Reshkova V, Bogdanova and Milanov I
Brainstem interneurons are suggested to play a key role in pain modulation and in nociceptive transmission in migraine, in tension type and in cluster headaches and according to the current understanding the primary headache disorders are caused by trigeminocervical pain dysfunction. Brainstem reflexes might be useful in patients with chronic pain syndromes, such as primary headaches and fibromyalgia in order to evaluate the possible pathophysiological mechanism. Patiets with chronic tension-type headache, depression, fibromyalgia and control group were examinated. The blink reflex was induced by surface electrostimulation with stimulus duration of 0,5 ms. The reflex activity was recorded bilaterally at the midline of the lower lid and the back of the nose with surface electrodes. The results of this neurophysiological study of trigeminal reflexes support the concept of primary brainstem dysfunction and central hyperexcitability of the trigeminal sensory pathways in patients with various types of chronic pain syndromes such as fibromyalgia and chronic tension-type headache.
