Hepatic Encephalopathy

Question 1

Hepatic encephalopathy

Answer 1

Neuropsychiatric syndrome caused by lack of function of the liver and diversion of portal blood to systemic circulation bypassing the liver

Question 2

Liver functions

Answer 2

Blood glucose regulation
Bile drainage
Blood circulation and filtration
Detoxification
Synthesis and storage of aa, proteins, vitamins and fats

Question 3

Acute hepatic failure

Answer 3

Failure of hepatic detoxification
Caused by toxins, medications and xenobiotics, heavy metals and infectious agents

Question 4

Hepatic fibrosis/ cirrhosis (chronic)

Answer 4

Failure of detoxification
Caused by idiopathic, hereditary and congenital

Question 5

Circulatory failure of hepatic detoxification

Answer 5

Portosystemic shunt
Portal atresia
Hepatic arteriovenous (AV) fistula

Question 6

Pathophysiology of hepatic encephalopathy

Answer 6

Loss of hepatic detoxification
Systemic accumulation of toxins
Toxins affect CNS
Toxins gut derived from break down of protein and short chain fatty acids

Question 7

Ammonia (toxic outcomes)

Answer 7

Alterations of BBB
Cerebral edema
Changes in brain energy metabolism (brain glucose)

Question 8

Changes in cerebral neurotransmission (toxic outcomes)

Answer 8

Benzodiazepines-like substances
Enhancement of gamma butyric acid (GABA) activity
Inhibition of glutamine

Question 9

Causes of Hepatic encephalopathy in young animals

Answer 9

Congenital (portosystemic shunt)
Toxins and biologicals

Question 10

Causes of Hepatic encephalopathy in middle-aged animals

Answer 10

Familial/ hereditary (chronic fibirosis)
Toxins, medication and biologicals

Question 11

Causes of Hepatic encephalopathy in older animals

Answer 11

Neoplasia
Familial/ hereditary (chronic fibirosis)
Toxins, medication and biologicals

Question 12

Causes of Hepatic encephalopathy in cats

Answer 12

Cholangitis/ cholangiohepatitis
Hepatic lipidosis
Medications

Question 13

CS of Hepatic encephalopathy: altered consciousness

Answer 13

Stupor/ Coma**
Depressed behavior
Anorexia/ lethargy
Difficulty housetraining
Ptyalism

Question 14

CS of Hepatic encephalopathy: personality changes

Answer 14

Vocalizing
Aggression/ submissive behavior
Dementia and disorientation (compulsive walking, head pressing, pacing)

Question 15

CS of Hepatic encephalopathy: motor dysfunction

Answer 15

Ataxia, wide base stance, tremors and circling

Question 16

CS of Hepatic encephalopathy: neurological

Answer 16

Sudden blindness (amaurosis)
Seizures (not as common)

Question 17

Accompanying signs of hepatic encephalopathy includes …..

Answer 17

Liver failure

Question 18

Dx testing

Answer 18

Neurological exam
ECG
Thoracic and abdominal rads
CBC, serum chemistry, electrolyte panel
Liver panel (bile acid assay, blood amonia)
Urinalysis
Shunt hunt (ultrasound, fluoroscopy, tomography)

Question 19

Diagnostic abnormalities

Answer 19

↑ ALP, ALT, AST, CK
↓ BUN bc liver not functioning → concentrates in the urine and USG will ↓
↑ blood ammonia and abnorm BA assay (↑)

Question 20

Abdominal rads

Answer 20

Non-specific findings
Shift gastric axis cranially
Microhepatica **
Poor serosal detail

Question 21

Surgery

Answer 21

Intraoperative fluoroscopy
Single extrahepatic portoazygous shunt near splenic vein
Surgical treatment ameroid constrictor occlusion

Question 22

Liver biopsy/ histopatholgy findings

Answer 22

Hepatocellular atrophy and periportal fibrosis