AUTONOMIC NERVOUS-SYSTEM AND NEUROENDOCRINE CHANGES IN PATIENTS WITH IDIOPATHIC TRIGEMINAL NEURALGIA

To investigate sympathetic nervous system and neuroendocrine changes i n idiopathic trigeminal neuralgia, we determined the plasma level of t he catecholamines norepinephrine and epinephrine, as well as cortisol and ACTH in 16 patients (55.3+/-8.3 years) with trigeminal neuralgia a t four different times during the day (7.00, 13.00, 17.00 and 23.00). Morning and evening values of plasma norepinephrine as well as the dai ly mean value (dmv) were significantly higher (p<0.01) in patients wit h trigeminal neuralgia than in an age- and gender-matched control grou p. Moreover, morning, afternoon and dmv epinephrine values were also s ignificantly elevated. The dmv norepinephrine levels correlated with t he intensity of the attacks (r=0.68, p<0.01), the frequency of the att acks (r=0.75, p<0.01) and the duration of the disease (r=0.78, p<0.01) . In addition to elevated catecholamines, trigeminal neuralgia patient s also demonstrated significantly increased morning, evening and daily mean values of plasma cortisol. Thus, patients with trigeminal pain h ave an increased sympathetic nervous system activity for an extended p eriod of time without a direct link to pain attacks, which suggests th at the sympathetic nervous system itself is at least fo-activated in t rigeminal neural,aia and perhaps plays a role in the induction and mai ntenance of trigeminal pain. The neuroendocrine changes are similar to cluster headache and point to a central dysregulation of the hypothal amic-pituitary-adrenal axis, possibly due to the cyclic phenomena in i diopathic trigeminal neuralgia.