Exam 2: CNS Flashcards
Reversible neuronal injury examples
Swelling of soma and axons
Aka spheroid
Spheroids can displace
Nissl bodies
Irreversible neuronal injury
Some shrinks
Pyknosis - nucleus necrosis
Eosinophilia
___ freq from acute hypoxia
Irreversible neuronal injury
Red neurons characteristic of
Irreversible neuronal injury
Astrocytes Function in
Gliosis
Activated astrocytes
Gemistrocytic astrocyte
Oligodendrocytes
Produce myelin in CNS
Oligodendrocytes can also be site for
Viral inclusions
Microglia
Phagocytes of CNS
Ependymal cells line
Ventricles and spinal cord
___ likes to infect ependymal cells
CMV
Viral infections: disease and inclusion
Rabies = negri body
CMV = owl’s eye appearance
Neurodegenerative diseases: name and inclusion
Parkinson’s = Lewy bodies
Alzheimer’s = beta amyloid plaques (tau protein); neurofibrillary tangles
Lipofuscin
Lipid accumulations
Increase in ICP can be due to
Blood
Pus
Tumor
Edema
Vasogenic edema
Disrupted BBB
Extracellular edema
Cytotoxic edema
Disrupted neuronal/glial membranes
Intracellular edema
Cerebral edema cause gyri to ___, sulci to ___, ventricles ___
Flatten
Narrow
Compressed
Hydrocephalus
Increase CSF volume in ventricles
Hydrocephalus can be due to
Disturbed CSF flow or resorption
Types of edema
Vasogenic
Cytotoxic
Hydrocephalus MC from
Choroid plexus tumor
Communicating hydrocephalus
Bilateral
Even
Noncommunicating hydrocephalus
Localized
Uneven
Under 2, hydrocephalus causes
Cranium expansion
Older than 2, hydrocephalus causes
Increase ICP
Enlarged ventricles
Half of all cases of hydrocephalus are
Idiopathic
Hydrocephalus Ex Vacuo
Due to infarction or neurodegeneration
Herniated brain tissue can shift where?
Across dural structures
Through foramen magnum
Herniation often follows
Increase in ICP
Types of herniation
Subfalcine (cingulate)
Transtentorial (uncinate)
Tonsillar
MC type of herniation
Subfalcine (cingulate)
Untreated hydrocephalus can cause
Respiratory arrest
Subfalcine herniation
Cingulate gyrus,under falx
Abnormal posturing
Coma
Transtentorial herniation
Uncinate fasciculus (temporal lobe) under tentorium
CN3 involvement, blown pupil, and diplopia can result from
Transtentorial herniation
Tonsillar herniation
Cerebellar tonsils through FM
Headache, cardiorespiratory arrest
Duret hemorrhage
Disrupts vessels in pons
Flame shaped bleeds indicates
Duret hemmorrhage
Duret hemorrahage can result from
Transtentorial herniation
Types of abnormal posturing
Decorticate rigidity
Decerebrate rigidity
Decorticate rigidity
Brachial flexion
Injury between cortex and red nuclei
Decerebrate rigidity
All limbs extended, flexed wrists
Injury in brainstem between red nuclei and vestibular nuclei
Mydriasis
Dilation of pupil
Anisocoria
Unequal pupil size
MC chiari malformation
Type 1
Type 1 chiari malformation
Mild
Low lying cerebellar tonsils
Downward extension through FM
Adults
Arnold-Chiari malformation
Small post fossa
Misshapen midline cerebellum
Downward extension through FM
Associated with myelomeningocele
Type 2 chiari malformation effects
Infants or in utero
Chiari malformations aka
Post fossa abnormalities
Tx for chiari malformations
Neurosurgical decompression
5th MC mortality in US
CVD
MC cause of neurological morbidity
CVD
3 mechanisms that cause CVD
Thrombotic occlusion
Embolic occlusion
Disruption of vessel wall
Stroke causes ___ to CNS tissues
Liquefactive necrosis
2 primary forms of stroke
Ischemic
Hemorrhagic
Ischemia
Lack of blood to area
Hemorrhagic
Injure CNS tissue + disrupt BBB
Features of stroke
Unilateral facial drooping
Difficulty speaking
Contralateral paralysis
Stroke preserves
Motor to upper face
- can close eyes tightly
- can wrinkle forehead symmetrically
With a TIA, normal function returns in
24 hrs from time of onset
Paralysis of CN7
Bell’s palsy
MC age for Bell’s palsy
15-45 yo
Features of Bell’s palsy
Asymmetrical forehead weakness
Unilateral paralysis of face
Potential causes of hypoxia
Altitude
CO
Anemia
Cyanide
Global cerebral ischemia
Low blood perfusion to entire brain
___ provides some collateral flow to brain
Circle of Willis
Isolated area of low blood flow
Focal cerebral ischemia
Deep tissues have minimal collateral supply, which include
Thalamus
Basal ganglia
Deep white matter
MC cause of focal cerebral ischemia
Emboli
Cerebral infarction: 12-48 hrs
Neutrophils
Red neurons
Edema
Cerebral infarction: 48 hrs-2 weeks
Nuclear fragmentation (karyorrhexis) Liquefaction
Hemorrhagic stoke involves
Reperfusion
Cerebral infarction: weeks-years
Macrophages
Gliosis
Cavitation
Causes of intracranial hemorrhage
Vascular injury
Malformations
Tumors
Trauma
Bleeding inside brain
Intracranial hemorrhage
MC cause of intracranial hemorrhage
HTN
Extravasation of blood will
Coagulate
Compress parenchyma
HTN MC cause of _____, which involves spontaneous microbleeds
Primary brain parenchymal hemorrhage
Berry aneurysm aka
Saccular aneurysm
Saccular aneurysm occur at branch points of
Circle of Willis
“ Worst headache I’ve ever head” indicates
Subarachnoid hemorrhage
MC cause of subarachnoid hemorrhage
Ruptured saccular aneurysm
1st episode of subarachnoid hemorrhage results in
25-50% lethal
Subarachnoid Bleeding is ____, and 1/3 come from increased ICP
Non-traumatic
Clinical decision rule for subarachnoid hemorrhage
- > 40 yo
- Neck pain or stiffness
- LOC
- Thunderclap HA
- Limited neck flexion
Saccular aneurysm associated with
Polycystic kidney disease
Method used to evaluate potential brain bleeds
CT scan
Polycystic kidney disease due to
Autosomal dominant PKD1 or 2 gene
Asymptomatic until 30s, flank pain, hematuria, HA all describe
Polycystic kidney disease
PKD can also cause cysts in ___ and saccular aneurysms
Liver
Berry aneurysm MC in
Anterior circulation of branch points of circle of Willis
Saccular aneurysm may scar and produce
Hydrocephalus
Arteriovenous malformation (AVM)
Tangle of arteries and veins
Fistula
AVM MC
Cerebrovascular malformation
AVM MC in ___ ages ___
Males
10-30 yo
“Worm-like” mass describes
AVM
___ weakens vessels walls that can easier rupture
HTN
Diastolic BP > 130 =
Severe ICP
HTN encephalopathy can break down
BBB
HTN encephalopathy can cause widespread
Cerebral edema
4 types of intracranial hemorrhages
Primary brain parenchymal
Subarachnoid
Ruptured AVM
Lacunar infarction and slit hemorrhage
__ 2X more likely to have CNS trauma
Males
CNS trauma can result in ___ and ___
Morbidity
Mortality
Suspected CNS injury, assess…
Airway
Breathing
Circulation
Disability
Chronic traumatic encephalopathy (CTE)
Dementia pugilistica
Repetitive trauma
Confusion
Cerebral hemorrhage
Laceration
Tears in cerebral parenchyma
__ more susceptible to contusion
Gyri (frontal and temporal)
Coup injury
At impact site
Contrecoup injury
Opposite site of impact
Laceration can be caused by
Bullet
Knife
Nail
Traumatic parenchymal injuries include
Contusions
Lacerations
Diffuse axonal injury
Diffuse axonal injury
Movement of one brain region, relative to another
DAI can cause
Diffuse white matter damage
Widespread edema
Coma
Death
DAI can be caused by
Angular acceleration
Shaken baby syndrome components
Subdural hematoma
Cerebral edema
Bilateral retinal bleeding
Shaken baby syndrome can cause
Severe brain damage Blindness Reduced cognition Motor impairment 25% fatal
In concussion, MRI and CT are
Normal
Concussion
Reversible alteration in consciousness from head injury
Post concussive syndrome
Prolonged symptoms of concussion, weeks to months
__ of concussions result in post concussive syndrome
15-20%
___ may be lethal, so concussion excludes return to play
Second impact syndrome
____ associated with skull fracture
Epidural hematoma
Subdural hematoma MC occur in
Infants
Geriatrics
Dural artery damage that compresses brain tissue and may cause lucidity during bleed
Epidural hematoma
Rapid movements tear veins, subdural bleeding that compresses brain
Subdural hematoma
Epidural hematoma MC involves
Middle meningeal A
Epidural hematoma is ___ within hours
Lethal
____ more common than subdural hematoma
Epidural hematoma
Neural tube fails to close
Neural tube defects
MC CNS malformation
Neural tube defects
Risks for neural tube defect
Low folate
Previous child
Types of neural tube defects
Spina Bifida Occulta
Myelomeningocele
Anencephaly
Encephalocele
Myelomeningocele
Extension of CNS through vertebral defect (lumbosacral)
Anencephaly
Absence of brain, rostral aspect
Encephalocele
CNS diverticulum, cranial
Encephalocele involves what characteristics
Craniofacial abnormalities
Larger = more severe
Hydromyelia
Extended 4th ventricle
Syringomyelia aka
Syrinx
Syrinx
Cyst within cord in adults
Syrinx can cause
Loss of pain/temperature sensation (shawl-like distribution)
Possible tissue atrophy or areflexia
Syrinx associated with
Type 1 chiari
Intraparenchymal hemorrhage
Deep (near ventricles)
Perinatal brain injuries
Intraparenchymal hemorrhage
Infarct
Cerebral palsy
Forms chalky plaques
Infarct
Non-progressive motor defects
Cerebral palsy
Things that can infect CNS
Bacteria
Viruses
Fungi
Epidural abscess
Infection in epidural space
Subdural empyema
Infection of subdural space