Figure 1

Neuropathology of AHL. Haemorrhages are present in the (a) leptomeninges (HE, scale bar = 500 μm), (b) temporal lobe (HE, scale bar = 1600 μm), (c) cerebellum (HE, scale bar = 200 μm), (d) medullary olive (LFB/HE, scale bar = 500 μm) and (e) vagus nerve root (LFB/HE, scale bar = 100 μm). (f) Ball (LFB/HE, scale bar = 100 μm) and (g) ring haemorrhages (LFB/HE, scale bar = 100 μm) affect the pontine white and gray matter, respectively. (h) An involved blood vessel shows evidence of fibrinoid necrosis and fibrin exudation (HE, scale bar = 50 μm). (i) Perivascular inflammatory infiltrates consist mainly of neutrophils (HE, scale bar = 33 μm). (j) Parenchymal microglial foci are confined to haemorrhagic areas [CD68/LFB/Nuclear Fast Red (NFR), scale bar = 100 μm]. (k) Myelin pallor is present in the cerebellar white matter and seems to be due to spreading of the myelin sheaths because of edema and diffusion of an eosinophilic fibrin-like substance conferring the white matter a sieve-like appearance (LFB/HE, scale bar = 100 μm). (l) High magnification visualization of the myelinated fibers reveals vacuolation and decompaction of myelin (arrow heads); rare apoptotic oligodendrocytes are present (arrow) (LFB/HE, scale bar = 33 μm).