Trigemino-autonomic activation in a human trigeminal pain model

Severe trigeminal pain was accompanied by autonomic symptoms in almost all subjects in this experiment. The pain rating and the severity of autonomic symptoms were significantly higher in female subjects than in male. The higher the pain the more severe was this autonomic activation. We conclude that activation of autonomic symptoms is an unspecific consequence of severe trigeminal pain. This does, however, not exclude the possibility that primary headache disorders might have an independent anatomic pathway to induce autonomic symptoms because these symptoms can, although very rarely, also occur without pain.