[A clinical approach to cranial neuralgias]

The International Association for the Study of Pain defines neuralgia as the pain that is felt in the distribution of a nerve or nerve root. Although the most important criterion for its diagnosis is spatial, distinguishing between neuralgia and other types of pain in the craniofacial area will only be possible by looking at a set of many clinical characteristics as a whole.

Knowledge of the territories of sensory distribution of the nerves or roots is essential to be able to define the location of the pain in neuralgias. Other attributes are also useful for diagnosing them: the quality of the pain (paroxysmal, stinging-burning, dull), the time profile (seconds-minutes versus hours-days), the absence of accompanying phenomena other than certain manifestations of sensory dysfunction, especially in the symptomatic forms (hypoanaesthesia, paresthesias, dysesthesias, allodynia, hyperalgesia, hyperpathy), pain triggered by tactile or mechanical stimuli in the painful territory ('trigger' zones) or a positive Tinel's sign, the response to anaesthetic blockade of the nerve or root, and the response to certain drugs.

Although trigeminal neuralgia is the most frequent, there are many other kinds of craniofacial neuralgias, in fact, theoretically, the total number is the same as the number of nerve roots and nerves responsible for the sensory innervation of these anatomical regions. It is essential to be familiar with them to obtain a correct diagnosis.