Ch 8 Degenerative Flashcards
What are general strategies for identifying degenerative diseases?
Young age, slowly progressive symmetrical signs, bilateral and symmetrical, select areas or specific pattern distribution, major specific patterns include:
* Loss of neurons/axons/myelin
* Pallor of white matter
* Spongy state
* Intracellular storage
* Malacia
Active degeneration might be minimal, and macrophages rarely accumulate.
List the major categories of degenerative diseases.
- Neuronal degeneration
- Axonal degeneration
- Spongy degeneration
- Myelin disorder
- Storage diseases
- Spongiform encephalopathies
- Selective symmetrical encephalomalacias
Keep in mind toxic-metabolic etiologies during diagnosis.
What is the hallmark of degeneration of neurons?
Degeneration and loss of neurons in a specific anatomical structure
Accompanied by diffuse micro and astrogliosis in affected areas.
What are common features of motor neuron diseases (MND)?
- Swollen motor neurons
- Chromatolysis
- Peripheral eccentric displacement
- Flattening/pyknosis of nucleus
- Eosinophilic neurons
- Glassy ghost-like neurons
- Neuronophagia
- Neuronal depletion
- Marked gliosis
MND can be found in small animals and includes hereditary conditions.
Identify a hereditary condition associated with motor neuron disease in dogs.
Hereditary canine spinal muscular atrophy (HCSMA)
Affects Brittany spaniels with an autosomal dominant inheritance pattern.
What is Stockard’s paralysis and which breeds are commonly affected?
A complex mode of inheritance affecting Great Danes and St. Bernard crosses, as well as Great Dane and Bloodhound crosses.
Symptoms can vary in severity.
What is the genetic basis of hereditary progressive neurogenic muscular atrophy in English Pointer pups?
Autosomal recessive
It involves an accumulation of numerous membranous cytoplasmic bodies.
What are the characteristics of cerebellar cortical abiotrophies?
- Hereditary or familial
- Progressive reduction in Purkinje cell population
- Early/more severe in vermis and paramedian lobes
- Secondary transneuronal retrograde degeneration of granule cells
- Gliotic cerebellar nuclei
Affects many breeds and is rare in cats.
What is olivopontocerebellar atrophy (OPCA)?
A degenerative condition affecting cats with severe depopulation of pontine nuclei and olivary complex.
Can be sporadic or genetic.
What are the symptoms of hypertonicity syndrome in Labrador Retrievers? What is the mode of inheritance?
- Extreme generalized muscle stiffness
- Continuous motor unit activity on EMG
- Diffuse gliosis in spinal cord gray matter
- Neuronal numbers decreased in specific rex lamina of spinal cord
This is an X-linked hereditary condition.
What are the key features of axonal degeneration?
- Wallerian degeneration
- Conspicuous focal swelling of axon (spheroids)
- Axonal necrosis with segmentation of myelin
- Removal of myelin and axonal debris by macrophages
Affects primarily white matter.
What is the significance of neuroaxonal dystrophy in small animals?
- Swelling (spheroid) in dystrophic axons
- Degeneration progresses proximally
- Affects gray matter in brain and spinal cord
Notable examples include Rottweilers and English Cockers.
What is the inheritance pattern of bovine spinal muscular atrophy (SMA)?
Autosomal recessive
Commonly found in Brown Swiss and Holstein-Friesian breeds.
What are the symptoms of multisystem neuronal abiotrophy in Miniature Poodles?
Combined with degenerative changes throughout the cerebral cortex.
This condition leads to progressive neurological deficits.
Fill in the blank: Alzheimer’s disease-like lesions in dogs involve the accumulation of _______ protein.
beta-amyloid
Concentrated in senile plaques and around blood vessels.
True or False: Neurofibrillary tangles (NFT) are common in dogs with Alzheimer’s disease-like lesions.
False
NFT are rare in dogs.
What is neuroaxonal dystrophy (NAD) in tricolored cats associated with?
Inner ear abnormalities, mild cerebellar atrophy, spheroids in various brain regions, and unknown genetic background in DSH and Siamese.
NAD stands for Neuroaxonal Dystrophy.
What are the characteristics of Giant axonal neuropathy (GAN) in German Shepherd Dogs?
Disorder of cytoplasmic intermediate filaments, affects peripheral nervous system, hind limb weakness, swollen axons with disorganized neurofilaments.
GAN primarily affects the peripheral nervous system but can also involve the brain and spinal cord.
What defines the central axonopathy observed in Scottish Terriers?
Severe whole body tremor, primary axonal damage, secondary vacuolation, enlarged axons without fragmentation, thin myelin sheaths.
Symptoms worsen with activity and abate during rest.
What is a common feature of leukodystrophies?
Disorders of myelin synthesis with often selective or bizarre distribution patterns.
These disorders can lead to significant neurological deficits.
What is necrotizing myelopathy and in which breeds is it commonly found?
Rapidly progressing spinal signs in young Afghan hounds, kooikers, and miniature poodles.
It is characterized by bilateral symmetrical lysis of white matter.
What is Krabbe’s disease also known as?
Globoid cell leukodystrophy.
It is a lysosomal storage disease affecting several dog breeds.
What is the primary defect in hereditary cavitating leukodystrophy found in Dalmatians?
Cavitation and malacia in the white matter of cerebrum and occipital lobes.
Subcortical fibers are typically spared.
What are the features of Alexander’s disease?
Myelin lesions associated with Rosenthal fiber formation, affecting cerebral white matter.
It is classified as fibrinoid leukodystrophy.
