Background: Recent studies suggest that superficially located cerebellar intracerebral hemorrhage (ICH) and microbleeds might point towards sporadic cerebral amyloid angiopathy (CAA).
Aims: We investigated the proportion of cerebellar ICH and asymptomatic macro- and microbleeds in Dutch-type hereditary CAA (D-CAA), a severe and essentially pure form of CAA.
Methods: Symptomatic patients with D-CAA (defined as ≥1 symptomatic ICH) and presymptomatic D-CAA mutation-carriers were included. We assessed magnetic resonance imaging scans for symptomatic (cerebellar) ICH and asymptomatic cerebellar macro- and microbleeds according to the STRIVE-criteria. Location was assessed as superficial-cerebellar (cortex, vermis or juxta-cortical) or deep-cerebellar (white matter, pedunculi cerebelli and gray nuclei).
Results: We included 63 participants (mean age 58 years, 60% women, 42 symptomatic). In total, the 42 symptomatic patients with D-CAA had 107 symptomatic ICH (range 1-7). None of these ICH were located in the cerebellum. Six of 42 (14%, 95%CI 4-25%) symptomatic patients and none of the 21 (0%, 95%CI 0-0%) presymptomatic carriers had ≥ 1 asymptomatic cerebellar macrobleed(s). All macrobleeds were superficially located. Cerebellar microbleeds were found in 40 of 63 (64%, 95%CI 52-76) participants (median 1.0, range 0-159), 81% in symptomatic patients and 29% in presymptomatic carriers. All microbleeds were strictly or predominantly superficially (ratio superficial versus deep 15:1) located.
Conclusions: Superficially located asymptomatic cerebellar macrobleeds and microbleeds are common in D-CAA. Cerebellar microbleeds are already present in the presymptomatic stage. Despite the high frequency of cerebellar micro and macrobleeds, CAA pathology did not result in symptomatic cerebellar ICH in patients with D-CAA.
Keywords: Cerebral amyloid angiopathy; D-CAA; cerebellum; intracerebral hemorrhage; microbleeds.