Anesthesia Dolorosa (AD) is one of the most dreaded complications of the treatment of trigeminal neuralgia. It occurs when the trigeminal nerve is damaged by surgery or physical trauma, resulting in numbness in the face, with pain present within the numb area.
AD is caused by injury to the trigeminal nerve, either deliberately as during ablative treatment for trigeminal neuralgia, or accidentally as during injury to the trigeminal nerve for some other reason.
The two main symptoms of AD are facial numbness (much like the numbness from a dental anesthetic injection) and constant pain. The pain is usually burning, pulling, or stabbing but can also include a sharp, stinging, shooting or electrical component. Pressure and “heaviness” can also be part of the pain symptoms. Often there is eye pain. Cold increases the feeling of numbness, sometimes making a face feel frozen.
The diagnosis of AD is made when patients have an area of total numbness in the face that is also painful. Quantitative sensory testing is a test that confirms that the affected area is, in fact, numb, but this test is not necessary to make the diagnosis. If the painful area of the face has partial sensation, then the correct diagnosis is trigeminal deafferentation pain (for patients whose injury occurs during treatment for trigeminal neuralgia) or trigeminal neuropathic pain (for patients without trigeminal neuralgia).
Unfortunately, there is no known effective treatment for AD. A multidisciplinary, pain-management-oriented approach is most appropriate. Some helpful strategies include anticonvulsants, antidepressants, opiates, psychological support, and complementary and alternative therapies. There are no good surgical options at this point, but motor cortex stimulation has shown some promise in preliminary studies.