Chapter 14
The Nervous
System Diseases
Zhou Hongyan
Infections,
Epidemic Eerebrospinal
Meningitis
Epidemic Encephalitis B
Degenerative diseases:
Alzheimer Disease
Parkinson,s Disease
Infecions,
Epidemic Cerebrospinal
Meningitis
Epidemic Encephalitis B
Degenerative diseases:
Alzheimer Disease
Parkinson,s Disease
Epidemic Cerebrospinal
Meningitis
also known as
Acute Purulent Lepomeningitis
Neisseria meningitidis
is the most common cause of
epidemic of acute
lepomeningitis
most cases occur in
winter or spring
via respiratory tract
children >adult
exudate is usually most
pronounced over the
cerebral convexities
“purulent”
gross appearance:
the meninges are intensely
congested and contain a
variable amount of
creamy exudates in the
subarachnoid space
microscope appearance:
the leptomeninges are
intensely congested and
contain neutrophils in
the subarachnoid space
fever,headache,
stiff neck ;
CSF is often turbid.
clinical features:
Waterhouse-Friederichsen
Syndrome:
DIC occurs quickly，
high mortality
Infections,
Epidemic Eerebrospinal
Meningitis
Epidemic Encephalitis B
Degenerative diseases:
Alzheimer Disease
Parkinson,s Disease
Epidemic Encephalitis B
encephalitis B virus is
the most common cause;
it is a arbovirus ;
most cases encephalitis
occur in late summer.
the viral infection is
associated with
brain parenchyma
microscopic appearance:
1.perivascular inflammatory
infiltrates
2.degeneration and necrosis
of the neurons
3.softening areas formation
4.microglial nodules
1.perivascular inflammatory
infiltrates
the perivascular inflammatory
infiltrates consist of
mononuclear cells,including
lymphocytes,plasma cells,
and macrophages
perivascular inflammatory
infiltrates
2.degeneration and necrosis
of the neurons
neuronophagia------
satellitosis------
normal
normal
degeneration of the neurons
neuronophagia
3.softening areas
formation
coagulation necrosis
satellitosis
softening areas
4.microglial nodules
localized aggregates of
microglial cells termed
microglial nodules
microglial nodules
Infections,
Epidemic Eerebrospinal
Meningitis
Epidemic Encephalitis B
Degenerative diseases:
Alzheimer Disease
Parkinson,s Disease
Alzheimer disease is the most
common cause of dementia
in the elderly.
Most cases of AD occur after
the age of 50,with a
progressive increase in
incidence with increasing age.
the cause remains unkown,but
a number of factors play a major role
1.genetic factors
2.deposition of a form of amyloid
3.hyperphosphorylation of the
protein tau
4.expression of specific alleles of
apoprotein E
1.genetic factors
2.deposition of a form of amyloid
3.hyperphosphorylation of the
protein tau
4.expression of specific alleles of
apoprotein E
1.genetic factors
2.deposition of a form of amyloid
3.hyperphosphorylation of the
protein tau
4.expression of specific alleles of
apoprotein E
1.genetic factors
play a role in the development
occurrence of familial cases
least 4 genes mutation
chromosome 21 —— APP
chromosome 14 —— PS
chromosome 1—— PS
chromosome 19 —— ApoE
early-onset family AD:
chromosome 1,14,21
late-onset family AD:
chromosome 19
sporadic AD:
chromosome 19
Patients with
Down syndrome
3 APP
amyloid↑
AD
APP gene mutation------chromosome 21
Mutation in two additional genes：
Chromosome 14 —— presenilin 1
Chromosome 1 —— presenilin 2
Mutations in the Presenilin genes:
increased production of amyloid
in the CNS
PS gene mutation------ Chromosome 14,1
normal miss-sense mutation
PS gene
mutation
apoprotein E(apoE)gene:
the ε4 allele of apoE
-------chromosone 19
1.genetic factors
2.deposition of a form of amyloid
3.hyperphosphorylation of the
protein tau
4.expression of specific alleles of
apoprotein E
? amyloid precursor
protein,APP,
?Secretase:
α -secretase
β -secretase
γ -secretase
α-secretase
γ -secretase
β-secretase
nomal
γ -secretase
α-secretase
nonpathogenic
fragment
APP
β-secretase
γ -secretase
Aβ Aβ
tau
老
年
斑
abnormal
1.genetic factors
2.deposition of a form of amyloid
3.hyperphosphorylation of the
protein tau
4.expression of specific alleles of
apoprotein E
microtubules,cytoskeletal
3.hyperphosphorylation of the
protein tau
Tau is an intracellular protein,
involved in the assembly of
intra-axonal microtubules
hyperphosphorylation
of the protein tau
microtubules↑
neurofibrillary
tangles
prtein tau
of AD
1.genetic factors
2.deposition of a form of amyloid
3.hyperphosphorylation of the
protein tau
4.expression of specific alleles of
apoprotein E
?Ε4 allele mutation？
? apoE(ε4 allele) may be
involved transport or
processing of the APP
molecule
gross appearance:
atrophy is most evident in
the frontal,temporal
or parietal lobes,
cut surface:
cerebral ventricles are
symmetric dilation
microscopic appearance:
1.senile plaques:
appear as aggregates of
coarse,tortuous neurites in the
neuropli
contain a central amyloid core,
β-AP
2.neurofibrillary tangles:
appear as coarse,
filamentous aggregates
within the cytoplasm;
composed of
insoluble,protein-rich paired
helical filaments(PHFs);
It is rather the density and
widespread distribution
of plaques and tangles in
neocortical areas in the
setting of dementia that
allows one to make a
diagnosis of AD.
Infections,
Epidemic Eerebrospinal
Meningitis
Epidemic Encephalitis B
Degenerative diseases:
Alzheimer Disease
Parkinson,s Disease
also named as
paralysis agitans
rigidity,
expressionless faces,
stooped posture,
gait disturbances,slowing
of voluntary movements,
pill-rolling tremor
gross appearance:
the substantia nigra
and locus ceruleus
are depigment
PD normal
microscopic appearance:
loss of melanin-
containing neurons in
the substantia nigra and
locus ceruleus ;
lewy bodies formation.
normal PD
Lewy body,HE Lewy body,IHS
The brain may be
mildly atrophic in
latter.