TOXIC METABOLIC DISORDERS

Question 1

Neurotoxins

Answer 1

toxic agent or substance that inhibits, damages or destroys the tissues of the nervous system, especially neurons, the conducting cells of your body’s central nervous system

Question 2

Brain damage directly related to alcohol (as opposed to damage via liver cirrhosis) types

Answer 2

intoxication – cerebral edema
Withdrawal state
Chronic effects
Cerebellar degeneration-neuronal loss
Cerebral atrophy-especially damage to white matter early in disease
Fetal alcohol syndrome

Question 3

CHRONIC ALCOHOL INTOXICATION

Answer 3

Earliest effects of etoh on white matter

brain atrophy and meningeal fibrosis

Vitamin deficiency in alcoholics may also play a role in addition to direct toxicity

Question 4

Wernicke’s encephalopathy

Answer 4

VITAMIN B1/THIAMINE DEFICIENCY

Syndrome of oculomotor abnormalities and mental symptoms
Most common in alcoholics, & hyperemesis

Ocular motility problems, nystagmus, ataxia, confusion

Mamillary body petechial hemorrhage

Question 5

Korsakoff’s psychosis

Answer 5

chronic memory disorder caused by severe deficiency of thiamine (vitamin B-1).

commonly caused by alcohol misuse

Question 6

Cobalamin deficiency

Answer 6

Vitamin B12

vegan diets/ malabsorption are the main causes of vitamin B12 deficiency

Dysfunction: incorporation of abnormal fatty acids into membranes–>myelin instability*

May also affect DNA synthesis

Question 7

Central Pontine Myelinolysis (CPM)

Answer 7

Occurs when hyponatremic patients have their serum sodium rapidly corrected

ventral pons, & areas w/ rich admixture of gray and white matter

Symmetric demyelination associated with dys-osmolar state/severe electrolyte abnormalities, esp. of serum sodium

Question 8

FETAL ALCOHOL SYNDROME

Answer 8

40,000 babies/ year in U..S. w/ etoh -related damage

Features include hyperactivity, poor motor skills, learning difficulties; severely affected kids have mental retardation

Question 9

Methanol on the brain

Answer 9

Hemorrhagic necrotic effect on putamen

Question 10

Acute Hepatic Encephalopathy

Answer 10

Symptoms: Confusion, Asterixis

path: Edema, Alzheimer type II cells

Question 11

______ readily crosses blood brain barrier

Taken up by astrocytes, Astrocytes rich in glutamine synthetase

Answer 11

Ammonia

Question 12

_______ is metabolic regulator of CNS

Answer 12

Astrocyte

in presence of ↑ ammonia, astro swells–> NT dysfxn

Question 13

______ is very susceptible to alcohol

Answer 13

Alcoholic* Cerebellar Degeneration

Question 14

NEUROLOGICAL COMPLICATIONS OF LIVER DISEASE

Answer 14

Hepatic encephalopathy elevation of blood ammonia, (200 μg/dL)

In liver failure, NH not converted to urea— (portal htn, ammonia bypasses liver, if liver diseased, cannot convert)

Rx: ↓ protein, suppres NH bacteria by antibiotics, addition of lactulose acidifies colon contents

Question 15

Chronic HE

Answer 15

Irreversible neurological damage in liver failure and repeated HE

In addition to Alzh. astrocytes, now brain shows destruction of neurons in deeper cortical layers and putamen

Known as chronic acquired non-wilsonian
hepatocerebral degeneration

Question 16

Wilson’s disease

Answer 16

inherited disorder of copper metabolism–> liver cirrhosis,

Brain damage is due the repeated bouts of HE, not to direct brain toxicity by copper

s/s: jaundice (mean age 12 years) and/or as a movement disorder

Question 17

NO abuse can cause?

Answer 17

B12 deficiency