We present the principal differential characteristics of neuralgia of symptomatic and idiopathic trigeminus. Out of 39 consecutive patients with neuralgia of trigeminus evaluated clinically and with neuroimage study, we find recognizable pathology in 10 (3 arterio-venous malformations, 1 dolichoestasia of basilar artery, 3 tumors, 3 multiple sclerosis). Symptomatic neuralgia occurs in patients with lower average age and is accompanied by atypical symptoms or abnormal neurological signs and is no different from idiopathy as a response to pain from medical treatment. Painful affectation of the trigeminus requires the realization of complementary explorations aiming to dismiss associated neurological pathology.