[Progression of cluster headache to Raeder's syndrome with marked response to corticosteroid therapy: a case report].

A 42-year-old man complained of severe left orbital pain for 7 months. The diagnosis of cluster headache was made on the basis of diagnostic criteria formed by the International Headache Society. Sumatriptan was effective in relieving pain to a certain degree, but the frequency of the occurrence of pain gradually increased. Subsequently, he presented sensory disturbances in the left trigeminal nerve, and was admitted to our hospital. On admission, his neurological examination revealed left miosis and paresthesia in the first branch of the left trigeminal nerve. Neither anhidrosis nor ptosis was noted. His autonomic failure was consistent with post-synaptic disturbance as determined by pharmacological analysis for pupil's function. On the basis of the unique combination of neurological sings and symptoms including the unilateral headache, partial Horner's syndrome, and V1 sensory disturbance, we diagnosed him as having Raeder's syndrome. To exclude the possibility of a lesion in the Gasser ganglion of the middle fossa of the cranium or carotid artery causing symptomatic Raeder's syndrome, imaging studies including brain MRI, cervical MRA, and Doppler ultrasonography were performed, which revealed normal findings. We started him on oral prednisolone at 1 mg/kg once a day, which resulted in a rapid and dramatic suppression of pain. Thus, this case showed a progression from cluster headache to idiopathic Raeder's syndrome, which suggests that these two disorders might share common pathological and anatomical lesions.