SA Med - Neuro - Degenerative and Anomalous Encephalopathies

drraythe's version from 2017-09-19 01:49


Question Answer
What are the 2 Congenital degenerative disorders?(1) Lysosomal storage Dz
(2) Abiotrophies
Lysosomal Storage Dz → how do they get this?(Typically) autosomal recessive inherited Dz
Pathophys of lysosomal storage Dz?Intracellular accumulation of waste by-product Due to an absence or dysfunction of enzyme required for its metabolism. Storage usually occurs w/in neurons, Although in some Dzs it affects non-CNS tissue. This leads to Neuronal death secondary to intracellular storage (unknown mechanism)
What are CSs like for lysosomal storage Dz? When do you start to see CSs?Normal at birth.... Progressive neurologic dysfunction typically at an early onset. Signs vary as to location. Many present w/ overt cerebellar syndrome, +/- involvement of non-CNS tissue
Tx for lysosomal storage Dz?Currently no clinically applicable Tx
What does abiotrophy mean?Degeneration or loss of function or vitality in an organism or in cells or tissues not due to any apparent injury
What does abiotrophy happen?Lack of nutrients to support growth
What is the most common form of abiotrophy, & when do signs start to present? What will you see?Normal at birth, slowly progressive. Usually cerebellar abiotrophy, so see cerebellar ataxia, etc.
WHO is most prone to getting abiotrophy? (Who doesnt really get it?)RARE in cats. In DOGS, Pit bull, Labrador retriever, Chinese crested, Kerry blue terrier (Multisystems degeneration)
Cognitive Dysfunction in animals is similar to what human Dz?Alzheimers
Who do you see cognitive dysfunction in?Seen in geriatric dogs (> 8 yr)
CSs of cognitive dysfunction?Sleeping during the day/restless at night, Disorientation, Altered interactions, Anxiety(ies), +/- Inappropriate urination/defecation
What is the pathophys of cognitive dysfunction?Multifactorial pathophysiology - Oxidative damage, Tau protein (abnormal protein) deposition
How do you Dx cognitive dysfunction?Very important to rule out overt organic brain Dz. Esp bc it's the Same signalment of dogs also get brain tumors. Will see Evidence of brain atrophy on MRI
What 3 things can you do/give to help Tx cognitive dysfunction? Prog?(1) Selegiline: Restore dopaminergic balance, reduce free radicals
(2) Dietary modification (more antioxidants)
(3) Environmental enrichment (exercise, toys)....guarded prog
Anomalous Brain Dz: CSs?Depend on location- forebrain vs cerebellar
When does anomalous brain Dz present, how does it progress?Present at an early age- Usually < 1 yr, but is Non-progressive (malformations/defects)(Developmental/degenerative conditions are progressive ) (so basically static at birth & stay that way through life )
Where is CSF made? how often is it made? Where is it gotten rid of? How does the flow work?Made in the choroid plexus & is constantly produced. Then it is Absorbed at arachnoid villi → In cerebral veins or venous sinuses. This means it's structured as a 1-way valve, so CSF flows into the venous system when CSF pressure exceeds venous pressure
What is the regular direction of flow of CSF relative to body position? What does this flow correlate w/?Flow is mostly cranial to caudal-- Correlates w/ cardiac cycle (Ca in systole, Cr in diastole-- but Ca flow predominates). So in a normal dog, Pulsatile CSF flow across the foramen magnum w/ each heartbeat
When do you see onset of CSs w/ Hydrocephalus, what ARE the CSs?Early onset! You will see a Large, dome-shaped head, Open fontanelles, Bilateral ventrolateral strabismus (setting sun) (eyes "down & out") Forebrain syndrome, to incld: Decreased intelligence, Decreased mentation, Behavior abnormalities (assholes), Seizures
Will Electroencephalography tell you anything about hydrocephalus?Actually yes, it has a very distinct wave pattern
Can you US the brain to Dx hydrocephalus?LoL actually yes, through the open fontanelles (Can also use CT to Dx)
Why is MRI useful for Dx hydrocephalus 2-fold?Also allows for visualization of the enlarged ventricles & rule out other structural Dz
Why would you do a CSF tap if you suspect hydrocephalus? What is the prog of hydrocephalus in general?To rule out encephalitis/meningitis-- bc same breeds are predisposed to autoimmune encephalitis. Prog is guarded.
What is going on here? This is hydrocephalus as Dx by MRI- in the top L you can see the huge ventricles as compared to the normal
What are 2 drugs you can use to medially Tx hydrocephalus?(1) Omeprazole (it's a H+ pump blocker but they have no idea why this help, it just does).
(2) Corticosteroids *SHORT TERM use only.
How can you sx Tx hydrocephalus?Ventriculoperitoneal shunt
Acquired Obstructive Hydrocephalus-- how is it "acquired"? Who does this tend to happen to, what is the usual Tx?Usually 2* to a mass, Infxn, or inflammation blocking flow of CSF. Happens in older animals subsequent to primary Dz process. Palliation w/ a ventriculoperitoneal shunt may be successful
What is a Chiari-like Malformation? & what are the 2 major sequelae?Basically, Caudal fossa is too small for its contents bc of Occipital hypoplasia. This leads to Compression & herniation of the cerebellum, & Brainstem kinking/cervicomedullary compression
(1) Secondary meningeal hypertrophy/band of fibrosis
(2) Can lead to the development of syringohydromyelia (syrinx) (CSF collecting in spinal cord)
What is the actual reason for most CSs associated w/ the Chiari-like malformation?It's actually the syringohydromyelia (syrinx) that cz the bulk of the CSs.
What is syringohydromyelia (syrinx)?This is accumulation of CSF in the central canal of the spinal cord
****Which breed is CRAZY prone to Chiari-like malformations? (In general what kinda breeds are predisposed?)****Cavalier King Charles spaniel! > 90% have malformation (Not all go on to develop a syrinx tho). Also Small breed dogs in general are predisposed (Chihuahua, Yorkie, Pomeranian).
What is an Intracranial Arachnoid Cyst?Meninges develop a slit in the membrane, CSF collects but cant leave