A 74‐year‐old man presented with a sudden onset headache, collapse, neck stiffness and photophobia. Extensive subarachnoid haemorrhage (SAH) with hydrocephalus was diagnosed on computed tomography. Negative cerebral artery angiography was carried out two times before he was discharged home 3 weeks later, having made a full recovery. About 15% of patients with SAH have no discernable cause of bleeding on angiography or other neuroimaging.1
The patient was readmitted 8 months later with headaches and a gradual onset of bitemporal hemianopia. A magnetic resonance imaging scan showed a pituitary tumour (fig 1), and arrangements were made for urgent surgery. The day before his surgery, his condition deteriorated acutely, he complained of headache and nausea and was barely able to perceive light in either eye. He underwent emergency trans‐sphenoidal hypophysectomy.
Figure 1 T2‐weighted axial magnetic resonance imaging scan showing a lesion in the pituitary fossa (arrow), displaying heterogeneous signal intensity suggesting recent apoplexy.
The presence of any visual disturbance (particularly of a bitemporal distribution) in conjunction with a sudden‐onset headache is an important clinical pointer to the diagnosis of pituitary apoplexy rather than SAH.
References
- 1.Flaherty M L, Haverbusch M, Kissela B.et al Perimesencephalic subarachnoid hemorrhage: incidence, risk factors, and outcome. J Stroke Cerebrovasc Dis 200514267–271. [DOI] [PMC free article] [PubMed] [Google Scholar]

