Consecutive light microscopy, scanning-transmission electron microscopy and transmission electron microscopy of traumatic human brain oedema and ischaemic brain damage
Cortical biopsies of 11 patients with
traumatic brain oedema were consecutively studied by
light microscopy (LM) using thick plastic sections,
scanning-transmission electron microscopy ((S)TEM)
using semithin plastic sections and transmission electron
microscopy (TEM) using ultrathin sections. Samples
were glutaraldehyde-osmium fixed and embedded in
Araldite or Epon. Thick sections were stained with
toluidine-blue for light microscopy. Semithin sections
were examined unstained and uncoated for (S)TEM.
Ultrathin sections were stained with uranyl and lead.
Perivascular haemorrhages and perivascular
extravasation of proteinaceous oedema fluid were
observed in both moderate and severe oedema.
Ischaemic pyramidal and non-pyramidal nerve cells
appeared shrunken, electron dense and with enlargement
of intracytoplasmic membrane compartment. Notably
swollen astrocytes were observed in all samples
examined. Glycogen-rich and glycogen-depleted
astrocytes were identified in anoxic-ischaemic regions.
Dark and hydropic satellite, interfascicular and
perivascular oligodendrocytes were also found.
The status spongiosus of severely oedematous brain
parenchyma observed by LM and (S)TEM was
correlated with the enlarged extracellular space and
disrupted neuropil observed by TEM. The (S)TEM is
recommended as a suitable technique for studying
pathological processes in the central nervous system and
as an informative adjunct to LM and TEM