"Intracranial mycotic aneurysms were first described by W S Church, an English physician, in 1869 1,12, with coinage of the term 'mycotic aneurysm' provided by Sir William Osler (1849-1919), a Canadian physician, in 1885 1,13. During this period, 'mycotic' was used to describe all micro-organisms, and thus 'mycotic aneurysm' described any infectious aneurysm - a term which has persisted in medical literature 1."
"Intracerebral mycotic aneurysms are nearly always secondary to bacterial infection, however rarely fungal (e.g. neurocandidiasis, CNS aspergillosis) and viral aetiologies (e.g. VZV, HIV-1) have been described 1-6. Viridans group Streptococcus (most common) and Staphylococcus aureus account for up to 90% of all intracranial mycotic aneurysms 1-4."
"Unruptured aneurysms present with non-specific clinical features, such as systemic symptoms (e.g. fever, weight loss), headache (localised or generalised), and transient focal neurological deficits from septic microemboli 1-4; very rarely are intracerebral mycotic aneurysms large enough to cause signs and symptoms of mass-effect 5. Ruptured aneurysms present with clinical features of subarachnoid haemorrhage or intracerebral haemorrhage, such as meningism or stroke 1-4,14."
"Even with management, prognosis is poor; unruptured intracranial mycotic aneurysms have a mortality of up to 30%, while ruptured intracranial mycotic aneurysms have a mortality of up to 80% 2. Outcomes are poorer for patients with multiple intracerebral mycotic aneurysms 1."
"Regardless of aetiology, once bacteria are in the vessel wall, there is local arteritis resulting in degeneration of the elastic lamina and vessel wall 1-4,6. There is then subsequent formation of pseudoaneurysm through hydrostatic pulsations 1-4,6."
"Intracranial mycotic aneurysms can be evaluated with CT angiography (CTA), MR angiography (MRA), or digital subtraction angiography 1-5,9,14. Digital subtraction angiography is the most sensitive, however, CTA and MRA become more sensitive as aneurysms become larger in size 14."
"CT is often utilised as a first-line imaging modality given its accessibility 1-4,9. Non-contrast studies may show complications of the aneurysm, such as subarachnoid haemorrhage (often convexal), intracerebral haemorrhage (often lobar), abscess, or ischaemic stroke, while the aneurysm may be identified with CT angiography 1-4,9."
"Intracranial mycotic aneurysms were first described by W S Church, an English physician, in 1869 1,12, with coinage of the term 'mycotic aneurysm' provided by Sir William Osler (1849-1919), a Canadian physician, in 1885 1,13. During this period, 'mycotic' was used to describe all micro-organisms, and thus 'mycotic aneurysm' described any infectious aneurysm - a term which has persisted in medical literature 1."