Krafts Diseases and Pearls Flashcards
cells of CNS
neurons astrocytes oligodendrocytes microglia ependymal (last 4: glial)
astrocytes Fx
“cell that does the most”
most important glial cells
star shaped, long processes (rosenthal processes)
big responders to injury
provide glucose for brain, ONLY source
oligodendrocytes Fx
myelin
microglia Fx
macrophages
ependymal cell fx
produce CSF
line ventricles
stain used to show astrocytes and their processes
silver stain
astrocyte vs oligodendrocyte
- astrocytes bigger
- astrocytes open chromatin pattern
- ogd chromatin black dot
- ogd in lacunae/space
ependymal cells have
cilia (motion)
microvilli (absorption)
when acute CNS injury, think
red neurons
associate red neurons with
acute injury
loss of blood flow
“red is dead”
inclusion bodies are
reactions of neurons to injury
by axonal spheroids
accumulations within nucleus or cytoplasm of neurons
cowdry a
herpes
“owl’s eye”
negri
rabies
neurofibrillary tangles
AD
silver stain, see accumulation of amyloid
lewy bodies
PD
gliosis
astrocyte proliferation
*important sign of infection
is like scarring in the brain
gemistocytic astrocytes
happy, make more proteins
inclusions in astrocytes*
rosenthal fibers (processes of astrocytes, thick, tumor, metabolic disease, nonspecific injurious process going on)
corpora amylacea (pearl like, light blue, due to aging)
microglial nodules
dead tissue, foreign substance that needs to be chewed up by microglia
genetic metabolic disease shows up when…
birth*
missing enzyme that primarily affects CNS –> build up –> lose function
genetic metabolic diseases
neuronal storage disease (storage disorders in CNS neurons)
leukodystrophies (affect white matter)
acquired metabolic diseases
vitamin deficients
metabolic and toxic disturbances
later in life*
NSDs
diagnose by clinical exam, labs, common look of neuron
- Neuronal ceroid lipofuscinoses: accumulation of lipofusin –> neuronal dysfxn. blindness, motor probe, seizures
- Tay-Sachs Disease: Ashkenazi Jews, deficiency in HEX-A, hexosaminidase A –> breaks down ganglioside (GM2) (a “food” for neurons). baby seems normal at birth, doesn’t meet development milestones (6-8mo), motor impair, paralysis, loss near fxn, death by age 4, cherry red spots
Tay-Sachs Disease
- Ashkenazi Jews
- deficiency in HEX-A
- hexosaminidase A –> breaks down ganglioside (GM2 type, a “food” for neurons)
- baby seems normal at birth, doesn’t meet development milestones (6-8mo)
- cherry red spots (macula sticks out)*
- motor impair
- paralysis
- loss neurological fxn
- death by age 4
cherry-red spots
whole retina contains neurons stuffed with gangliosides that are white, so entire retina becomes palsied, white —> makes macula more red
Leukodystrophies
myelin abnormalitis (ogds, not neurons)
- Krabbe Disease
- galactosylceramidase deficiency
- accumulation of galactocerebrosie –> TOXIC to OGDs –> loss of myelin –> axons conduct poorly
- globoid cells: fat macrophages stuffed full of the toxic metabolite, released as OGD dies **does see in other disorders
- motor
difference between NSDs and LDs?
LDs: deterioration of motors skills, spasticity, hypotonia, ataxia (less cognitive issues)
Krabbe Disease hallmarks
- globoid cells
- motor
- galactosylceramidase deficiency –> accum galactrocerebroside (TOXIC)
B1 deficiency
Thiamine deficiency
- chronic alcoholism, starvation
- -> Wernicke/Korsakoff
First stage B1 deficiency (in CNS)
Wernicke encephalopathy mammillary bodies starved --> hemorrhage, necrosis, eaten up by microglia EARLY AND REVERSIBLE (give thiamine) 1. confusion 2. ophthalmoplegia 3. ataxia
Second stage B1 deficiency
Korsakoff syndrome mammillary bodies atrophied NOT REVERSIBLE 1. Wernicke encephalopathy 2. memory disturbances 3. confabulation
B2 deficiency
cobalamin
needed to make DNA
anemia
subacute combined degeneration of spinal cord
Subactue combined degeneration of SC
B12 deficiency
motor and sensory tracts loss myelin (ascending and descending)
numbness, ataxia, weakness REVERSIBLE
paraplegia IRREVERSIBLE
*distribution dorsal column, and dosrsolateral columns
Toxins affect CNS
carbon monoxide
methanol
ethanol
CO
confusion, disoriented –>
delirium –>
coma
goes to CNS first*
particularly: hippocampus, parking cells, cortex
high affinity for Hb (won’t allow proper O2 delivery)
pink discoloration of tissues**
Methanol CH3OH
30-100ml fatal
4ml cause blindness
prefers to go to ganglionic cells in retina
Ethanol CH3CH2OH
prefers to go to cerebellum (middle --> ataxia) acute effects REVERSIBLE ataxia, nystagmus Bergmann gliosis --> cerebellar atrophy
Bergmann gliosis
proliferation of astrocytes collect where purine cells should be
Peripheral Nerve Diseases
neuropathies
- Guillian-Barre Syndrome
- Hansen’s Disease
- VZV
- Charcot-Marie-Tooth Disease
- Peripheral Neuropathy in Diabetes
- Neuropathies associated with malignancy
Guillian-Barre Syndrome
= Acute Inflammatory Demyelination Polyradiculoneuropathy
- ascending parasthesia
- flu-like illness prior
- immune-mediated (T cells and macrophages cause segmental demyelination*** after having attacked virus)
- resolves over time
- plasmaphoresis: remove ab, seem to get better
- respiratory therapy if paralysis into lungs
clinical course of Guillian-Barre
symmetric ascending paralysis > rapid-onset weakness > loss deep tendon reflexes > loss of sensation > elevated CSF protein > 2-5% mortality from respiratory paralysis, autonomic instability, cardiac arrest
Hansen’s Disease
slowly progressive infection of skin and nerves Mycobacterium leprae most of world is naturally immune endemic in poor tropical countries disabling deformities
- tuberculoid leprosy (less severe, skin disorder, nerve degeneration - anesthesia, ulcers)
- lepromatous leprosy (more sever, skin, nerves, eye, mouth, tests, hands, feet - immune system doesn’t respond well to kill pathogen)
Tuberculoid leprosy
nice T cell response to make enough granulomas, decrease pathogen
Mycobacterium leprae
skin rash*
Lepromatous leprosy
leonine facies*
autoamputation*
Mycobacterium leprae
immune system doesn’t respond as well
VZV
common viral inf of PNS dormant in DRG, cord, or brainstem neuronal destruction --> pain "dew drop on a rose petal" dermatomes multinucleate giant cells
most common hereditary neuropathy
Hereditary Motor and Sensory Neuropathy Type 1 = Charcot-Marie-Tooth disease
Charcot-Marie-Tooth disease
de-myelination then re-myelination*
muscle loss, sensory loss but pain intact**
childhood/early adulthood
autosomal dominant
pes cavus (high arch), foot drop, hammer toes, muscle atrophy
normal life span
Peripheral Neuropathy in Diabetes
too much sugar in blood > glucose stick to peripheral nerves > irreversible connections with cells
autonomic neuropathy (difficult bladder control) or asymmetric neuropathy (involve one nerve)
*symm M and S neuropathy in distal
decreased pain sensation > ulcers, injury > no heal > amputations
*stocking glove distribution
Neuropathies associated with malignancy
- neoplasms: metastatic, mononeuropathy (push on nerve)
eg. lung pressing on brachial plexus, obturator palsy from pelvic neoplasms, cranial nerve palsies from brain tumors - paraneoplastic effects: look like hormone effects, polyneuropathy (tumor production of substances/antibodies that start reacting with nerves)
eg. small cell lung cancer, plasma cell malignancies
Skull fractures
Linear
Depressed
Diastatic
Basal
Linear skull fracture
most COMMON
STRAIGHT crack
usually not serious
Depressed skull fracture
bone displaced INWARD
comminuted (in pieces)
can damage brain
Diastatic skull fracture
across a SUTURE
suture widens
usually in children
Basal skull fracture
more force required
distant hematoma (battle sign behind ear, raccoon eyes)
CSF drainage from nose or ear*
frontal bone fracture
patient unconscious, couldn’t stop self from falling on face
Parenchymal injuries
- Concussion
- Second-impact Syndrome
- Chronic traumatic encephalopathy
- Direct Parenchymal injury
- Diffuse axonal injury
- Traumatic vascular injury
Concussion
altered consciousness from head injury due to change in momentum of head (stretching and snapping back of brain)
Sx: amnesia, confusion, HA, visual disturb, N/V, dizzi
Second-impact Syndrome
rare
CATASTROPHIC: brain swells rapidly
second concussion before first healed
Chronic traumatic encephalopathy
multiple conconsions
life changing effect on person/personality
progressive degenerative disease
histologically looks like AD: tau protein
Sx: progressive dementia, poor judgement, apathy depression, memory loss, confusion, aggression
Direct Parenchymal injury
laceration (eg. knife wound)
contusion (bruising)
coup/contrecoup injury
Diffuse Axonal injury
rotational acceleration, torque side to side > shearing of axons
injury to axons in deep white matter
coma (can exist)
eg. shaken baby syndrome, boxing
Direct parencymal vs concussion
direct parenchymal: can point to lesion in one localized area
Traumatic vascular injury
epidural hematoma
subdural hematoma
subarachnoid hemorrhage
epidural hematoma
above dura
SURGICAL EMERGENCY
rupture middle meningeal artery*
contours are smooth: lens on MRI/CT “tough mother, dura is so tough”
ex: baseball hit to the temple, lucid period*
subdural hematoma
between dura and arachnoid
shearing of cerebral veins*
contours are not smooth
ex: elderly patient falls, ripped veins as as they run through dura. 1. acute (hours) numbness one side, 2. chronic (months) numb and personality changes
subarachnoid hemorrhage
in arachnoid space NEUROSURGICAL EMERGENCY actual bleed cerebral arteries* contusions, ruptured berry aneurysms* (40% ACA, 20% internal carotid, 34% MCA branches, 4% PCA)
ex: “worst headache I have ever had”
ICP increased in
brain swelling/inflammation hematoma rumors hydrocephalus increased CSF
cerebral edema
- vasogenic
cause: leaky vessels/inc vascular permeability
space between cells
localized or generalized - cytotoxic
cause: cell membrane injury (hypoxia or metabolic damage > messes channels in/out of cells)
space within cells: cells r swole
often occur together whenever cerebral edema
local vasogenic cerebral edema tx
- steroid: dexamethasone (reduce water permeability of tight junctions)
- mannitol: osmotic diuretic, will draw water out of CSF into blood
cytotoxic tx
no known treatment
hydropcephalus
accumulation of excessive CSF within ventricular system
infancy > head enlarges (sutures aren’t closed)
adulthood > ventricles expand, increased ICP
Five kinds hydrocephalus
- communicating
- non-communicating
- ex vacuo
- increased CSF production
- normal pressure
Non-communicating
blockage in one way circulation
eg. congenital malformation, mass, collection of blood/hematoma
Communicating
block exit of CSF into sinus
eg. resolving meningitis
Craniopharygioma
blocks CSF, pituitary oma, rare
Ex vacuo
no block in ventricular system
degenerative
BRAIN ATROPHY > RESULTING HYDROCEPHALUS
dilated ventricular system
Choroid Plexus Papilloma
increased CSF production?, rare
Normal pressure
Triad: wet, wobbly, wacky 1. urinary incontinence 2. magnetic gait 3. dementia REVERSIBLE no cortical atrophy, ventricles enlarge can be confused with AD *something blocked CSF by some arachnoid blockage, CSF couldn't get out, then somehow, pressure normalizes*
How differentiate normal pressure hydrocephalus from AD?
Dementia is different. NP H the gait is unusual, patient doesn’t really care about incontinence issues (frontal lobe changes, apathy)
Tx hydrocephalus
goal: reduce fluid volume and pressure
1. surgery, shunt to drain CSF
2. decrase CSF production with acetazolamide (CA inhibitor) or furosemide (NKCC inhibitor)
critical enzyme: carbonic anhydrase
converst CO2 and water to H ion and bicarbonate
block CA > reduce HCO3 > less transport of Cl and Na > less production of CSF
SE: reduced stomach acid production, more sodium release, increased urine output, many
increased ICP
mass effect (edema, tumor, hematoma)
compromised blood flow to brain > pain, papilledema, decreased consciousness
feared outcome: herniation
common herniations
- subfalcine hernation
- transtentorial hernation
- tonsilar hernation
herniation Sx
focal neurological symptoms
brainstem symptoms: respiratory and cardiac arrest, coma
often fatal
subfalcine herniation
cingulate gyrus pushed under falx cerebri
compresses ACA
transtentorial uncinate hernation
uncus through tentorium
compresses:
- CN III (fixed, dilated pupil, ophthalmoplegia)
- brainstem (rip blood vessels, duret hemorrhages) FATAL
- PCA (ischemia in 1* visual cortex)
- contralateral cerebral peduncle (hemiparesis)
tonsilar hernation
cerebellar tonsils through foramen magnum
compresses medulla (compromises vital resp and cardiac centers)
LIFE THREATENING