Where does the name ‘ Trigeminal Neuralgia’ come from?
There are two nerves-one on each side of the face- which carry the sensation of face and gums to the brain, where we can appreciate them. They are the Trigeminal nerves. For example, sensations from the right side of the face are carried by the right trigeminal nerve.
‘Neuralgia’ means nerve pain.’
Combining the two words gives the term Trigeminal Neuralgia, meaning pain in the region of the Trigeminal nerve; in short, pain on one side of face and gums. (usually this disease is unilateral).
What are the other names of Trigeminal Neuralgia?
Trigeminal neuralgia is also called TN, Tic douloureux, facial pain, Fothergill’s disease, Prosopalgia (prosopos=face, algos=pain), prosopodynia (dynos=pain), prosoponeuralgia, trifacial neuralgia etc.
But there are other causes of facial pain and gum pain. So, how does one diagnose TN specifically?
TN is basically a clinical diagnosis. What it means is that we make the diagnosis by carefully listening to the patient’s history and the description of the pain. The typical TN pain has following characteristics:
-It comes suddenly and lasts from a second to many minutes.
-It is in the distribution of the Trigeminal nerve, on one side of the face.
-It can start from upper or lower gum, teeth, nose, chin, cheek, just in front of the ear, forehead, eye, temple and spread to other parts of the face.
The Trigeminal neuralgia pain is very severe and is often described as:
-Sudden electric current
-Sudden, piercing, sharp knife in the face
-Electric shock like
-Pricking of multiple sharp needles
-Sudden blast of hot bomb in the face
-Like somebody putting red chilli powder on the face.
-Like a lightning striking the face
The attack terminates in a few seconds or a few minutes and then the person is usually pain-free till the next attack.
In advanced stages, the pain remains for a longer duration of time. Also, there could be continuous low intensity pain between the Trigeminal Neuralgia attacks.
Which Trigeminal nerve division is most commonly affected?
The V2-V3 division is most commonly affected in about 40% patients( jaw and cheek pain). All three branches are affected in only about 10 % of patients.
What are trigger factors or trigger points for Trigeminal neuralgia?
There are a few commonly seen trigger points, which when stimulated start the attack. These trigger points could be:
- Upper lip, Ala of the nose
- Forehead just above the eye, just below the lower eyelid.
- Just in front of the ear, Upper or lower gum
Touching one or more of these points, blast of cold, even a gentle breeze against the face, brushing teeth (the toothbrush touching the gums), washing face, shaving, jaw movements while talking or chewing etc bring on the attack.
Is the pain really that severe?
This pain surpasses any other pain experienced by humans in severity. Various patients have described this pain as:
- “The worst pain experienced by mankind”
- “The pain you should not wish even your enemies to have”
- “Death be better than this suffering”
- “Deadly curse”
- “Pain of thousand knives piercing the face”
- “A hot chilli bomb exploding on one side of the face”
How do the relatives of the patient see the TN attack?
Often, in the initial phases, the relatives of the patient are bewildered as they see the patient hale & hearty one moment and, as the attack is brought on, the excruciating pain makes the patient miserable.The patient becomes suddenly immobile.
- Face is contorted in severe agony
- He/she tilts the bead towards the shoulder on the same side.
- Covers the painful side of the face with hand or cloth to avoid any blast of air.
- Does not talk, lest the attack should increase
- Sometimes there is loud groan and shriek, which indicates the unbearable nature of this pain.
- The patient slowly relaxes after the attack is over.
What are the personality changes which develop as the disease progresses?
Along with these acute effects, the life-pattern slowly changes. The relatives observe that:
- The patient avoids sitting in cold surroundings like air-conditioning
- Avoids going in windy atmospheres, avoids sitting in fast moving car especially near the window.
- Is reluctant to go to events needing socialization which involves talking and eating (for fear of having an attack).
- Is reluctant to brush teeth, wash face, shave or rub, apply cosmetics on the face.
- Seems to have reduced appetite-even skips meals.
- Constantly feels tired and psychologically worn out.
- Severe depression may follow.
- High doses of nerve and brain numbing medications makes him/her sleepy, lose balance while walking, have memory loss, sexual dysfunction etc
- May have suicidal ideation.
How does Trigeminal neuralgia progress?
In the initial phase, the attacks are short and there is a long gap between them. Progressively the attacks tend to become longer, more severe and more frequent. There may be sudden disappearance of the attacks for a few days or months, but gradually these attack ‘Holidays’ also become rare and then disappear. In patients who are not treated in time, the attacks become almost continuous and the sufferer is reduced to a miserable person, begging for relief.
What is the cause of Trigeminal Neuralgia Pain?
The Trigeminal nerve is like a phone cable. As you know, a phone cable has insulation from the outside. But inside there are smaller cables tightly packed. Each individual small cable has, in turn, its own insulation and that’s why they cannot normally ‘Cross talk’ with each other. Otherwise an impulse from one cable can short circuit to the other cables.
Similarly, inside the trigeminal nerve, there are smaller nerve fibres. Each one has its own insulation preventing a ‘Cross talk’ between them. The insulation is made up by a substance called the ‘myelin’. The character of this myelin changes at and around the region where the nerve enters in to the brain.This is called the Root Entry Zone (REZ).
Towards the end of the last century, it was discovered that one or more blood vessels compressing this zone (i.e. the REZ) can cause Trigeminal neuralgia. It was postulated, and then proven that one or more blood vessels cause severe indentation in the REZ portion of the nerve. Months and years of continuous pulsations against this portion of the nerve damages it. This compression seems to cause damage to the myelin, which normally provides insulation to the individual nerve fibres.
As a result, the nerve impulses cross fire. A simple ‘touch’ to a portion of cheek or lip or gum gets cross fired and is perceived as sudden, severe sharp pain. This is the classical Trigeminal neuralgia ‘attack’.
As is well known, blood vessels in human body ‘elongate’ and harden with age. It is known as the process of ‘ectasia’. In the individuals prone to TN, the vessels originally are in close contact with the nerve. As age advances, they elongate and literally start indenting on, and indeed “burying” themselves into the REZ portion of the nerve, causing damage to the myelin and starting the disease process of TN.
In some patients, during the initial days and months of the disease, the body tries to repair this damage by re-forming the myelin, thus causing spontaneous disappearance of the attacks (‘pain holidays’), only to reappear with continued pulsatile compression or ‘hammering’ of the nerve by these blood vessels.
Generally, as the days, months and years pass, the attacks become more severe and more frequent. Subsequently, the pain becomes almost continuous. Excluding a small proportion of TN patients with multiple sclerosis or tumours or infarcts, the remaining majority of the patients get TN due to the blood vessel compression.
As Dr Peter Jannetta says… “in such patients, a careful and experienced surgeon always finds an offending vessel that is causing damage to the nerve.”
What are other reasons behind TN?
As we have seen, majority of the TN patients get the pain due to severe compression by a blood vessel. In a small proportion, tumours or cysts at the root entry zone of the nerve, causing compression and displacement of the REZ can cause TN.
However, I personally would seriously doubt that a static compression by tumour would cause TN. After resecting the tumour, I would look for an artery lodged deeply into the REZ . This vessel may be pushed by the tumour into the nerve. It is also possible that the blood vessel is on the opposite side of the tumour; and the tumour has pushed the nerve into the blood vessel.
In one series, all the tumour-related neuralgias were caused by the tumour displacing a blood vessel against the nerve. This is a very major corroborative evidence that a pulsatile blood vessel compression causes TN, in majority of the cases.
Multiple sclerosis (MS), a demyelinating disease affecting the REZ or trigeminal nucleus can also cause TN in small proportion of cases. Other less-common causes could be post-meningitis, brain infarcts etc.
Which investigations are carried out in TN patients?
The diagnosis of TN is made on the basis of a good medical history. Usually, the description of pain and the patient’s severe agony while talking, typical facial contouring and defensive facial posturing to avoid an attack immediately give away the diagnosis.
However, I always feel that along with the diagnosis of the disease, one has to acquire a fair idea about the severity of the disease.
It is very easy to assume that the patient’s pain is well controlled, if, at the moment of consultation, due to the effect of an anticonvulsant medication the patient appears free of pain. Many patients take the medication sometime before they come to see the doctor as they rightly expect that they will have to talk a lot during the consultation. I have found time and again, that a normal looking patient gives history of having had severe, unbearable pain attacks that very morning.
On probing carefully, the spouse, daughter or brother of the patient describes the pain attacks are brought on by eating. I have found that the patients learn to tolerate certain amount of pain as they fear that increasing the dose of sedative anti-convulsants will make them non-functional (based on their previous experience).That is the reason why a detailed history is a must.
A good quality MRI with Trigeminal nerve sequences is the next step, primarily to rule out tumours. An MRI-demonstrable vessel compressing the nerve is helpful, but is not a pre-requisite for surgical decision.
This is because, severe vascular compression does exist, demonstrable at surgery even when MRI does not show it.
THIS POINT IS IMPORTANT and CANNOT BE OVER EMPHASISED ENOUGH.
What is the treatment for Trigeminal Neuralgia?
In the initial phase of the disease, some medicines like Carbamazepine (Tegretol) and Gabapentin are useful. However, they are nerve-numbing medicines and act only for a short time. They do not treat the root-cause of the disease.
Furthermore, as the disease advances, the medicine doses also go high up and start numbing the whole nervous system. Some patients start feeling drowsy, may lose balance while walking, cannot work while on high doses of the medicines.
Though drugs are an option in the initial phases of the disease, we feel that surgical option can be considered before the patient becomes a nervous wreck.
At our Trigeminal neuralgia centre, we have been relieving these patients of pain, with a surgery known as Microvascular Decompression (MVD). This surgery is performed with a neurosurgical microscope, and if done in time and by an experienced team it gives excellent results in more than 95% of the patients.
MVD surgery has a great potential to give a long-term relief from pain and may permanently cure the patients. More importantly, the patient can stop their brain-numbing anti-epileptic medicines. Our team has performed more than 1000 surgeries over the period of last 20 years which has allowed us to start the ‘Centre of excellence’ in treating Trigeminal neuralgia by MVD surgery.
With national and international references to this centre, we have been fortunate in making these patients pain-free and medicine-free. Our aim is to fight this disease which is called as “Suicide Disease”.
So many of our patients relieved by surgery ask the question- “Doctor why were we not informed about this surgery before? We would not have wasted so many years of life in agony, pain and the brain-numbing state due to medicines”.
What are our conclusions after 20 years of dedicated work in MVD?
- We have found an offending blood vessel or vessels compressing the REZ of the trigeminal nerve in almost every TN patient when other less common causes of tumours, multiple sclerosis etc are ruled out.
- If done in time and by a team experienced in MVD surgery, pain relief is found in nearly 98% patients.
- MVD has the highest chance of providing long term pain relief and indeed has a potential of offering cure from this severe pain. The results of MVD have remarkably improved in the recent years with the advent of high-tech, modern neuro-microscopes and better neuro-anaesthesia techniques. The risks in this surgery have accordingly gone down.
- This surgery gives best results if done fairly early in the course of the disease and is done by the right surgical team. The later the surgery is done, the greater is the chance of demyelination and lesser the chance of permanent cure. (Lesser the duration for which the compressing vessels are allowed to pulsate against the nerve, better are the results).
- The results are also better with a higher potential for cure, if MVD is performed before any nerve/ ganglion destructive procedures (e.g. Radiofrequency or glycerol rhizotomy).
- The MVD surgery is technically easier in elderly patients, as the cerebellum is shrunken (atrophied) and the approach to the trigeminal nerve is easier, without needing much retraction. This is especially true in the modern era as anaesthesia for the elderly has become remarkably safe and potential risks minimal.
Why is MVD better than medicines or nerve- destructive procedures?
In the initial phase of the disease, the pain can be controlled by drugs like Carbamazepine, Gabapentin, Phenytoin (all anti-epileptics) and with Tricyclic antidepressants and baclofen (all to be taken only on a Doctor’s prescription).
Normally the dosages of these drugs go on increasing, numbing the nervous system, causing excessive sleepiness, memory problems, problems of unsteady gait, failure to concentrate, sexual dysfunction etc.
Even with these, the deadly sword of the next attack is still hanging over their heads. Social life is severely disturbed, to say the least. Interpersonal communication suffers.
This is the stage (or perhaps earlier), when MVD has to be seriously considered and carried out as early as possible, and at a centre of excellence for this Trigeminal Neuralgia.
It must be made clear that each and every modality used to treat TN can have small but definite risks:
High dosage of drugs can cause ‘Zombie’ like condition. Severe concentration problems, memory problems and drunken man’s walk; these problems can, in a way, make the person non-functional. And all this, without treating the root cause of the pain.
Destructive procedures like alcohol/ glycerol injections, RFLG and Gamma knife burn the nerves; corneal anaesthesia is a serious possibility. There have been episodes of sudden hypertensive crises during administration of current to the nerve, and brain bleeds have been reported. There is also a risk of infection & meningitis.
When the agony and misery of the disease becomes unbearable and simpler alternatives fail, the sufferer gladly accepts and welcomes the potential risks of a major brain surgery, and it is at this stage that MVD is rewarding and has a very handsome potential of giving a new pain-free life to the patients.
An MVD surgery in the hands of a neurosurgeon committed to this surgery, and who has been repeatedly and successfully doing it has the best potential for offering cure. Complications like meningitis, stroke etc. are extremely rare but certainly possible. Chance of death is very minuscule.
Why I prefer MVD to other procedures?
After trying a few of the treatment options for Trigeminal Neuralgia, we strongly feel that MVD is the one procedure which has the best chance of curing this disorder (if done in time, and by a surgeon and team performing these procedures routinely and successfully for a significant number of years).
We have seen the happiest patients with complete disappearance of the Trigeminal Neuralgia pain, after MVD surgeries done at our centre. This personal observation and opinion is formed after 10 years of concentrated battle waged by our team against this severe pain.
We have also used other modalities like Radio-Frequency Ablation in the past and still do use it in resistant cases as a rescue procedure. But having said this, we strongly feel that the best long-term results are achievable by an MVD surgery done rightly, and in time.
Why have a “Micro vascular Decompression (MVD) Centre?
After performing over 800 MVDs for Trigeminal Neuralgia, in the last 10 years (and more than 1000 in the last 20 years), with the help of more or less same team, I am personally convinced that the surgical results are significantly better if the same surgeon and the same theatre-team perform these surgeries. We ourselves have seen remarkable betterment in the surgical outcome and quality of pain relief progressively in our own series over the period of the last 10 years.
I also think that the nature of this surgery is very different from other neurosurgeries. Here, we are working around an autonomically active nerve, which is already traumatised due to months/years of continuous pulsatile compression by vascular structures. Also, we are working through a narrow corridor and we have to be continuously aware of the degree of tolerance or rather intolerance of the structures to manoeuvring.
There are issues of preservation of draining veins, extent of mobilisation of the vessels. Assessing the curvature memory of the offending artery etc. There is no single definable pathology in these cases. Every case is unique and has to be assessed on the spot, during surgery. It is for these reasons that we believe that these cases should be operated by the surgical team highly experienced in this surgery.
It was with this conviction, that we started this centre for Micro vascular decompression surgery.