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152 Cards in this Set
- Front
- Back
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Possible etiologies for acute to subacute onset with rapid progession:
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Infectious/Inflammatory
Type I Disk Disease Some malformations. |
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Possible etiologies for acute onset with static progression or improvement:
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Vascular
Trauma Some Toxins |
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Some etiologies for subacute onset with waxing and waning signs:
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metabolic
some nutritional |
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Chronic onset and progression:
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Degenerative
Neoplastic Some metabolic and nutritional |
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Signs of UP deficits in the gait:
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Ataxia often with truncal sway
Hypermetria Loss of Stride synchrony |
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Hypometria may be a sign of what?
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Motor system dysfunction: weakness
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What is extensor postural thrust and what does it test?
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Pick up animal under axillary region and lower. Rear legs step backward as they contact the ground.
Tests CP and vestibular system. |
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True/False. The knuckling test is the more reliable test of CP deficits in cats.
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False. Hopping is more reliable.
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True/False. The menace response may be absent in the post-ictal state.
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True.
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True/False. THe most common cause of an abnormal PLR is Horner's.
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False. Inadequate light source (Horner's doesn't cause abnormal PLR)
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A lesion of which nerve results in a ventrolateral strabismus?
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CN III
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Which cranial nerves are required for the Doll's eye reflex?
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VIII
III IV VI |
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True/False. Hyperflexion is seen in UMN lesions during the flexor withdrawal reflex.
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False. Just normal.
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Most common signs of cerebral cortex disease?
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Seizures
Behavior change Circling toward side of lesion CP deficits contralateral Visual deficits contralateral Facial sensory deficits contralateral |
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True/False. Unilateral lesions of diencephalon cause similar signs to cerebral lesions, including seizures.
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False. Similar signs except seizures.
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A lesion of the diencephalon may cause nystagmus. Why?
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A large lesion that increases intracranial pressure may activate the vestibular system.
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What causes circling in cerebral versus brainstem lesions?
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Cerebellar- hemineglect
Brainstem- vestibular involvement |
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What type of ataxia is seen in brainstem lesions?
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Vestibular
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When might CP deficits be ipsilateral to the side of the lesion?
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If the lesion is in the brainstem caudal to the midbrain.
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True/False. Decreased level of consciousness and respiratory/CV dysfunction may occur with very severe brain stem lesions.
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True.
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The menace response is lost ipsilateral/contralateral to a cerebellar lesion?
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Ipsilateral
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Weakness without true CP or UP dysfunction is a primary sign of what type of disease?
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Motor unit/LMN dysfunction
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Is incontinence usually seen with motor unit disease?
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No. Cranial nerves and motor pathways for continence are usually spared.
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What characteristic of the flexor withdrawal reflex may help differentiate a motor unit disease?
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A reduced flexor withdrawal that may fatigue over time.
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Discospndylitis
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Inflammation of the disc and adjacent vertbral body. Can result in cord compression
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Granulomatous Meningoencephalitis
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Small and toy breeds
Angiocentric Mononuclear Inflammation of white matter of BS and SC Accumulations of MHC-II positive macros and T-lymphocytes is hallmark |
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Define hamartoma.
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aggregate of bland, largely normal tissue. Ex- vascular hamartomas are most common
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What kind of cysts are seen in the CNS?
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Epidermoid/dermoid cysts- swuqmous epithelial-lined masses that can form during defective neural tube closure.
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True/False. Arachnoid cysts are not true cysts.
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True. They are not lined by epithelium, but arise for leptomeninges.
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What is the most common primary CNS tumor in dogs and cats?
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Meningioma
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Name common sites of meningiomas
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Over corticies
Attached to falx cerebri Below brainstem Attached to tentorium cerebelli Intraventricular Retrobulbar |
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What are the various histological patterns meningiomas can have?
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Meningothelial
Fibroblastic Transitional- mix of meningothelial and fibroblastic Angioblastic- fibroblastic with vascular channels Psammomatous- mineralized neoplastic cells and blood vessels |
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How are granular cell tumors differentiated?
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plump, round cells with bright eosinophilic granular cytoplasm
Most common in rats |
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What is the most common primary intracranial tumor, especially in brachycephalic breeds?
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Astrocytoma
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What is a glioblastoma multiforme?
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A highly greded astrocytoma associated with hemorrhage and necrosis.
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What might a well demarcated, gelatinous mass found in cerebral white matter with a honeycomb appearance histologically be?
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Oligodendroglioma
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Are ependymomas common and are they benign or infiltrative?
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Rare
Large, infiltrative and typically destructive |
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Where are ependymoma typically found?
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Gray and fleshy, arise from 3rd ventricle
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How do ependymomas appear histologically?
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pseudorosettes around vessels or rosettes around a potential lumen
densely cellular |
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What are tumors of the choroid plexus called and which domestic species has them?
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Benign: papilloma
Malignant: carcinoma Dog |
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Describe choroid plexus papillomas.
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Well defined reddish to gray masses, papilliferous
Rows and trabeculae of epithelial cells supported by a fibrovascular CT stroma |
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Define gliomatosis cerebri.
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Diffuse infiltrating tumor seen in dogs.
No tumor mass, but diffuse enlargement of affected regions |
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Gangliocytoma vs ganglioglioma?
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Gangliocytomas: rare tumors that have a predilection for the cerebellum
Ganglioglioma: rare tumor composed of neuronal cells and neoplastic astrocytes |
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Esthesioneuroblastoma
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Arises from primitive neurosensory cells present in the olfactory mucosa
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A cerebellar primitive neuroectodermal tumor seen mainly in young calves and dogs.
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Medulloblastoma
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What is the most common round cell tumor in the brain of domestic animals?
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Lymphosarcoma
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Histiocytic sarcoma
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Grossly like a meningioma
Arise from distinct macro population of the spinal cord |
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Where is an area of predilection of germ cell tumors in the CNS?
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Sellar region of the pituitary.
Hepatoid-like cells. |
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What tumor arises from the remnants of Rathke's pouch?
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Craniopharyngioma
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True/False. Bone tumors can cause compression of the brain and direct invasion.
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False. Not direct invasion.
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What are some secondary symptoms of pituitary tumors?
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Compression of hypothalamus or optic chiasm
Invasion of 3rd ventricle and hydrocephalus |
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What peripheral nerve sheath tumor commonly involves the brachial plexus?
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Schwannoma
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What is the condition of multiple well differentiated schwannomas in cattle?
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Neurofibromatosis
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What are the 3 categories of primary neuronal degeneration?
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Multisystemic- affect functionally related neuronal groups in basal ganglia, brainstem and cerebellum
Cerebellar Neuraxonal dystrophies- spinal neurons |
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In which breeds are multisystemic neuronal abiotrophies known to occur?
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Kerry Blue Terriers, Rough Coated collies, min poodles: primarily cerebellar
Cocker spaniels: Neuronal loss in cerebrocortical nuclei as well --> mental deterioration Cairn terriers- chromatolysis |
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Which dog breeds are known to be susceptible to canine cerebellar abiotrophy?
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Airedale
Gordon setter Collie Beagle Brittany Spaniel American Staffordshire Terrier |
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What are signs of cerebellar abiotrophy?
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Intention tremor
progressive ataxia dysmetria |
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Which large animal breeds are prone to cerebellar abiotrophy
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Arabian horses
Abderdeen, Angus, Holstein Yorkshire pigs Merino sheep |
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Which breeds are affected by neuraxonal dystrophies?
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Rottweilers
Collie Chihuahua Suffolk sheep horses |
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Which 2 neurodegenerative diseases of the horse may be linked to vitamin E deficiency?
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Equine LMN Disease
Equine Degenerative Myeloencephalopathy |
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Equine grass sickness and Key-Gaskell syndrome are two examples of what type of CNS degenerative disease?
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Dysautonomias
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What sort of lesions are seen in mitochondrial encephalopathies?
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bilateral status spongiosis
necrosis cavitation |
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What histological/EM changes may be seen in gangliosidoses?
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concentric cytoplasmic whorls
stacked, parallel membranes aka zebra bodies |
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Which lysosomal storage disease also involves accumulation of a toxic metabolite?
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Globoid Cell Leukodystrophy aka lgactocerebrosidosis
psychosine is toxic to oligodendrocytes |
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Glucocerebrosidosis
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Gaucher's Disease
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Sphingomyelin lipidosis
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Neimann-Pick Disease
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What is the most common lysosomal storage disease in vet med?
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Alpha-mannosidosis
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Accumulation of substrate from which lysosomal storage disease can also be caused by a toxin?
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alpha mannosidosis
Swainsonine ingestion can also cause accumulation of oligosaccharides |
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Which mannosidosis form is most severe? What histological lesions are characteristic of both?
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Beta. Gross ventriculomegaly
vaculolization |
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Mucopolysaccharidosis I
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Hurler's
Progressive pelvic limb gait disorder |
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Mucopolysaccharidosis II
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Hunter's
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Mucopolysaccharidosis III
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Sanfilipo
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Mucopolysaccharidosis VI
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Maroteux-Lamy
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Mucopolysaccharidosis VII
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Sly
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What are general symptoms of Mucopolysaccharidoses?
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corneal opacities
skeletal deformities lax joints valvular thickening |
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True/False. Any enzyme involved in synthesis or degradation of glycogen can be responsible for a glycogen storage disease.
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True. But only Type II involved lysosomes (degradative enzymes)
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What substrate accumulates in ceroid lipofuscinosis?
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Subunit C of mitochondrial ATP synthetase
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Which lysosomal storage disease is seen in guinea pigs?
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alpha mannosidosis
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Depressed or absent patellar relex is only seen in which motor unit problem(s)?
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neuropathy
botulism tick paralysis |
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True/False. Muscle atrophy will be seen in neuropathy, myopathy or junctionopathy.
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False. Neuropathy and myopathy.
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Can a chronic motor unit disorder be a junctionopathy?
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No
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Will motor unit disease cause ataxia or CP deficits?
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NO
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Which characteristic distinguishes motor unit disorders from CNS disorders?
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Tend to be symmetric symptoms of weakness, reflex loss and muscle tone.
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When are muscle and nerve biopsies generally not needed?
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Trauma
Nerve Sheath Tumor Acute junctionopathy Idiopathic polyradiculoneuritis Myotonia |
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Motor unit disorders that may manifest as acute tetraplegia?
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Idiopathic polyradiculneuritis
Botulism Tick paralysis rare fulminant form of myasthenia gravis |
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Radiculoneuropathy
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Subset of neuropathies affecting the nerve roots
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Transport by slow anterograde?
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cytoskeletal components
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Transport by fast anterograde?
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NT
mitochondria secretory vesicles proteins growth factors |
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Transport by fast retrograde?
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waste products
some growth factors some disease agents |
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True/False. The axon provides trophic support for Schwann cells.
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True. And the other way is true as well.
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Define motor endplate
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focal area on myofiber innervated by axon collateral and its branches.
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Where are Na+ channels and AChR located on the postynaptic membrane?
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AChR and ligand gated Na+ channels occupies peaks
Voltage gated Na+ channels in troughs |
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Which proteins facilitate NT vesicle docking?
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SNARE
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What determines the size of the EPP?
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quantal content
functional integrity of AChR AChE activity Synaptic fold deph |
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True/False. There is an excess of available AChR channels relative to the threshold needed to generate a muscle AP
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True.
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Type I myofibers
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Mitochondria Rich
Highly aerobic Slow Twitch Stain lightly |
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Type II myofibers
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moderate aerobic to high anaerobic metabolism
fast twitch Stain darkly |
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What can be seen after axonal injury?
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swelling and fragmentation of neurofilaments and myelin
Digestion chambers |
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What can be seen during axonal regeneration?
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Bands of Bungner: Schwann cells multiply and hypertrophy
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What is dying back neuropathy?
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Neuropathy due to axonal transport dysfunction
distal to proximal neurofilament loss axon atrophy myelin loss complete axonal loss with fibrous replacement |
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What are some major causes of dying back neuropathy?
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metabolic defects
toxins |
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True/False. Primary demyelinating disorders are more common than secondary in domestic animals.
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False.
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What is the most common primary demyelinating disease of peripheral nerves in vet med?
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IPR/Coonhound Paralysis
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Can a pure myelinopathy cause neurogenic muscle atrophy?
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No
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Characteristics of neurogenic muscle atrophy
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Atrophy of adjacent myofibers with eventual formation of nuclear remnants of degenerated fibers- nuclear bags
Reinnervation can lead to fiber type grouping |
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Causes of primary myopathies?
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Degenerative- endocrine, metabolic, inherited
Inflammatory Functional defect |
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What histological features of myopathies are not seen in neuropathies?
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Muscle necrosis: pallor or eosinophilia with loss of striations. Vacuolization and inflammatory infiltrates
Rounded, atrophic fibers of variable size (not angulated or grouped) |
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Histological features of myositis
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inflammatory cell infiltrates
split or whorled fibers interstitial fibrosis |
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what type of myopathy causes ragged red fibers?
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mitochondrial
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Histological features of myotonia
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central nuclei
hypertrophied fibers |
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What can cause selective type II fiber type atrophy?
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Endocrine disorders such as hypothyroidism and Cushing's.
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When is CSF evaluation indicated?
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To determine presence of inflammatory disease (meningoencephalitus)
Some neoplasia (lymphosarcoma) |
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Why is CSF sampling done post-MRI?
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To gauge brain swelling and potential for herniation.
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After a CSF tap, which cells die first?
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RBCs
Neutrophils |
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What factors influence CSF character?
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Type of lesion
Location Degree of lesion necrosis Stage of disease Previous treatment Amount of blood contamination |
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What may cause an increase in cell count of CSF fluid (pleocytosis)?
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Tissue necrosis
Inflammatory CNS disease |
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What are the landmarks for a cerebellomedullary CSF tap?
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Occipital protuberance
Wings of the atlas |
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What are the CSF collection sites for the various species?
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cerebellomedullary cistern (all)
lumbar (dogs) lumbosacral intervertebral space (cats and large animals) |
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What parameters should be closely monitored during a CSF tap?
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Respiratory rate and pattern
Heart rate and regularity Blood pressure |
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What are normal CSF protein values?
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< 25 mg/dl for dogs
<50 mg/dl for cows, sheep, pigs <75 horses |
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What is the most frequent abnormality in a CSF tap?
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Change in protein concentration
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What is albuminiocytologic dissociation and when does it occur?
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Increase in protein, normal cell counts
degenerative diseases ischemia/infarction idiopathic polyradiculoneuritis neoplasia |
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What type of tumors result in a VERY high protein concentration?
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Choroid plexus tumors
ependymomas |
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Does inflammation result in increased CSF protein?
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Yes, secondary to Ig production and BBB disruption
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What are normal CSF white counts?
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WBC = 0-5 /ul
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What are some causes of CSF white count of 5-50?
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viral infection
trauma vascular disease |
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What sort of things cause severe pleocytosis (WBC: > 200)
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bacterial infection
immune-mediated disease |
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What sort of things cause moderate pleocytosis? (WBC 50-200)?
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fungal or protozoal infections
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What is a normal RBC count of CSF fluid?
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0-5.ul
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Relative WBC makeup of CSF?
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Monocytes > lymphocytes in dogs, cats and horses
lymphocytes > monocytes in cattle |
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What would bacterial infection, severe viral infection, acute trauma or tumor necrosis look like on CSF cytology?
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Increased neutrophils
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What diseases are associated with increased lymphocytes +/- monocytes on cytology?
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Fungal, protozoal infections
Listeriosis Granulomatous meningoencephalomyelitis necrotiing meningoencephalitis? |
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What diseases are associated with mixed cell pleocytosis?
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Acute granulomatous meningoencephalitis
Chronic bacterial infection Fungal, protozoal disease |
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Causes of eosinophilic pleocytosis?
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Parasites
Fungal, Protozoal disease Algal disease Idiopathic eosinophilic meningoencephalitis |
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T1 relaxation
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Return of proton magnetic fields to original alignment
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T2 relaxation
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Protons tend to stop rotating in unison
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Relative opacities of a T1 weighted sequence?
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Short relaxation times appear hyperintense:
fat gadolinium > brain parenchyma > free water |
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Which type of lesions result in increased relaxation time?
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inflammation
edema tumor infiltrations |
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Which type of lesions result in decreased relaxation time?
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fat
hemorrhage melanin |
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On a T2 weighted sequence, what appears white?
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Substances with long relaxation time (more free water)
tumors edema inflammation |
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How does the appearance of fat look different on T2 compared to T1 sequences?
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Fat is darker- helps to differentiate from fluid (edema)
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What can be differentiated on protein density sequence (long TR short TE)
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Attenuate CSF fluid so can differentiate between solid mass (gray) and CSF (dark)
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What materials appear void on protein density sequence?
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Dense cortical bone
calcification fibrous tissue hoof |
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What type of work is protein density helpful for?
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Orthopedic
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What type of sequence differentiates cystic from solid lesions?
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FLAIR:
Low cellularity fluid appears black, edema or inflammation appears white. |
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What does gradient echo (aka FLASH) help us see?
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Hemorrhage:
Iron, manganese, copper and Ca++ salts appear void |
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Which MRI sequence shows greater anatomical resolution? The least?
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Proton Density
Gradient Echo (T2*-W) |
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What is one limitation of gradient echo (T2*-W)?
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Void artifact over soft tissues surrounded by air
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What does FLAIR tell us?
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Edematous versus solid tissue. Cysts and edematous tissue appear hyperintense.
Improves visualization of lesions close to ventricles and sulci |
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How does CSF appear on FLAIR?
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hypointense
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Benefit of FatSat?
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Eliminates false lesions caused by presence of yellow fat inside bone
Turns fat from white to darker |
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What does gadolinium show?>
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vascularization
damaged blood brain barrier |
