Case ReportThunderclap Headache: Presentation of Intracranial Sinus Thrombosis?
Introduction
Intracranial sinus thrombosis (ICST) and subarachnoid haemorrhage (SAH) are common presentations to neuroscience departments, which may indicate potentially life-threatening neurological conditions, however the two disorders require completely different treatment. Non-thrombotic SAH is most frequently the result of ruptured berry aneurysm and often presents with a sudden onset of severe headache. ICST may uncommonly present with thunderclap headache, that is, sudden onset severe headache, thereby mimicking SAH. The classic computed tomography (CT) appearances of SAH and ICST are different and not usually a source of diagnostic mistakes. However, errors can occur and in this paper, we present three cases of ICST that were misdiagnosed as SAH on the clinical presentation and on the initial CT brain examinations.
Section snippets
Case 1
A 33 year-old woman presented 1 day after a sudden onset severe headache. The headache was associated with vomiting and blurred vision, but no neck stiffness or photophobia. She was taking the oral contraceptive pill, but had no other significant medical history. Clinical examination was normal, specifically there was no abnormal neurological findings or indirect signs of raised intracranial pressure. CT of the brain at the referring hospital was reported as normal and cerebrospinal fluid (CSF)
Conclusion
We emphasize that thunderclap headache is a presenting feature of ICST, particularly in young females taking oestrogen, and therefore this diagnosis should be entertained. Although MR of the brain is the investigation of choice in patients with suspected ICST, CT is still the first line of investigation in patients presenting with thunderclap headache. It is important therefore to recognize that not everything that looks like subarachnoid haemorrhage on CT, is subarachnoid haemorrhage. It is
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