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Neuro- CNS - Metabolic Disease > Neuro - CNS - Metabolic DIsease > Flashcards

Neuro - CNS - Metabolic DIsease Flashcards

1
Q

Central Pontine Myelinolysis

A
  • represents a non-inflammatory demyelination of the pons secondary to the rapid correction of a hyponatremic state or production of a hypernatremic state.
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2
Q

Central Pontine Myelinolysis - Epidemeology

A
  • Incidence unknown
  • CPM was present in 29% of postmortum exams of liver transplant patients; 2/3 of these patients had serum sodium fluctuations of only plus/minus 15-20mEq/L
  • In consecutive series of autopsies, CPM was found in 9 cases or 0.25%
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3
Q

Central Pontine Myelinolysis - Etiology

A
  • More than half of the cases have appeared in association with severe alcoholism
  • Other associated diseases include renal dialysis and hepatic failure and other severe terminal diseases
  • ** Rapid correction of hyponatremia to normal hypernatremic levels is the causal factor (also assoc. with severe electrolyte /osmolar imbalance.
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4
Q

Central Pontine Myelinolysis - Pathology

A
  • Lesion involves severe demyelination beginning in the geometric center of the pons (basis pontis, pontine tegmentum) sparing eriventricular and subpial regions.
  • Reactive phagocytes and glial cells are present but no signs of inflammation.
  • Lesions can also appear in the thalamus, supratentorium but rarely below pontomedullary junction
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5
Q

Central Pontine Myelinolysis - Presentation

A
  • Acute to subacute
  • Rapidly evolving flaccid quadriplegia
  • ++Inability to chew, swallow or speak
  • Eye movements and facial expressions are often spared.
  • Survival is followed by the development of spasticity
  • ** Locked-in Syndrome can present (patient is aware and awake, but cannot move or communicate verbally due to paralysis of nearly all voluntary muscles in body except for eyes)
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6
Q

Central Pontine Myelinolysis - Prevention

A
  • Prevent rapid correction/over-correction of sodium levels
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7
Q

Ethanol Toxicity

A
  • The presence of ethanol in the body fluids at levels that are toxic to neurons
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8
Q

Ethanol Toxicity - Etiology

A
  • Alcoholism
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9
Q

Ethanol Toxicity - Pathogenesis - Direct Effects

A
  • Cerebellar (vermal) atrophy - particularly anterior lobe
  • Truncal ataxia, unsteady gait, nystagmus
  • Loss of purkinje and granule cells and Bergmann gliosis
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10
Q

Ethanol Toxicity - Pathogenesis - Indirect Effects

A
  • Vitamin deficiency with Wernicke-Korsakoff or subacute combined degeneration
  • Cerebral traumatic injury
    Liver cirrhosis with hyperammonemia and hepatic encephalopathy
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11
Q

Ethanol Toxicity - Presentation

A
  • Peripheral neuropathy; bilateral limb numbness, tingling, paresthesias
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12
Q

Ethanol Toxicity - Diagnosis

A

MRI, CT Scan

* Brain atropgy: ventricular enlargement, widended cortical sulci

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13
Q

Ethanol Toxicity - Management with Complication

A
  • Development of Wernicke-Korsakoff Syndrome

* Liver Cirrhosis, failure and hepatic encephalopathy

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14
Q

Hepatic Encephalopathy

A

a metabolic toxification of the brain due to portosystemic shunting of blood secondary to hepatic resistance such as seen in cirrhosis.

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15
Q

Hepatic Encephalopathy - History

A
  • Associated with liver disease (or any situation where portal blood is shunted around the liver ot the systemic circulation
  • Subtle signs of hepatic encephalopathy are present in approximately 70% of the patients with cirrhosis
  • Ammonia Theory
  • normally 90% of ammonia is removed by the liver
  • normally, astrocytes remove brain NH3 by conversion to glutamine
  • HE pathology includes the presence of abnormal astrocytes n the cerebral cortical tissue
  • elevated blood NH3 concentration detected in HE
  • High NH3 damages the astrocyte’s ability to remove NH3 from the neuron, and impairs neuron function
  • GABA-benzodiazepine theory
  • increased production of endogenous benzodiazepines
  • Increase in GABA content of the brain
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16
Q

Hepatic Encephalopathy - Presentation

A
  • Initially:
  • derangement of consciousness
  • mental confusion
  • increased psychomotor activity
  • Eventually
  • drowsiness
  • stupor
  • coma
  • Asterixis (intermittent muscle contraction when attempting a postural fixation; non-rhythmic rapid extension-flexion movements of the head and extremities
  • grimacing, suck and grasp reflexes
  • exaggerated or asymmetric tendon reflexes, babinski sign
  • focal or generalized seizures
17
Q

Subacute Combined Degeneration

A

Degeneration fo the posterior and lateral columns of the spinal cord secondary to a deficiency in vitamin B12 (cobalamin) (vitamin B12 deficiency)

18
Q

Subacute Combined Degeneration - History

A
  • Failure to transfer minute amounts of B12 across the intestinal wall
  • Can be precipitated by exposure to nitrous oxide gas
19
Q

Subacute Combined Degeneration - Pathology

A
  • Deficiency leads to spongy vacuolation, intramyelinic and interstitial edena of myelin sheaths and their eventual destruction and astrocytosis.
  • Initially, the heavily myelinated posterior and lateral columns of the spinal cord are prime targets
  • With time, both the ascending sensory tracts and the descending motor tracts become demyelinated (hence name subacute combined degeneration)
20
Q

Subacute Combined Degeneration - Presentation

A
  • Subacute and progressive development of ataxia, numbness and tingling in the LE. Progresses to weakness and spasticity and increased DTR
  • Loss of 2PV
  • Pernicious anemia (decreased RBC)
  • Spinal cord myelopathy (injury relating to spinal cord)
  • Diffuse and symmetric presentation
  • Paresthesias in hands and feet
  • peripheral neuropathy: swelling of myelin layers
    Dementia
21
Q

Subacute Combined Degeneration - Treatment

A
  • Prompt B12 supplements may be reversible

* Irreversible with complete paraplegia has developed

22
Q

Thiamine Deficiency

A
  • Thiamine is a water soluble vitamin and must be acquired from the diet. A deficiency state (in famine-affected parts of the world, alcoholics, or medical patients with dietary problems) can result in cardiac problems and peripheral neuropathy (beriberi)
23
Q

Thiamine Deficiency - Etiology

A

Deficiency can cause:

  • Wernicke’s encephalopathy - gaze palsies, ataxia, confusion
  • Korsakoff’s Syndrome : memory difficulties and confabulation
  • In alcoholics, the two often occur together
24
Q

Thiamine Deficiency - Pathology

A
  • Characterized by foci of hemorrhage and necrosis in structures around the third ventricle
  • classically the mamillary bodies
  • also the colliculi, DM thalamus, hypothalamus
  • Lesions eventually infiltrated by macrophages > cystic
25
Q

Thiamine Deficiency - Presentation

A
  • Cardiomyopathy: peripheral vasodilation, high output cardiac failure, peripheral edema
  • Peripheral neuropathy (dry beriberi); toe drop > foot drop > wrist drop, hyporeflexia, muscle weakness
  • Encephalopathy: Wernicke-Korsakoff
26
Q

Thiamine Deficiency - Diagnosis

A

High resolution MRI may show mammillary body atrophy

27
Q

Wernicke-Korsakoff Syndrome (alcoholic encephalopathy)

A
  • This syndrome is actually two processes: Wernicke’s syndrome and Korsakoff’s syndrome.
  • However, they often present together particularly in alcoholics where they tend to associate with a thiamine deficiency
28
Q

Wernicke-Korsakoff Syndrome - Epidemiology

A
  • Incidence of 10/1000 per year in the US

* ** Alcoholism is the most common cause

29
Q

Wernicke-Korsakoff Syndrome - Etiology

A
  • Appears in approximately 3% of the alcoholic population in the US
  • Other causes: malnutrition due to hyperemesis, starvation, renal dialysis, cancer, AIDS or extreme diets
  • Syndrome is associated with thiamine deficiency
30
Q

Wernicke-Korsakoff Syndrome - Pathogenesis

A
  • Lesions in the paraventricular regions of the third ventricle (mamillary bodies) and cerebral aqueduct such as the thalamus, hypothalamus and midbrain
31
Q

Wernicke-Korsakoff Syndrome - Presentation

A

Wernicke Syndrome - Abrupt onset

  • Nystagmus
  • Abducens or horizontal gaze palsy
  • Gait ataxia
  • Mental confusion

Korsakoff Psychosis (prolonged and irreversible)

  • Learning and retentive memory defect out of proportion with all other mental status changes
  • Confabulation
32
Q

Wernicke-Korsakoff Syndrome - Diagnostic Testing

A
  • Diagnosis on clinical findings
  • MRI can be helpful
  • Vestibular testing in impaired
  • CAGE screen for alcoholism
33
Q

Wernicke-Korsakoff Syndrome - Treatment

A
  • Medical emergency
  • Administration of thiamine
  • only within first days of symptom onset because Korsakoff psychosis produces irreversible damage to the mamillary bodies.
34
Q

Wernicke-Korsakoff Syndrome - Management with Complications

A
  • Recovery with thiamine treatment canbe dramatic
  • Sequelae of ethanol toxicity
  • Complications include such thing as:
  • Signs and symptoms of alcohol withdrawl
  • Liver failure
  • Systemic infection
35
Q

Wernicke-Korsakoff Syndrome - Prevention

A
  • Life style changes
  • Improved Diet
  • Avoidance of Alcohol
36
Q

Wilson’s Diseases ( hepatolenticular degeneration)

A
  • autosomal recessive disorder resulting in defective metabolism of copper and copper toxicity
  • Sequale primarily involve the liver and brain
37
Q

Wilson’s Diseases - Epidemiology

A
  • Worldwide incidence is 10-30 million cases, with increased rates in areas of consanguinity
  • 9,000 patients in the US
  • manifests between 6-40 years of age
  • The heterozygote carrier rate is 1 case per 100 persons, corresponding to a gene frequency varying between 0.3% - 0.7%
  • The frequency ranges worldwide from 1 case per 30,000 in Japan to 1 case per 100,000 in Australia.
38
Q

Wilson’s Diseases - Pathology

A
  • Mutation on the ATP7B gene (Chromosome 13), a copper-transporting ATPase > failure of biliary copper execretion > copper accumulation in liver > toxic injury through copper catalyzed formation of reactive oxygen species.
  • Low blood levels of ceruloplasmin > low blood levels of copper > copper built up in body tissue (liver brain eye) > copper toxicity
39
Q

Wilson’s Diseases - Presentation

A
  • Latent period for accumulation followed by onset of critical systemic illness
  • Hepatic: Hepatitis, cirrhosis and or hepatic failure (most common)
  • Neurologic:
  • dystonia, incoordination and tremor
  • autonomic dysfunctions include orthostatic hypotension, sweating, bladder and bowel
  • memory loss, migraines and seizures
  • parkinson disease-like syndromes (tremors)
  • Psychiatric
  • behavioral disturbances, frank psychosis, can precede the clinical manifestations
  • increased copper output in urine

Neuro- CNS - Metabolic Disease (2 decks)

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