May 7th, 2005 Recap
Trigeminal MeetingThornton Hospital- Dr. Ian Purcell, Speaker
Dr. Purcell started off saying, “the patient should know more about their problem than
the Doctor does!” Too many times we go into the doctors office, and when s/he asks
how we are doing, we really don’t say how badly we are doing unless we have just had
a sever bout with TN pain.
With TN 60% of the problems are on the right side, 39% on the left side and 1% on
BOTH sides. We don’t know why most people have it on the right side, if it is because
most people are right handed, or what? It may be that the vascular artery typically
moves off to the right side as it comes up the pons (connecting part), that is a known
anatomical factor. 80-90% of TN is caused by an artery or vein loop.
There is a lot of variation, it ranges from 4-5 people out of 100,000 diagnosed with
TN. The ratio of men to women is l, man to 1.8 women. There are 15,000 people from
the U.S. every year diagnosed with TN. Most of the people with TN are over the age of
50. Most of the idiopathic (unknown cause) diagnosis are totally negative, no tumors,
masses, or vascular loops.
We have very little data on familial cases. I have never seen one, where it runs in the
family, although I am sure there are some out there. (There was three in our group
that it has run in their family).
Of the three areas of TN, D1, D2, and D3, the most common areas to have TN is the
D2, and D3, areas and it is very rare to have it in all three divisions.
Dr. Purcell reinforced what we have learned over the years, that the myelin sheath that
covers the nerves is very thin. The artery/vein rubbing up against the nerve causes
the myelin to wear out, which causes a short circuit at the root entry zone. Then what
we get is emphatic cross talk between fibers with mediating light touch and this
involves pain, like turning the switch on in the facial trigger zones. This aberrant input
may disinhibit pain pathways at the ganglia level/spinal trigeminal central pain
mechanism. The brain is very excitatory, it wants to go all the time 100 miles an hour.
The cortex on the other hand is there to inhibit the brain. The cortex spends it’s entire
life trying to slow the brain down.
Central pain mechanism includes: refractory periods (hard or impossible to manage)
after ‘trigger episodes which can last for seconds, minutes, or hours. This is just like
having a seizure where the brain is firing 100 miles an hour.
With TN it’s irritate and fire, irritate and fire. With a central nerve you will have a lot
firing, then no matter what you do it won’t fire again for a while.
Demyelization: - irritate the ganglia or nerve group(s) - plaque in brain stem
Clinical features of TN:
- Sharp pain attacks
- Pain is confined to the area served by one or more branches of the trigeminal
nerve
- Pain is almost always limited to one side, and does not cross over the midpoint
of the face
- Pain has trigger points (touch, breeze, etc.)
- Pain runs in cycles and can disappear for weeks, months even years
- D1, D2 involved more frequently than D1
- TN usually does not wake you up at night, especially when you are in your REM
sleep. It can wake you up from a nap in that you are not in a REM mode
Cluster headaches are very painful, just like TN. However the differ in a couple of
ways:
-80-90% men
-10% women
Cluster headaches typically 0ccur in a series of throbbing attacks that last 15minutes
to three hours at a time. Attacks may occur several times a day every few days, then
remission. Attacks also tend to cluster in certain time periods especially in the spring
and fall.
Unlike TN, cluster headaches may occur during sleep. Pain is often worse when lying
down. Light touch does not tend to trigger pain.
Q. Does alcohol precipitate TN pain?
A. No, but after the effect of the alcohol wears off, you may (!) have Pain. Alcohol
may even enhance tegretol, then the chances of pain are again enhanced.
Q. What is the difference between a MRI and a MRA?
A. a magnetic scan with computer images to produce a photograph of the brain’s
interior. Dr. Purcell states it is better than dissecting a real brain. MRI’s are clear
enough to get a good look at tumors, abnormal blood vessels, plaques and the
trigeminal nerve itself. However, you should probably get a ‘thin-cut MRI’ to be able to
see both the trigeminal nerve and the artery/vein.
MRA scans not only show the trigeminal nerve and vessels as small as 1mm, they
can tell the difference between arteries and veins in most cases, especially when the
gadolinium dye is injected into the patient's bloodstream to enhance the image.
Q. Does coffee (caffeine) affect TN? A. If you don’t normally drink coffee more
than once a month, then it may settle down a TN attack. But if you use coffee every
day, and go 6-8 hours with out coffee when you get in the morning, the coffee may
bring on an attack.
Q. What about narcotics?
A. I do not prescribe narcotics for TN since they do not work for this particular
problem. (tegretol, trileptal, Neurontin etc.) which are anti-seizure medications. None
of these drugs are good, but they are needed. You should meet with your doctor
every 3-4 months and have everything checked out. Do your own research on the
drugs you are using, know what the side affects are and how to deal with them.
When you come off the medication be sure to taper down, do not go right off the
drug—taper down over a period of weeks.
Be sure you let your doctor know what you want and need, especially if you are on
certain medications. The average Doctor spends about 15 minutes with you. In that
time you (the patient) must get across to your doctor what it is you need. If you think
you need blood drawn to check on your liver etc. then tell the doctor!
Do good research on the surgeon you are going to use, whether it is for an MVD,
Gamma Knife, Rhizotomy, no matter what the procedure. How many have they done in
the past year, what is their success rate, what are the complications?
Today, there are no long-term statistics on Gamma Knife procedures. One year or ten
years, no one has done a follow-up study on this procedure.
Recent statistics on MVD out of 2300 surgery’s, 85-95% success rate, Dr. Jeffrey
Brown found the average initial success rate to be 92.7% successful.
The study found that about 82% of patients had no pain, 16% had at least 75%
reduction in pain, 2% either had no relief or only minor improvement.
Dr. Purcell hopes that in the near future there will be such study done on the Gamma
Knife, with one year, five year, and ten year follow up on pain reduction, and any
complications.
Dental Differential Diagnosis of Facial Pain
Workshop by David Sirois, DMD, Ph.D.
Recap by Don Jeffries
Dentists play an important role in facial pain, and many TN patients begin by
undergoing dental treatments in an effort to alleviate pain that is thought to be related
to dental disease. Education is key, to reducing misdiagnosis and unnecessary dental
interventions.
Dr. Sirois lists the dentist’s role in managing chronic facial pain. These include : ·
Diagnosis and (misdiagnosis)
· Treatment of the correct disorders
· Minimizing the risk of future or worsened pain
· Provide dental treatment without worsening injury
· Addressing the impact of TN and facial pain on oral health
Most acute facial pain is dental pain and most dental diagnoses are straightforward.
Problems arise when the diagnosis is not clear and dentists try to treat the pain. In the
case of TN, the site of the pain is not the source of the pain. A national database
shows that more than half of TN patients underwent dental procedures to try to relieve
their facial pain before they were correctly diagnosed. Some had numerous
unnecessary procedures, such as root canals, but it should be obvious if the first of
second procedure does not resolve the problem that a new approach is needed.
Dr. Sirois explains three categories of common facial pain and the characteristics of
each category:
· Somatic
· Musculoskeletal (can’t find in dictionary) · Neuropathic orofacial pain
Recognizing the differences between normal and neuropathic pain processes would
go a long way to helping solve this problem.
The prevalence of TN is only about four people in 100,000. The epidemiology of
orofacial pain, including TN and other forms of pain include burning mouth, phantom
tooth pain and atypical facial pain, which is even less common. Perception is a
product of nerve activity, so abnormal nerve activity can result in the perception of
something that is not there. hyperalgesia (increased sensation to painful stimuli
following damage to soft tissue or to a peripheral nerve) and allodynia, (all-powerful) in
which even a very slight touch is extremely painful, are two forms of abnormal sensory
perception. The key point for dental practitioners is that if pain persists after
inflammation subsides, it is likely nerve pain.
The nervous system provides information about both the quality and the intensity of
the stimuli with different parts of the body mapped out in the brain, with the face and
mouth occupying a disproportionately large share of the map.
Recognizing the difference between inflammatory and neuropathic pain are key to
correct diagnosis. Most diagnostic errors are made when the site of the pain is
confused with the source of the pain. It is important to remember that these are not
always the same. Normally, administering a stimulus can provoke a predictable
response, but this does not happen in TN. The quality of pain in TN also differs from
more typical inflammatory pain, which is deep and dull. Other characteristics of
neuropathic pain set it apart from pain from other causes, and anti-inflammatory
medication won’t relieve neuropathic pain.
Now that we have read the preceding article, What Role does Dental Intervention play
in the Etiology (the study of causes) of Facial Pain?
Ninety-five percent of facial pain is related to dental disease. There are five basic
explanations for TN, and all five have to do with the irritation of the trigeminal nerve.
In dentistry Dr. Bradley Eli notes that dentists use their understanding of nerves and
specific nerve block sites to perform painless dental work. Dr. Eli uses the analogy of
a bundle of telephone cable to describes the trigeminal nerve, which consists of
smaller fibers that are normally insulated with myelin.
There are many different dental procedures that might cause nerve trauma related to
facial pain. The tools of dentistry are powerful, including drills and acids used in
restorative and cosmetic work. Endodontic procedures can result in tearing of the
nerve end, neuroma formation or inflammation. Complications of oral surgery include
nerve trauma, numbness of the lips and tongue that last for some time and
complications from implants that are to close to the nerve.
As Dr. Eli stresses the importance of determining whether the onset of the symptom
can be linked to a specific, traumatic event. Other considerations are whether the
pain is worsening and how the pain relates to the progress of inflammation. He points
out there are four points about TN.
· Demyelination of the nerve can lead to a ‘short circuit,’ allowing signals to jump
from a touch fiber to a pain fiber.· Lesions or infections in the bone can cause
irritation of the nerve.
· The trigeminal nerve may be damaged due to compression by a blood vessel.
· Facial pain can also be due to dental problems, such as unidentified tooth
damage.
(Out of 100.000 people, 99,996 who visit the dentist, it is a tooth problem!)
Return to Archives
Return to Home Page
Dr. Purcell started off saying, “the patient should know more about their problem than
the Doctor does!” Too many times we go into the doctors office, and when s/he asks
how we are doing, we really don’t say how badly we are doing unless we have just had
a sever bout with TN pain.
With TN 60% of the problems are on the right side, 39% on the left side and 1% on
BOTH sides. We don’t know why most people have it on the right side, if it is because
most people are right handed, or what? It may be that the vascular artery typically
moves off to the right side as it comes up the pons (connecting part), that is a known
anatomical factor. 80-90% of TN is caused by an artery or vein loop.
There is a lot of variation, it ranges from 4-5 people out of 100,000 diagnosed with
TN. The ratio of men to women is l, man to 1.8 women. There are 15,000 people from
the U.S. every year diagnosed with TN. Most of the people with TN are over the age of
50. Most of the idiopathic (unknown cause) diagnosis are totally negative, no tumors,
masses, or vascular loops.
We have very little data on familial cases. I have never seen one, where it runs in the
family, although I am sure there are some out there. (There was three in our group
that it has run in their family).
Of the three areas of TN, D1, D2, and D3, the most common areas to have TN is the
D2, and D3, areas and it is very rare to have it in all three divisions.
Dr. Purcell reinforced what we have learned over the years, that the myelin sheath that
covers the nerves is very thin. The artery/vein rubbing up against the nerve causes
the myelin to wear out, which causes a short circuit at the root entry zone. Then what
we get is emphatic cross talk between fibers with mediating light touch and this
involves pain, like turning the switch on in the facial trigger zones. This aberrant input
may disinhibit pain pathways at the ganglia level/spinal trigeminal central pain
mechanism. The brain is very excitatory, it wants to go all the time 100 miles an hour.
The cortex on the other hand is there to inhibit the brain. The cortex spends it’s entire
life trying to slow the brain down.
Central pain mechanism includes: refractory periods (hard or impossible to manage)
after ‘trigger episodes which can last for seconds, minutes, or hours. This is just like
having a seizure where the brain is firing 100 miles an hour.
With TN it’s irritate and fire, irritate and fire. With a central nerve you will have a lot
firing, then no matter what you do it won’t fire again for a while.
Demyelization: - irritate the ganglia or nerve group(s) - plaque in brain stem
Clinical features of TN:
- Sharp pain attacks
- Pain is confined to the area served by one or more branches of the trigeminal
nerve
- Pain is almost always limited to one side, and does not cross over the midpoint
of the face
- Pain has trigger points (touch, breeze, etc.)
- Pain runs in cycles and can disappear for weeks, months even years
- D1, D2 involved more frequently than D1
- TN usually does not wake you up at night, especially when you are in your REM
sleep. It can wake you up from a nap in that you are not in a REM mode
Cluster headaches are very painful, just like TN. However the differ in a couple of
ways:
-80-90% men
-10% women
Cluster headaches typically 0ccur in a series of throbbing attacks that last 15minutes
to three hours at a time. Attacks may occur several times a day every few days, then
remission. Attacks also tend to cluster in certain time periods especially in the spring
and fall.
Unlike TN, cluster headaches may occur during sleep. Pain is often worse when lying
down. Light touch does not tend to trigger pain.
Q. Does alcohol precipitate TN pain?
A. No, but after the effect of the alcohol wears off, you may (!) have Pain. Alcohol
may even enhance tegretol, then the chances of pain are again enhanced.
Q. What is the difference between a MRI and a MRA?
A. a magnetic scan with computer images to produce a photograph of the brain’s
interior. Dr. Purcell states it is better than dissecting a real brain. MRI’s are clear
enough to get a good look at tumors, abnormal blood vessels, plaques and the
trigeminal nerve itself. However, you should probably get a ‘thin-cut MRI’ to be able to
see both the trigeminal nerve and the artery/vein.
MRA scans not only show the trigeminal nerve and vessels as small as 1mm, they
can tell the difference between arteries and veins in most cases, especially when the
gadolinium dye is injected into the patient's bloodstream to enhance the image.
Q. Does coffee (caffeine) affect TN? A. If you don’t normally drink coffee more
than once a month, then it may settle down a TN attack. But if you use coffee every
day, and go 6-8 hours with out coffee when you get in the morning, the coffee may
bring on an attack.
Q. What about narcotics?
A. I do not prescribe narcotics for TN since they do not work for this particular
problem. (tegretol, trileptal, Neurontin etc.) which are anti-seizure medications. None
of these drugs are good, but they are needed. You should meet with your doctor
every 3-4 months and have everything checked out. Do your own research on the
drugs you are using, know what the side affects are and how to deal with them.
When you come off the medication be sure to taper down, do not go right off the
drug—taper down over a period of weeks.
Be sure you let your doctor know what you want and need, especially if you are on
certain medications. The average Doctor spends about 15 minutes with you. In that
time you (the patient) must get across to your doctor what it is you need. If you think
you need blood drawn to check on your liver etc. then tell the doctor!
Do good research on the surgeon you are going to use, whether it is for an MVD,
Gamma Knife, Rhizotomy, no matter what the procedure. How many have they done in
the past year, what is their success rate, what are the complications?
Today, there are no long-term statistics on Gamma Knife procedures. One year or ten
years, no one has done a follow-up study on this procedure.
Recent statistics on MVD out of 2300 surgery’s, 85-95% success rate, Dr. Jeffrey
Brown found the average initial success rate to be 92.7% successful.
The study found that about 82% of patients had no pain, 16% had at least 75%
reduction in pain, 2% either had no relief or only minor improvement.
Dr. Purcell hopes that in the near future there will be such study done on the Gamma
Knife, with one year, five year, and ten year follow up on pain reduction, and any
complications.
Dental Differential Diagnosis of Facial Pain
Workshop by David Sirois, DMD, Ph.D.
Recap by Don Jeffries
Dentists play an important role in facial pain, and many TN patients begin by
undergoing dental treatments in an effort to alleviate pain that is thought to be related
to dental disease. Education is key, to reducing misdiagnosis and unnecessary dental
interventions.
Dr. Sirois lists the dentist’s role in managing chronic facial pain. These include : ·
Diagnosis and (misdiagnosis)
· Treatment of the correct disorders
· Minimizing the risk of future or worsened pain
· Provide dental treatment without worsening injury
· Addressing the impact of TN and facial pain on oral health
Most acute facial pain is dental pain and most dental diagnoses are straightforward.
Problems arise when the diagnosis is not clear and dentists try to treat the pain. In the
case of TN, the site of the pain is not the source of the pain. A national database
shows that more than half of TN patients underwent dental procedures to try to relieve
their facial pain before they were correctly diagnosed. Some had numerous
unnecessary procedures, such as root canals, but it should be obvious if the first of
second procedure does not resolve the problem that a new approach is needed.
Dr. Sirois explains three categories of common facial pain and the characteristics of
each category:
· Somatic
· Musculoskeletal (can’t find in dictionary) · Neuropathic orofacial pain
Recognizing the differences between normal and neuropathic pain processes would
go a long way to helping solve this problem.
The prevalence of TN is only about four people in 100,000. The epidemiology of
orofacial pain, including TN and other forms of pain include burning mouth, phantom
tooth pain and atypical facial pain, which is even less common. Perception is a
product of nerve activity, so abnormal nerve activity can result in the perception of
something that is not there. hyperalgesia (increased sensation to painful stimuli
following damage to soft tissue or to a peripheral nerve) and allodynia, (all-powerful) in
which even a very slight touch is extremely painful, are two forms of abnormal sensory
perception. The key point for dental practitioners is that if pain persists after
inflammation subsides, it is likely nerve pain.
The nervous system provides information about both the quality and the intensity of
the stimuli with different parts of the body mapped out in the brain, with the face and
mouth occupying a disproportionately large share of the map.
Recognizing the difference between inflammatory and neuropathic pain are key to
correct diagnosis. Most diagnostic errors are made when the site of the pain is
confused with the source of the pain. It is important to remember that these are not
always the same. Normally, administering a stimulus can provoke a predictable
response, but this does not happen in TN. The quality of pain in TN also differs from
more typical inflammatory pain, which is deep and dull. Other characteristics of
neuropathic pain set it apart from pain from other causes, and anti-inflammatory
medication won’t relieve neuropathic pain.
Now that we have read the preceding article, What Role does Dental Intervention play
in the Etiology (the study of causes) of Facial Pain?
Ninety-five percent of facial pain is related to dental disease. There are five basic
explanations for TN, and all five have to do with the irritation of the trigeminal nerve.
In dentistry Dr. Bradley Eli notes that dentists use their understanding of nerves and
specific nerve block sites to perform painless dental work. Dr. Eli uses the analogy of
a bundle of telephone cable to describes the trigeminal nerve, which consists of
smaller fibers that are normally insulated with myelin.
There are many different dental procedures that might cause nerve trauma related to
facial pain. The tools of dentistry are powerful, including drills and acids used in
restorative and cosmetic work. Endodontic procedures can result in tearing of the
nerve end, neuroma formation or inflammation. Complications of oral surgery include
nerve trauma, numbness of the lips and tongue that last for some time and
complications from implants that are to close to the nerve.
As Dr. Eli stresses the importance of determining whether the onset of the symptom
can be linked to a specific, traumatic event. Other considerations are whether the
pain is worsening and how the pain relates to the progress of inflammation. He points
out there are four points about TN.
· Demyelination of the nerve can lead to a ‘short circuit,’ allowing signals to jump
from a touch fiber to a pain fiber.· Lesions or infections in the bone can cause
irritation of the nerve.
· The trigeminal nerve may be damaged due to compression by a blood vessel.
· Facial pain can also be due to dental problems, such as unidentified tooth
damage.
(Out of 100.000 people, 99,996 who visit the dentist, it is a tooth problem!)
Return to Archives
Return to Home Page
| Dr. Ian Purcell |
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