Amyloid Angiopathy: MRI

64 year old male with a known chronic kidney dysfunction  & myocardial ischaemia presence with altered sensorium. The MRI brain shows  extensive parenchymal bleeds of varying sizes in the entire cerebral, cerebellar parenchyma,  basal ganglia & brain stem with T1 hyperintensity and blooming on SW with atheromatous circle of Willis branches with no extra axial or  intraventricular extension, possibly representing cerebral amyloid angiopathy. Case submitted by Dr MGK Murthy, Mr Venkat and Mr Senthil

Teaching points :

1. Predominantly seen in elderly, and results from beta-amyloid protein deposition in cortical, subcortical or lepto meningeal vessels (in the media and adventitia of small and medium sized vessels) .
2.  CT or MRI  are the imaging modalities of the choice.
3. Though hereditary forms are known in the younger age group, sporadic age related form is the commonest.  Incidence increases with age reaching 75% of those older than 90 years.   Not associated with systemic amyloidosis.
4. Asymptomatic to severe intracranial bleeds and TIAs are the usual presentations.
5. Boston criteria specifies four categories – definite CAA, probable CAA (with pathological evidence), probable CAA, and possible CAA. Petechial haemorrhages (less than 5 mm) in size are usually asymptomatic.