Brain 2001 Aug;124(Pt 8):1635-45
De Groot CJ, Bergers E, Kamphorst
W, Ravid R, Polman CH, Barkhof F, van Der Valk P.
Department of Pathology, Division
of Neuropathology, MS Centre for Research and Care (MSCRC), Departments
of Radiology and Neurology, MS-MR Centre, Vrije Universiteit Medical Centre
and Netherlands Brain Bank, Amsterdam, The Netherlands.
Macroscopic sampling of multiple
sclerosis lesions in the brain tends to find chronic lesions.
For a better understanding of the
dynamics of the multiple sclerosis disease process, research into new and
developing lesions is of great interest.
As MRI in vivo effectively demonstrates
lesions in multiple sclerosis patients, we have applied it to unfixed post-mortem
brain slices to identify abnormalities, in order to obtain a higher yield
of active lesions.
The Netherlands Brain Bank organized
the rapid autopsy of 29 multiple sclerosis patients.
The brain was cut in 1 cm coronal
slices.
One or two slices were subjected
to T(1)- and T(2)-weighted MRI, and then cut at the plane of the MRI scan
into 5 mm thick opposing sections.
Areas of interest were identified
based on the MRI findings and excised.
One half was fixed in 10% formalin
and paraffin-embedded, and the corresponding area in the adjacent half
was snap-frozen in liquid nitrogen.
In total, 136 out of 174 brain tissue
samples could be matched with the abnormalities seen on T(2)-weighted MRIs.
The stage of lesional development was determined (immuno) histochemically.
For 54 MRI-detectable samples, it
was recorded whether they were macroscopically detectable, i.e. visible
and/or palpable.
Histopathological analysis revealed
that 48% of the hyperintense areas seen on T(2)-weighted images represented
active lesions, including lesions localized in the normal appearing white
matter, without apparent loss of myelin but nevertheless showing a variable
degree of oedema, small clusters of microglial cells with enhanced major
histocompatibility complex class II antigen, CD45 and CD68 antigen expression
and a variable number of perivascular lymphocytes around small blood vessels
[designated as (p)reactive lesions].
From the macro-scopically not-visible/not-palpable
MRI-detected abnormalities, 58% were (p)reactive lesions and 21% contained
active demyelinating lesions.
In contrast, visible and/or palpable
brain tissue samples mainly contained chronic inactive lesions.
We conclude that MRI-guided sampling
of brain tissue increases the yield of active multiple sclerosis lesions,
including active demyelinating and (p)reactive lesions.
PMID: 11459754 [PubMed - in process]