Anesthesia dolorosa (AD) and trigeminal deafferentation pain (TDP) are two other types of pain associated with the trigeminal nerve, unique in that they are caused not by a vascular compression, but by damage to the nerve. Dreaded even among trigeminal neuralgia sufferers, both are often intractable and resistant to treatment.
The Difference Between AD and TDP
AD is characterized by:
- total, one sided, facial numbness from the chin to the top of the head, ear to facial midline
- severe and constant deafferentation pain in the same area
TDP is only slightly different from AD in fact that the numbness is not always 100%.
The medical term, “deafferentation,” means the elimination or interruption of sensory nerve impulses resulting from the destruction of or injury to the sensory nerve fibers. This nerve damage results in severe, unceasing pain.
AD/TDP is characterized by constant pain on the forehead, cheek, and/or chin accompanied by numbness to the same area(s). It is not uncommon for an AD/TDP patient to also report pain in the mouth. Unlike the other cranial neuralgias, there are no periods of remission and the pain is unceasing. Words used to describe the pain of AD/TDP:
- ice cold
In many cases, AD/TDP is accompanied by sensations of parts of the affected area being pulled or tugged at, particularly in the teeth and gums.
As it results from injury to the trigeminal nerve itself, it is almost always limited to one side of the face.
As a potential complication of rhizotomy, radiosurgery, and microvascular decompresson surgery, AD is one of the most dreaded risks of TN treatment. It occurs when the trigeminal nerve is damaged by surgery or physical trauma causing deafferentation to occur.
The same drugs that are used to treat the other chronic facial pains are used to treat AD/TDP, with varying degrees of success. The results of drug therapy for AD/TDP are generally unsatisfactory.
Nerve damaging procedures for AD/TDP are particularly risky because, while they can potentially produce pain relief, they can also potentially cause an increase in the pain.
Because AD/TDP is not the result of a nerve compression, microvascular decompression surgery is not indicated.
Motor Cortex Stimulation shows some promise as a treatment for the pain of AD/TDP, but there are no statistics available on the success/failure rates of MCS for AD/TDP in actual practice. Studies have shown that patients with AD/TDP who had previously undergone ablative trigeminal procedures respond poorly to MCS. MCS requires the surgical placement of an electrode panel on the surface of the brain and surgical implantation of a control device elsewhere in the body.
It is currently beyond the scope of medical science to repair chronic nerve damage, such as that which causes AD/TDP. Hope for repair awaits new research and therapies that might be possible, but do not yet exist.
Anesthesia Dolorosa pronunciation:
Deafferentation Pain pronunciation:
Columbia University Medical Center: Anesthesia Dolorosa
Wikipedia: Anesthesia Dolorosa
Mirror Therapy for AD Pain *
Motor cortex stimulation for trigeminal neuropathic or deafferentation pain: an institutional case series experience.
Elahi, F., Ho, K. W. D. (2014). Anesthesia Dolorosa of Trigeminal Nerve, a Rare Complication of Acoustic Neuroma Surgery. Case Reports in Neurological Medicine, 2014, 496794. http://doi.org/10.1155/2014/496794.https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4195256/
Kolodziej MA, et al.
Treatment of Central Deafferentation and Trigeminal Neuropathic Pain by Motor Cortex Stimulation: Report of a Series of 20 Patients. J Neurol Surg A Cent Eur Neurosurg. 2016 Epub 2015
*Admin has used mirror therapy for TDP with some success.