One Man's TN.

13 May 2003.                                     

Introduction.

            My Name is Magic (John) Kent, I am a sixty two years old male with Trigeminal Neuralgia (TN) on the left hand side of the head. I have had TN for seven years.  Drugs such as Tegretol, Neurontin, Phenytoin, Trileptal etc., can no longer control the pain, even in overdose quantities. A recent cryogenic block on the Maxillary branch of the trigeminal nerve failed to have any effect on the pain. Local anesthetic injections into the face also failed to affect the pain. I am still waiting to see if Gamma Knife treatment received in February will have any effect.  Eating, drinking, washing, cleaning teeth, moving and talking is almost impossible without going into pain spasms. 

           My TN started off as a barely perceptible tingle in the cheek and over a period of six months developed into a vicious, ‘electric’, stabbing pain. Imagine having an ice pick stabbed upwards through the gum, through the eyeball and into the brain and you will get the basic idea of what it feels like. The perceived amplitude of the pain spikes increased with time and then leveled out at around the six month.  The spikes became more frequent with time.

          When the brain gets a ’pain’ signal it does two things. First it signals the receptor site to start generating opiates to suppress the pain. Second, it signals muscles adjacent to the pain site to ’flinch’.  The resultant facial tic can clearly be seen on many TN patients when they have pain spikes. The problem is that the muscle flinching causes a small vibration in the face. This vibration is picked up by the damaged trigeminal nerve that in turn sends a pain signal to the brain. This forms a positive feedback loop from nerve receptor, Brain, Muscle motor, Vibration, Nerve receptor etc., etc., and the system begins to oscillate at a few cycles per second (the natural loop response frequency). Applying a higher level of vibration to the damaged nerve increases the frequency of the pain spikes. At about 10-20 Hz. The oscillation flips into a high frequency mode and becomes self-sustaining. It gives the sensation that a drunken gorilla is ripping the top of your head off with a blunt chainsaw!.

            Eventually the opiates generated by the body at the pain site de-sensitise the receptor nerve and open the loop. In the early stages of the condition, self-sustaining spasms lasted exactly 12 seconds each and I had several hundred such pain spasms each day. It was impossible to do anything while in a spasm. With time, spasm length increased to five hours per spasm and the loop could only be broken by remaining perfectly still during this time. Any vibration re-triggers the spasm and that includes moving the eyeballs and breathing !.

 

Project Approach.

          I have ‘trigger spots’ on the upper left gum. These trigger spots ‘migrate’ within that quadrant, although twice they have moved to the lower mandibular branch. I noted that a 3% Lidocaine injection into the area of the trigger spot(s) stops all TN pain activity for the effective duration of the local anesthetic.  I feel sure that this will be the case for all typical TN cases.  Again, no one has told me, but I have assumed that the trigger spots are actually the termination points on the gum, of the traumatised nerve fibres within the Maxillary branch nerve bundle.  Of interest, was the observation that although TN generally renders the whole length of the nerve from trigger point to brain, ultra-sensitive to minute levels of vibration. A Local anesthetic into the area of the trigger spot stopped all TN pain communication along the complete path to the brain. 

         For want of a better idea, I wondered if electronic stimulation of the damaged nerve ending could be as effective as the Lidocaine injections.  So I have decided to have a look at the electronic suppression of face pain in the hope that I may find something that may be of benefit to those with face pain such as TN, ATN, GN, TMJ, and PHN etc.

 

December 2002

The story of TN would not be complete without mention of the drug Tegretol. Tegretol is an anti convulsion drug used to open the pain loop at the point between the brain and the motor  muscles in the face.  This prevents the facial 'twitch' caused when the face muscles receive a pain 'flinch' signal from the brain.  Normally the induced facial twitch generates a small vibration which is picked up by the damaged trigeminal nerve and the end result is another pain signal is sent to the brain. This is repeated several times a second.

My own condition was considerably advanced when it was finally diagnosed and I started off taking 600 mg of Tegretol per day.  This had to be increased shortly after to 800 mg per day. At 600 mg I was subjected to the first side effects of Tegretol ..... The dreaded "Tegretol Fog" and extreme tiredness.  As the underlying condition gets worse, larger amounts of Tegretol have to be taken to keep the TN pain under control.

At 1000 mg tiredness was becoming a real problem and I used to fall asleep for about four hours, starting at noon every day. 

At 1200mg I became sick and dizzy.

At 1400 mg  I started to lose my short term memory and noticed an inability to focus the eyes. I also lost my sense of balance and started falling, causing other injuries. I had to carry notes to remind me of what I was supposed to be doing.

At 1600 I could only read with a powerful magnifying glass and had double vision. By this time I had to resort to crawling around the house in order to reduce the distance I fell.

At 1800 mg, the maximum recommended I lost control of my lower limbs and the Tegretol stopped controlling the TN pain.

At 2000 mg I became unconscious and collapsed. I was admitted into hospital with toxic poisoning and stopped taking all medication as it no longer had any effect on the pain.  If the required blood tests had been carried out to monitor Tegretol level, this would not have happened.

Six months after stopping taking Tegretol,  most of my eyesight has returned as has my sense of balance. Some of my short term memory has also returned, but remains a big problem.  I can now only handle logic with a maximum of two variables.  I also have a problem of registering the obvious. For example, I may have a note in my hand but it does not occur to me to read it.

Another side effect is the "Tegretol Rash".  Mine was on the face, neck and chest.  This cleared up when I stopped taking the drug.

I think the lesson is that Tegretol is a blessing in the early days of TN because it will stop TN pain, but surgery must be considered long before Tegretol causes permanent damage to the body.

 

 22nd June 2003

Two months ago the Gamma knife treatment I had in February has taken effect and I am now almost 100% pain free.  At those times I feel pain it has been because of my own over confidence and carelessness. After seven months on a starvation diet, I now tend to stuff things into my face without thinking !.  Pork cracking and rock hard rice crackers are my downfall ..... peanut brittle is a push-over Hi!.

OK that is my problem over for awhile. How long I will be pain free I have no idea so I will relish each day without my beast.  I suppose it would be a natural feeling to want to walk away from the misery that we have shared .... and simply try to forget it ever happened.  However there are a lot of people in this world still sharing that same  pain and for that reason I can't walk away from the problem, so the project will continue to a conclusion.