I was just doing an internet search for answers to this question, and came across a link to the "Living With TN" forum and a discussion that took place over a year ago. One reply in particular caught my attention (underlined emphasis is mine):
I do. have Post Herpetic Atypical Trigeminal Neuralgia. My TN is caused from the Herpes virus. I finally was diagnosed after having sinus surgery, root canaling all my upper teeth left had side, then eventually pulling them all. I was referred to a Maxofacial pain specialist and he iidentified the correlation between my Herpes cold sore break outs and my TN. I used to have pain every time I had a breakout usually breakout and pain were on the same side, in my mouth, tongue, lips and gums. Now I have had it so long that I have constant pain from the virus damaging the nerve.T he HSV-1 virus lives in the the trigeminal nerve and is usually dormant until time of stress, mental, physical or emotional and sometime sun exposure.
I am aware that post herpetic neuralgia can be caused by the herpes zoster virus, but I have not seen anything in the literature, with the exception of a hypothesis, that implicates the herpes simplex I virus as a major player in TN: http://www.medical-hypotheses.com/article/S0306-9877(02)00177-9/abstract "We suggest that its (trigeminal neuralgia's) primary cause is a single, active DNA sequence in the persistent but non-integrated genome of latent herpes simplex virus type 1 commonly observed in a few infected A-delta nerve fibers of the cheek. Facial pain occurs as a result of herpes virus reactivation and when supplies of neurotrophins controlling normal transport functions of axolemmal ion channels become depleted."
My wife has suffered from the herpes simplex I virus since early childhood. She takes Acyclovir when she feels an attack coming on and this is generally very effective. Her TN-II symptoms began last September, strangely about the same time that she spontaneously stopped having cold sores on her lips and inside her nose. Is anyone out there seeing a physician that is attempting to treat TN-II by addressing issues related to the herpes simplex I virus? Is anyone aware of any studies or treatment protocol that links the two illnesses?
I've recently talked with a couple of prominent physicians in the TN treatment community about HS-I and TN. The prevailing opinion seems to be that while there is some evidence of a connection between Herpes Simplex I and the emergence of TN pain, that connection doesn't appear to be direct "cause and effect". So we are still at the level of speculation with regard to the role that Herpes I may play.
Thanks for the update, Red. We have had one very favorable experience recently that I almost forgot to mention. I went with my wife to see her internist two days ago, and told him that we wanted to get more aggressive in finding out what may and may not be causing my wife's problem. I had prepared the following document before going to his office:
For Consideration: Imaging Procedures to be Performed at Palmetto-Richland Radiology Dept.
I.Vascular Compression of the Trigeminal Nerve
The “gold standard” of TN imaging assessments is a FIESTA MRI procedure (Trigeminal Protocol) conducted both with and without contrast agent. The procedure is performed to generate sub-millimeter resolution on the trigeminal nerve (0.66 millimeter, thin-slice MRI done with and without contrast agent). Post-procedure 3-D reconstruction is recommended for maximum clarity and detail of medical assessment.
II. MultipleSclerosis
FLAIR MRI (fluid-attenuated inversion recovery) of the brain and spinal cord with contrast.
He looked at the document, dropped it to the floor next to his computer, and began to type the Order Requisition for the scans almost verbatim. These procedures will be done this coming Tuesday, and they are covered by our insurance. I guess it's a good thing that I didn't emphasize the negatives after all. It must have been my "winning personality" that ruled the day (more than likely he just wanted to get me out of there). Regardless, I'll take it any way I can get it right now................
Most scientists believe that a viral infection such as viral meningitis or the common cold sore virus - herpes simplex - causes the disorder. They believe that the facial nerve swells and becomes inflamed in reaction to the infection, causing pressure within the Fallopian canal and leading to an infarction (the death of nerve cells due to insufficient blood and oxygen supply). In some mild cases (where recovery is rapid), there is damage only to the myelin sheath of the nerve. The myelin sheath is the fatty covering-which acts as an insulator-on nerve fibers in the brain.
===============
Could you please quote the original source for this conclusion? I very much doubt that "most scientists" believe any such thing about this disorder. Consensus cannot be stated without evidence. And I don't see the evidence. To the contrary, I've talked with a number of physicians who regularly treat TN, and heard that a connection to HS-I is at this stage a speculation not demonstrated by consistent evidence.
information is from: http://www.ninds.nih.gov/disorders/bells/bells.htm National Institute of Neurological disorders and YOU ARE CORRECT and I FIXED THE BLOG INFO to say that I was talking about BELLS PALSY not TN.
(sorry for the mix up, in my research that particular info was on bells palsy and I mixed it up, my VERY bad mistake and I am SO glad you caught that)
Bell's palsy is a form of temporary facial paralysis resulting from damage or trauma to one of the facial nerves. It is the most common cause of facial paralysis. Generally, Bell's palsy affects only one of the paired facial nerves and one side of the face, however, in rare cases, it can affect both sides. Symptoms of Bell's palsy usually begin suddenly and reach their peak within 48 hours. Symptoms vary from person to person and can range in severity from mild weakness to total paralysis. These symptoms include twitching, weakness, or paralysis, drooping eyelid or corner of the mouth, drooling, dry eye or mouth, impairment of taste, and excessive tearing in the eye. Bell’s palsy often causes significant facial distortion. Most scientists believe that a viral infection such as viral meningitis or the common cold sore virus -- herpes simplex-- can cause the disorder when the facial nerve swells and becomes inflamed in reaction to the infection.
The underlying mechanisms in Bells Palsy appear to be somewhat different than in neuralgias. Neuralgias are characterized by pain, rather than paralysis. A useful analogy might be Parkinson's Disease, Alzheimer's, and MS. All three are nerve disorders associated with voluntary movement and cognitive memory problems. But it is now understood that the underlying mechanisms for all three are different -- implying different modalities of treatment.
Please note that I'm not claiming there is "no" connection for TN to Herpes viruses. But the connection has not been demonstrated beyond patient testimonials. Correlation is not cause.
One thing that hasn't been suggested by my wife's doctors is a trial of continuous, large doses of Acyclovir to go along with her Neurontin. She only takes the Acyclovir as needed for a short period of time when she feels a fever blister coming on. It seems that it might be worth a try, but I'm sure there's a reason why it has not been suggested (other than the lack of cause-effect evidence). I'll probably bring it up the next time we go to the doctor for what it's worth.
Richard A. "Red" Lawhern said:
The underlying mechanisms in Bells Palsy appear to be somewhat different than in neuralgias. Neuralgias are characterized by pain, rather than paralysis. A useful analogy might be Parkinson's Disease, Alzheimer's, and MS. All three are nerve disorders associated with voluntary movement and cognitive memory problems. But it is now understood that the underlying mechanisms for all three are different -- implying different modalities of treatment.
Please note that I'm not claiming there is "no" connection for TN to Herpes viruses. But the connection has not been demonstrated beyond patient testimonials. Correlation is not cause.
UK, my intuition -- and I really shouldn't lend more credibility to this thought than that term intuition -- is that doctors resist long-term prescription of Acyclovir out of a concern for either building immunity to the medication, or killing off friendly viruses deemed necessary for normal physiological function. So yes, it's wise to ask explicitly about the rationale. It may well prove to be a meaningful one.