13.1.2.3 Painful post-traumatic trigeminal neuropathy

Previously used term:
Anaesthesia dolorosa.

Coded elsewhere:
Here are described painful post-traumatic neuropathies; most trigeminal nerve injuries do not result in pain and therefore have no place in ICHD-3 (beta).

Description:
Unilateral facial or oral pain following trauma to the trigeminal nerve, with other symptoms and/or clinical signs of trigeminal nerve dysfunction.

Diagnostic criteria:
A. Unilateral facial and/or oral pain fulfilling criterion C
B. History of an identifiable traumatic event1 to the trigeminal nerve, with clinically evident positive (hyperalgesia, allodynia) and/or negative (hypoaesthesia, hypoalgesia) signs of trigeminal nerve dysfunction
C. Evidence of causation demonstrated by both of the following:

    1. pain is located in the distribution of the same trigeminal nerve
    2. pain has developed within 3-6 months of the traumatic event

D. Not better accounted for by another ICHD-3 diagnosis.

Note:
1. The traumatic event may be mechanical, chemical, thermal or caused by radiation.

Comment:
Pain duration ranges widely from paroxysmal to constant, and may be mixed. Specifically following radiation-induced postganglionic injury, neuropathy may appear after more than three months.