Pituitary hormone tests revealed elevated growth hormone levels. Asking the patients about signs of acromegaly she confirmed recent changes in her face and hands. The ophthalmological examination was normal apart from a minimal visual field defect consistent with a chiasmal lesion.

Surgery was scheduled on February 26, 2009, but the patient said that she would not be able to stand the headache up to this date. Considering that analgesics and NSAIDs had failed, occipital and supraorbital nerve block with a long-acting steroid was performed resulting in complete resolution of the headache for 4 weeks. After transsphenoidal resection of the pituitary adenoma, a residual tumour encircling the right carotid artery had remained. Therefore, the patient underwent gamma knife treatment on June 30, 2009.

The patient was not seen in the headache outpatient clinic up to November 2009, when she presented again, because of persisting continuous right-sided headache associated with conjunctival injection and ptosis during periods of pain exacerbations. Again, an occipital nerve block was performed with significant improvement of headache. At follow-up 4 weeks later, a rounder and fuller face was noticed, and therefore, occipital nerve block was not repeated. Instead, topiramate was described. When the patient presented again in April 2010, she reported about side-shifting headaches with fullness of the ear and subjective hearing impairment. She had stopped topiramate because of side effects. During further follow-up, she continued to have chronic headache, but the side locked strictly to the right side with cranial autonomic symptoms changed to a bilateral headache being most severe on the right frontal and orbital regions and not accompanied with cranial autonomic symptoms anymore. MRI showed complete resolution of the residual tumour and pituitary hormone tests had become normal. She failed several prophylactic treatments and underwent inpatient treatment for medication overuse headache. At the last follow-up visit in April 2014, she reported almost daily headaches of varying intensity and bilateral localisation with a maximum in the right frontal and orbital regions, frequent use (but not overuse) of dexibuprofen and some benefit of amitriptyline 25 mg taken 2 h before bedtime.

In conclusion, this is the complex history of a patient with pre-existing migraine with aura who developed first daily headaches, headache resembling tension-type headache and later a continuous, strictly unilateral side-locked headache with exacerbations and ipsilateral cranial autonomic symptoms leading to the detection of a pituitary macroadenoma. After surgery and gamma knife treatment, headache evolved first to a unilateral headache with side shift and later to a bilateral headache with its intensity being most prominent on the right fronto-orbital region without cranial autonomic symptoms complicated by medication overuse requiring inpatient treatment. Obviously, the resolution of the hemicrania continua like headache has paralleled with the resolution of the pituitary macroadenoma, thus suggesting a causal relation.