ABSTRACT
Trigeminal autonomic cephalalgias are a collective term for headache disorders that are characterized by unilateral head and/or face pain with accompanying autonomic features. Activation of the superior salivary nucleus is responsible for the cranial and facial parasympathetic outflow via the facial nerve. Given the anatomical connections, trigeminal efferent activation also results in pain in the distribution of the trigeminal and upper cervical nerves in addition to stimulating the facial nerve parasympathetic outflow. Prolonged stimulation of the posterior inferior hypothalamus resulted in long-lasting pain relief without side effects. Interestingly, when the electrode stimulation was discontinued without the knowledge of the patient, the pain reappeared but gradually disappeared when the device was turned back on. These observations, in addition to the lasting pain relief, appear to exclude a placebo effect. Neurosurgical procedures involving hypothalamic stimulation may be a treatment alternative for patients with intractable short-lasting unilateral neuralgiform headache attacks with conjunctival injection and tearing.
