Nervous system Flashcards
GBS
acute inflamatory demyelinating neuropathy
dec nerve conduction velocity
inc csf proteins
dec reflexes
Chronic inflamatory demyelinating polyradiculopaty
2m +
recurrent de and re myelination
proliferative onion bulb schwann cells
steroid responsive
leprosy
schwann cells invaded by mycobacterium
sympetric polyneuropathy, esp pain
Diphtheria neuropathy
bulbar and resp dysfunction
Vitamin eficiecy neuropaty
B1,6,12 folate, vitmain E, copper, zinc
Skull ~ clasification
displaced if >thickness bone
diastatic if crosses suture lines
DAI
asymmetrical swelling axons deep white matter
present in 50% who develop coma
SDH time frame blood removal
1 week - clot lysis
2 weeks - fibroblasts from dural space into haematoma
1-3m - hyalinoid CT
Brain CO and O2 consumption
15% CO 20% O2 consumption (same as skeletal muscle)
Effect ischaemia on brain
dec ATP and dec membrane potential
inc Ca2+ causing cellular injury
inc glutamate release further inc ca2+ into cell (via NMDA)
BP for global cerebral ischaemia
<50 systolic (autoregulation 50-150)
morph global cerebral ischaemia
12-24h red neurons, eosinophilia, pyknosis
24h-2w necrosis, macrophages, reactive gliosis
2w + removal necrotic tisssue, gliosis
astrocytes from 1w
cerebral embolism
most common cause focal ischaemia
main from cardiac mural then carotid
cerebral thrombosis
plaque rupture
carotid bifurcation, origin mca, basilar
gross morphology brain post thrombosis
48h pale
2-10d gelatinous
2-3w liquefactive
Lacunar infarcts
<15mm
lenticular nucleus and thalamus and internal capsule
tissue loss surrounded by gliosis
HTN CVD sequelae
lacunar infarcts
split haemorrhage
encephalopathy
ICH - mostly putamen
Location SAH
90% ant circulation
- 40%ACA
- 20% branch 1 MCA
- 34% higher up MCA
4% PCA
Meningioma
F>M
slow growing but faster during pregnancy
CSF
volume in humans is 150mls and the rate of production is about 550ml/day
osmolality same as plasma
Main cause atraumatic ICH
hypertension and cerebral amyloid angiopathy
Retinoblastoma
from neural cells
most common intraoccular ca kids
spreads to brain and BM
Meningitis organisms
infants - e.coli/ GBS
young adults - n meninitides
older adults - strep pneum, listeria
CSF bacterial meningitis
rasied protein, WCC and opening pressure
low glucose
turbid, 90% PMNs
viral meningitis organism
enterovirus, however not normally identified
CSF viral meningitis
mild inc wcc and protein
normal opening pressure and glucose
lymphocytic pleocytosis
Central TB
mainly meningioencephalitis
CSF v high protein with pleocytosis and dec gluc
tuberculoma - looks like CNS tumor
HSV1 encephalitis
children young adults
only 10% prior herpes
HSV2 encephalotis
neonatal
meningitis in older
CMV encephaliti
foetal microcephaly
immunosupressed
Rabies
negri bodies pathognomonic
parasthesia around bite site
incubation 1-3m dependant on disctance from brain
HIV encephalitis
- during seroconversion
- opportunistic cmv/ toxo
- EBV +ve CNS lymphoma
PML
JC plyomavirus
MS
neurological episodes seperated by time, WHITE matter lesions seperated by space
IgG and inc protein in CSF
Alzheimers
abeta placques, tau tangles
most common ementia
5-10% familial
fontotemporal lobar degenerations dementia
personality, behaviour language changes pre memory loss
tau inclusions and TDP43 inclusion
Progressive supranuclear palsy
parkinsons plus
trunkal rigidity
disequelibrium with falls
difficulty voluntary eye movements
corticobasal degeneration
parkinsons plus
extrapyramidal rigidity
asymetric motor disturbance
impaired higher cortical function - apraxia
Huntingtons
AD
chorea
movement pre dementia
caudate nucleus and ptamen
friedrich ataxia
AR
cardiomyopathy
deep tendon refelx absent, plantar present
Thiamine deficiency
B1
wernickes
encephalopathy - psychosis and ophthalmoplegia reversible
syndrome - short term memory and confabulations
B12 deficiency
cobalamin
subacute combined degeneration spinal cord with bilateral symetrical numbness
Mechanism CO poisoning
decreased O2 carrying blood
via cytochrome C oxidase blocks electron transport in mitochondria and thus tissue utilisation O2
Acute angle closure glaucoma stages
in hyperopia (primary)
opposition iris to ant surface lens
dec flow aqueous humour
inc pressure post chamber
