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SA Med - Neuro - Intracranial Neoplasia, Inflam and Infxn

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drraythe's version from 2017-09-19 02:08

Neoplasias

Question Answer
Age typically affected?Geriatric
*CSs of intracranial tumors?CSs reflect localization- Some tumors have a specific locale. But CONSIDER *** SEIZURES IN THE OLD ANIMAL (!) (bc 12yo dog proll doesnt have idiopathic epilepsy...derp)
3 medical Tx you can use for brain tumors?(1) Anticonvulsants (tumors can cz seizures)
(2) Prednisone (anti-inflammatory dose to Decrease peritumoral inflammation & edema)
(3) Chemotherapy
2 surgical things you can do to help w/ brain tumors- & then 2 other Tx modalities that aren’t medical managing?SX: Debulking, Removal en bloc. Can also try radiation therapy & gene therapy.
*What is the Most common intracranial neoplasm for dogs & cats?Meningioma
What is signalment like for a DOG w/ meningioma? CAT?DOG: Dolichocephalic, females
CAT: Males slightly over-represented
What are the things you'd see w/ MRI to have you know you have a meningioma? (What sign is pretty specific to it too?)**Dural tail sign
Extra-axial mass (Extra-axial is a descriptive term to denote lesions that are external to the brain parenchyma)
Contrast-enhancing
Distinct margins
Can see a mass effect
How can sx Tx of meningioma differ btwn cats & dogs? Other Txs?Surgical removal (cats) or debulking (dogs), Oftentimes followed up w/ radiation therapy. You might also consider chemo (Hydroxyurea, lomustine/CCNU)
Prog of meningioma is...sx removal? Radiation therapy alone? Sx & radiation therapy?In CATS, sx removal can be curative. In dogs, w/ sx only you get about 1yr. Radiation alone is about 1 yr. sx+radiation = about 1.5yr
What are the 3 Glial Tumors?(1) Oligodendroglioma
(2) Astrocytoma
(3) Glioblastoma multiforme (GBM) (Anaplastic astrocytoma)
NOTE: They are often a mixture but w/ 1 predominant cell type
Glial Tumors: which breeds are most affected?Tend to affect brachycephalic dogs (Boxers, Boston terriers, bulldogs)
Where is the location of glial tumors? What does this mean for enhancing w/ contrast on MRI?Intra-axial in location (bc made of brain cells. in brain itself.). May not enhance w/ IV contrast on MRI
Are glial cells infiltrative or are they pretty separate?Infiltrative, Impossible to remove en bloc (debulking sx). However this means Cz less of a mass effect
What are Tx options for a glioma?Surgical debulking, Radiation therapy. Chemo (Temozolamide - she doesnt recc), Gene therapy
Prog of glioma?6-12 mos w/ definitive therapy (anecdotal experience)....In humans, prognosis remains poor (1-2 yrs) despite exhaustive research into new therapies
What are 2 kinds of Choroid Plexus Tumors?(1) Choroid plexus papilloma
(2) Choroid plexus adenocarcinoma
Choroid plexus papilloma usually occur where? What kinda problems do they cz? How do you Tx them?Typically occur in the 4 th ventricle, & can Cz a secondary hydrocephalus
Tx: Not radiation sensitive, so do surgical removal. Consider ventriculoperitoneal shunting for palliation also (prevent hydrocephalus)
Which choroid plexus tumor has the worst prog?Choroid plexus adenocarcinoma - May display intracranial metastasis (via CSF paths).
CNS Lymphoma- where does this lymphoma usually start?Can be part of multicentric lymphoma- Less commonly occurs as primary CNS lymphoma
Which parts of the CNS are most often affected by a CNS lymphoma?Tends to affect cranial nerves, meninges
How do you Tx CNS lymphoma?As for lymphoma elsewhere. Can give intrathecal (injected into spinal canal) chemotherapy (Cytosine arabinoside)
Histiocytic Sarcoma- location? How can this appear on the MRI?Can be located anywhere - MigHT be a forebrain predilection. There are no specific MRI characteristics so this tumor can be the great imitator as other neoplasms or even Encephalitis
How do you Tx a CNS histiocytic sarcoma? Prog?Can try chemo stuff: Lomustine/CCNU. Guarded to poor prog.
Which type of tumor are pituitary tumors usually?Usually adenoma.
What are the 2 types of adenomas the pituitary can get? Explain how they act/affect the brain differentlymicroadenoma & macroadenoma. MICRO: This 1 is associated w/ pituitary dependent hyperadrenocorticism (True cushing’s Dz). In the CAT you will see acromegaly & insulin-resistant diabetes mellitus. There is No neurologic dysfunction (directly) related to this
MACROADENOMA: These are Large enough to invade/displace surrounding brain tissue, can cz Diencephalic syndrome (forebrain signs)
What is diencephalic syndrome?Basically forebrain signs
How can you treat the 2 kinds of pituitary tumors? Prog?(Micro & macroadenoma)
(1) Hypophysectomy (surgical removal of the hypophysis (pituitary gland) )
(2) Radiation therapy (These tumors are radiation sensitive). PROG: Fair prognosis, Median survival time > 1-2 yrs after radiation therapy
What are CSs associated w/ Trigeminal Nerve Sheath Tumor?******Unilateral masticatory muscle atrophy (bc Affects the mandibular branch of cranial nerve V). W/ extension into the brainstem you will see Other cranial nerve dysfunction, Ataxia, paresis, mentation changes, etc.
How do you Dx trigeminal nn sheath tumor? how do you Tx?DX: MRI
TX: (1) Radiation therapy (Stereotactic radiosurgery)
(2) Surgery may be attempted (difficult location :( )
Secondary Brain Tumors occur when...Hematogenous metastasis from a distant site
What are the most common secondary (metastasizing) brain tumors? How do they look on imaging?Multifocal
Contrast-enhancing lesions
Carcinomas (mammary gland, lung)
Melanoma
Hemangiosarcoma
What are the most common secondary (local extension) brain tumors?Calvarial tumors (skull dome)
Nasal tumors
Squamous cell carcinoma (sinuses, eye)
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The autoimmune encephalitides + little white shakers

Question Answer
What are the 3 kinds of ‘Autoimmune’ Encephalitis?Granulomatous meningoencephalitis
Necrotizing meningoencephalitis & leukoencephalitis
Little white shaker dog syndrome
What is the localization of autoimmune encephalitis(s) like? How do you definitively diagnose?Multifocal localization. All require biopsy/necropsy for definitive Dx (needless to say, Presumptive diagnoses are commonly made via MRI, CSF findings)
Granulomatous Meningoencephalitis- where does this occur in the CNS? What is the signalment of someone affected by this?Brain & SC can be affected (So if brain + SC, consider GME), Young to middle-aged small breed dogs (might have a female predilection but can affect genders equally)
CSs of GME (Granulomatous Meningoencephalitis) & how they present (onset & stuff)?Acute onset & progressive, Oftentimes hindbrain signs
If you do a MRI scan of GME, what will you see? Where is it likely to be?May or may not see a lesion, Predominantly occur in the white matter (Mild contrast enhancement w/ indistinct margins)
What will CSF look like in a GME dog?Mononuclear pleocytosis & increased protein. (Pleocytosis = too many WBCs in the CSF)
What should you know about definitively diagnosing GME?Will need brain biopsy for antemortem definitive Dx. Localization of Dz limits the ability to biopsy - Forebrain = yes; brainstem = probably not
Necrotizing Meningoencephalitis (NME) - signalment of who gets this? What are the CSs of this Dz?Young to middle-aged dogs, ESP *Pugs (‘pug encephalitis’), & Maltese* (‘Maltese encephalitis’). CSs= forebrain= **SEIZURES
Necrotizing Meningoencephalitis (NME) - where do you see lesions on the MRI, & how would you describe them?Lesions predominate in the cerebral grey/white matter Jnxn, & are cavitary (kinda makes sense- necrotizing= dead stuff)
What will CSF be like w/ Necrotizing Meningoencephalitis (NME)?Mononuclear (mostly lymphocytic) pleocytosis & high protein
Necrotizing (Leuko)encephalitis (NLE/NE) signalment?Young to middle-aged Yorkshire terriers (‘yorkie encephalitis’)
CSs of Necrotizing (Leuko)encephalitis (NLE/NE)?Has more of a predilection for the hindbrain, but might also have forebrain signs
What is NLE/NE like on MRI, what is CSF like?MRI: white matter & areas of cavitation. Mononuclear pleocytosis & high protein
So GME vs NME vs NLE/NEIn short
GME = fore & hind brain, white matter. Small breeds
NME= pug & maltese, forebrain = SEIZURES. Cavitary lesions
NLE= YORKIES, white matter & cavitary lesions. More hindbrain but can do forebrain.
How can you Tx the autoimmune encephalitis's (GME/NME/NLE) & what supportive therapy can you provide?SUPPORT W/: Anticonvulsants if necessary, Meclizine if vestibular syndrome. Then TX W/: IMMUNOSUPPRESSION: Mainstay is a slowly tapering immunosuppressive dose of prednisone. Can ad additional chemotherapeutics for immunosuppression if needed ((mainstay is steroids tho. Tx is LIFELONG)
Prog of the autoimmune encephalitis?Poor long-term prognosis... but Good short-term prognosis (& we aim for a good quality of life in the meantime)
Little White Shaker aka? & Signalment?Corticosteroid responsive tremor syndrome. Signalment is Young, small breed dogs (terriers, toys, etc)
CSs of little white shakers?Acute onset of fine tremors
How can you Dx little white shaker?CSF shows mild lymphocytic pleocytosis
How do you Tx little white shaker? prog?Immunosuppression w/ prednisone, +/- diazepam or Benadryl to aid in controlling tremors. Prog is good
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Infectious Encephalitis

Question Answer
Infectious czs of encephalitis in the dog/cat....which is NOT common?Bacterial meningoencephalitis is rare in the dog & cat
What czs rabies? How do animals get it? (Pathophys)it is a Lyssavirus, xmitted via bite. Virus makes its way to the CNS via retrograde axoplasmic flow (Has a predilection for the limbic system). Then there is centrifugal spread back to salivary glands
CSs of Rabies? How does it present/emerge?There will be Paresis/paralysis & ataxia.....2 forms:
(1) Dumb: Mentation changes, Profuse salivation & depressed gag reflex
(2) Furious form: aggression. Is uncommon, but keep this on your list for any peracute onset of severe neurologic dysfunction.
Canine Distemper Virus-- what type of virus? How is it xmitted?Morbillivirus (family Paramyxoviridae), xmitted via Respiratory route. Virus carried into the CNS about 1 week later via infected WBCs & platelets
**What are the 4 Neurological presentations of canine distemper?(1) Younger dogs w/ grey matter Dz
(2) Older dogs w/ predominantly white matter (demyelinating) Dz
(3) ‘Old dog encephalitis’
(4) Post-vaccinal encephalitis
Distemper neuro presentation: for Younger dogs w/ grey matter Dz, what are the main CSs?Seizures - can be fatal.
Distemper neuro presentation: for Older dogs w/ predominantly white matter (demyelinating) Dz , what are the main CSs?Mentation & behavior changes
Ataxia
Paresis
Cerebellovestibular syndrome
Distemper neuro presentation: for old dog encephalitis, what are the main CSs?Behavior changes
Circling
Blindness.
Distemper neuro presentation: for Post-vaccinal encephalitis, what are the main CSs?1-2 weeks after vaccination (modified live virus)
Bizarre behavior
Ataxia
Paresis
Recumbency
Death
What CS can be a sequelae of Infxn w/ canine distemper?Myoclonus, which is Rhythmic, repetitive muscle contraction. Lower motor neuron acts like a pacemaker
What is myoclonus, what Infxn is this associated w/?Sequelae of canine distemper, it is a Rhythmic, repetitive muscle contraction. Lower motor neuron acts like a pacemaker
3 ways to Dx canine distemper?(1) Serum or CSF titers
(2) In the serum you will see mononuclear pleocytosis w/ high protein (Lymphocytes )
(3) Urine PCR
Which pleocytosis is common in viral Infxns?Lymphocytic
How do you Tx the canine distemper neuro probs?Anti-inflammatory to immunosuppressive dosages of steroids (controversial)...
WHITE matter Dz = inflammatory (Virus has already come & gone)
GREY = non-inflammatory
What czs FIP? Which type of FIP is related to neuro signs?Czd by mutation of a Coronavirus. Dry form can cz CNS signs
DRY FIP czs neuro signs-- what are the CSs/why?Has a predilection for the caudal fossa (Lateral apertures of the 4th ventricle) so see Cerebellovestibular signs, Forebrain signs → Obstructive hydrocephalus
Dx & Tx for dry FIP neuro complications?Dx: MRI, CSF shows mononuclear pleocytosis & very elevated protein
Tx: not very effective :(
Rickettsial Dz → what neuro problems does this cz? CSs?Cz meningitis (meningoencephalitis) CSs vary & all can have non-neural manifestations. Can see seizures.
3 main rickettsial Dzs which can cz neuro signs? (Which vectors)(1) Rocky Mountain spotted fever (Rickettsia rickettsii) carried by Dermacentor & Amblyomma ticks
(2) Ehrlichiosis (E. canis) Rhipicephalus tick
(3) Salmon poisoning (Neorickettsia helmintheca) - Pacific NW, Snails & salmon
Along w/ pleocytosis & high protein, what other systemic abnormalities might you see w/ rickettsial Dzs?Petechiae
Ecchymoses
Thrombocytopenia
Elevated globulin
Lymphadenomegaly
Fever, etc.
What are the 2 causative agents of Fungal Encephalitis?Cryptococcus neoformans
Blastomyces dermatitidis
CSs of fungal encephalitis?Reflect the location of Dz! Extraneural signs: Upper & lower respiratory, Dermatologic, Skeletal
What does fungal encephalitis look like on MRI?Intra-axial
Contrast enhancing lesion
Perilesional edema
What will CSF look like w/ fungal encephalitis?Pyogranulomatous inflammation & high protein, May see the organisms
What antifungal crosses the BBB so you can treat fungal encephalitis?Fluconazole!! (Although others might work if the BBB is inflamed) Needs to be LONG TERM Tx. +/- Steroids.
2 things that cz Protozoal Encephalitis?(1) Toxoplasma gondii
(2) Neospora caninum
Who can get toxo Infxn? How do you Dx? Tx? Prog?Dogs & cats (but cats DH)
May or may not see a granuloma on MRI
CSF analysis: neutrophilic pleocytosis & high protein. Titers might be unreliable
TX: ~Clindamycin, Trimethoprim sulfa). Prog guarded
Neospora caninum - who is affected by this? Is there predilection?Similar clinical picture to toxoplasmosis, onLY DOGS affected tho. Predilection for cerebellum?
A recommended titer for dogs? Cats?DOGS: Canine distemper virus
Neospora caninum
Toxoplasma gondii
Ehrlichia canis
Rocky Mountain spotted fever
CATS: FeLV, FIV, Coronavirus, Cryptococcus, Toxoplasma gondii
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