Alzheimer’s disease
If
some brain cells are killed by viral infection
or damaged in another way, it will probably trigger a similar cascade
as in
post-polio syndrome. The post-polio syndrome is gradually worsening and
often
after a long time. Compared to men, larger cell mosaic in women, and
especially in
people with Down’s syndrome, may explain why these groups are
more exposed to
both conditions than men. Even if a possible viral infection of brain
cells did
not kill them, the infected cells will probably be perceived as different from
uninfected
cells and increase the cell mosaic and the forgetfulness.
Since
TT virus infection is detected in many
people and in some cases has been detected in the brain, the virus is a
possible candidate.
We
do not know the cause of Alzheimer’s disease,
but it occurs earlier in people with Down’s syndrome.
Therefore, it is possible
that increased cell mosaic predisposes. If an association also contains
a
mosaic of more than two cell types in humans with Down’s
syndrome, it is
assumed that the associations must be extra-large
for
being remembered well.
But
if Alzheimer’s disease is caused by a virus,
it is likely that such an infection in the brain of a patient with
Down’s
syndrome fast would increase the tendency of the associations to be
forgotten
since then the cell mosaic will increase further.
Also
the expected renewal of glia cells from the
bone marrow may fail, and if so, the working memory will suffer first.