection getting deeper into the fluid around the spinal cord.  An infection in this fluid is called meningitis and could be lethal if untreated.  Since we began this operation a decade ago, I have not had any meningitis (although it is always a possibility) related to surgery.  We have had technical malfunctions where the tube leading from the pump has become dislodged or blocked.  This can be fixed with a new tube but it means another operation. We have had a patient develope a serious infection after a pump refill more than a decade after the original surgery.

There are other rare complications associated with this operation.  I am aware of patients who have had spinal cord injury from this operation and sustained permanent neurological deficits.

Long term Care

Patients will be followed by the Baclofen Pump Clinic at GF Strong Hospital. The dosage of baclofen will be adjusted and refilled by the physiatry team at that hospital and not by the neurosurgery team. There are 3 rare but potential problems that patients and their families should watch out for.

1. Infection: Any fever that is accompanied by headache should be evaluated by your family doctor. If you have a stiff neck it could be a sign of meningitis and this needs to be treated in hospital.

2. Baclofen Withdrawl: If the delivery of baclofen is stopped or reduced for some reason (e.g. blocked catheter or defective pump), the patient may have a withdrawl syndrome. Patients may develope a variety of symptoms including: a dramatic increase in spasticity, as well as fever and seizures. This is an emergency and requires restarting the baclofen in hospital.

3. Baclofen Overdose: If too much baclofen is released at once (e.g. defective pump), the brain will be sedated by the drug. This can cause sedation and, if severe, the patients will be too comatose to breath. This requires emergency hospitalization.

Download a PDF for your post-operative instructions after a new pump implantation:

Post-op Care after new implant Feb 2016

Download a PDF for your post-operative instructions after a Pump Replacement:

Post-op Care after Pump Replacement Feb 2016

Download a PDF for nursing instructions following Baclofen Pump surgery:

Post-op Baclofen Pump – Nursing Care Plan Feb 2016

Patients should speak directly with their neurosurgeon to fully understand the benefits and risks of this surgery.

Over the years, a variety of different operations have been tried to treat the pain of Post-Herpetic Neuralgia (PHN).  The literature has been clouded by different investigators using different outcome scales so that it has been difficult, if not impossible, to compare one study with another.  I believe a second difficulty has arisen because there are (at least) two different types of pain associated with PHN and one operation may be effective at one type of pain and not the other.  With this in mind, our approach to PHN begins with trying to understand which component of pain is disabling the patient.

Touch-induced electrical pain can be reduced by eliminating the ability of the face to feel the touch.  Percutaneous trigeminal rhizotomy can create numbness in the region of the face that was triggering the electrical pain.  This is analogous to trigeminal rhizotomy for trigeminal neuralgia.  It is important to be aware that the rhizotomy will not be expected to reduce the constant burning pain (and may even increase this aspect of the pain).  The operation, however, is relatively easy to perform and we have gained an experience with over 1000 cases in the treatment of trigeminal neuralgia.  One warning is especially warranted- the pain of PHN is often in and around the eye.  A rhizotomy in this location will leave the covering of the eye (cornea) numb.  A numb eye has an increased risk of corneal abrasion because you can not feel anything scratch your eye.  If your eye becomes red or inflamed, you must seek medical attention even if it does not hurt – you may have scratched your cornea and just not feel it.  Ignoring this may result in blindness if the cornea gets infected.  Most patients check their eye each day (while brushing their teeth) and if it is white there is no problem.  On the rare occasion that it is red, they should get it checked by their family doctor of ophthalmologist.

The burning pain is more difficult to treat.  We believe that this pain is due to inappropriate over activity in the brain following the nerve damage.  This type of pain is called ‘neuropathic’ pain because it is due to injury of the nervous system.  Sensation from the face is relayed to the brain along the trigeminal nerve.  This nerve carries all the information received from the face including touch, movement of the jaw as well as pain and temperature.  Once the trigeminal nerve enters the brainstem, however, the information is relayed to different areas.  The pain and temperature area is different from the touch area and that is the key to our surgical attack on this pain.  We can destroy the area of the brain responsible for receiving and transmitting facial pain (and temperature) and leave the region responsible for touch alone.

The spinal dorsal root entry zone (DREZ) lesion is effective for PHN in the body.  It therefore makes sense that a similar operation would be effective for PHN in the face.  The operation of trigeminal caudalis nucleotractotomy is the analogous operation.  The name of this operation varies because both the fibres leading to the trigeminal nucleus and the nucleus itself are very close together and a lesion in this area destroys both the fibres (tractotomy) and the nucleus (nucleotomy).  The trigeminal nucleus is separated into three parts.  One deals with proprioception (monitoring movements of the jaw), one deals with touch and one deals with pain and temperature.  It is therefore possible to destroy the nucleus dealing with pain and temperature and leave the nucleus dealing with touch sensations uninjured.  This anatomical separation allows us to destroy the pain centre (nucleus trigeminal caudalis) without injuring the touch centre.  Following the operation, therefore, the patient is expected to lose the ability to feel pain in the affected area of the face (and thus no longer feel the burning pain of PHN) but will still be able to feel light touch in the same area.  Although most patients do not notice, they will also lose the ability to feel temperature differences (i.e. hot or cold) in the same area of pain loss.  Interestingly, there is also some touch fibres which descend into the caudal is nucleus therefore the patient will notice some ‘numbness’ in the face but this sensation usually fades and the eye remains protected with a blink reflex.

We consider this operation a major undertaking.  It is performed under general anesthetic and involves placing a few very small lesions (each the size of an apple seed) in the upper spinal cord where the trigeminal nucleus caudalis is located.  There are very few centres in the world performing this operation.  The risks of this operation are related to placing the lesions in the right location.  If they are misplaced the patient could suffer incoordination of their arm or weakness of their arm and leg.  Additional potential risks must be discussed directly with your neurosurgeon.

We would not recommend this operation for everyone with PHN in the face.  Many patients will get adequate pain relief with appropriate medications or will learn to adapt to the pain after several years.  For those with incapacitating pain there is hope.  This operation is an option that needs to be discussed with those who have medically intractable pain.  Patients need to understand the potential benefits (dramatic pain relief) and the potential risks (a small chance of arm/leg weakness or arm incoordination) before making a decision about surgery.

This operation typically does not work for teeth pain because the nucleus for teeth is too high up the brainstem to reach.

Patients should speak directly with their neurosurgeon to fully understand the benefits and risks of this surgery.

The operation Motor Cortex Stimulation or MCS was developed in Japan in the 1980’s to treat post-stroke pain.  It is performed in specialized centres around the world.  The most difficult aspect of this operation is selecting the correct patient.  In the treatment of pain, it is widely accepted that a ‘successful’ procedure (or pill) is one that reduces the pain by more than 50%.  With this standard, MCS has a success rate of approximately 50% for pain in the body and 70% for pain in the face.

This operation is performed under a general anesthetic with electrophysiological monitoring.  The scalp is incised and a small window of skull removed.  An electrode is placed on the dura (the leather-like covering over the brain) directly over the motor cortex.  The skull and scalp are closed and the electrode is connected by a wire to a pacemaker, which is placed under the skin in the chest (or a convenience site).  After the operation, the stimulation from the pacemaker is directed through the wire to the electrode over the motor cortex.  Stimulating the motor cortex is thought to ‘down regulate’ the abnormal brain activity causing the pain syndrome.  How this occurs is still debated.  Activity in the motor cortex (the part of the brain initiating movement) is known to down regulate the sensation from the part of the body moving.  For example, someone throwing a spear cannot feel fine touch in the hand throwing the object as well as if their hand was still.  This may have provided an evolutionary advantage on the African savanna millions of years ago.  We know that the sensory system is abnormally up regulated when someone has neuropathic pain.  The drugs that treat neuropathic pain all tend to dampen the function of the nervous system – but unfortunately their sedative side-effects are predictable.  MCS may use this ancient neural pathway from the motor system to quiet the activity in the sensory system.

When this operation is successful, patients report that their pain drops from an average 8 or 9 out of 10 down to a 2 or 3 out of 10.  We have not had a patient report that all of their pain has disappeared although there are reports of this in the literature.  The potential complications of this operation include infection (1%) or a brief seizure triggered by too much stimulation of the motor cortex.  A full description of all potential complications requires direct discussion with your neurosurgeon.  After the operation, patients must come to the clinic for adjustment of their stimulation on a monthly basis for several months.  Eventually the pacemaker will run out of power and need elective replacement.  This is done as an outpatient procedure under local anesthetic and usually takes twenty minutes of operating time.

Download a pamphlet on Pallidotomy and Thalamotomy 

Introduction

Patients should speak directly with their neurosurgeon to fully understand the benefits and risks of this surgery.

Before the advent of l-dopa, there was little treatment for Parkinson’s Disease. Clinicians had recognized that PD patients who developed a stroke in the basal ganglia stroke occasionally had improvements in their Parkinsonian symptoms. Neurosurgeons therefore attempted to induce basal ganglia strokes in PD patients. The results were unpredictable and complications were frequent and severe. Initially the pallidum became the favoured target and the operation, designed to make a small hole in it, was called the pallidotomy. Wycis and Spiegel reported that tremor was reduced in 78 percent of PD patients following pallidoansotomy. Reports of reduced tremor and improved rigidity after pallidotomy followed from the United States, Japan and Sweden. Fewer pallidotomies were performed after the introduction of l-dopa in the 1960s and the realization that thalamotomy was better at tremor reduction than pallidotomy. A Swedish report highlighting their results for PD patients following pallidotomy in the posteroventral pallidum (a slightly different target than the previous standard) was published in 1992. This led to a resurgence of interest in pallidotomy. This new found interest was bolstered by animal models which suggested Parkinson-like symptoms in primates were due to overactivity of the pallidum (inhibiting the motor thalamus) and that lesioning the overactive pallidum improved these symptoms. A number of well design prospective studies on the effects of pallidotomy were published in the 1990s. Pallidotomy was a very common operation in the 1990s (we performed over 250 at Vancouver General Hospital) but has been much less common following the introduction of deep brain stimulation.

Benefits

Pallidotomy is currently performed at VGH for patients with dyskinesia interfering with their quality of life. A left sided pallidotomy would be expected to reduce dyskinesia on the entire right side of their body by approximately 90%. Following pallidotomy, patients remain on their PD medications to help their bradykinesia. In fact, their medications can be increased (to help their bradykinesia) without causing dyskinesia. There is also some improvement in bradykinesia, PD related pain, sleep and some weight gain after pallidotomy. We have only performed unilateral (one side only) pallidotomy because the risk of complication increases dramatically with bilateral (both sides) procedures.

Risks

The risks of pallidotomy include a rare chance of stroke (approximately 1%) and a rare chance of one sided weakness or visual field defect (reduced vision towards one side). Although these complications may be mild for the general public, they can be devastating for an already compromised patient with Parkinson’s disease. If patients have bilateral symptoms, they should consider deep brain stimulation (which can be done bilaterally).

This video shows the view down our microscope of a trigeminal nerve being hit by a curving red artery (from the left). Eventually, I pushed the artery away from the nerve (to the left) and put some Teflon on it to keep it in place. The patient was cured of trigeminal neuralgia and had no complications.

This video is a .mp4 file and should run on most PCs and MACs. It is very large, 5.2 MB, and may take a while to download.

Download a pamphlet on Microvascular Decompression

Introduction

Patients should speak directly with their neurosurgeon to fully understand the benefits and risks of this surgery.

The MVD operation is designed to cure the problem. It is very similar to that described on the MVD for Hemifacial Spasm page only in this case, it is the Vth cranial nerve (the trigeminal nerve) that is decompressed. This operation is done under a general anesthetic and takes approximately three hours. Patients typically go home after several days in hospital. The scalp behind the ear (on the side of the pain) is shaved and an incision made through the skin and muscles. A small hole is drilled through the skull. The surgeon operates around the outside of the brain until the trigeminal nerve is seen through the microscope (see video above). The offending artery or vein is identified and moved away from the nerve. A small patch of padding is placed between the nerve and artery to prevent future compression. The hole in the skull is replaced with acrylic and the muscles and scalp sutured closed.

Benefits

The cause of the trigeminal neuralgia is fixed and the patient is left with normal sensation and movement in their face. The surgery decompresses the nerve from the pounding by the blood vessel. This typically stops the pain (90%) but occasionally the nerve is too damaged from the long-term compression that it does not heal (10%) and patients continues to have pain. Over time, there can be a recurrence of pain. At one year after surgery, 90% of patients are pain free and by ten years post-op approximately 80% remain pain free.

Risks

Patients are urged to speak directly with their surgeons about complication rates, which can vary among institutions. This is a complex operation and has potentially serious risks. With the general anesthetic and operating close to the brain stem there is the rare chance of death or disabling stroke. We have not had a death but is has been reported in the literature. Injury to the surrounding nerves could cause permanent deafness, facial droop, double vision, facial numbness, or difficulty swallowing. There is a risk of infection or delayed CSF leak (salt water-like fluid escaping from around the brain and draining through the middle ear into the back of the throat). Patients can expect temporarily discomfort at the incision but this is rarely permanent. Patients can develop a chemical meningitis which causes a new severe headache several days after the surgery. There is a small chance that the pain will not be fixed or will recur.

Post-operative Instructions

Patients typically leave hospital after two nights.  There will be a small wound behind their ear covered with a bandage and a tensor bandages wrapped around the head.  Keep the wound dry (no swimming or shower but bath is OK if bandage stays dry) until the family doctor removes the stitches.  Stitches should be removed after 10 days and the tensor bandage can be thrown away at that time as well.  There should be no strenuous activity for 6 weeks.  “Strenuous activity’ means anything where you might grit your teeth in order to lift something.  Lifting a bag that does not change the way you breath is OK.  Walking is fine.  Avoid any activities where you might fall and hit your head (e.g. bicycling, roller-blading, skiing etc.)  We expect that you will have some headache or wound discomfort for a few weeks.  This discomfort responds to Tylenol.

If there are any problems with the wound (your family doctor thinks it might be infected) please call us.  If you develop a severe headache a few days after discharge from the hospital, please call us.

We expect to see you in our office 6 weeks after surgery for a follow-up examination.

If you continue to have hemifacial spasm after surgery do not panic.  The operation was designed to decompress the nerve to not heal it.  Your body will take time to heal the facial nerve (i.e. remyelinate it).  This can take up to a year.  Many patient, however, are spasm free immediately after surgery.

This video shows the view down our microscope of a facial nerve being hit from below (loop of red artery curving to the right hitting the nerve on its left side). Eventually, I pushed the artery down (to the left) and put some Teflon on it so that nothing was touching the facial nerve. The patient was cured of HFS and had no complications.

This video is a .mp4 file and should run on most PCs and MACs. It is very large, 5.2 MB, and may take a while to download.

Download a pamphlet on Microvascular Decompression

Introduction

Patients should speak directly with their neurosurgeon to fully understand the benefits and risks of this surgery.

The MVD operation is designed to cure the problem. It is very similar to that described on the MVD for Trigeminal Neuralgia page only in this case, it is the VIIth cranial nerve (the facial nerve) that is decompressed. This operation is done under a general anesthetic and takes approximately three hours. Patients typically go home after several days in hospital. The scalp behind the ear (on the side of the spasm) is shaved and an incision made through the skin and muscles. A small hole is drilled through the skull. The surgeon operates around the outside of the brain until the facial nerve is seen through the microscope. The offending artery or vein is identified and moved away from the nerve. A small patch of padding is placed between the nerve and artery to prevent future compression. The hole in the skull is replaced with acrylic and the muscles and scalp sutured closed.

We perform this operation is performed with intraoperative monitoring (IOM) of the facial and acoustic (hearing) nerves. The IOM team is led by Dr. Charles Dong and provides the surgeons with crucial information about when the facial nerve is adequately decompressed and if the hearing nerve is being compromised. 

Benefits

The surgery decompresses the nerve from the pounding by the blood vessel. This typically stops the spasm immediately but occasionally it takes a year to heal. Occasionally the nerve is too damaged from the long-term compression that it does not heal and patients continues to have spasms. Over time, there can be a recurrence of spasm. At one year after surgery, 90% of patients are spasm free and by ten years post-op approximately 80% remain pain free.

Risks

Patients are urged to speak directly with their surgeons about complication rates, which can vary among institutions. This is a complex operation and has potentially serious risks. With the general anesthetic and operating close to the brain stem there is the rare chance of death or disabling stroke. We have not had a death but is has been reported in the literature at approximately 1%. Injury to the surrounding nerves could cause permanent deafness, facial droop, double vision, facial numbness, or difficulty swallowing. There is a risk of infection or delayed CSF leak (salt water-like fluid escaping from around the brain and draining through the middle ear into the back of the throat). Patients can expect temporarily discomfort at the incision but this is rarely permanent. Patients can develop a chemical meningitis which causes a new severe headache several days after the surgery. There is a small chance that the spasms will not be fixed or will recur.

Post-operative Instructions

Patients typically leave hospital after two nights.  There will be a small wound behind their ear covered with a bandage and a tensor bandages wrapped around the head.  Keep the wound dry (no swimming or shower but bath is OK if bandage stays dry) until the family doctor removes the stitches.  Stitches should be removed after 10 days and the tensor bandage can be thrown away at that time as well.  There should be no strenuous activity for 6 weeks.  “Strenuous activity’ means anything where you might grit your teeth in order to lift something.  Lifting a bag that does not change the way you breath is OK.  Walking is fine.  Avoid any activities where you might fall and hit your head (e.g. bicycling, roller-blading, skiing etc.)  We expect that you will have some headache or wound discomfort for a few weeks.  This discomfort responds to Tylenol.

If there are any problems with the wound (your family doctor thinks it might be infected) please call us.  If you develop a severe headache a few days after discharge from the hospital, please call us.

We expect to see you in our office 6 weeks after surgery for a follow-up examination.

If you continue to have hemifacial spasm after surgery do not panic.  The operation was designed to decompress the nerve to not heal it.  Your body will take time to heal the facial nerve (i.e. remyelinate it).  This can take up to a year.  Many patient, however, are spasm free immediately after surgery.

Download a pamphlet on Percutaneous Trigeminal Rhizotomy 

Introduction

Patients should speak directly with their neurosurgeon to fully understand the benefits and risks of this surgery.

There are two different surgical operations available at Vancouver Functional Neurosurgery for TN. The first is a small operation called Percutaneous Trigeminal Rhizotomy (or Rhizotomy for short). The second is a larger operation called Microvascular Decompression of the Trigeminal Nerve (or MVD for short). There is a third operation for trigeminal neuralgia called “gamma knife rhizotomy” which is not available in British Columbia but can be done in Winnipeg or Edmonton. Patients who would like this surgery can be referred by us to those centres.

The rhizotomy operation is designed to trade the patient’s pain for numbness. We have performed over 1,000 rhizotomies over the last 20 years.

If a patient develops numbness in the same division(s) of the trigeminal nerve where they had their neurlgia (TN), then their pain will be blocked. Some patients already know this because TN can be temporarily blocked by a local anesthetic (e.g. by a dentist’s injection or topical Oragel).  The pain will be blocked as long as there is sufficient numbness in the face. Over time, the patient will heal from the rhizotomy and the numbness will fade. Eventually the neuralgia may break through again and the rhizotomy may need to be repeated. How long the rhizotomy lasts is directly related to how strong the post-operative numbness is (and how fast they can heal).

The operation is performed as day surgery (i.e. the patient goes home the same day a few hours later). The procedure is performed in the sterile conditions of the operating room. A brief pulse of anesthetic is given through an intravenous line and the patient is unconscious for a minute. A needle is then introduced through the cheek and up into the trigeminal nerve. An electrode is then placed through the needle so that its tip is touching the trigeminal nerve. When the patient wakes up, we confirm that the tip of the electrode is touching the correct division of the nerve. Small pulses of electricity are sent down the electrode until the patient feels “tingling” in one division of the nerve. The electrode can be moved slightly until the “tingling” is felt in the same division of the nerve that is causing the pain. Once the correct location is confirmed, another pulse of anesthetic is given while the electrode is used to burn the offending branch(es) of the nerve. When the patient wakes up, we check that the nerve has been sufficiently lesioned. They will have numbness in the division of the nerve that was lesioned. Typically a patient will still feel a pin touching their face but it will be described as feel dull rather than sharp.

This type of rhizotomy is called a radiofrequency rhizotomy because the nerve is heated with a radio frequency to damage it – i.e. make it numb. Rhizotomies can also be performed by crushing the nerve (balloon rhizotomy) or chemically damaging the nerve (glycerol rhizotomy) or by shooting radiation throughout the head and focusing it on the nerve to damage it (gamma knife rhizotomy). The strengths and weakness of each of these approaches is best described by your personal neurosurgeon.

Two important concepts to keep in mind when talking to your neurosurgeon are:

1. “Can you do either operation?” If they can only do one of the operations, it is almost assured that they will recommend that procedure.
2. “What are your personal success and complication rates?” It is important that surgeons quote their our statistics not those in the text books or published by those of us with very large experience.

Benefits

This operation is quick and effective. It does not have the anesthetic risks associated with the MVD operation and is therefore preferred by older patients or those with poor health. The patient goes home the same day and their TN pain is gone. Most people get used to the numbness and do not notice it after a few weeks. Similar to getting used to ‘a white noise’, their face is still numb but they do not notice it.

Risks

Patients are urged to speak directly with their surgeons about complication rates, which can vary among institutions. This operation does not fix the cause of TN – only the symptoms are blocked. Patients will have numbness in an area of the face. This numbness is rarely annoying but in 1% of patients their symptoms can worsen into a syndrome called anesthesia dolorosa. Infection is rare. There are potential problems when treating V1 (forehead) TN because the rhizotomy will leave the eye numb. The same problem can occur if the numbness in the face spreads upwards to include the eye. With a numb eye or corneal, a patient can not feel an eyelash or dirt in that eye and this could lead to a corneal ulcer. A corneal ulcer can cause blindness in that eye. There is mild post-operative discomfort (where the needle was placed) and patients can report soreness or weakness when chewing. Very rarely can the rhizotomy cause double vision. The area of numbness usually gets smaller with time because the nerve heals. If the nerve heals sufficiently, it will begin to pass the TN pain signals again. The operation may then need to be repeated.

Post-operative Instructions

You will leave the hospital the same day you arrived (i.e. day surgery). It is important someone come to get you because you will have had some sedation during the surgery and should not drive that day.  You will have new numbness in your face – that is the goal of the operation.  Most patients (but not all) report that their trigeminal neuralgia is gone immediately. If you are pain free (i.e. no trigeminal neuralgia) you can beginning to reduce your anti-neuralgia medications.  There is no set rule for this but my practice is to advise patients that if they are pain free for a week, they can reduce their anti-neuralgia medications by one pill a day.  That means if you are taking 6 pills a day for your neuralgia, and are pain free for a week, you can take 5 pills a day for the next week.  Each week reducing by one pill will mean that it will take you 6 weeks to get completely off the medications.  If you are on two different types of pills (e.g. Tegretol and Neurontin), reduced one pill completely before starting on the second one.

You might have some new soreness in your jaw after surgery. This is probably a discomfort from the rhizotomy needle and responds to typical painkillers like Tylenol. It does not respond to your anti-neuralgia medications.

Download a pamphlet on Pallidotomy and Thalamotomy 

Introduction

Patients should speak directly with their neurosurgeon to fully understand the benefits and risks of this surgery.

The thalamotomy procedure is designed to reduce tremor on the opposite side of the body (i.e. a left thalamotomy reduces tremor in the right hand). It is most commonly used for patients with Essential Tremor but also used for patients with Parkinsonian tremor, multiple sclerosis tremor or post-traumatic tremor. If you have ‘tremor dominant’ Parkinson’s Disease, then this operation may be ideal. Tremor dominant Parkinson’s disease is a subtype of PD where patients have minimal problems with bradykinesia or rigidity but major problems with tremor. This tremor is interfering with their quality of life and is not controlled by medications.

The results of placing a lesion in the thalamus, or thalamotomy, were first published by Hassler in 1954. Throughout the 1960’s different thalamic targets were lesioned until the ventral intermediate (VIM) nucleus emerged as the most effective target for tremor reduction.

Benefits

Currently, the expectations following thalamotomy is that your tremor (on the opposite side of the body) will be reduced about 80%. We are aiming for the arm – since that will provide the most improvement in quality of life – but leg tremor will also be reduced. Head, jaw and body tremor will not be eliminated after a unilateral procedure since the other side of the body will not be affected. Thalamotomy does not benefit bradykinesia or rigidity. Patients with PD and symptoms of bradykinesia and rigidity that are progressing might want to consider STN-DBS instead of thalamotomy since that operation may control bradykinesia and tremor (especially if the tremor responded to medications).

Risks

The risks of thalamotomy include but are not limited to contralateral weakness, arm and foot incoordination, difficulty speaking or swallowing and cognitive decline.  There is a rare (1%) chance of stroke causing death.