AP: Alcohol & Demyelination

Question 1

Name some ethanol-related disorders

Answer 1

• Fetal alchol spectrum disorder
• Acute intoxication and withdrawal syndrome
• Alcoholic dementia
• Alcoholic cerebellar degeneration
• Central pontine myelinolysis
• Wernicke-Korsakoff syndrome
• Peripheral neuropathy
• Hepatic encapholpathy

Question 2

Ingestion of large quanties of alcohol can lead directly to death from what?

Answer 2

Cardiorespiratory paralysis

Question 3

What are the presentations of FAS?

Answer 3

• Microcephaly - most common
• Agensis of corpus callosum
• Hypoplasia of mid-face
  
  • ocular abnormalities
  • hearding disorders
  • cerebellar symptoms

Question 4

Explain alcoholic dementia AKA “thiamine deficiency dementia”

Answer 4

• Neuropsychological impairment in chronic alcoholics
• CT changes of atrophy
• Changes due to nutritional deficiencies
• Dry Beriberi
  
  • loss of reflexies
  • emaciation
  • aphonia
  • wrist drop
• Wet Beriberi
  
  • dyspnea
  • Wernicke’s syndrome
  • Edema

Question 5

What is Wernicke-Korsakoff syndrome?

Answer 5

• Thiamine deficiency
• Malnourised chronic alcoholics
• Excessive vomiting
• Acute (Wernicke syndrome) and Chronic (Korskakoff psychosis) phases

Question 6

What are hallmarks of Wernicke syndrome?

Answer 6

• Triad: confusion, ataxia, abnormal eye movements
• Encephalopathy of mammilary bodies (most commonly), also thalamus, midbrain, wall 3rd ventricle, floor 4th ventricle

Question 7

What are the signs of Korsakoff psychosis?

Answer 7

• Severe irreversible STM loss
• inability to learn and later recall new info
• confabulation
• No consciousness clouding
• No impairment of other cognitive functions
• 25% full recover, 50% partial, 25% no recover

Question 8

What are the 2 types of disorders of myelin?

Answer 8

• Demyelination
  
  • autoimmune, viral, toxin, drugs
• Abnormal myelin formation
  
  • leukodystrophies, dysmelinating diseases

Question 9

What are some demyelinating diseases?

Answer 9

Primary:

• Multiple sclerosis (MS) - banner bearer
• Acute disseminated encephalomyelitis (ADEM)
• Acute haemorrhagic leukoencephalopathy (AHL)

Secondary:

1. Viral
   
   1. progressive multifocal leukoencaphlopathy (JC virus)
2. Metabolic/nutritional
   
   1. central pontine myelonylsis
3. Toxic
   
   1. methotrexate
   2. carbon monoxide
   3. solvent abuse

Question 10

What is multiple sclerosis?

Answer 10

Autoimmune, episodic, activity separated in time, lesions separated in space.

• Most common demyelinating diseases affecting CNS
• Well circumscribed plaques of demyelination
• Loss of normal myelyn sheaths with relative axonal sparing
• Autoimmune response

Question 11

What are the relevant clinical features and pathology of multiple sclerosis?

Answer 11

Clinical features:

• Focal lesions
• Peak onset 20-40 years
• Relapses and remission
• Progressive deteroriation

Pathology:

• Well circumscribed areas of gray discoloration within white matter
• Periventricular, deep cerebral white matter

Question 12

What are the 2 post-viral autoimmine reactions to myelin?

Answer 12

Acute-onset, monophasic:

1. Acute disseminated encephalomyelitis (ADEM)
   
   1. self limiting
   2. after non-sepicity URTI
   3. immune mediated demyelination due to production of Ab whichi cross react with CNS myelin protein
2. Acute necrotissing haemorrhagic ecphalomyelitis/leukoencephalitis (AHL)
   
   1. same as ADEM but u get vasculitis
   2. petechial haemorrhages throughout white matter

Question 13

Describe central pontine myelinolysis (osmotic demyelination syndrome)

Answer 13

• Symmetrical demyelinating lesions in the centre of the pons
• Usually surrounding rim of preserved myelin
• Caused by metabolic derangement - specifically associated with rapid iatrogenic correction of hyponatremia