Chronic cluster headache and the pituitary gland

Abstract

Background: Cluster headache is classified as a primary headache by definition not caused by an underlying pathology. However, symptomatic cases of otherwise typical cluster headache have been reported.

Case presentation: A 47-year-old male suffered from primary chronic cluster headache (CCH, ICHD-3 beta criteria fulfilled) since the age of 35 years. A magnetic resonance imaging (MRI) study of the brain in 2006 came back normal. He tried several prophylactic treatments but was never longer than 1 month without attacks. He was under chronic treatment with verapamil with only a limited effect on the attack frequency. Subcutaneous sumatriptan 6 mg injections were very effective in aborting attacks. By February 2014 the patient developed a continuous interictal pain ipsilateral to the right-sided cluster headache attacks. An indomethacin test (up to 225 mg/day orally) was negative. Because of the change in headache pattern we performed a new brain MRI, which showed a cystic structure in the pituitary gland. The differential diagnosis was between a Rathke cleft cyst and a cystic adenoma. Pituitary function tests showed an elevated serum prolactin level. A dopamine agonist (cabergoline) was started and the headache subsided completely. Potential pathophysiological mechanisms of pituitary tumor-associated headache are discussed.

Conclusion: Neuroimaging should be considered in all patients with CCH, especially those with an atypical presentation or evolution. Response to acute treatment does not exclude a secondary form of cluster headache. There may be shared pathophysiological mechanisms of primary and secondary cluster headache.

Keywords: Cluster headache; Pituitary gland; Secondary headache.

Fig. 1

MRI of the pituitary gland. T1 contrast-enhanced images. Left image: sagittal view. Right image: coronal view. White arrow indicates cystic structure in the pituitary

Fig. 2

Potential pathophysiological links with the pituitary gland in cluster headache. (+) arguments pro (-) arguments con. “Size is not everything” is a reference to an article of Levy et al. [16]. V1 is the ophthalmic branch of the trigeminal nerve. HPA = hypothalamic-pituitary axis. The figure is further explained in the text under the heading “pathophysiology”