Charcot-Bouchard aneurysms are minute aneurysms which develop as a result of chronic hypertension and appear most commonly in the basal ganglia and other areas such as the thalamus, pons and cerebellum, where there are small penetrating vessels (diameter <300 micrometers) 1-3.
They should not be confused with saccular aneurysms found in larger intracranial vessels in the subarachnoid space 1,4.
Rupture of Charcot-Bouchard aneurysms is probably the most common cause of intracerebral hemorrhage and is commonly seen in patients on anticoagulation 2.
Patients will present depending on the region and size of the hemorrhage:
- putaminal hemorrhage usually presents with ipsilateral deviation of the eyes due to descending capsular pathways from the frontal eye field
- thalamic hemorrhage often presents with downward deviation of eyes and lack of pupillary response to light
- pontine hemorrhage usually causes coma due to disruption of the reticular activating system (unless small) and quadriparesis due to disruption of the corticospinal tract 4
Chronic hypertension causes lipohyalinosis of small arterioles so that there is a defect in the muscular coat and only a thin intimal layer with some surrounding gliosis 3. This makes Charcot-Bouchard aneurysms prone to rupture, with the inability to control bleeding by vasomotor spasm 3.
- 1. Kumar, Abbas, Aster. Robbins and Cotran Pathologic Basis of Disease. 9th Edition. Chapter 28 - The Central Nervous System. Elsevier Saunders. 2015. Page 1268.
- 2. Gates P. Clinical Neurology: A Primer. Churchill Livingstone Elsevier Australia. 2010. Chapter 10 - Cerebrovascular Disease. Page 208-209.
- 3. Pryse-Phillips W. Companion to Clinical Neurology. 2nd Edition. Oxford University Press. 2003.
- 4. Kandel et al. Principles of Neural Science. 5th Edition. McGraw-Hill. 2013. Appendices C - Circulation of the Brain. Page 1563.