Encephalopathic Disorders

Question 1

Spongiform Encephalopathy

Answer 1

• Definition:
  
  • group of progressive, invariably fatal, conditions that affect the brain that are caused by the accumulation of misfolded prion proteins giving the brain a “spongy” appearance
• Transmission:
  
  • consumption of infected meat, blood transfusions, corneal transplants, and contaminated surgical instruments
• S/sxs:
  
  • May take decades to become symptomatic but then progresses rapidly and can cause death
  • Dementia
  • -Ataxia
  • -Poor Memory
  • -Behavioral Changes
  • -Dementia
  • -Myoclonus
• Types:
  
  • Creutzfeldt-Jakob Disease:
    
    • -4 main forms:
      
      • 1.Familial CJD: mutation in PRNP Gene
      • 2.Variant CJD: eating the meat of cows with prions in muscle tissue (mad cows disease)
      • 3.Iatrogenic CJD: caused by medical procedures
      • 4.Sporadic CJD: no clear cause
  • Kuru:
    
    • Caused by cannibalism of infected flesh
  • Fatal Familial Insomnia:
    
    • mutation in PRNP gene, prion proteins build up in thalamus and affect sleep, patients develop insomnia, exaggerated startle response
• Dx:
  
  • -MRI
  • -Lumbar puncture = increased levels of 14-3-3 protein
  • Definitive diagnosis = brain biopsy
• Tx:
  
  • No treatment
  • genetic counseling for familial form, restrict blood transfusions

Question 2

Hashimoto’s Encephalopathy

Answer 2

• Definition:
  
  • Syndrome of acute or subacute encephalopathy that is associated with elevated anti-thyroid antibody titers
• Dx:
  
  • Presence of elevated Anti-thyroid antibody titers and the exclusion of the causes of encephalopathy
• Tx:
  
  • Corticosteroids

Question 3

Wernicke Encephalopathy

Answer 3

• Definition:
  
  • complication of Thiamine (Vitamin B1) deficiency
  • acute syndrome requiring emergent treatment to prevent death and neurologic morbidity
• Most common cause = chronic alcoholism
• Risks:
  
  • poor nutrition caused by malabsorption, poor dietary intake (anorexia), increased metabolic requirement (e.g. during systemic illnesses), or increased loss of water-soluble vitamin Thiamine (e.g. renal dialysis)
• S/sxs:
  
  • Ophthalmoplegia: weakness or paralysis of eye muscles
  • -Ataxia
  • -Changes in mental state: confusion, apathy, difficulty thinking
  • -Coma and death
• Dx:
  
  • Thiamine levels and LFTs (AST > ALT)
  • Confirmed by MRI: degeneration of mammillary bodies
• Tx:
  
  • Medical Emergency!
  • Infusion of thiamine over a few days to normalize the thiamine levels → given with Glucose *** must have normal thiamine levels first or will cause metabolic acidosis due to increased lactic acid

Question 4

Korsakoff Syndrome

Answer 4

• Definition:
  
  • refers to a chronic neurological condition that usually occurs as a consequence of Wernicke Encephalopathy
• S/sxs:
  
  • -severe memory impairment
  • -confabulation: creates stories to fill in memory gaps

Question 5

Hepatic Encephalopathy

Answer 5

• Definition:
  
  • Toxins that are produced by the digestive breakdown of proteins, such as ammonia, and normally cleared in the liver accumulate in the blood and eventually travel to the brain and cause damage.
• Risks:
  
  • chronic liver disease such as cirrhosis or hepatitis
• Triggers:
  
  • infection, dehydration
• S/sxs:
  
  • Early Symptoms:
    
    • -forgetfulness, confusion, breath with a sweet or musty odor
  • Advanced Symptoms:
    
    • shaking of hands or arms (asterixis), disorientation, and slurred speech, coma
• Tx:
  
  • Remove toxic substances from the intestine
  • Lactulose (pulls ammonia into the GI lumen which is then excreted) and rifaximin (decrease intraluminal NH3 production by killing ammonia producing bacteria)