Even though there is no known association of CAA and dolichoectasia,5
they both share a common pathology: they both are “media diseases”. “Intracranial dolichoectasia” (also known as “fusiform aneurysm” or “dilatatory arteriopathy”) is characterised by disruption of the internal elastic lamina (IEL) of large vessels,5
most commonly affecting the vertebrobasilar system6
and, if symptomatic, usually presents with compressive symptoms of the brain stem or stroke.7
Most of the strokes are ischaemic, but up to 18% of patients can develop either parenchymal or subarachnoid haemorrhages.8
Dolichoectasia also has associations with abdominal aortic aneurysm, carotid artery enlargement, and coronary artery disease,7,9
as well as small vessel disease of the brain (lacunar infarcts, leukoaraiosis, and état criblé). This suggests that the media of small arteries might be affected similarly to that of large arteries.5–7,9
These associations support the idea that a systemic media dysfunction exists in dolichoectasia. Some animal studies have shown that artery wall shear stress is a probable factor involved in the abnormal dilatation of the artery. The augmented dynamic forces would activate the endothelium with a cascade of complex mechanical and biochemical signals that lead to a media transformation and probably deformation.10
The degree of dolichoectasia of the anterior and posterior vessels in our patient is suggestive of an advanced disease when compared to other patients6,7
and, as implied by others, age and hypertension are key factors involved in this disease.5–9
It is interesting that on admission our patient did not have significantly elevated blood pressure as might be expected for intracranial bleeding, and no gross evidence of atherosclerosis in large vessels was found.
We believe that dolichoectasia is a marker of arterial disease, that the small arteries are as affected as the medium or large arteries, and that the bleeding in this case could have happened in the context of a weakened small artery rather than just having been a coincidental finding. The acute trigger could have been the urinary infection, minor trauma, and mild diastolic pressure elevation in combination with an antiplatelet agent, or even an elevated homocysteine level secondary to vitamin B12 deficiency, but always in the context of an abnormally fragile artery wall.
To our knowledge, this is the first case report of severe anterior and posterior intracranial dolichoectasia presenting with simultaneous multiple parenchymal haemorrhages in a patient with hypertension, dementia and an abdominal aortic aneurysm. Larger and systematic studies are needed to better characterise this “systemic dilatatory arteriopathy”.
- Intracranial dolichoectasia is a differential diagnosis in patients with intracranial haemorrhage.
- Intracranial dolichoectasia can coexist with other large artery disease—that is, aortic aneurysm, carotid ectasia, hepatic artery ectasia, etc.
- Intracranial dolichoectasia can coexist with small artery disease—that is, lacunar infarcts, leukoaraiosis and état cribble.
- Dolichoectasia of the brain arteries should be looked for in every brain imaging study since mounting evidence suggests that this arterial deformation is pathological rather that an indolent incidental finding.