Strictly Limited Orbital Pain as Sentinel Headache of Subarachnoid Hemorrhage.

BACKGROUND: The headache preceding an intracranial aneurysm rupture is called a sentinel headache (SH), and it is characterized by a sudden, intense, and persistent headache. As subarachnoid hemorrhage (SAH) often develops within several weeks of SH, its rapid diagnosis and treatment can improve the prognosis. CASE DESCRIPTION: A 52-year-old woman with migraine in her medical history visited the outpatient clinic due to left orbital pain. There was no neurologic deficit. Although magnetic resonance imaging examination found no SAH, a left internal carotid artery-posterior communicating artery bifurcation aneurysm was detected by magnetic resonance angiography. Ten days after the onset of orbital pain, the patient consulted our hospital for a second opinion. We scheduled an elective clipping because the irregular shape of the aneurysm had a high risk of rupture. On the day before surgery, the aneurysm ruptured and led to SAH. Clipping was performed immediately. The patient was discharged with no neurologic deficit. CONCLUSION: Clinicians must take into consideration that unilateral orbital pain, though atypical, may be a symptom of SH.