CNS Flashcards
Breakdown of cytoplasmic Nissl bodies. Indicates neuronal cell injury.
Chromatolysis
These neurons are shrunken and exhibit cytoplasmic eosinophilia and nuclear pyknosis. What has caused these cell changes?
Ischemia
What is this histo of the brain showing?
Satellitosis/Neuronophagia
This pathological process can be caused by prion diseases, hepatic encephalopathy, and canine distemper virus:
Status spongiosus
Focal Symmetric Encephalomalacia is seen here with the presence of what phagocytic cells?
Gitter cells. (foamy machrophages)
What dat?
Anencephaly
What dat?
Microencephaly
Yoooo what dat?
Diprosopus (2 faces)
*Can also see synopthalmia in these cases
2 heads, 1 body, what do we call it?
Parapagus Dicephalus
Name him after his malformation (2 correct answers)
Mr. Cyclopia
Mr. Synopthalmia
This pig has meninges and cerebrum protruding through a defect in the cranium. What do we call it?
Meningoencephalocele
What’s this defect called?
Fissure
What mechanism causes this condition?
Increase in CSF.
Hydrocephalus. Can be compensatory or obstructive. Internal is the most common, where fluid accumulates in the ventricles.
This puppy presents to your clinic with seizures, exopthalmos, and ventrolateral strabismus. These are characteristic signs of what disorder?
Hydrocephalus
This guy has 2 things going on, increased CSF and the brain and meninges are protruding through the cranium. What’s the diagnosis?
Hydrocephalus and meningoencephalocele
Cases in which CSF fills the ventricles and cavitated parenchyma of the brain, although there is no gross deformation of the brain, are called ______ for small cavitations and _______ for larger cavitations.
Porencephaly; Hydranencephaly
What condition can feature an almost complete absence of the cerebral hemispheres, leaving only membranous sacs filled with CSF?
Hyranencephaly
Which viruses can lead to hydranencephaly and porencephaly when the fetus is exposed in utero?
Akabane
Bluetongue
Rift Valley Fever
BVDV
Cats and calves may present with ataxia, wide-based stance, and intention tremors as a result of exposure to which viruses in utero?
Cats: Feline Panleukopenia (parvo)
Calves: BVDV
What is the cause of spina bifida (rachischisis) in this animal?
Defective closure of the bony encasement of the spinal cord.
*May lead to meningocele or myelomeningocele
Cerebrocorticlal atrophy in this sheep is caused by an accumulation of ______ because of a lysosomal storage disease.
Lipofuscin
*Ceroid Lypofuscinosis
Betsy the cow’s favorite snack just happens to be these flowers. What lysosomal storage disease killed her?
Mannosidosis
*ingestion of locoweeds causes acquired mannosidosis. They contain inhibitors of alpha-mannosidase
Why is cerebrl edema so severe?
Leads to increased intracranial pressure (compression, ischemia, necrosis)
What is the pathological process?
Cerebral edema
(Note the cerebellar coning. Part of the cerebellum will be pushed out of the foramen magnum when intracranial pressure increases)
Cerebral edema is causing ____ ______ in this horse.
Gyral herniation
Factors involved in the protection of the brain:
Cranium rigidity
Round shape of skull
Parietal, Temporal and Occipital bones are 2 layers (diploe)
Suture, sinuses, ridges
Meninges
CSF
Name the routes of traumatic injury:
Red: angular rotation
Green: vertical rotation
Blue: lateral rotation
Yellow: caudal displacement
Traumatic brain injury that does not cause a gross lesion and features reversible cerebral dysfunction. May have some Wallerian degeneration, neuron death, and brain swelling.
Concussion
Spinal trauma that causes temporary loss of function and usually affects the long tracts/bundles of nerve fibers (funiculi).
Spinal concussion
Traumatic brain injury that that causes rupture of vessels (bruising), grossly detectable lesions, and can result in unconsciousness and death.
Brain contusion
What is the mechanism of injury for a concussion?
Rotation of cerebral hemispheres around fixed brainstem
What is the mechanism of injury for a contusion?
Deceleration of the brain against the skull
____ contusions occur at the site of impact, while ________ contusions occur at the point opposite the impacting surface, and rarely appear at the occipital lobes.
Coup; Countrecoup
Intervertebral disk disease, vertebral abscesses, and cervical stenotic myelopathy (Wobblers) are examples of ______ spinal cord injuries.
Intrinsic
Concussion, contusion, laceration, transection, and compression are examples of _____ spinal cord injury.
extrinsic
What artery is a likely cause of cortical hemorrhage?
Meningeal artery
Hemorrhage in animal brains can be caused by:
Vasculitis (infectious)
Damage to endothelium (infectious)
Trauma
Contusion
Penetrating wounds
You are performing a necropsy on a horse that fell backwards and died shortly after. What is the pathology in the brain?
Basilar fracture and associated hemorrhage
What are some causes of polioencephalomalacia?
Lead
Sulfur
Thiamine deficiency
Water deprivation
Salt toxicity
These animals exhibiting opisthotonus due to polioencephalomalacia are likely deficient in ______.
Thiamine
What are the fluorescent areas?
Polioencephalomalacia
A fox farm calls you out to do a necropsy on one of their foxes who became paralyzed shortly before death. You discover necrotic lesions on the gray matter of the cerebellum and brainstem, confirming Chastek paralysis. What was the farm likely feeding this fox?
Mainly raw fish or cooked meats.
These are characteristic lesions of thiamine deficiency in carnivores. Fish contains high levels of thiaminase, while cooked meats lack thyamine.
This cat presents to your clinic with head drop syndrome. This has happened over the few months that the owner has been feeding a raw fish homemade diet she found on Google. What is the best treatment for this cat?
Thiamine injection and change diet
A farm has multiple pigs die during the winter and you are called to do a necropsy. You send samples of the brain for histo, and along with polioencephalomalacia, the pathologist sees eosinophilic infiltration of the vessels. What happened to these pigs?
Salt toxicity/water deprivation
Histo from a steer whose neurological signs worsened after eating. Brain shows spongiform change. What is the underlying disease?
Severe liver disease
A sheep exhibited blindness and recumbance shortly before death. PM examination of the brain revealed symmetrical brown areas in the internal capsule, thalamus and cerebellar peduncles (focal symmmetrical encephalomalacia - FSE). What are the risk factors for this infection?
C. perfringens type D
Factors: insufficient immunity (no vax), diets with highly fermentable carbs (enterotoxemia)
You are performing a necropsy on one of many horses that died after episodes of circling, staggering, difficulty backing up, seizures, and recumbancy. A couple of them seemed blind, and one died suddenly without symptoms. The brain has asymmetrical areas of necrosis in the white matter of the cerebrum. What caused the clinical signs in these horses?
Fusarium verticillioides (moldy corn toxicity)
Equine leukoencephalomalacia. PM findings: necrosis and cavitation of white matter (unilateral or asymmetrical)
A farmer requests a necropsy on one of his horses who died after repeated episodes of purposeless chewing, but not eating. You find these symmetrical lesions of liquefactive necrosis within the substantia nigra, the area of the brain that controls muscles of mastication. What is the disease and how did the horse likely acquire it?
Equine Nigropalladial Encephalomalacia
Acquired by eating Centaurea plants (thistle, knapweed)
You find these plants in your friend’s horse pasture and tell her to get rid of them asap because they cause equine nigropalladial encephalomalacia. What is the mechanism of injury?
Repin toxin depletes glutathione and causes oxidative damage and neuronal cell death
What’s the pathology?
Meningitis
Mdx:
Supperative meningitis
What bacterial agent is likely to cause this in a pig?
Streptococcus suis
A cat with a chronic eye infection is admitted to the hospital with signs of meningitis. What is the most likely route of infection?
Transferred from eye infection via the optic nerve.
What is a likely source of supperative myelitis in pigs?
Infection from septum ring travels up olfactory nerves
You perform a necropsy on one of a few feedlot cattle in Texas, who suffered from depression and recumbancy shortly before death, and find the brain to have hemorrhagic and necrotizing meningoencephalitis. What are the 2 modes of transmission for this particular infection?
Inhalation from nasal and urogenitl sectretions
Possible venereal transmission
(Histophilus somnei)
What bacterial agent causes thrombotic meningoencephalitis in sheep?
Histophilus ovis
Considering the pathology of this vessel in the brain, what is the likely disease and causative agent?
Thrombotic meningoencephalitis (TME) caused by H. somnei
You find this abscess on the brainstem of a sheep who died after exhibiting neurologic symptoms, such as circling, head tilt, facial paralysis, and drooling. You inspect the silage and suspect Listeria monocytogenes. How did this bacterium travel into the CNS?
Via the trigeminal nerve
Presence of neutrophil invasion indicates microabscesses in the medulla oblongata of this sheep. What is the likely causative agent?
Listeria monocytogenes
What pathogenic agents can cause these lesions on the brainstem of horses?
EEEV
WEEV
VEEV
Equine Herpervirus
West Nile virus
The small, oval inclusion bodies found in this perkinje cell in the cerebellum are called _____ _____ and are confirmatory for rabies virus.
Negri bodies
These are characteristic signs of what viral infection?
Canine distemper virus
You receive a brain sample from a dog who developed neurologic signs after a 2 week long respiratory illness. Grossly, the brain has signs of nonsupperative meningitis. What can you find on the histo slide to confirm infection with Canine Distemper virus?
Inclusion bodies within astrocytes
Vacuolation of white matter of the cerebellum
Gliosis
You receive the brain of an old dog who suffered from encephalitis. Grossly, you find that there is no longer demarcation between the white and gray matter, likely due to inflammation and degeneration. Histology shows viral inclusions in neurons and astrocytes. What feature of the dog’s medical history will explain this encephalitis?
Previous infection with canine distemper virus
What form of FIP (coronavirus) causes pygranulomatous meningoencephalitis and opthalmitis?
Non-effusive (dry) form
Hydrocephalus in cats can be a result of what viral infection?
Feline coronavirus (FIP)
Asymmetric gross lesions in the white matter of the spinal cord (leukomyelitis) from a horse who exhibited hind limb paresis before death. What is the causative agent and source?
Sarcocystis neurona
Source is infective sporocysts in the feces of opossums
What can you see in this histo image from the brain of a horse who was infected with S. neurona?
Gliosis and bradyzoites
Although dogs are the definitive hosts, this protozoan causes abortions in dairy and beef cattle, and can cause arthrogryposis and ataxia in calves that aren’t aborted.
Neospora caninum
You receive an aborted fetus from a cow believed to have been exposed to Neospora caninum. Grossly, the fetus is autolysed, but there are no other lesions. What do you expect to find on histo if this was a case of bovine neosporosis?
Multifocal, necrotizing encephalitis and hepatitis
Pericarditis and Epicarditis
Immunohistochemistry on the brain of a calf who died from bovine neosporosis shows multiple brown spots. What are there?
Ag for N. caninum
Histo slide of a horse with cerebrospinal nematodiasis. What is the responsible agent?
Strongylus vulgaris
Cat with nonsupperative encephalitis, and cysts containing bradyzoites. What is the pathogen?
Toxoplasma gondii
The neuronal vacuolation (spongiform encephalitis) in these brain samples can be attributed to what type of infectious agent?
Prions
The viscous mucoid exudate in this brain of a cat with meningoencephalitis points to what pathological agent?
Cryptococcus neoformans
Staining histo slides with _______ is best for identifying the capsule of Cryptococcus neoformans yeasts.
Mucicarmine
This well demarcated tumor was found in the subdural leptomeninges of a 10 year old Boxer, and had compressed the brain in that area. What kind of primary CNS tumor is this?
Meningioma (derived from the cells that line the arachnoid villi)
Most common in dogs (45%) and cats (60%)
Mostly intracranial (82%)
This type of primary CNS tumor has infiltrated the nasal cavity.
Meningioma
A 6 year old dog with hydrocephalus dies suddenly at home and is brought in for necropsy. You find the following tumor within the ventricle, with some metastasis to the subarachnoid space. What type of primary CNS tumor is this?
Choroid Plexus papilloma
Most commonly in 4th ventricle
A necropsy on a 10 year old Boston Terrier shows this non-encapsulated tumor in the white matter of the cerebrum. What kind of primary CNS tumor is this?
Astrocytoma
Can be infiltrative or well-circumscribed
An 11 year old Boston Terrier is dropped off for necropsy with a history of neurologic disease. You find this well,-demarcated tumor that has arisen in the gray matter of the cerebrum, but has infiltrated the white matter, effacing the gray-white junctions grossly. What kind of primary CNS tumor is this?
Oligodendroglioma
