What is Anesthesia Dolorosa?
Anesthesia Dolorosa (AD) literally means painful numbness. This painful condition occurs when the trigeminal nerve is damaged in such a way that the sense of touch is diminished or eliminated while a malfunctioning sensation of pain is left intact. AD is referred to as a deafferentation pain syndrome.
The cause of AD
AD can result from any surgery around the trigeminal ganglion.
Many doctors feel the procedures most likely to produce AD are percutaneous (through the cheek) procedures using radiofrequency, balloon compression, or glycerol. AD may also occur following a trigeminal rhizotomy, in which a surgeon intentionally cuts the trigeminal nerve root.
Why AD Occurs
The touch-carrying nerve fibers are injured by surgery, while little or no damage occurs to pain-carrying fibers.
Surgical injury may also prevent nerve fibers from overlapping as they normally should, resulting in distorted signals being sent to the brain.
AD pain is much like phantom limb pain, but is occurring to an amputated trigeminal nerve branch instead of an arm or leg. After surgery, when these pain signals suddenly stop, the brain may deal with this loss of input by remembering and replaying old pain signals.
Symptoms of AD
Pain for an AD patient is constant and is felt in their area of numbness. They describe it as: burning, boring, prickling, or as a feeling of heaviness, tightness, or pressure. Diagnosis is generally based on the description of symptoms
Difference Between AD and TN
AD pain is usually constant with a burning or jabbing quality, while TN is intermittent, with sharp, electric-like jabs.
The distinction between the two can affect the course of treatment. Further destructive procedures for an AD patient may make the condition worse.
Treatments for AD
- Muscle relaxants (Baclofen, Zanaflex)
- Antidepressants like amitriplyline (Elavil), nortriptyline (Pamelor), clonidine (Catapres), paroxetine (Paxil)
- Anticonvulsants such as TN- carbamazepine (Tegretol, Carbatrol), oxcarbazpine (Trileptal), gabapentin (Neurontin), clonazepam (Klonopin), valproate (Depakote), topiramate (Topamax), phenytoin (Dilantin)
- Topical anesthetic (EMLA)
- Topical ointments (Zostrix, Capsazin-P)
- Anesthetic Injections (lidocaine), opiods, such as a transmucosal fentanyl (Actiq)
- Oral Morphine drugs (oxycontin)
Complementary and Alternative Therapies (CAM)
Include acupuncture, upper-cervical chiropractic, nutrition therapy, hot and cold compresses, biofeedback, and electrical stimulation (TENS, SCENAR).
Anesthetic injections (nerve blocks), motor cortex stimulation (an implanted electrode gives constant electrical stimulation), Drez procedure (a last-ditch surgery, because arm-or leg-coordination difficulties may be post operative complications, this surgery injures the origin of the trigeminal nerve in the upper spinal cord.
As medical science better understands the brain, surgeons also are looking into the newer field of stimulating or selectively disabling parts of the brain that process pain signals.