Diffuse Brain / Bilaterall symmetrical Forebrain Disease Flashcards
Why do diffuse brain diseases present as bilateral forebrain disease?
Cerebral neurons are largest population of metabolically active neurons so they’re the first to show disease.
What diffuse brain diseases can be rapidly reversed?
Metabolic, Nutritional, Toxic and Vascular if they are identified
What diffuse brain diseases can benefit from “routine and commonly available tests?
Metabolic, Nutritional, Toxic and Vascular
What does T2*GRE MRI imaging show?
HEMORRHAGE
used for Cognitive Dysfunction Syndrome aka Canine Dementia
- will see multiple pinpoint dark spots indicating hemorrhage
Histopath of neurons with Canine dementia show what?
Amyloid plaques in both humans and dogs in atrophied brain matter
Clinical signs of dog/cat with Dementia?
D - disorientation I - interaction changes S - sleep/wake cycle abnormalities H - house soiling A - activity changes or Anxiety
TX of Cognitive Dysfunction Syndrome?
combo of pharma and behavior modification
- Selegeline ~ Anipryl only approved drug
- environmental enrichment
- antioxidants (ess. fatty acids, SAMe, etc.)
- behaviorist referral to make sure no other disease present
Will not cure patients, only delay onset of other clinical signs.
Age of presentation of Cognitive Dysfunction syndrome
geriatric
Define congenital hydrocephalus
Internal, non-obstructive hydrocephalus without apparent cause
What does fusion of the rostral colliculi show you?
Stenosis or Atresia of the mesencephalic aqueduct
CS of hydrocephaly
“Setting Sun Strabismus” - orbits formed too shallow
enlarged, open fontanelle
Dome-shaped skull
Neuro deficits: seizures, circling, bizarre behaviors
Degree of clinical signs more related to RATE of enlargement than amount
What indicates specifically that the 4th ventricle is involved in hydrocephaly?
cerebellovestibular signs – the 4th ventricle is just underneath and if it’s putting pressure on the cerebellum you will see signs.
What’s more important, rate or amount of enlargement in hydrocephaly?
RATE is more important
Define Lissencephaly
abscence or paucity (scarce formation) of gyral formation and pachygyri (thickening of gyri)
Rat brain!
What is the MOST SEVERE disease of neurobiotaxis that is still compatible with life?
Lissencephaly - the absence or pauctiy (scarce formation) of gyral formation and pachygyri (thickening of gyri)
what is neurobiotaxis?
the embryological organization the layers of the nervous system in the brain.
mutation prevents cortex from forming correctly
What breed is pre-disposed to Lissencephaly?
Lhasa Apso
Most common clinical sign of lissencephaly
medically refractory seizures; “Rat brain” smooth cerebrum
TX of lissencephaly
try and control seizures; most cases are identified at necropsy
seizures don’t go away but you can control with anti-convulsants
2 most common metabolic diseases that cause diffuse brain
hypoglycemia
hepatic encephalopathy
2 major histopath changes in Hepatic Encephalopathy
- Polymicrocavitations of white matter (spongy change from edema of white matter)
- Alzheimer’s Type 2 Astrocytes (clear, swollen nuclei)
CS of thiamine deficiency
Brainstem issue:
- anorexia
- vestibular ataxia
- mydriasis
- seizures, tetraparesis
- cervical ventroflexion
Thiamine deficiency causes these lesions in the brain
in the BrainSTEM: Bilateral hemorrhagic necrosis of brainstem
What’s the underlying etiology of ivermectin toxicity?
mutation in MDR-1 gene
