Background and Purpose: Cerebral amyloid angiopathy (CAA) typically involves the cerebral cortex but whether it affects the cerebellum remains uncertain, and its relationship to deep white matter changes is not well understood. 
Methods: Patients with intracerebral hemorrhage (ICH) who underwent magnetic resonance imaging were prospectively enrolled. Patients were diagnosed with CAA according to the Boston criteria and their hemorrhage types were categorized as macro-hematoma (MH) or microbleeds (MB). We compared white matter hyperintensities using the Fazekas scale comparing those with cerebellar involvement and without cerebellar hemorrhages. 
We also compared white matter hyperintensities using the Fazekas scale comparing those with cerebellar involvement and without cerebellar hemorrhages. 
Results: Out of 614 patients with ICH, 96 (16%) had a post-ICH MRI. Of those, 41 (43%) were diagnosed with possible (n=19), probable (n=21) or definite (n=1) CAA. Cerebellar involvement was seen in 14/41 (34%) patients with CAA. A more severe white matter hyperintensities grade (Fazekas 2-3) was more frequent in patients with cerebellar involvement (12/14; 86% vs. 8/27; 30% p=0.002).
Most cerebellar lesions were of the MB type (35%) and most patients had several cerebellar MB typically involving the cerebellar cortex (85%). Patients with cerebellar involvement had larger numbers of lobar MB but clinical variables including age, gender, risk factor profile, mRS scores at 90 days or survival did not differ between those with and without cerebellar involvement.
Conclusions: Cerebellar involvement in not rare in CAA. These patients tent to have more white matter hyperintensities, even when clinical variables were adjusted for risk factor profile. Most patients have multiple superficial cerebellar MB. Clinical characteristics do not differ between CAA patients with or without cerebellar involvement. Patients presenting with cerebellar ICH and sever with matter disease (Fazekas 2-3) should be screened for CAA with MRI.
Key words: amyloid angiopathy, intracerebral hemorrhage, cerebellum

ESOC-2019