Abstract

There are no lymphatics within the brain like other organs in our body with traditional anatomical understanding until Iliff and Nedergaard demonstrated a system of cerebrospinal and brain interstitial fluid flow systems that appears to be like the lymphatic system in rodents. They created the term “glymphatic”. More recent studies by using MRI tracer studies in humans demonstrated evidence of a similar glymphatic system in humans. It is logical to believe that such a system functions as an important waste clearance system in health and disease. However, the function of such a system has been questioned by more recent studies. There has never been any real human case to confirm the pathophysiologically the dysfunction of such a system as the reason for the underlying disease. Furthermore, there has never been any explanation how beta-amyloid synthesized in the brain can be transported retrogradely to the small brain arteries and arterioles in amyloid angiopathy. We report a case of relatively rapid development of amyloid angiopathy over a few years after an acute subarachnoid hemorrhage secondary to rupture of the posterior communicating aneurysm. The amyloid angiopathy is relatively localized over the site of subarachnoid hemorrhage. There are also associated local changes and amyloid deposition in the brain parenchyma. We believe this case evidently and adequately demonstrated the function and dysfunction of the glymphatic system in waste clearance and movement of solutes in the brain parenchyma. It also demonstrated how a-beta amyloid is synthesized in the brain parenchyma and transported retrogradely towards and got deposited in the small cerebral arteries in amyloid angiopathy.

Keywords: Glymphatic; A-beta amyloid; Amyloid angiopathy; Proteinopathy