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213 Cards in this Set
- Front
- Back
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How do neurons react to injury?
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Shrink (ischemia)
Swell (fluid comes in) |
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Does swelling mean that a neuron is going to die?
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No, it may be able to recover
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True or false. Neurons have the capacity to regenerate.
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False, neurons do not have the capacity to regenerate
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Why do neurons require adequate blood flow at all times?
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They do not have glucose reserves so they require adequate blood flow at all times.
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What is astrocytic scarring?
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Astrocytes can proliferate during injury=astrocytic scarring
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What causes swelling in axons?
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When axons are injured they cannot perform retrograde transport to take everything that is degraded and processed back up
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What are 3 ways that demyelination of CNS axons can occur?
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1) Oligodendrocytes die
2) Axon dies (Wallerian Degeneration) 3) Primary demyelination |
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What is the function of astrocytes?
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Protect and stabilize the neuonal environment
-Protects neuron from neurotransmitters and toxins that are in the vessels |
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How do astrocytes react to CNS injury?
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1) Proliferate
2) Swell 3) Swell & hypertrophy 4) Develop extensive processes (glial scarring) |
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How do axons respond to injury?
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-Can swell to form spheroids, swelling may or may not be reversible
-Can also fragment |
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How do astrocytes repair CNS injury?
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Astrocytic swelling and division and abundant proliferation of astrocytic processes=astrogliosis
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How do astrocytes participate in the immune response and inflammation in the CNS?
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1) Can express MHC I & II antigens
2) Produce cytokines and chemokines and secrete growth factors and adhesion molecules that modulate inflammatory events in CNS 3) Produce ECM molecules that play a role in repair of CNS (& development) |
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What happens to the space formed when neuronal cell bodies die?
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Filled in by processes of astrocytes (astrogliosis)
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What is Wallerian degeneration?
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Primary axonal injury with secondary demyelination
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How does the regenerative capacity of the CNS compare to that of the PNS?
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PNS can regeneration, CNS cannot
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What is the blood brain barrier comprised of?
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1) Nonfenestrated capillaries
2) Basement membrane 3) Astrocyte foot processes |
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What is the primary blockage of the blood brain barrier?
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Tight junctions b/w endothelial cells of the non-fenestrated capillaries
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What molecules readily pass through the blood brain barrier?
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Oxygen, carbon dioxide, glucose, sodium, potassium, chlorine, water and non-polar anesthetics & antibiotics
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What does the blood-CSF barrier consist of?
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1) Fenestrated capillaries
2) Basement membrane 3) Choroid epithelial cells |
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What provides the primary blockage in the blood-CSF barrier?
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Tight junctions b/w choroid epithelial cells
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How does movement b/w the CSF-blood brain barrier occur?
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B/w the arachnoid villi
-CSF--> blood flow allows easy escape of many molecules |
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Give 3 examples where damage to one component of the CNS alters structure or function of another CNS component.
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1) Oligodendrocyte damage--> lose myelin
2) Astrocyte damage--> dysfunction of neurons, immune system damage, NTs etc 3) Interfere w/ blood flow--> ischemia and neuronal cell death & no room to swell |
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Why doesn't the CNS heal with fibrosis?
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The only places there are fibroblasts in the CNS is the meninges and around the blood vessels.
-Astrocytes perform a similar function following damage as fibroblasts do in other tissues |
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List blood vessels, astrocytes, neurons, oligodendria and microglia in order of highest to lowest susceptibility to ischemic injury.
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Neurons> oligodendria > astrocytes> microglia> blood vessels
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What is excitotoxic injury (glutamate toxicity)?
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Cells are overstimulated w/ glutamate and it is toxic
Glutamate released when neurons injured--> damages neighboring neurons by over stimulation (secondary damge) |
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What happens when there's poor perfusion into the CNS?
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ATP depletion and lack of glucose
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What happens when there's reperfusion of the CNS?
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Get high calcium and low ATP
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Why is high calcium a problem in the CNS?
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Neurons have a limited ability to buffer shifts of calcium ions into the cell, which can interfere w/ oxidative phosphorylation and ATP production (like w/ ischemia)
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What damage do free radicals in the CNS cause?
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Increases calcium
Damages cell membrane |
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When do excitotoxins result in neuronal degeneration and death?
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Normally astrocytic processes surrounding synapses remove excitotoxins but in excessive quantities, persistent binding of excitotoxins to receptors leads to neuronal death
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Why can eating shellfish and marine mammals cause sometimes fatal CNS disease in people?
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Can be contaminated w/ marine algal blooms that produce domoic acid, a glutamate analog, which causes excitotoxic injury to the CNS
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True or false. It is uncommon to see a gross lesion in cases of CNS disease.
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True
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What is a grand mal seizure?
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When the animal loses consciousness
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If an animal presents in your clinic and is seizuring, what questions should you ask the owner?
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How long did it last?
Is the animal aware of you?* Did the animal lose consciousness? |
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What is the neuroanatomic diagnosis associated with seizures (what part of the brain is malfunctioning)?
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Prosencephalon (cerebrum) and thalamus
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The neurophysiologic basis for seizures is related to what?
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A focus of abnormal electrical activity
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What are 9 extracranial causes of seizures?
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1) Hypoglycemia
2) Hypocalcemia 3) Liver disease 4) Hypoxia 5) Hypokalemia 6) Hypomagnesemia 7) Hyperlipoproteinemia 8) Hyperthermia 9) Intestinal parasitism in PUPPIES |
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What are 6 intracranial causes of seizures?
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1) Idiopathic epilepsy
2) Inflammation 3) Neoplasia 4) Malformation 5) Injury-traumatic & toxic 6) Neuronal degeneration |
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What are 3 common causes of seizuring in puppies?
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1) Intestinal parasites ***
2) Hypoglycemia 3) Malformation |
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What are 5 common causes of seizuring in dogs up to 6 months of age?
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1) Hypoglycemia
2) Portosystemic shunt 3) Malformation 4) Canine distemper 5) Protozoa (toxoplasma, neospora) |
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What are 4 common causes of seizures in a dog 1-3 years of age?
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1) Idiopathic epilepsy*
2) Distemper 3) Portosystemic shunt 4) Malformation |
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What are 2 common causes of seizures in a middle aged to older dog or cat?
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1) Tumors
2) Metabolic disorders |
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What is a common cause of a seizure in a dog or cat of any age that occurs suddenly and rapidly leads to death?
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Toxicity
SEND LIVER!!!! |
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A dog comes into your hospital and isn't seizing anymore but is still alive what should you do?
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Neurological exam-idiopathic epilepsy would be normal, tumor in cerebrum will see signs on opposite side of damage, look for evidence of a space occupying lesion
-Puppy-do fecal -Routine blood work to rule out extracranial causes |
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True or false. Severe cerebral dysfunction is also seen in animals with renal encephalopathy.
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False, with hepatic encephalopathy
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What animals is hepatic encephalopathy most commonly seen in?
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Horses & dogs
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What are the clinical signs of hepatic encephalopathy?
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Vary from severe depression, blindness, and head pressing to maniacal behavior & seizures
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What type of clinicopathologic testing should be done if you suspect hepatic encephalopathy?
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Liver parameters, bile acids and especially blood ammonia
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Why does liver dysfunction lead to brain problems?
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Liver is important for waste removal for what comes from GI and ammonia compounds that need to be detoxified because if go to brain are small enough to go through BBB so astrocytes have to remove them and if damaged ammonia gets through
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What are 5 conditions that can lead to hepatic encephalopathy?
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1) Hepatocellular necrosis-severe or diffuse, liver enzymes are released
2) Hepatic cirrhosis-liver is scarred & disrupts circulation 3) Portosystemic shunt 4) Portal vein thrombosis 5) Equine idiopathic hyperammonemia (not really a liver disease)-something goes wrong in intestine and makes so much ammonia the liver is overwhelmed (presents like liver disease) |
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What does it mean if there are liver enzymes in circulation?
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Means the hepatocytes are no longer intact
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How much liver has to be non-functional for hepatic encephalopathy to develop?
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A lot
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True or false. The microscopic changes of hepatic encephalopathy are rather obvious causing severe dysfunction.
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False, the microscopic lesions are subtle but cause severe dysfunction-hard to detect in fixed brain
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Malformations that affect CNS function can result from abnormal development of the _________ and from abnormal development of the _______ & ________.
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Neural tube
Cranium Vertebral column |
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Explain how malformations of the vertebral column and of the associated spinal cord can be related. That is how can an abnormality of one result in an abnormality of the other?
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They are intimately related during development and there's lots of cell migration and signaling between the tissue forming the spinal cord and the neural tissue.
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What does myelodysplasia mean with reference to the CNS?
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A general term for malformation of the spinal cord.
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What animals are most commonly affected by myelodysplasia (of CNS)?
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Cattle & dogs
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What is spina bifida?
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A common defect in which the vertebral arches fail to fuse dorsally-neural tube doesn't close and have a visible spinal cord
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What do terms such as meningocele and meningoencephalocele refer to?
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Lesions in which meninges or meninges and spinal cord protrude through the defect
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What is it called when the cranial bones failure to fuse properly?
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Cranium bifidum
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What can happen when an animal has cranium bifidum?
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Can have meningocele of the cranium or meningoencephalocele
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What is a type of cephalic disorder wherein the brain is located outside of the skull?
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Exencephaly-not compatible w/ life
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What is lissencephaly?
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Cerebrum doesn't develop correctly and has no gyri or sulci so do not have a normal functioning brain ("difficult to train")
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Lissencephaly is most common in what animal?
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Lhaso Apso dogs
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What CNS malformation is common in Manx cats?
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Spina bifida (Segmental vertebral hypoplasia)
-Inherited as an autosomal dominant trait |
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What CNS malformation is common in English bull dogs?
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Spina bifida (Segmental vertebral hypoplasia)
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What CNS malformation is common in Burmese cats?
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Exencephaly
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What is kyphosis?
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A curving of the spine that causes a bowing of the back, which leads to a hunchback or slouching posture (spine bends up, protrudes dorsally in column)
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What is lordosis?
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Spine bends down (like a U)
-Inward curvature of a portion of vertebral column |
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What is scoliosis?
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Lateral curving of the spine
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Does kyphosis, lordosis and scoliosis and other vertebral anomalies always result in spinal cord dysfunction?
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No
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What is the most common mechanism by which skeletal abnormalities result in CNS dysfunction when the CNS is not malformed?
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Spinal cord compression
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How can you determine whether a vertebral abnormality is the cause of neurologic disease?
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Perform a neuro exam, maybe myelogram or other imaging
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What are the most common caudal cranial (that is, posterior portion of cranial bones) or vertebral malformations that cause spinal disease in horses?
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Cervical vertebral malformation/cervical stenotic myelopathy (see abnormalities during growth)-"wobbler"
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What cervical vertebral malformation is inherited in Arabian horses?
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Occipitoatlantal malformation
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What are the most common caudal cranial (that is, posterior portion of cranial bones) or vertebral malformations that cause spinal disease in toy breeds of dogs?
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Hypoplastic dens
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What are the most common caudal cranial (that is, posterior portion of cranial bones) or vertebral malformations that cause spinal disease in Great danes and doberman pinschers?
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Caudal cervical vertebral malformation
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In what age group will signs of caudal cranial or vertebral malformations typically appear?
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Relatively young/growing animals
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What is hydrocephalus?
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Obstruction of internal flow pattern of CSF resulting in back up and pressure necrosis of the periventricular tissue and enlarged ventricles.
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What general processes can cause hydrocephaly?
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Failure of CSF absorption due to some type of diffuse obstruction in subarachnoid space i.e. inflammatory diseases, external communicating hydrocephalus can occur.
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What is hydranencephaly?
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Destruction of periventricular white matter (corona radiata) resulting in compensatory hydrocephalus i.e. sheep in utero infection w/ blue tongue virus or copper deficiency
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What is the primary and secondary lesion associated w/ hydranencephaly?
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Primary lesion: tissue destruction and/or cavitation
Secondary: enlarged ventricles are a phenomenon |
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What is measured when a clinician suspects hydrocephalus?
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CSF pressure
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What do you call a smooth brain?
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Lissencephaly
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Hydrocephalus is a common malformation of the brain in animals and occurs most commonly in the ________.
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Dog
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What produces CSF?
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Choroid plexus-vessels in lateral, third and fourth ventricles
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What absorbs CSF?
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Choroid plexus epithelium--> arachnoid villi (absorbs)
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What's the only way to decrease CSF production?
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Change the osmotic pressure of the blood (if interfere w/ absorption just keeps building up!)
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What are the clinical signs associated with hydrocephaly?
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Behavioral changes, poor motor skill development, delay in learned behavior, somnolence (drowsiness), dullness, episodic confusion, circling, periodic aggression, seizures, cortical blindness
-Cerebral localizing signs -*Changes in mentation & behavior! |
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What is the neuroanatomic diagnosis of hydrocephaly?
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-Increased CSF fluid in the lateral ventricles w/ hydrostatic edema of the periventricular white matter.
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What physical findings are associated w/ congenital hydrocephalus?
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Domed head
Open fontanelle (where bones bones of cranium all fuse, but can have a soft spot-doesn't always mean hydrocephaly) |
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What breeds are predisposed to hydrocephaly?
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Brachycephalic breeds and small breeds w/ small heads: chihuahua, yorkshire terriers, manchester terries, boston terriers, toy poodles, pekinese, english bull dogs, pomerranians
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What causes congenital hydrocephalus?
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Malformations that obstruct flow of CSF
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What is the most common malformation that leads to hydrocephalus?
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Stenosis (narrowing) of the mesencephalic aqueduct
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What animal has a recognized inherited hydrocephalus?
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Angus cattle
-Thought to be autosomal recessive |
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Is acquired hydrocephaly or congenital hydrocephaly more common?
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Congenital
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What can cause acquired hydrocephaly?
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Any inflammatory or space occupying lesion that interferes w/ the flow of CSF
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What is associated with cerebral edema?
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Increased intracranial pressure
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What kind of CNS disease does cerebral edema cause?
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Diffuse cerebral disease-increased pressure can cause change in shape of brain, including flattening of cerebral gyri and flattening and herniation of the caudal cerebellum through the foramen magnum
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Why are even slight increases in intracranial pressure so detrimental to the brain? (2)
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1) Boney casing doesn't allow for expansion
2) No lymphatics, can't drain extra fluid |
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Why can herniation of the caudal cerebelum through the foramen magnum happen?
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Coning of the cerebellum happens because the foramen magnum is the only way out of the cranium
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Why do patients die with coning of the cerebellum?
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Because this is the part of the brain where the respiratory centers and cardiovascular control are
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What should you do if you suspect brain edema?
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Take a CSF tap from caudal cerebellum area
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What are some causes of local cerebral edema?
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Neoplasm, infections, parasitic cysts,space occupying lesions, trauma
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What causes generalized cerebral edema?
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Systemic conditions
Postmortem change |
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What is vasogenic edema?
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Increasd vascular permeability ---> increased ECF
-Vasculopathy, trauma, space occupying lesion |
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What is cytotoxic edema?
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Increase in intracellular fluid
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What is the most common type of cerebral edema?
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Vasogenic edema
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What is interstitial (hydrostatic) edema?
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-Associated w/ hydrocephalus leading to increased ventricular hydrostatic pressure and movement of fluid from ventricles into the brain parenchyma
-Less common form of brain edema |
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What is hypo-osmotic edema (osmolar imbalance)?
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Big differences in osmotic pressure b/w the brain vasculature and brain parenchyma can cause fluid movement from the vessels into the brain
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What type of cerebral edema is related to water toxicity (overconsumption of water)?
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Hypo-osmotic edema, too much water leads to reduced osmolality of the blood and fluid movement into the brain
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What type of cerebral edema is associated with the breakdown of the blood-brain-barrier?
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Vasogenic edema-damage to the endothelium allows leakage of plasma constituents
-Traumatic, inflammatory or hemorrhagic conditions |
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What are 3 ways that trauma can cause increased intracranial pressure and edema?
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1) Contusion=bruising (ruptured vessles)
2) Concussion-temporary loss of consciousness w/ head injury 3) Generalized acute swelling |
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What is coup-contrecoup contusion?
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-Coup contusion=brain injury on same side as impact
-Contrecoup contusion=injury to side opposite of impact -Both present=coup-contrecoup |
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How can infection cause increased intracranial pressure and edema?
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Inflammatory swelling
Break down of BBB |
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How does a space occupying lesion cause an increase in intracranial pressure and edema?
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Block CSF drainage
Cause inflammation Break down BBB |
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How can vascular leakage cause increased intracranial pressure and edema?
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Leakage of blood vessel constituents--> vasogenic edema
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Define polioencephalomalacia
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Cerebral cortical necrosis- defines a diffuse grey matter degenerative process that can be due to several causes
-Often used to define a specific disorder in cattle, sheep & goats |
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How is the pattern of necrosis in any form of polioencephalomalacia often described? why?
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As laminar due to selective involvement of neurons within the laminae of the cerebral cortex
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True or false. Gross lesions are always evident in cases of polioencephalomalacia.
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False, not always evident but can be
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What is the neuroanatomic diagnosis of polioencephalomalacia?
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Diffuse cerebral disease
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What are the clinical signs associated with diffuse cerebral disease?
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Cortical blindness, seizures, depression
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What are 4 common causes of diffuse cerebrocortical grey matter degeneration (polioencephalomalacia) in cattle, sheep & goats that have to do w/ thymine?
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1) Decrease in ruminal thiamine production (over growth of thiaminase-producing microbes)
2) Ingestion of thiaminase-containing plants (bracken fern) 3) Production of inactive thiamine analogs 4) Decreased absorption of thiamine (thiamine in feces) -Young ruminants fed high concentrate diets |
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What are 3 common causes of polioencephlomalacia in cattle, goats and sheep that are unrelated to thiamine?
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1) High sulfur diets
2) Hydrogen sulfide gas-pit gas 3) Cobalt deficiency, molasses and urea based diets |
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What is the significance of sulfur in development of cerebrocortical necrosis in cattle?
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Within the rumen, microorganisms will ferment sulfur containing substrates and produce hydrogen sulfide gas. The animal belches the gas from the rumen and can inhale the gas, hydrogen sulfide interferes w/ energy metabolism of the CNS
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Why can mineral deficiencies result in polioencephalomalacia?
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Form insoluble mineral complexes e.g. copper can bind to sulfur and iron in the rumen
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What commonly causes polioencephalomalacia in pigs?
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Sodium chloride toxicity-overconsumption of NaCl accompanied by water deprivation
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How does sodium chloride toxicity cause polioencephalomalacia in pigs?
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Animals have hyperosmolality due to excessive salt intake, then are exposed to water and drink until shift to hyponatremia and the brain attempts to offset this by elimination Na+ and Cl- ions by exporting them into vasculature, but this doesn't offset the gradient and water moves into the brain=brain swelling--> necrosis
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What pathologies are associated with sodium chloride toxicity in pigs?
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Cerebral edema and necrosis
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What type of edema occurs with sodium chloride toxicity in pigs?
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Astrocytic edema (astrocytic swelling)
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What are the clinical signs of sodium chloride toxicity in pigs?
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Head pressing
In-coordination Blindness Circling Paddling Convulsions Death |
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What are 2 common causes of polioencephalomalacia in many species?
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1) Lead poisoning-disrupts calcium homeostasis
2) Anesthetic accident-hypoxia |
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How does a Wood's lamp help to make the diagnosis of polioencephalomalacia in livestock?
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In some cases of cerebral necrosis the dead grey matter will fluoresce under a Wood's lamp
-Negative doesn't rule out condition |
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What skin disease can be diagnosed using a Wood's lamp?
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Dermatophytoses
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What is leukoencephalomalacia?
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Necrosis of white matter in the brain
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When is leukoencephalomalacia most common?
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In the cerebrum of horses with the disease known as equine leukoencephalomalacia
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What causes equine leukoencephalomalacia?
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"Moldy corn toxicity"-fungal toxin
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What is fusarium verticilliodes?
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Acute fungal neurologic disease in horses
Mycotoxin: Fumonisin B1--> yellow gelatinous malacia and liquefication of white matter |
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What clinical signs would you expect in a horse w/ leukoencephalomalacia?
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Depression, somnolence, head pressing, aimless wandering, blindness, seizures, death 1-10 days of onset
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What are 3 deficiencies that can cause CNS injury?
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Copper
Thiamine (vit B1) Vit A and E deficiency |
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What are 6 toxins that can cause CNS injury?
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1) Organophosphates
2) Selenium 3) NaCl 4) Arsenic 5) Lead 6) Organotins (organic compounds based on tin) |
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What nutritional deficiency is associated with equine motor neuron disease?
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Vitamin E deficiency (same as equine degenerative myeloencephalopathy)
-Adults |
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What nutritional deficiency is associated with Swayback and enzootic ataxia in sheep & goats?
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Copper deficiency
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What nutritional deficiency is associated w/ Equine degenerative myeloencephalopathy?
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Vitamin E deficiency
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What are the signs of a horse with equine degenerative myeloencephalopathy?
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UMN-spastic, hypertonus, hyperreflexia
-Young horses characterized by gait abnormalities |
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What nutritional deficiency is related to neurologic disease in carnivores (dogs, cats, mink & foxes) and people as well as ruminants?
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Thiamine deficiency
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What are the clinical signs of a horse with equine motor neuron disease? Compare them to equine degenerative myeloencephalopathy.
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Short strided gait, hypotonic, weakness
In EDM: Hypertonic, hyperreflexia, spastic |
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How do animals get lysosomal storage diseases?
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Inherited disorders-most often result from a deficiency in specific lysosomal enzyme that leads to storage of substrate rather than degradation within the lysosome
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Lysosomal storage diseases are most common in what animals?
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Dogs & cats
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True or false. Storage diseases usually result in abnormal storage disease in cells of the CNS so it almost always reflects CNS dysfunction.
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False, abnormal storage material is present in many cells of the body but usually reflects CNS dysfunction
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What type of clinical signs are usually seen w/ storage diseases?
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Cerebellar signs are most common, but visual deficits due to dysfunction of the visual cortex or retina and UMN spinal cord signs also occur
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What is the stored material with storage diseases?
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Lipid, protein, carbohydrate or a combination of these substrates
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What causes CNS dysfunction due to storage disease?
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Can be due to death of affected neurons or to development of structural abnormalities in the neuron and associated abnormal synaptic connections (changes in neurites)
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What is the typical signalment and history of an animal with an inherited storage disease?
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Young purebred animals w/ progressive neurologic dysfunction
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Are the clinical signs of storage disease symmetric or asymmetric?
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Symmetric
Clinical signs: cerebellar, spinal cord, visual |
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What is the most common mode of inheritance of lysosomal storage disease?
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autosomal recessive
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What part of the brain is most susceptible to damage from storage disease?
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Cerebellum (why it can mimic cerebellar abiotrophy)
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What are 3 causes of acquired storage disease in livestock?
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1) Plant toxicity-locosim
2) Inhibit cellular lysosome enzymes 3) Locoweeds |
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How do storage diseases cause the clinical signs that are related to them?
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Not enough neuronal cell death to explain signs, but alterations in neurites (input signals) result in electrical dysfunction
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True or false. CNS dysfunction from locoweeds is irreversible.
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False, If take them off the feed signs should reverse
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What is another name for globoid cell leukodystrophy?
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Krabbe's disease
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What 3 things are different and unique about the mechanism of nervous system damage in the storage disease known as globoid cell leukodystrophy?
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1) Affects CNS and PNS
2) Rapid progression to cell death 3) Enzyme defect leads to toxic metabolite (psychosine) causing death of oligodendrocytes and Schwann cells |
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What dogs are affected by Krabbe's disease?
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Westies and Karen terriers
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What age of animals get Krabbe's disease? what is the progression of the disease like?
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Young animals
Rapid progression* |
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Tumors and inflammation have a _______ ______ effect and show localizing signs.
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Space occupying
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What is the most common mesodermal tumor of the brain in animals?
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Meningioma
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What animals are meningiomas fairly common in?
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Dogs and cats (mostly cat)
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What type of damage can meningiomas cause?
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Atrophy of adjacent surfaces
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What are the most common cells to develop neoplasia in the CNS?
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Glial cells-gliomas
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What are two types of gliomas?
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Oligodendroglioma
Astrocytoma |
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What breeds are predisposed to gliomas?
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Brachycephalic breeds (astrocytoma)
Boston terriers, boxers, bull dogs |
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True or false. Primary tumors are more common than secondary tumors in the brain.
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False, secondary tumors are more common than primary tumors in the brain
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**What is the most common metastatic tumor in the brain of dogs?
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Hemangiosaroma
NOT mammary carcinoma |
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What are primitive neural tumors?
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Poorly differentiated tumors within brain-don't know what they want to be
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What are primitive neuroectodermal tumors?
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Groups the primitive neural tumors together e.g. of types:
Medulloblastoma Ependymoblastoma Neuroblastoma |
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What is a neoplasm of neuronal origin called?
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Medulloblastoma
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What is the location of a medulloblastoma?
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Cerebellum
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What species are affected by medulloblastomas?
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Young animals
Dog, cat, pig |
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What do you call a neoplasm of oligodendroglial origin?
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Oligodendroglioma
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What is the location of oligodendrogliomas?
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Cerebrum
Brain stem Interventricular septum |
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What species are affected by oligodendrogliomas?
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Dog, cat, cow
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What do you call a neoplasm of astroglia origin?
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Astrocytoma
(Glioblastoma multiforme: very aggressive astrocytic tumor don't live long) |
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What do you call a neoplasm of ependymal cell origin?
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Ependyoma
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What is the location of ependyomas?
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Ventricular system
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What animals are affected by ependyomas?
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Dog, cat, cow, horse
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What do you call a neoplasm of choroid plexus epithelium origin?
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choroid plexus tumor
-In ventricular system |
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What animals get choroid plexus tumors?
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Dog, horse, cow
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What do you call a tumor of microglial cell origin?
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Microgliomatosis
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Where are microgliomatosis' located?
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Cerebrum, brain stem
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What animals get microgliomatosis?
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Dogs
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What do you call a neoplasm of endothelial cell origin?
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Hemangiosarcoma
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Where do dogs get hemangiosarcomas in the CNS?
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Cerebrum, brain stem
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What animals are affected by hemangiosarcomas in the CNS?
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Dogs
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What do you call a neoplasm of mesothelium origin in the CNS?
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Meningioma
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Where are meningiomas located?
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On the meningeal surface
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What animals get meningiomas?
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Most-cats, dog, horse, cow, sheep
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What do you call neoplasms that have many very primitive cells in the CNS?
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Primitive neuroectodermal tumor (PNET)
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Where are PNETs located?
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Anywhere
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What animals get PNETs?
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Tumors of childhood
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True or false. In large animals inflammatory lesions are a more common space occupying lesion than neoplasia.
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True
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What is the only common space-occupying lesion in the horse besides pituitary adenomas and occasional streptococcus equi abscesses?
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Cholesterol granulomas
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Where are cholesterol granulomas located in horses?
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Common incidental findings in the choroid plexus of the lateral ventricles
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Do cholesterol granulomas cause clinical signs?
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They can become large enough to cause clinical sign
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What are the clinical signs of a cholesterol granuloma?
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Related to cerebral disease, most likely due both to secondary hydrocephalus and to direct pressure of the mass on the adjacent brain
Cerebral signs: seizures, behavior changes, ataxia, cortical blindness |
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Diffuse cerebral signs in a horse can be what what 2 differentials?
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Hepatic encephalopathy from liver failure
Cholesterol granulomas |
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What will you see externally when there's a space occupying lesion in the CNS?
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Varies, but may see nothing, may see coning of cerebellum due to increased intracranial pressure leading to cerebral edema or slight swelling of brain
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What would you see in an animal who has a space occupying lesion in the lateral ventricles?
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Generalized cerebral signs-seizures, behavioral changes, ataxia, cortical blindness
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What two types of inflammation most often cause intracranial space occupying lesions?
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Abscesses-suppurative bacterial
Granulomatous or granuloma- bacterial, fungal, parasitic |
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What are the 2 most common space occupying lesions in ruminants?
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Bacterial abscesses
Granulomas |
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Why is the pituitary gland often involved in space occupying inflammatory lesions in cattle?
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May relate to anatomic features of the pituitary circulation in cattle, specifically the presence of the rete mirable which can trap bacteria
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What reportable disease should you consider when you see a granulomatous to pyogranuloamtous space-occupying lesion in a ruminant? How can you diagnose it?
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Mycobacterium tuberculosis
-Perform a quick acid fast stain on an impression smear |
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How can the dark pigmentation in the cat brain specimen aid in differentiating the cause?
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Fungal make melanin
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What type of abscesses are fairly common in cattle?
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Pituitary abscesses
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