CNS & Special Senses Flashcards
Keith's Path Final Cutdown & Muzzy's TQ's
1
Q
What is a severe case of diffuse destruction of brain w/ no cerebral hemispheres called?
A
Hydranencephaly
2
Q
Is the stroma destroyed in Hydranencephaly?
A
Yes
3
Q
What is Congenital Hydranencephaly associated with?Examples?
A
CerebrumFetal viral infxnsEx: Calves BVD & prego Sheep (Blue Tongue) vax at day 50-58
4
Q
What is a typical lesion of hydranencephaly?
A
Absence of Telencephalon w/ complete or almost complete absence of cerebral hemispheres
5
Q
Hydrancephaly: On necropsy what would you see in the cranial cavity?
A
Membranous sac of CSF made up of enclosed leptomeniges inside a complete cranial cavity
6
Q
Hydrancephaly: What would the skull look like?
A
Mostly normal but could have mild doming & thickening of cranial bones
7
Q
Is there an epindymal lining with Hydranencephaly?
A
NO
8
Q
What viruses are associated with Hydrancephaly?
A
AkbaneBluetoungeRVFWessel-bronBVDBorder Dz
9
Q
If Porencephaly occurs prenatal what will the brain look like?
A
Focal destruction of White Matter w/ caveated cysts in the cerebral hemisphere
10
Q
What is Porencephaly?
A
A congenital anomaly that effects the White Matter of the Cerebrum
11
Q
How do the the cysts in Porencephaly appear and what are they filled with?
A
Smooth walled & filled with clear fluid
12
Q
Associated viruses of Porencephaly?
A
Border DzBVD
13
Q
What deficiency is associated with Porencephaly?
A
CU deficiency
14
Q
What is Internal Hydrocephalus?
A
Abnormal accumlulation of CSF ventricles
15
Q
What is External Hydrocephalus?
A
Abnormal accumulation of CSF in the Subarachnoid Space
16
Q
Is Stroma present in Hydrocephalus?
A
YES
17
Q
What can cause Congenital Hydrocephalus?
A
IdiopathicViralNutritional Deficiency
18
Q
What are the lesions of Congenital Hydrocephalus? TQ
A
Lateral ventricular distention w/ domed shaped, thin boned ENLARGED cranium
19
Q
What animals are more prone to congenital hydroencephalus?
A
Dogs-BrachycephalicCalvesFoalsPigs(familial)
20
Q
What can cause Acquired Hydroencephalus?
A
Anything that Obstructs the flow of CSF leading to pressure atrophy.Progressive dz
21
Q
What are the lesions of Aquired Hydroencephalus? TQ
A
Lateral ventricular distention with NO cranial malformationLipping is present
22
Q
What is Acquired Hydroencephalus a sequele of?
A
Bacterial meningitisGranulomatous meningitis (TB)FIP CryptococcosisIntracranial Neoplasms Parasitic cystsCholestratoma (horse)
23
Q
What is Abiotrophy?
A
“Cerebellar Atrophy” Premature apoptosis of Cerebellum
24
Q
What is the primary metabolic defect/degeneration of the Cerebellum? TQ
A
Abiotrophy Happens after the cerebellum has reached full size
25
Where are the lesions seen in Abiotrophy?
Cerebellar Cortex - basal ganglia
26
What are the lesions of Abiotrophy?
Loss of Perkinje cells & granule cells
27
How does Cerebellar Hypoplasia occur?
Inherited or Intra Uterine viral infection
28
What are the lesions of Cerebellar Hypoplasia?
loss of purkinje cells & granular cells
29
What viruses are associated with Cerebellar Hypoplasia?
Feline Panleukopenia BVD-calvesHerpesvirus- dogs
30
What is Syringomyelia?
Inhereted dz causing a syrnx (tubular cavity) of cavitation in Grey Matter of the lumbar spine
31
What breed would you most likely see Syringomyelia in?
Apparently Weimaraners but really in CKCSLeads to bunny hopping
32
What is a Prion Dz?
Abnormal protein causing spongiform changes in the brain
33
What are the lesions of Prion Dz?
No inflammationCytoplasmic vacuolationAstrocytosis
34
How do you DX a Prion dz?
Examine the obex and use IHC
35
What are some examples of Prion dz?
ScrapieBSEChronic Wasting Dz Deer,Transmissible Mink Encephalopathy
36
What is Sphingolipidoses?
Globoid Cell Leukodystrophy
37
What is Sphingolipidoses caused by?
Lysosomal storage dz = Microglia cells --\> Giant Globoid cells
38
What are the lesions of Sphingolipidoses?
White Matter degeneration that are ID'd with PAS stain
39
What is focal malacia?
Softening & necrosis of CNS tissue associated with specific toxins
40
What causes FSE (focal symmetrical encephalomalacia)? TQ
Hemorrhages from Clostridium perfringins D infection in sheep
41
What causes Equine leukoencephlomalacia?
Toxins from eating moldy corn
42
What causes Equine Nigropallidal malacia?
Yellow star thistle toxicity
43
What causes Avian encephalomalacia?
Hypovitaminosis E
44
What is laminar malacia? TQ
softening of cerebrocortical grey matter in a layered laminar pattern based on how susceptible the cells are to hypoxia
45
What are the two types of laminar malacia? TQ
Cerebrocortical Necrosis (CNN)Polioencephalomalacia (PEM)
46
What is the susceptibility of cells to laminar cortical necrosis from greatest to least? TQ
1. Neurons2. Oligodendrocytes3. Astrocytes4. Microglial cells
47
What is the eitiology of laminar malacia/laminar cortical necrosis?
Lead poisoning-chronic → Cattle → CNNSalt poisoning → Pigs → PEMSelenium poisoning (acute) → Pig → Bilateral PEMThiamine depletion/deficiency → Rumi/Cats → CNN/PEM
48
Active Hyperemia to the brain is what?
Increased arterial blood flow
49
Passive congestion to the brain is what?
Increased venous flow
50
How does hypoxemia/Ichemia kill neurons?
Leads to hypoglycemia → energy depletion → increased Glutamate → neurotoxicity → neuronal death
51
Which type of animal is more resistant to hypoxemia?
Neonates
52
How does the brain get reprofusion injury?
Lactic acidosisCalcium influxOxygen free radicals Glutamate release
53
What are examples of causes hypoxemia/ishemia in Horses, Dogs, and Cats?
Horse: Anesthesia related Dog: Fibrocartilaginous Embolic Myelopathy (FCEM)Cat: Feline Ischemic Encephalopathy (Cuterebra)
54
What is the most important change that accompanies all Intracerebral lesions?
Cerebral edema
55
What is the etiology of Cerebral Edema? TQ
Increased ICP due to: Inflammation Hypoxia Ishcemia Toxins
56
What is a differentiating finding of cytotoxic intracellular cerebral edema?
No oozing blood on cut surface
57
What is a differentiating finding of Vasogenic cerebral edema?
Blood oozes on cut surface
58
Lesions of inflammation of the CNS?
Pronounced vascular responsePerivascular Cuffing w/ Mononuclear cellsNeuronal DegenerationGliosisDemyelination (rare)
59
What causes CNS inflammationin dogs and cats?
Dogs: Idiopathic inflammatory brain disordersCats → Infectious meningoencephalitis
60
What is Thrombotic Meningoencephalitis (TME)? TQ
Acute Suppurative/Purulent inflamation caused by histophilus somni
61
What are the gross & microscopic lesions of TME?
Gross: hemorrhagic fociMicroscopic: Vasculitis w/ thrombosis & septic infarction (hallmark)
62
What does listeria monocytogenes cause in Adult ruminants? TQ
Encephalitis or meningoencephalitis
63
What does listeria monocytogenes cause in young ruminants & monogastrics? TQ
Septicemia & hepatic necrosis
64
How does listeria monocytogenes get into the brain? TQ
Affinity for brainstem: Ascends trigeminal nerve to the medulla & pons causing severe lesions (multifocal microabcesses)
65
What does clostridium perferingens type D cause? TQ
Focal Symmetrical Encephalomalacia (FSE) from the epsilon toxin causing vasculitis
66
What are the lesions of FSE in the Basal ganglia and the white matter? TQ
Basal Ganglia: Hemorrhage & softening (malacia)White Matter: lysis & liquefacation
67
What causes edema disease of pigs and what does it cause?
E.coli → shigella toxin → vasculitis → bilateral symmetrical encephalomalacia of the brain stem
68
What histological changes would you see with Viral inflammation of the CNS? TQ
Vascular - perivascular cuffing of PMN cellsNeuronal - degenerationWhite matter - Gliosis & demylinationMeningitis - Lyphocystic +/- plasmacysticInclusion Bodies
69
What histological changes would you see in the brain with Canine Distemper Virus? TQ
Gliosis & Demylination of White MatterIntranuclear inclusion bodies
70
What inclusion bodies would you see with rabies and herpes?
Herpes - IntraNuclearRabies - IntraCytoplasmic (Negri)
71
How does Cuterebra cause Feline Ischemic Encephalopathy? TQ
Larvae migrate to brain via nasal cavity causing vascular lesions
72
What does cerebral nematodiasis cause in the brain?
MalaciaHemorrhages Migratory tracts Space occupying lesions
73
How does Oestrus ovis cause cerebral nematodiasis?
Penetrates ethmoid bone and makes cysts in the cranial vault
74
How does hypoderma bovis cause cerebral nematodiasis?
Pentrates spinal canal during migration making cysts
75
What causes equine protozoal encephalomyelitis?CS?
Sarcocystosis (Sarcocystis neruona) Horse is dead-end host --\> affects spinal cord, focal liquafactive necrosisCS: ataxia & CNS signs
76
How do you Dx EMP?
Biopsy of spinal accessory nerve and see Wallerian degeneration
77
Neoporosis is caused by Neospora caninum. What does it cause in Horses, Dogs & Cattle?
Horses (DH) → meningoencephalomyelitisDogs (DH) → Polyradiculoneuritis & polymyositisCattle (IH) → Multifocal necrosis +/- abortion
78
How does cryptococcus neoformans cause dz in dogs?
Infects meninges & paranasal sinuses → granulomatous meningioencephalitis (soapy looking lesions)
79
How does cryptococcus neoformans cause dz in cats?
Infects Nasal cavity & Pharynx → non-supurative meningioencephalitis (soapy looking lesions)
80
What causes polioencephalomalacia (CNN of cerebral cortex) in ruminants? TQ
Vit B deficiency from Brackenfern or Horse tail ingestion
81
What is the pathophysiology of Vit B deficiency in ruminants?
Grey matter degeneration & bilateral symmetrical edema due to increased thiaminase levels
82
What is the pathophisiology of avian encephalomalacia?
Hypovitaminosis E → Focal necrosis Cerebellum → exudative diathesis & muscular distrophy
83
What causes bilateral cerebral cortical necrosis (CNN) in Lambs & kids?
CU defeciency affecting both grey & white matter → axonal degenerationIf present at birth = sway backDelayed onset (upto 6mths) = enzootic ataxia
84
What does NaCl toxicosis do?
Affects grey matter of cerebral cortexCS: blindness, deafness & convulsions
85
What are THE PATHOGNOMONIC lesions of NaCl toxicosis?
Eosinophilic meningioencephalitis + encephalomalacia (pigs) & polioencephalomalacia
86
What are your ddx for NaCl tox?
CNNBut CNN → laminar necrosisNaCl tox → Eosinophilic meningitis + laminar necrosis
87
What causes leukoencephalomalacia in horses?
Ingestion of Fusarium moniliforme from moldy corn
88
What is the pathophysiology of leukoencephalomalacia in horses? TQ
Mycotoxin fumonisin B1 → focal necrosis of white matter of cerebral hemispheres via vascular damage → infarction lipid per-oxidation inhibiting DNA synthesis
89
Where would you see the hemorrhagic lesion of coup?
At the site of impact (moving object hitting stationary head)
90
Where would you see the hemorrhagic lesion of Countrecoup? TQ
Opposite the site of impact (moving head hitting stationary object)
91
What is hansen type 1 V disc degeneration?
Degeneration of annulus fibrosis involving multiple discs (acute dz)Nucleus protrudes & puts pressure on spinal cord
92
Who is predisposed to hansen type 1 V disc dz?
Chondrodysplastic breeds
93
What is hansen type 2 V disc dz?
Bulging of disc, fewer discs involved (gradual dz)Nucleus puts pressure on annulus which puts pressure on spinal cord
94
Who is susceptible to hansen type 2 V disc dz?
Any Breed Old dogs
95
What is the most common tumor of the CNS? TQ
Meningiomas → well circumscribed & encapsulated w/ streams & whorls of fusiform CT
96
Who gets Glial tumors most commonly? TQ
Brachycephalic breeds
97
What is the most common glial tumor? TQ
Astrocytoma --\> Not well demarcated
98
What is the 2nd most common glial tumor? TQ
Oligodendrioma --\> well demarcated
99
If a dog has a metastatic (2dary) CNS neoplasm what is your highest rule out?
Mammary carcinoma --\> most common mammary tumor of dogs
100
What is cyclopia and what is it's etiology?
A single medial globe (eye ball)From Ingestion of Veratrum californicum ( veratrum alkaloid) at day 14 of gestation
101
What is Synophtalmia?
Incomplete separation or early fusion of globes
102
What is Coloboma?
Failure of choriod fissure to close (optic cup) Normally found at the optic disc
103
What is Scleral ectasia?
Cavity of choroid lined by retinal layer & associated with CEA --\> retinal degeneration or detachment
104
Who gets collie eye anomoly (CEA)? TQ
Inherited in collies & shelites
105
What is the pathology of Collie Eye (CEA)? TQ
Coloboma --\> incomplete closure/development of the optic cup --\> ABNORMAL Choriod & Retina --\> retinal degeneration or detachment
106
What are the lesions of CEA? TQ
Chorio-retinal dysplasia/hypoplasiaEctasia of optic disc/scleraAbnormal retinal vessles+/- Vision
107
What is suppurative focal blepharitis?
Hordeolum (stye): suppurative adenitis (inflammation)
108
What is External Hordeolum?
Suppurative adenitis of adnexal galnds: Moll- apocrine or Zei- sebaceous
109
What is Internal Hordeolum?
Suppurative adenitis of melbomian gland
110
What is sterile Blepharitis?
Chalazion: sterile granulomatous inflammation of internal melbomian gland
111
What is the most common neoplasm of the canine eyelid?
Melbomian Gland adenoma
112
What is the 2nd most common neoplasm of the canine eyelid?
Melanocytoma
113
What is a Dermoid? TQ
A congenital teratoma tumor on the conjuctiva with at least 2 embryonic layers. Contains Skin & hair!
114
Where do dermoids occur on dogs & cattle?
Dogs: Lateral canthus & limbusCattle: Medial canthus, eyelid & 3rd eyelid
115
What animals get infectious conjunctivitis more commonly?
Cattle & Cats
116
What are the viruses that can cause infectious conjunctivitis?
Feline Herpes & IBR (BHV-1)Infect the eye and make it more susceptible to 2dard bacterial infection
117
What bacteria is associated with pink eye in cattle? TQ
Moraxella
118
What other bacteria can cause infectious conjunctivitis?
MycoplasmaChlamydia psittaci
119
What parasites can cause infectious conjunctivitis? TQ
Thelaziasis (cattle/horse)Habronema (horse)Oestrus ovis (sheep)
120
Who gets idiopathic eosinophilic conjunctivitis?
Horses & Cats
121
What are the lesions of Idiopathic eosinophilic conjunctivitis?
UlcerativeEpithelial hyperplasiaCellular infiltrate of lymphs & eos
122
What is Non-infectious conjuctivitis?
Nodular granulomatous episcleritis (NGE) --\> nodules in lamina propria made up of macrophages, fibroblasts & lymphcytes
123
What is the most common neoplasm of the conjunctiva?
SCCCattle \> Horse \> dog & cat
124
What predisposes animals to SCC on their conjunctiva?
IBR (BVH-1)Genetic --\> HerefordsActinic irradiationHypomelanosis
125
What in an infectious cause of ulcerative dz of the cornea?
Infectious Bovine Keratoconjunctivitis - (Moraxella bovis)
126
What are dendritic ulcers of the cornea?
Branching tracts of necrosis
127
What is a viral cause of dendritic ulcers?
FeHV-1: neutrophils infiltrate & release enzymes --\> descemetocoele
128
What is a melting ulcer? TQ
Suppurative keratomalcia
129
What is the pathology of melting ulcers? TQ
Neutrophils infiltrate & release Proteases/collagenases liquify stroma (keratomalcia) --\> descemetocoele --\> perforation
130
What is Equine keratomuycosis (mycotic keratitis)?
Opportunistic infection of Aspergillus in corneal wounds
131
Why does Equine keratomycosis cause descemtocoeles?
Aspergillus has high affinity for descemet membrane
132
What can predispose a horse to keratomycosis?
Long term use of antibiotics or corticosteroids
133
What is pannus?
A non-ulcerative superficial lesion of the cornea with marked pigmentation
134
What is the etiology of pannus?
Sun alters antigen in the cornea --\>cell mediated response --\> cell membrane grows across cornea
135
What is canine pannus keratitis?
Uberreiter's syndrome/superficial stromal keratitistypically bilateral vascularized opacity of cornea
136
What is the etiology of eosinophilic keratitis?
Idiopathic in cats
137
What is primary KCS?
congenital lack of lacrimal secretions or caused by old age (dry eye)
138
What is secondary KCS?
More common form of dry eye that arises from anything that destroys the lacrima lduct
139
What is dacryodadenitits?
autoimmune inflammation of the lacrimal gland --\> eptithelia hyperplasia --\> metaplasia of cuboidal to squamous cells --\> dry eye
140
What is the etiology of anterior uveitis?
toxic damage, hematogenous infections or extention of deep corneal ulceration alters formation of aqueous = decreased IOP
141
What are the lesions of anterior uveitis?
Hyperemia & congestion of cilliary body & irisAqueous flare--\>exudateHypopyon --\> white/pink/yellow flocculant sediment in aneterior chamberHyphemia --\> blood in Ant. ChamberGlaucomaKeratitis punctate
142
What is hyphemia? TQ
Blood in anterior chamber
143
What is keratitis punctate?
adherence of inflammatory cells to posterior corneal endothelium
144
What is the sequele of anterior uveitis?
Anterior synechiaPosterior synechiaIris bombe
145
What is anterior synechia? TQ
Iris adhering to cornea
146
What is posterior synechia? TQ
Iris adhering to lens
147
What do both forms of synechia lead to ?
Glaucoma
148
What is an Iris bombe?
Complete posterior synechia (360) --\> blocks papilary flow --\> increases Posterior chamber pressure --\> iris bulges --\> & can attatch to anterior cornea
149
What can dz conditions can have the sequele of iris bombe?
Ulcerative keratitisHematogenous InfectionAnterior Uveitis
150
What is the etiology of posterior Uveitis (chordidits)?
Direct or hematogenous infection
151
What are the lesions of posterior uveitis (chorditis)?
Hyperemia of cilliary body & choroid --\> retinal detachment & degeneration
152
What is staphyloma?
When Iris is incorporated into corneal stroma. Most common w/ posterior uvitis but can happen with anterior.
153
How is Stapyloma different from coloboma?
Lesion is off center of optic disc while it occurs at the optic disc with coloboma
154
What are two sepcific examples of posterior uveitis (chorditis)?
Equine recurrent Uveitis (ERU) - moon blindness from repeated episodes of chroditisFeline Idiopathic Lymphonodular uveitis
155
What is the etiology of ERU/moonblindness?
Leptospira or onchocerca antigens have delayed reaction --\> neutrophilic uveitis --\> eosinophilic hyaline membrane on non-pigmented cilliary epithelium (resembles amyloid)
156
What is the most common histological patter of uveitis in cats & what can cause it?
Feline Idiopathic lymphonodular uveitisLymphoplasmatic pan uveitis, FIP, FIV, FeLV, toxo & choroidal hypoplasia
157
What causes primary glaucoma?
Bilateral decrease in drainage
158
What causes congenital glaucoma?
abnormal development of anterior chamber
159
What are the lesions of primary glaucoma?
goniodysgenesis - maldevelopment of trabecular meshwork where aqueous humor drains
160
What is secondary glaucoma, example?
Secondary Unilateral blockage Ex. Iris bombe (form of papillary blockage)
161
What is retinal dysplasia?
failure to completely develop
162
What are the lesions of retinal dysplasia?
cells in rosettes & granules, retinal fold & undifferentiatied photo receptors
163
What is retinitis?
Systemic infection that causes vascularization and exudation leading to retinal degeneration
164
What can acguired retinitis lead too?
Choroidial infection --\> retinal detachment
165
What infections can lead to retinitis?
CDV, MCF, FIP & toxo
166
What is retinal degeneration?
retinal atrophy--\> loss of photoreceptors, formation of spaces in the retina & decreased thickness of retina
167
What is generalized progressive retinal atrophy (PRA)?
Photoreceptor dysplasia (inherited)Rods and cones never reachmaturityLoss of night vision leading to complete blindness
168
What is central progress retinal atrophy (PRA)?
Pigmented epithelia degeneration (later onset)defective removal ofshed components --\> accumulation of lipofuscin --\> dark macules
169
What are the types of retinal detachment?
Congenital --\> micropthalmiaTractional --\> shrinking vitreousExudatvie - accumulation in sub retinal spaceRhegmatougenous - peripheral sensory eptithelium tears away from ora ciliaris --\> fills with exudate & looks like funnel from ora ciliaris to optic disc
170
What is the most common disease of the lens?
Cataracts
171
What can cause cataracts?
Hydration of lens stroma due to loss of osmoregulation from DM or congenital infection of BVD
172
What are the most common occular neoplasms?
SCC: Primary tumor hereford cattle, sun, bovine papilloma virus (locally invasive)Uveal Tract Melanoma: Primary tumor most common intraocular tumor of dogsLymphosarcoma: secondary tumor associated w/ BLV & exopthalmos most common ocular tumor is Cats
173
What is otitis externa?
Most common ear dz. Irritation --\> hyperplasia of ceruminous glands
174
What is the eitiology of Otitis Externa? TQ
ParasitesBacTFungiFBMetabolic DisorderChronic InflammationAutoimmune Dz
175
What can predispose and animal to Otitis Externa? TQ
Excessive MoistureIncreased CerumenAnatomy of canalImpeded DrainageFBLipid rich environmentInappropriate Treatment
176
What causes auricular hematomas?
Trauma
177
What causes auricular necrosis?
InfarctionVasoconstrictionSeptic emboli in pigs Frost bite - cattle
178
What is the most common neoplasm of the ear and what animal is it seen in most commonly? TQ
Ceruminous Gland Adenoma/CarcinomaCats
179
What can cause Otitis Media? TQ
Extension of otitis externaAscending URT infxn from nasopharynx (cat flu)Causing nasopharyngeal polyps or hyperplastic glands
180
What is the sequele of otitis media in horses? TQ
Salpingitis/Eustachitis --\> inflammation of eustachian tubes
181
What is the sequele of otitis media, empyma?
Accumulation of exudate in the gutteral pouch after URT Ifxn. Can involve the carotid artery by extension --\> epistaxis
182
What causes otitis interna?
suppurative infection from extension of otitis media
183
What is the lesion of congenital deafness?
absence or degeneration of organ of corti
184
What is the most prevelant type of deafness in animals? And what is the pathology?
CongenitalAssoc w/ piebald & merle genes --\> cochlea-saccular degeneration --\> collapse of walls --\> secondary neuronal degeneration
185
What does ototoxicity do?
Degenerates the vestibular sensory epithelium & organ of corti --\> head tilt, atacia & nystagmus
186
What can cause ototoxicity commonly? TQ
Aminoglycoside antibiotics--\> degenerate cochlear hair cells
187
What species is very susceptible to aminoglycoside antibiotic ototoxicity? TQ
Cats
188
What can cause peripheral vestibular dysfunction?
Uncontrolled otitis media destroys labyrinths of inner ear
