Congenital Abnormalities - Neuro

Question 1

pale areas in neuronal cytoplasm from dispersion of Nissl’s substance

Answer 1

chromatolysis

Question 2

loss of myelination with preservation of the cell body and axon

Answer 2

demyelination

Question 3

selective degeneration of myelin sheaths with axon intact

Answer 3

1 demyelination

Question 4

mechanisms of 1 demyelination

Answer 4

inherited enzyme defects
impaired synthesis
cytotoxic edema
destruction of myelin by metabolites
immunologic

Question 5

1 demyelination - inherited enzyme defect

Answer 5

leukodystrophy

Question 6

1 demyelination - impaired myelin synthesis and maintenance

Answer 6

viral infection
nutritional deficiency
toxins

Question 7

1 demyelination - cytotoxic edema

Answer 7

status spongiosus

Question 8

1 demyelination - destruction of myelin by metabolites

Answer 8

lysolecithin

Question 9

1 demyelination - immunologic

Answer 9

cell mediated

Question 10

consequence of primary destruction with the loss of axon and not selective injury of myelin sheath

Answer 10

2 demyelination

Question 11

pale, swollen fibers (+/- axonal loss)

Answer 11

axonal degeneration

Question 12

destruction of axon and myelin sheath following trauma or toxic injury

Answer 12

wallerian degeneration

Question 13

accumulation of glial cells around damaged neurons

Answer 13

satellitosis

Question 14

macrophagic phagocytosis of necrotic neurons

Answer 14

neuronophagia

Question 15

microglial proliferation (viral infection)

Answer 15

microgliosis

Question 16

astrocytic proliferation in damaged areas

Answer 16

astrocytosis

Question 17

accumulation of leukocytes in perivascular spaces

Answer 17

perivascular cuffing

Question 18

softening and liquefaction of nervous tissue from necrosis of neurons and glial cells

Answer 18

malacia

Question 19

rare or cysts are found where nervous tissue was destroyed

Answer 19

scar formation

Question 20

eosinophilic; usually single and displaces the nucleolus with a clear halo specific for viral infections

Answer 20

intranuclear inclusion bodies

Question 21

eosinophilic with internal granules which stain purple specific for rabies

Answer 21

intracytoplasmic
(Negri bodies)

Question 22

neural tube closure defects

Answer 22

dysraphia

Question 23

total absence of the entire brain even though a small portion of the brain persists
(medulla / mesencephalon)

Answer 23

anencephaly

Question 24

anencephaly lesions

Answer 24

absence of cerebral hemispheres
failure of forebrain fusion

Question 25

failure of bilateral separation of the primitive single telencephalic cavity into 2 hemispheres common in pigs and lambs

Answer 25

prosencephalic hypoplasia

Question 26

lesions of prosencephalic hypoplasia

Answer 26

single central ventricle absence of the longitudinal fissure, corpus callosum, olfactory bulb + optic tract BRAIN STEM NORMAL

Question 27

protrusion of the brain through a defect in the cranium (cranium bifidum)

Answer 27

meningoencephalocele and cranium bifidum

Question 28

protrusion of the meninges - fluid-filled

Answer 28

meningocele

Question 29

dorsal defect in closure of one or several vertebral arches that form the dorsal spinal column covering the spinal cord

Answer 29

meningomyelocele and spina bifida

Question 30

sequelae of meningomyelocele or spina bifida

Answer 30

meningocele meningomyelocele

Question 31

occurs most frequently in brachycephalic breeds of dogs is inherited in Manx cats

Answer 31

spina bifida / sacrococcygeal agenesis

Question 32

abnormal dilation of the central canal of the spinal cord / infectious or genetic injury

Answer 32

congenital hydromyelia

Question 33

obstruction of the central canal CSF flow due to infection, inflammation and neoplasia

Answer 33

acquired hydromyelia

Question 34

absence of primary gyri - "smooth brain" -- due to defective neuronal migration

Answer 34

lissencephaly (agyria)

Question 35

2 types of encephaloclastic defects

Answer 35

porencephaly (focal) hydranecephaly (diffuse)

Question 36

cysts or cavities in the white matter walls of the cerebral hemisphere causing cystic cavitation of the brain

Answer 36

porencephaly

Question 37

complete or almost complete absence of the cerebral hemispheres in a brain of normal size and formation most common in calves with cerebellar hypoplasia

Answer 37

hydranencephaly

Question 38

slight to marked decrease in size of cerebellum or stump of tissue commonly seen in dogs/cats/ calves following intra-uterine viral infections or inherited

Answer 38

cerebellar hypoplasia

Question 39

tubular cavitation of the spinal cord over several segments leaving the animal unable to completely extend the hind limbs, normal posture or attitude is crouched with symmetrical hopping gait at 8 months of age

Answer 39

syringomyelia

Question 40

simple dilatation of the central canal of the spinal connected with the central canal and lined by ependymal cells

Answer 40

hydromyelia

Question 41

abnormal accumulation of fluid in the ventricles of the brain and sub-meningeally common in brachycephalic breeds

Answer 41

hydrocephalus

Question 42

type of hydrocephalus with fluid accumulating in the ventricles

Answer 42

internal hydrocephalus

Question 43

type of hydrocephalus with fluid accumulating in the sub-arachnoid space

Answer 43

external hydrocephalus

Question 44

type of hydrocephalus with fluid accumulating in both ventricles and sub-arachnoid space

Answer 44

communicating hydrocephalus

Question 45

causes of congenital hydrocephalus

Answer 45

idiopathic intra-uterine viral infections nutritional deficiencies malformation of the cranium

Question 46

consequence of a periductal gliosis of the aqueduct of Sylvius

Answer 46

congenital hydrocephalus

Question 47

lesions of congenital hydrocephalus

Answer 47

dilated ventricles or duct system dome-shaped, thin-boned and enlarge cranium

Question 48

obstruction of flow due to an accumulation of and organization of exudate commonly as an internal hydrocephalus with no malformation of the cranium

Answer 48

acquired hydrocephalus

Question 49

causes of acquired hydrocephalus

Answer 49

bacterial meningitis granulomatous meningitis intracranial neoplasms parasitic cysts cholesteatoma (horses)

Question 50

lesions of acquired hydrocephalus

Answer 50

pressure atrophy of the septum pellucidum and hippocampus with ventricular dilatation and atrophy of cerebrocortical white matter *may be difficulat to see in neonates*