Poisoning the Mind Flashcards
Give examples of psychological harm related to drinking?
Insomnia Depression/anxiety Personality hanges Dementia Amnesia Delirium Tremens Hallucinations
What is thiamine? How much do we need daily?
Vitamin B1.
1-2mg
Where is thiamine stored and how much is stored?
Liver
3-4mg
What is Wernickies Encephalopathy?
Neurological symptoms due to CNS problems caused by thiamine deficiency.
Describe features of Wernickes Encephalopathy?
Acute phase - confusion, excited delirium, nsytagmus, gaze paralysis and severe ataxia.
What is Korsakoffs Syndrome?
An amnestic disorder caused by thiamine deficiency associated with prolonged ingestion of alcohol
Describe symptoms of Korsakoffs syndrome?
Anterograde and Retrograde amnesia
Deficit in executive function
Aphasia - cant comprehend or formulate language
Apraxia - Can motor plan
Agnosia - Difficulty processing sensory information
Confabulations - tell ‘lies’ to fill gaps in memory.
Retain Intellegence e.g. can do maths.
What anatomical affects does Korsakoffs syndrome have on the brain? Why is this?
Mamillary bodies and dorso-medial thalamic nuclei shrink.
This is because these areas rely on thiamine for glucose metabolism, so thiamine depletion means cells cant maintain their energy and die.
What is alcoholic dementia?
Memory loss cause by excessive, chronic alcohol consumption.
What symptoms occur in alcoholic dementia?
Memory loss aphasia apraxia Agnosia Loss of executive function
What anatomical changes are seen in alcohol dementia?
Cortical shrinkage
Ventricular enlargement
Shrunken Cerebellum
Deeper, wider sulci.
List causes of alcoholic brain damage?
Seizures Injury B1 deficiency Hepatic Encephalopathy Neurotoxicity Cerebrovascular incidents
What is the result of alcoholic neurotoxicity and B1 deficiency?
Irreversible impairment do to cortical damage (alcohol) and subcortical damage (alcohol and B1 def).
This causes a spectrum of disorders from dementia to WK syndrome.
What effect does long term alcohol use have on the peri-cerebral space?
More alcohol = more pericereberal space and brain is no longer flush with the skull.
Describe how nitrogenous waste from the gut is normally removed?
Gut bacteria generate nitrogenous waste. This is transported by the portal vein to the liver and the liver metabolises it before it is excreted.
How can alcohol impair the process of nitrogenous waste excretion?
By causing damage to hepatocytes so that waste products cant be metabolised.
Or because increased portal venous pressure (from cirrhosis) causes venous blood to by-pass the liver through collateral circulation.
What is the result of nitrogenous waste products entering the systemic circulation?
Ammonia can accumulate and can cross the BBB. It can then be absorbed and metabolised by astrocytes which synthesis glutamine from glutamate.
Increased glutamine causes increased osmotic pressure as astrocytes swell up. The inhibitory GABA system increases (works more?) and this decreases energy supply to other cells.
What factors can increase the change/make hepatic encephalopathy worse?
Increased protein load e.g. variceal bleed.
Decreased ammonia excretion e.g. renal failure
Dehydration.
How is hepatic encephalopathy treated?
Lactulose - inhibits ammonia production in the large intenstine.
Dietary measures to reduce nitrogen load.
Closure of shunting vessels.
Liver transplant.
Describe how the effects of alcohol change with ageing?
Decreased lean body mass, decreased body water, decreased gastric alcohol dehydrogenase, and decreased liver alcohol oxidation all results in an increase in blood alcohol concentration.
Also the brain becomes more sensitive to alcohols effects.
What is delirium tremens?
Occurs from alcohol withdrawal and results in a rapid onset of global confusion and autonomic hyperactivity.
When does delirium tremens typically occur?
Around 3 days after alcohol withdrawal.
How long does delirium tremens typically last?
2-3 days
What are symptoms of delirium tremens?
confusion, shaking, irregular HR, sweating.
High body temp and seizures could result in death.
