Path Buzzin Flashcards
chromatolysis
seen in wallerian degeneration
red neurons
ireversible hypoxic injury - acute CNS injury
hepatic encephlaopathy
alzheimer type II astrocytes - they are damaged d/t high ammonia resulting in leakage and parenchymal edema –> cerebral edema
gliosis
GFAP + … think chronic CNS injury
test for CSF rhinorrhea
beta-2 transferrin
tumor in ventricle in kids?
lateral ventricle = choroid plexus papilloma- see papillary features
fourth ventricle = ependymoma - see rosettes
choroid plexus in adults is usually 4th ventrcile
SBS triad
encephalopathy, SD hematoma, retinal hemorrhages
- as well as severe brain atrophy and DAI
DAI
MVA or blow to unsupported head
- damages deep white matter –> wallerian degeneration
axonal swellings w/ beta amyloid protein build up
chronic traumatic encephalopathy
–> progressive depression and dementia d/t repetive DAI’s + concussions
build up of tau proteins, + tau stain - atrophy and loss of gray and white matter and dilated ventricles
subfalcine hernation
displaces cingulate gyrus under falx - may compress ACA
central herniation
CN VI –> lateral rectus palsy (inability to turn eye outward) and diplopia
bilateral uncal herniation –> paresis –> coma
uncal transtentorial herniation
herniation of medial temporal lobe through tentorium membrane
- impingement on corticospinal tract (cerebral peduncles) : hemiplegia, coma
o ipsilateral (kernohon’s) or contralateral d/t direct compression of uncus
o Compression of the cerebral peduncles → hemiplegia (paralysis of half of the body).
o often the hemiplegia is contralateral to the lesion either because of uncal herniation compressing the ipsilateral corticospinal tract in the midbrain, or because of a direct effect of the lesion on the ipsilateral motor cortex, or because of both.
o sometimes in uncal herniation, the midbrain is pushed all the way over until it is compressed by the opposite side of the tentorial notch (see Figure 5.6). In these cases the contralateral corticospinal tract is compressed, producing hemiplegia that is ipsilateral to the lesion. This is called Kernohan’s phenomenon. - CN III compromised → blown pupil
- may compress posterior cerebral artery, affecting primary visual cortex
tonisllar hernation
brain stem compromise –> resp and cardio effects –> death
duret hemorrhage
- herniation onto the brainstem compresses vessels and causes localized ischemia and bleeding into the pons and brainstem area
- caused by traumatic downward displacement of the brainstem, often secondary to raised ICP and formation of transtentoria pressure cone
- may be d/t uncal herniation
- results in ipsilateral hemiparesis to the lesion, often a false loclalizing sign
HIE
gray matter affected more than white
- see red neurons after reperfusion, interstitial edema, gliosis
** first affected are pyramidal cells of cA1 of hippocampus, layers 3,5,6 of neocortex, purkinje cells and striatal neurons === trouble with memory!
lacunar infarcts
d/t HTN and DM – seen in lenticulostriate aa. or small vessels – small infarcts on basal ganglia
atherosclerosis causing cerebral infarct?
often seen in carotid bifurcation or MCA or basilar aa.
small vessel disease causing cerebral infarct?
d/t HTN or DM or amyloid angiopathy –> results in vessels breaking causing hemorrhagic infarct or vessels causing lacunar infarcts
** occurs in lenticulostriate and mediastriat aa **
anterior chorodal artery small vessel disease
, usually supplies the medial globus pallidus, posterior limb of internal capsule, tail of caudate and optic tract.
** interruption of blood flow from this vessel can result in hemiplegia on the contralateral (opposite) side of the body, contralateral hemi-hypoesthesia, and homonymous hemianopsia
watershed infarct
b/w ACA-MCA or MCA-PCA areas – located at 2 and 3 o’clock
“man in barrel syndrome” areas involving trunk and proximal mm. are most affected
MCA occlusion vs. internal carotid artery?
both cause hemiplegia of that side as well as aphasia
however u/l blindness is only seen in internal carotid occlusion d/t this artery giving off the opthalmic artery
pathology of ischemic stroke
see edema dn loss of gray white matter junction, necrosis, liquefication and cyst formation
microscopic changes: 0-24 hours: red neurons 1-3 days: neutrophils/necrosis 3-10 days: microglia 2-3 weeks: gliosis and neovascularization months: psuedocyts w/ gliotic lining
wallenburg syndrome
lateral medullary syndrome
- PICA syndrome = loss of pain and temp on conralateral side of body and ipsilateral side of face
hemorrhagic strokes
result from rupture of lenticulostriate arteries, often d/t HTN And DM
lobar hemorrhage
think cerebral amyloid angiopathy - often leptomeningeal and cerebral cortical arterioles are affected
d/t accumulation of beta amyloid in the walls, seen w/ AD… and someimtes w/out AD
** Congo Red + depositions **
AVMs
lcoated in SA space -> can cause hemorrhage
port wine staine
sturge-weber syndrome = proliferation of vessels in SA space - can over time cause ischemia
HIE in infants
seen in mature infants - watershed lesions affecting gray matter! b/w MCA/ACA
moderate –> cerebral cortex –> triangular appearance
severe –> cortical and deep nuclei/brainstem damage –> thalamic calcification rimming ventricles
cause: infection, diff. delivery, abruption
PVL
periventricular leukomalacia - seen in preterm infants
ischemic damage to white matter near ventricles!
cause of CP
periventricular region is last to receive O2 b/c vessels grow down from surface
germinal matrix hemorrhage
occus in small babies who have hyaline membrane disease/RDS
symmetrically enlarged cerebral ventricles at 8 months of age!!! w/ seizures
• cause: vessels coming into the base of the brain that infuse the germinal matrix are weak and bleed into the germinal center
Morphology:
• hemorrhage associated with the ventricular wall : starts b/w the thalamus and the caudate nucleus and eventually ruptures into ventricles if large
• often bilateral
porecenephaly
fluid filled cavity confined to brain parenchyma – doesn’t spill into the SA space or ventricular system
schizencephaly
fluid filled clefts – lined by grey matter, can communicate with SA space and ventricular system
hydranencephaly
large obstruction of carotid artery → large portion of cerebrum undergoing autolysis → cyst replaces the whole cerebrum. This transilluminates!
- babies appear normal at first b/c brain stem is intact!
anencephaly
• = incomplete NT fushion, resulting in exposure of the dura and meninges to amniotic fliud → causes destruction of dura as well as underlying cerebrum
o initially the brain is protruding through the cranial vault
o Eventually, all that is left is a small, vascular mass of disorganized neural tissue (cerebrovasculosa) mixed with choroid plexus
o damage to hypothalamus → adrenal hypoplasia
• ~1 in 10,000 births: One of the most common neural tube defects
o Elevated alpha-fetoprotein and acetylcholinesterase in amniotic fluid and maternal blood
o Usually detected on ultrasound
o Folic acid
o incompatible w/ survival
• Anencephaly is often accompanied by spina bifida.
Craniorachischisis:
• most severe NTD, caused by defective closure of the hindbrain-cervical junction – the zipping doesn’t take place throughout the ENTIRE length of cord and head
Myelomeningocele
= Spina bifida
• Herniation of CNS tissue through vertebral defect
• (menigocele is same thing but it does not contain CNS tissue aka meninges)
• Common neural tube closure defect
• Can occur at any level, but»_space; lumbosacral
• Risk of infection
• Some loss of sensation/paralysis
• Folic acid
• Surgical correction
Meningocele = bulge through
defect w/ no CNS protrusion
Cause: failure of closure of NT
and lack of fusion of the vertebral arches, soft tissues and skin that cover the back
encephalocele
• Defect of cranial mesodermal development → Herniation of brain through an axial mesodermal (osseous) defect of the skull
o protruding part gets destroyed b/c of mechanical disruption/ ischemia
o large occipital encephaloceles are incompatible w/ life
o Meninges herniate with (less commonly without) normal brain tissue…tissue in sac gets destroyed
• 75% occipital, less commonly fronto-ethmoidal
Cause/Associations:
• Ciliopathies ??
• Sporadic or associated with other malformations…cardinal feature of Meckel-Gruber syndrome
Meckel-Gruber syndrome
rare lethal cioliopathic AR genetic disorder: MKS1 and MKS3 genes
• occipital encephalocele
• renal cystic dysplasia
• polydactyly
• hepatic development defects
• pulmonary hypoplasia d/t oligohydramnios
hydromelia
(over distension of the central canal):
• = syringomyelia = xs CSF in the central canal of the spinal cord
Symptoms:
• Pain in the neck; shoulders are usually numb
• headaches
• leg or hand weakness
• numbness or loss of sensation in the hands and feet
• problems with walking
• loss of bowel and bladder control
• spasticity and paralysis of the legs
chiari type I
: less severe
• small posterior fossa → herniation of a peg of cerebellar tonsil
• Skeletal abnormalities suggesting that occipital dysplasia is a major pathogenic factor
• There is no neural tube defect
• NOTE: there is no fourth ventricle herniation
Symptoms:
• Asymptomatic or neck pain, lower cranial nerve palsies, sleep apnea, sudden death
• Cerebellar ataxia, late onset hydrocephalus, long tract signs, signs of syringomyelia
• Syringomyelia (90%) – cape like distribution of loss of sensation of pain and temp – tubular cavitation where the central portion of cord gets large and filled with CSF
chiari type II
more severe
• Almost invariably with lumbosacral myelomeningocele
• Craniolacunia: shallow posterior fossa and enlarged foramen magnum, low tentorial insertion→herniation of vermis and tonsils
• Low torcula, short fenestrated falx
• Hydrocephalus (>80%)
Cause:
• small posterior fossa → downward extension of vermis through foramen magnum → hydrocephalus and almost always myelomeningocele (spina bifida)
Symptoms:
• damage results in cerebellar ataxia and loss mm. coordination
o vermis is imp. in mvmt and coordination as well as receiving info of sense and proprioception
o vermis is important in spatial position and movment
• Clinical findings in babies d/t brainstem compression:
o 1) These include stridor secondary to vocal cord paralysis
o 2) Central obstructive apnea
o 3) Swallowing difficulty
o 4) Breath-holding spells
o 5) Hypotonia
• Clinical findings in children:
o 1) Occipital and cervical pain
o 2) Myelopathy with weakness of the upper extremities
o 3) ataxia
o 4) strabismus
o 5) nystagmus;
o 6) defects of smooth pursuit and optokinetic movements
o 7) defect of convergence
o 8) scoliosis
dandy walker malformation
- large posterior fossa with absence of vermis
- usually associated with hydrocephalus (obstruction of CSF flow from fourth ventricle)
- genetically sporadic cause
holoprocencephaly
= cyclops
- absence of cleavage of forebrain, along with external features
- 50% w/ chromosomal anomaly, trisomy 13!!!
- accutane
agenesis of corpus collosum
ACC - asymptomatic! subltle perceptual deficits and some retardation
“bat wings”
PNH
Periventricular Nodular Heterotopia (PNH):
• neurons do not migrate AT ALL from the ventricle: the nodules on the ventricle contain gray matter w/in the ventricular wall
o PNH is characterized by unorganized islands of neurons under the ependyma of the lateral ventricles
lissencephaly
(smooth brain):
• Defective neuronal radial and tangential migration – no normal cortical layers are formed
• Absence of normal convolutions (smooth brain)
• Several underlying genetic abnormalitie -LIS1 mutation
• Some of these genes are associated with microtubule motor proteins and some disrupt microtubule dynamics
• Type I = smooth = complete loss of LS1
• Type 2 = “cobblestone”
polymicrogyria
• cortical organization is disrupted → increased number of gyri – surface shows multiple small bumps
o gray matter has 4 layers or less
o see small, unusually numerous cerebral convolutions
• Diffuse or focal, bilateral or unilateral, symmetric or asymmetric
• Variable neurologic disability
• Seizures, severe psychomotor retardation, spasticity
• Caused by disruptions after neuronal migration
• Intrauterine ischemia, twinning, infections
• Rarely in inherited metabolic syndromes
FCD
Focal cortical dysplasia (FCD):
• FCD is a sporadic developmental malformation of the cerebral cortex that causes intractable seizures and cognitive impairment.
o The core pathology of FCD is an abnormal cortical cytoarchitecture characterized by loss of normal layering.
o loss of layering of germ cells going to the surface, don’t utilize scaffold properly
• **The most frequent pathology in brain tissue removed in epilepsy surgery in children is focal cortical dysplasia. **
• Glioneuronal tumors (ganglioglioma, dysembryoblastic neuroepithelial tumor), vascular malformations, and other lesions are less frequent.
• A significant proportion have hippocampal sclerosis (HS), which is the most frequent lesion in older patients.
CSF in bacterial meningitis
high pressure, high protein, low glucose, lots of polys
CSF in viral meningitis
normal/slightly increased pressure, normal/slightly increased protein, normal glucose, monos present
meningitis birth to 2 mos
E Coli
Group B strep
Listeria
child/adult meningitis
Strep pneumonia Neisseria meningitidis (meningococcus)
