Headache caused by pituitary apoplexy, usually with sudden (even thunderclap) onset and severe intensity, and accompanied from onset or later by visual symptoms and/or hypopituitarism.
A. Any new headache fulfilling criterion C
B. Acute haemorrhagic pituitary infarction has been diagnosed
C. Evidence of causation demonstrated by at least two of the following:
1. headache has developed in close temporal relation to other symptoms and/or clinical signs of pituitary apoplexy, or has led to the diagnosis of pituitary apoplexy
2. either or both of the following:
a) headache has significantly worsened in parallel with other symptoms and/or clinical signs of pituitary apoplexy
b) headache has significantly improved in parallel with other symptoms and/or clinical signs of improvement of pituitary apoplexy
3. headache is severe and of sudden or thunderclap onset
D. Not better accounted for by another ICHD-3 diagnosis.
The rare clinical syndrome of pituitary apoplexy is an acute, life-threatening condition. It is one of the causes of thunderclap headache. Most cases occur as the first presentation of rapid enlargement of non-functioning pituitary macroadenomas due to haemorrhage and/or infarction. It is one of the causes of non-aneurysmal subarachnoid haemorrhage.
MRI is more sensitive than CT scan for detecting intrasellar pathology.