Nervous System Flashcards
Alzheimer Type II cells are found in hepatic encephalopathy and represent a reactive type of what kind of glial cell? Where are they normally located and what can be helpful in identifying them?
astrocyte; gray matter; they usually occur in pairs (cuddling cells) or clusters
Rosenthal fibers represent what?
GFAP aggregates of astrocyte processes and cell bodies. They are complexed with ubiquitin and heat shock proteins. Found in Alexander’s disease AKA axonal dystrophy, a genetic disease of astrocytes that occurs rarely in humans, dogs and sheep
Which mouse phenotype is considered the model for neural tube defects?
curly tail mouse
Cerebral aplasia results from:
failure of closure of the rostral portion of the neural tube, which allows the skin to not form and exposes rudimentary neural brain cells to the amniotic fluid leading to degeneration.
Meningocele is reported in Burmese cats as a result of treatment during pregnancy with:
griseofulvin, hydroxyurea, diphenylhydantoin
Feline panleukopenia virus, BVDV and border disease virus all cause cerebellar hypoplasia through the selective necrosis of what layer of the cerebellum?
external granular cell layer
Perosomus elumbus is:
agenesis of the lumbar, sacral and coccygeal spinal cord segments; occurs in calves and lambs
Myelodysplasia is best detected histologically by the presence of:
aberrant central canals (up to 6)
The classic teratogenic lesion of Akabane virus infection in calves is:
arthrogryposis and hydranencephaly
Examples of teratogenic Orthobunyaviruses are? Which one is endemic to North America?
Akabane virus, Schmallenberg virus, Cache Valley virus. Cache Valley virus is endemic to NA.
The teratogenic effects of BVD occur during what gestational age?
100-170 days
What is the most common teratogenic defect of BVD?
Cerebellar hypoplasia
Infection with BVD after 170 days of gestation is most likely to result in what?
no teratogenic/abortive effects, potential for growth retardation and atrophy of thymic and lymphoid tissues
Fetal death and abortion are most likely to occur in cases of Border Disease Virus infection in sheep during what gestational age?
Days 16-80
The fetal histologic lesion of Border Disease virus infection in sheep infected after 90 days of gestation is?
nodular periarteritis of small to medium arterioles, mostly within the meninges and CNS
An early infection fetal histologic lesion in Border Disease Virus is?
hypomyelinogenesis
Gross features of Border Disease virus infected lambs include:
long hairy birth coats and gross tremors (hairy shaker)
Cavitating cerebral defects and cerebellar dysplasia in Border Disease Virus infection arise from:
A. infection of oligodendroglia
B. infection of astroglia
C. vasculitis
D. infection of glial progenitor cells
C. BDV does not infect CNS cells themselves, and the cavitating lesions are most likely secondary to vasculitis
Growth arrest lines are a feature of in utero infection with what family of viruses?
pestiviruses, specifically BVD and BVDV
Mucosal disease in BVDV infection in cattle is the result of what two possible situations?
Infection of a previously infected calf by a different strain of BVDV (superinfection) or homologous virus mutation in animals that are persistently infected
Teratogenic effects of Border Disease Virus in goat are (more common/less common) than in sheep.
They don’t occur at all. Just fetal death/mummies/abortion.
Congenital tremors in piglets can be the result of in utero infection with what organism?
Classical Swine Fever
Inclusion bodies of Feline Panleukopenia virus are found in what cell type in the cerebellum?
external granular cell layer
GM1 Gangliosidosis is a deficiency of what enzyme? What category of lyosomal storage disease is is?
beta-galactosidase; sphingolipidoses
GM2 gangliosidosis accumulates because of a deficiency of what enzyme?
hexosaminidase or of activatory protein
Neurons with foamy, faintly eosinophilic cytoplasm is typical of what kind of lyosomsal storage disease?
sphingolipidosis (gangliosidoses)
This lysosomal storage disorder, known in people as Tay-Sachs disease, is most likely what based on the EM image?
GM2 gangliosidosis
The dual deficiency of beta1-galactosidase and alpha-neuraminidase found in this form of G1 gangliosidosis is present in what species and breed?
Suffolk sheep
A mutation in what gene in cats is responsible for sphingomyelinosis
NPC2 - this disease has the human analog of Niemann-Pick Disease
Defective degradation of the carbohydrate component of N-linked glycoproteins describes what group of lysosomal storage diseases? What three forms occur in these diseases? How are these diseases detected clinically?
Glycoproteinoses: Alpha-mannosidosis, Beta-mannosidosis, Alpha-L-fucosidosis. Detected in the urine.
Alpha-mannosidosis is best characterized in what breeds of what species?
Angus, Murray Grey and Galloway breeds of cattle; also cats
Beta-mannosidosis is best characterized in what species and breed?
Nubian goats; also Salers cattle
Alpha-L-fucosidosis is best characterized in what breed and species?
dog; English Springer Spaniel
Defective catabolism of glycosaminoglycans best describes what lysosomal storage disorder?
A. Alpha-mannosidosis
B. Sphingomyelonosis
C. GM1-gangliosidosis
D. Mucopolysaccharidosis
GAG’s are mucopolysaccharides!!
Mucopolysaccharidosis Type I is a defiency of what enzyme?
alpha-L-iduronidase
The presence of zebra bodies on EM is characteristic of what group of lysosomal storage disorders?
mucopolysaccharidoses BUT THE MATERIAL IS SPHINGOLIPIDS AND SECONDARY TO THE MUCOPOLYSACCHARIDE DISEASE
Type II glyogen storage disease, otherwise known as Pompe disease, is a deficiency of what enzyme
alpha-1,4-glucosidase.
Curvilinear bodies within Pukinje cells on EM is characteristic of what lysosomal storage disease?
Neuronal ceroid-lipofuscinosis
Vitamin A deficiency causes increased intracranial pressure by what mechanism?
Increased production of CSF by choroid plexus and decreased absorption by arachnoid villi; reversible
Feline ischemic encephalopathy is secondary to migration of what organism?
Cuterebra
What is the neurologic histologic lesion associated with hepatosis dietetica in swine?
hyaline necrosis of meningeal vessels
Cerebrospinal angiopathy in pigs is secondary to what disease?
Edema disease causing alimentary enterotoxemia from E. coli
Steroid-responsive meningo-arteritis in the dog is the new name for what disease? What is the major target organ and lesion?
Beagle pain syndrome; spinal artery periarteritis
Polioencephalomalacia can be caused by all of the following except:
A. lead poisoning in cattle
B. salt poisoning in swine
C. cyanide toxicity in any species
D. excess production of thiaminase in the rumen
E. yellow star thistle (Centaurea solsitialis) poisoning in horses
E. yellow star thistle poisponing in horses causes nigropallidal encephalomalacia
The laminar cortical necrosis in PEM is related to the field of supply of what artery?
middle cerebral artery
Sulfur causes PEM by what mechanism?
Cleaving thiamine into its constituents, rending it inactive
Chastek paralysis is due to:
A. excess thiamin in the diet
B. decreased dietary thiamine
C. excess sulfur in the diet
D. thiamine converting enzyme present in fish
D. Chastek paralysis is found in carnivores like foxes and mink, and is due to a thiamine-splitting enzyme present in fish
The lesions of Chastek paralysis mimic that found in PEM, except that the most profound lesions are located in these two places in the brain:
periventricular areas and caudal colliculi
Lead chiefly exerts clinical signs of toxicity in this tissue:
A. kidney
B. liver
C. GIT
D. nervous tissue
D. brain. Lead chiefly causes neurologic signs in all species, but does not accumulate in the nervous tissue. The kidney does develop acid-fast lead inclusions in the nucleus of tubular epithelial cells, but no evidence of renal toxicity occurs.
Cerebellar cortical degeneration affecting the Purkinje cells with retrograde degeneration of granular cells is present in what species?
dogs
Compressive optic neuropathy of piglets and calves is related to deficiency of what vitamin? What is the pathogenesis? What is the histo lesion?
Vitamin A deficiency; stenosis of the optic foramina; Wallerian degeneration of the optic nerves and tracts
The histologic lesion of Equine degenerative myelopathy is:
ongoing Wallerian degeneration and post-Wallerian astrogliosis in all funiculi throughout the spinal cord, most severe in the thoracic cord
Equine degenerative myeloencephalopathy involves:
A. ascending tracts only
B. descending tracts only
C. ascending and descending tracts
C. ascending (dorsolateral and spinocerebellar) and descending (ventromedial and motor) tracts
Where is Clarke’s column located in the spinal cord?
dorsolateral and immediately adjacent to the central canal of the cord between the first thoracic and mid-lumbar segments. It is the nucleus of the dorsal spinocerebellar tract, and where lesions of EDM are most pronounced.
What is the common characteristic of axonal dystrophies in various species?
massive numbers of axonal spheroids
Organophosphate toxicity is based on their ability to:
inactivate esterases, including acetylcholinesterase (not as important for vet path) and neuronal esterases that are irreversible.
The histologic lesions associated with organophosphate toxicity include
degenerative changes in the distal axons, loss of myelin, axon swelling and lysis, microcavitation and neuronal chromatolysis in the brain and spinal cord
What is a common clinical sign associated with organophosphate toxicity and why does it occur?
aphonia; results from involvement of the recurrent laryngeal nerve as it undergoes axonal degeneration
Coyotillo poisoning occurs as a result of the toxin __________ and mosly affects this species ________ leading to a central/peripheral axonopathy with secondary CNS changes.
tullidinol; goats; peripheral
The gross lesions of arsenic poisoning include:
NONE!!
Arsenic causes toxicity through its inactivation of:
A. thiamin
B. sulfhydryl
C. thiocyanate
D. glycine
B. sulfhydryl groups are inactivated by arsenic causing general depressions of metabolic activity
The loss of white matter in this image is most likely the result of:
copper deficiency. This is swayback, a congenital form.
The spinal cord lesions in delayed swayback include Wallerian degeneration of:
A. dorsolateral tracts
B. ventromedial tracts
C. both dorsolateral and ventromedial tracts
C. This is a distal axonopathy and affects both tracts.
Equine grass sickness is otherwise known as :
dysautonomia
A histologic lesion in the ganglia associated with equine grass sickness would be:
central chromatolysis of the neurons
Clinical signs of dysautonomia include:
A. diarrhea
B. drooling
C. dilated pupils
D. constricted pupils
C. dilated pupils are characteristic of autonomic dysfunction along with megaesophagus, dry mucous membranes, constipation, vomiting and prolapsed TEL’s
Sampling for dysautonomia should be done from which tissue?
A. dorsal root ganglia
B. mesenteric ganglia
C. superficial cervical ganglia
B. mesenteric or pelvic ganglia are the best sampling choices. A is for sensory or afferent neurons. C is an autonomic ganglia but not the best samping site for lesions.
Equine laryngeal hemiplegia result from denervation atropy of what?
the intrinsic muscles of the left side of the larynx from idiopathic degeneration of the left recurrent laryngeal nerve leading to inability to retract the arytenoid cartilage and vocal fold, partial obstruction, and roaring (inspiratory stridor)
What are two differentials for equine laryngeal hemiplagia as a result of left recurrent laryngeal nerve damage?
lead and OP poisoning can cause widespread axonopathy and can lead to laryngeal paralysis