Trigeminal Neuralgia associated with Multiple Sclerosis

Here is My Question:
I have been living with MS for 33 years. About 10 years ago I was also diagnosed with trigeminal neuralgia. This condition is extremely painful. Although I have times of remission it has always returned to haunt me. I currently take Tegretol to help manage my pain. I have had the Gamma Knife procedure years back in hopes of some relief but that was not successful. I am not quite sure if surgery is the way I want to go at this point but would consider if pain becomes unbearable. My question is are there any new treatments out there for this horrific painful condition? Thank you.

Answer:
Trigeminal Neuralgia associated with Multiple Sclerosis is usually treated with Percutaneous needle ablation procedures or gamma knife radiosurgery if the pain is refractory to medications. Microvascular decompression is rarely the procedure of choice in Multiple Sclerosis patients. For medical treatment, we usually give trials of carbamezipine (or oxcarbezipine) as first line with the addition of gabapentin or pregabalin as needed. Second line treatments include lamotrigine, phenytoin and occasionally baclofen before sending patients to neurosurgery for a percutaneous procedure. 

Most surgeons do not use microvascular decompression to treatment Trigeminal neuralgia associated with Multiple sclerosis even though it is the preferred procedure for idiopathic (not related to MS) trigeminal neuralgia. I have found that different surgeons have a preference for different types of percutaneous procedures; some still prefer the older glycerol injection while others have a preference for either radiofrequency rhizotomy or balloon compression.  All procedures typically cause some degree of facial numbness, at least temporarily, and all procedures, except gamma knife radiosurgery, immediately eliminate or reduce neuralgic pain in more than 90 % of patients. Generally, the recurrence rate for neuralgia after one of these procedures is in the 20-30 % range. Thankfully, patients tend to respond to repeat  procedures for recurrent pain. There is a very low rate of analgesia dolorosa  (burning pain in an area completely numb to sensation) with all these procedures:

Pros and Cons for each procedure are as follows:

1. Microvascular decompression: This is open surgical procedure that require a craniotomy (major surgery). It is the most effective procedure for patients with idiopathic (i.e. not related to MS or another condition) trigeminal neuralgia under the age of 70 but of questionable benefit in patients with Multiple Sclerosis who do not have known vascular compression of the trigeminal nerve root. This is not frequently done in MS patients

2. Gamma Knife radiosurgery: Requires greater than a month after the procedure for any reduction in pain with the lowest rate of effectiveness of all the procedures but also the lowest rate of facial numbness after the procedure: Not generally recommended unless all other procedures are contraindicated, patient has failed prior percutaneous or surgical procedures or patient prefers this approach first to avoid any invasive procedure

3. Percutaneous Glycerol Rhizotomy: The oldest procedure. No anesthesia required and performed quickly. This is a non selective procedure favored by some because of the perception that patients experience less facial numbness post procedure. This procedure is associated with the highest rate of recurrent neuralgia often within 1 1/2 years

4. Percutaneous balloon decompression Rhizotomy: This seems to be the favored, non-selective percutaneous procedure for the past decade.  This is a vary rapid procedure with no anesthesia required and an excellent success rate. The recurrence rate within 2 years is relatively high but the procedure is easy to repeat or follow with a different procedure

5. Percutaneous radiofrequency rhizotomy: This is a selective procedure which is excellent for trigeminal neuralgia involving just the second or third division of the trigeminal nerve. Thankfully, more than 90% of patients only have involvement of one or both of these divisions of the nerve. This procedure require more skill and training, requires anesthesia, and takes several hours to perform. It also requires a cooperative patient who can be awakened during the procedure to make sure that correct zone of the ganglion is ablated. Surgeons skilled in this procedure prefer this technique because of the selective ablation of the nerve, the selective degree of facial numbness post procedure and the lower recurrence rate.

Revere (Rip) Kinkel MD
Director of the Multiple Sclerosis Program
Director of Hillcrest Neurology
Professor of Clinical Neurosciences
University of California San Diego