Exam 2 (Chapter 22: CNS) Flashcards
Decreased axonal transport (spheroids), swelling of soma, displacement of Nissl bodies, and central chromatolysis are are possible signs of what type of injury?
Reversible Neuronal Injury
Type of injury that results from an acute hypoxic injury resulting in soma shrinkage, pyknosis, and red neurons all within 12-24 hours
Irreversible Neuronal Injury
T/F Cerebral edema, loss of nucleolus and nissl body are all found in reversible neuronal injury
FALSE.
All are examples of Irreversible neuronal injury
Pattern of neuronal injury in Astrocytes
- CNS fibrosis
- Injury causes hypertrophy and hyperplasia enlarging the nucleus and being eosinophilic
- Causes glial filaments to sprout (
Patterns of neuronal injury in Oligodendrocytes
- Produce myelin in CNS
- Causes white matter damage and potential nuclear swelling
- Enlarged nucleus present
- May produce viral inclusions
Patterns of neuronal injury in Microglia
- Resident phagocytes of the CNS
- Cells proliferate and enlarge in response to injury, infection, etc. causing demyelination, infarctions, and hemorrhaging
- Neurophagia = active microglia
Patterns of neuronal injury in Ependymal cells that line ventricles and the spinal cord
- Prone to infections like CMV
- Affected with irregularities of ventricular surface (possibly from viral inclusions)
- May involve the choroid plexus (fxn: produces CSF)
Intracellular inclusion associated with Rabies
Negri body
Intracellular inclusion associated with CMV
Owls eye (aliens head)
Intracellular inclusion associated with Parkinson disease
Lewy body
Intracellular inclusions associated with Alzheimers disease
Neurofibrillary tangles
Beta-amyloid plaques
Protein that accumulates in any neurodegenerative diseases
Tau proteins
Edema resulting from a blood-brain-barrier disrupton causing increased permeability leading to extracellular edema
Vasogenic edema
Examples that cause localized and generalized vasogenic edema
Local- tumors, infarction, inflammation
General- Severe trauma
Edema caused by neuronal/glial membrane injury causing intracellular edema
Cytotoxic edema
Examples that cause Cytotoxic edema
Hypoxic-ischemic injury
Toxic exposure
Physical signs of cerebral edema (post-mortem)
Flattened gyri
Narrow sulci
Ventricular compression
Condition caused by an increase in CSF volume within the ventricles
Hydrocephalus
T/F Hydrocephalus is most likely caused by an overproduction of CSF (like a choroidoma) instead of a disturbance in flow or resorption
FALSE.
Disturbance in flow/ resorption is more likely to cause hydrocephalus
What affect would hydrocephalus have on someone < 2 years old? >2 years old?
- < 2 years old = cranial enlargement
- >2 years old = increased ICP and ventricular enlargement
Intracellular inclusion caused by aging
Lipofuscin (lipid accumulation)
Treatment for hydrocephalus
Shunting
Compensatory hydrocephalus causing infarction and neurodegeneration
Hydrocephalus ex vacuo
Herniation of the brain across the dura or through the foramen magnum causing compression on neurons and vessels
Cerebrum shifts
Displaced cingulate gyrus under falx cerebri causing abnormal posturing or a coma
Subfalcine (cingulate) brain herniation
Displaced temporal love under the anterior tentorium causing cranial nerve involvement, hemiparesis, and brainstem compression
Transtentorial (uncinate) brain herniation
Abnormal vision and a blown pupil are symtpoms of what type of brain herniation
Transtentorial (uncinate) brain hernation
-Involves compromise of the oculomotor nerve (CN III)
Displaced cerebellar tonsils through the foramen magnum. Can cause cardiorespiratory arrest, hydrocephalus, and headache
Tonsillar brain herniation
T/F Transtentorial (uncinate) brain herniation is the most common type of brain herniation
FALSE.
Subfalcine (cingulate) brain herniation is the most common type
When a brain herniation causes disruption of vessels that enter the pons, producing a flame shaped hemorrhage
Duret hemorrhage
Malformations and types that cause herniation of the cerebellar tonsils
Arnold-Chiari malformations
- Type I = MC, milder, present in adults
- Type II = severe, present in infants
Cerebrovascular disease causing no infarction and temporary neurological dysfunction that do not exist past 24 hours.
Transient Ischemic Attack (TIA a.k.a. Mini-stroke)
Cerebrovascular disease caused by an infarction that produces acute function. Results from either an occlusion or a rupture
Stroke
Types of stroke
Thrombotic occlusion
Embolic occlusion
Vascular rupture (dissection)
T/F The top 3 leading causes of mortality in the U.S. are: 1) Heart disease 2) Cancer 3) Stroke
True
Ischemia/hypoxia causes what type of necrosis in the CNS?
Liquefactive necrosis
A decrease in oxygen partial pressure or oxygen availability to the brain causes this type of hypoxia
Functional hypoxia
A decrease in oxygen to the brain caused by a occlusion, TIA, or stroke
Ischemic hypoxia
Widespread ischemic-hypoxic injury to the brain severe enough to cause widespread neuronal death leading cerebral edema,gliosis, and red neurons. Results in neurological impairment or coma.
Global cerebral ischemia
Condition where a person has been unconscious for more than 6 hours
Comatose
What can limit injury caused by cerebral ischemia?
Collateral circulation (from circle of Willis)
What parts of the brain have minimal collateral circulation and are therefore more susceptible to damage from ischemia?
Deep brain structures
-Thalamus, basal ganglia, deep white matter
T/F Emboli are more common to cause focal cerebral ischemia than thrombi
True
What blood vessels are emboli and thrombi more likely to originate from in focal cerebral ischemia?
Emboli- carotid artery or middle meningeal artery
Thrombi- carotid artery, aortic arch, middle cerebral artery
Spontaneous hemorrhage of small intraparenchymal vessels causing a cerebral microbleed that can range from clinically silent to lethal. Most commonly caused by hypertension in people over the age of 60.
Primary brain parenchymal hemorrhage
Accumulation of blood in the suparachnoid space. Most commonly results from a rupture of a berry aneurysm originating from a defect in the tunica media of the vessel.
Subarachnoid hemorrhage
Your patient comes into your office complaining of the worst headache they have ever had. Their history shows no history of headaches. What life threatening condition should you always rule out first?
Subarachnoid hemorrhage
Condition caused by a tangle of arteries or veins with at least 1 fistula present. Most common in males (2x) 10-30 years old and increases a persons risk of developing seizures or hemorrhaging
Arteriovenous malformations (AVM)
Hypertensive cerebrovascular disease caused by a single artery occlusion.
Lacunar infact
Hypertensive cerebrovascular disease caused by a ruptured small cerebral vessel that hemorrhages, it resorbed, and leaves a slit-like cavity
Slit hemorrhage
Hypertensive cerebrovascular disease that causes global cerebral dysfunction. Biastolic BP > 130 causing increased intercranial pressure, headache, confusion, coma, vomiting, and convulsions
Acute hypertensive encephalopathy
Vessel wall inflammation
Vasculitis
Systemic autoimmune vasculitis causing fibrinoid necrosis in the small cerebral arteries and heart
Polyarteritis nodosa
Condition causes chronic inflammation in multiple parenchymal and subarachnoid vessels. Idiopathic, but more common in males and is associated with diffuse encephalopathy (like decreased cognition)
Primary Angiitis of the CNS
T/F There is no sexual preference for male or females to develop CNS trauma
FALSE
Males are 2x as likely as females to have CNS trauma
