In
the cerebral hemispheres, periventricular white matter ap-
peared to be most affected, with better preservation of
subcortical U-fibers (41). Rare perivascular, periodic
acid-Schiff (PAS)-positive macrophages stuffed with
dense, coarse granular debris were noted even in areas
with seemingly intact myelin, but no lymphocytic inflam-
mation was identified. Although gliosis was not evident
on the Holzer and phosphotungstic-acid-hematoxylin
methods for glia available to us at the time of the report,
recent reexamination of this case with immunostaining
for glial fibrillary acidic protein (GFAP) demonstrated
reactive gliosis even in cerebral white matter areas where
myelin loss was undetectable. Because cerebral and cer-
ebellar neurons were intact and axons were preserved in
areas of myelin pallor, toluene was hypothesized to be a
pure myelin toxin (41). A 1992 study of toluene concen-
trations in various brain regions in an autopsied case of
a chronic abuser offered corroborative data that the cor-
pus callosum was preferentially targeted and the cerebral
cortex was spared, although no neuropathological fea-
tures of this case were provided (42).