Intro to Neuropathology part 2 Flashcards
What type of necrosis occurs with CNS infarcts?
Liquefactive Necrosis
Describe Liquefactive Necrosis
Digestion of tissue into liquid viscous mass with NO architectural remnants!
Liquefactive Necrosis involves the loss of architectural remnants. How does that differ from coagulative necrosis that occurs in other organs besides the CNS?
Coagulative necrosis involves the architecture remaining!
Describe the general steps that occur in the CNS with an acute ischemic injury
- Red neurons
- Presence of macrophages and reactive gliosis
- CNS infarct and liquefactive necrosis
What malformations/developmental disorders are the most common with the CNS?
Neural tube defects
Neural tube defects involve the failure of the tube to close or a portion reopening. What deficiency is common? When does the tube usually close?
Folate deficiency
– Tube closes by day 28 = before pregnancy is usually noticed
List some of the possible Neural Tube Defects
Spina Bifida – occulta/meningocele/myelomeningocele
Encephalocele
Anencephaly
Spina Bifida Occulta
Asymptomatic bony defect
Meningocele
Bony defect with meninges protruding in a pouch
Myelomeningocele
Bony defect with meninges + CNS tissue protruding in a pouch
Meningocele and Myelomeningocele neural tube defects may present with what symptoms?
LE deficits
Bowel issues
Infections
Encephalocele and Anencephaly neural tube defects occur in what trimester?
1st
Encephalocele
Disorganized brain tissue extends through a defect in the cranium
– usually posterior fossa
Anencephaly and when it occurs?
Absence of most of the brain and calvarium
– forebrain development disrupted at 28 days gestation
Forebrain Anomalies involve abnormalities in?
Generation and migration of neurons
List some of the possible Forebrain Anomalies
Mega/microcephaly Lissenencephaly Polymicrogyria Neuronal Heterotopias Holoprosencephaly Agenesis of corpus callosum
Microcephaly involves a decreased number of neurons and a small head. What is it associated with?
Fetal alcohol syndrome, HIV1, Zika virus
Lissenencephaly
DECREASED # of gyri = smooth or cobblestone surface of brain
Polymicrogyria
Small and numerous irregular gyri
– gray matter is < 4 layers and meningeal tissue is trapped
Neuronal Heterotopias
Collections of neurons in inappropriate locations along pathway
What are Neuronal Heterotopias associated with?
Epilepsy
If the X chromosome Filamen A and DCX proteins are altered, what forebrain anomalies will occur in males and females respectively?
Males = lissenencephaly Females = Neuronal Heterotopias
Holoprosencephaly and its possible symptoms
Incomplete separation of cerebral hemispheres
- cyclopia, absent CN1, associated with trisomy 13
Agenesis of corpus callosum appears how?
Bat wing lateral ventricles
– normal or decreased IQ
List some of the Posterior Fossa Anomalies
Arnold-Chiari Malformation
Dandy-Walker Malformation
Syringomyelia/Hydromyelia
Joubert Syndrome
Arnold - Chiari Malformation
SMALL posterior fossa
Type 1 Chiari malformation
Low-lying cerebellar tonsils
== Usually SILENT
Type 2 Chiari malformation is more severe. Describe it.
Downward extension of cerebellar vermis through the foramen magnum
– usually with a myelomeningocele and hydrocephalus
Dandy - Walker Malformation
ENLARGED posterior fossa
What are the manifestations in the brain of the Dandy-Walker Malformation?
Expanded roofless 4th ventricle = ABSENT cerebellar vermis
– Replaced by ependymal cyst
Syringomyelia (syrinx)
Fluid filled cavity in inner portion of spinal cord
What are the symptoms of Syringomyelia (syrinx) and why?
Loss of pain and temperature sensation in the UE only!!
– interrupts fibers that cross the white commissure
Hydromyelia
Expansion of ependymal-lined central canal of spinal cord
Joubert Syndrome
Vermis hypoplasia that creates a “molar tooth” sign
What are some Perinatal Brain Injuries that can occur?
Cerebral palsy Intraparenchymal hemorrhage Periventricular leukomalacia Multicystic Encephalopathy Ulegyria
Cerebral palsy
Non-progressive neurologic motor deficit attributable to insults that occurred during the prenatal/perinatal period
Where and in who are Intraparenchymal Hemorrhages seen?
In the germinal matrix (between thalamus and caudate nucleus) of preemies
Periventricular Leukomalacia
Infarcts in supratentorial white matter
= Chalky yellow plaques that turn into large cystic spaces in preemies
Multicystic Encephalopathy
Ischemic damage –> large destructive lesions
Ulegyria
Ischemic lesions in the depth of sulci –> thinned gliotic gyri
If a person is awake and they fall, the likely direction was? If a person loses consciousness and they fall, the likely direction was?
Awake = occipital injury by falling back
Loss of consciousness = frontal injury by falling forwards
Diastatic skull fracture
Fracture that crosses a suture
What is unique about later skull fractures?
They do NOT cross previous fracture lines
Displaced/Depressed skull fractures
Bone displaced into cranial cavity by a distance > bone thickness
Basal skull fracture
Break of bone in the base of the skull
– orbital or mastoid hematomas
What are the signs of a basal skull fracture?
- CSF drainage from ear or nose
- Raccoon eyes
- Battle’s bruise behind the ear
What are the 3 parenchymal injuries?
- Concussion
- Direct Parenchymal Injury
- Diffuse Axonal Injury
A concussion is a _____ syndrome that is brought about by?
CLINICAL syndrome
– head momentum change
Concussions involve transient neuro dysfunction. The patient will fully heal although they may have?
Amnesia of event
Direct Parenchymal Injury
Contusions from blunt trauma and lacerations due to kinetic injury to the brain
What area of the brain is the most susceptible to direct parenchymal injuries and what is the shape of the contusion?
Crests of gyri with wedge shaped contusion
Coup
Contusion at the point of impact
Countercoup
Contusion opposite of the site of impact – ex. deceleration
Plaque Jaune
Old countercoup lesions that are depressed yellow/brown patches
What can Plaque Jaunes become?
Epileptic focus
Diffuse Axonal Injury
Axonal swelling +/- focal hemorrhagic lesions
What stains can be (+) with Diffuse Axonal Injuries?
Silver stain
Amyloid precursor protein
Alpha Synuclein
What constellation of injuries is usually present with Shaken Baby Syndrome?
Diffuse Axonal Injury/cerebral edema
Subdural hematomas
Retinal hemorrhages
Altered state of consciousness with brain function temporarily or permanently impaired
Traumatic Brain Injury
Chronic Traumatic Encephalopathy (CTE)
Repetitive brain trauma
What are the signs of CTE on the brain?
Atrophy
Enlarged ventricles
Tau neurofibrillary tangles
Epidural hematomas occur rapidly. What type of blood, its source and why?
Arterial blood from middle meningeal artery due to skull fracture
Subdural hematomas occur slowly. What type of blood?
Venous blood
