Case 20 questions 21-40

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Question 21

Which statement best describes the afferent and efferent connections of the cerebellum?

  1. The posterior spinocerebellar tract is a second order neuron
  2. Mossy fibres are the only efferent fibres of the cerebellum
  3. The inferior olivary nucleus is mostly involved in the sensory understanding output of the cerebellum
  4. The posterior spinocerebellar tract ascends ipsilaterally and then decussates in the medulla
  5. The posterior spinocerebellar tract carries sensations of pain and temperature

The correct answer is option d, The posterior spinocerebellar tract ascends ipsilaterally and then decussates in the medulla

The posterior spinocerebellar tract is a first order neuron; there are several fibres that enter the cerebellum including climbing and mossy fibres; the fibres carry proprioceptive information. This is a toss-up between the olivary nucleus and ipsilateral ascension answers.

The most correct answer is the later because the olivary nucleus is the main source of input, climbing fibres to the cerebellum, also, proprioceptive information isn’t described as ‘sensory’.

Question 22

Sarah is a 68-year-old lady who presented to the GP with indigestion for the last 8 weeks. She has not previously suffered with similar symptoms.

She has a past medical history of hypertension, hypercholesterolaemia and had a TIA 2 months ago.

Her regular medications include Ramipril, amlodipine, atorvastatin, clopidogrel and aspirin.

Which of her medications could be causing these problems?

  1. Ramipril
  2. Indapamide
  3. Atorvastatin
  4. Clopidogrel
  5. Aspirin

The correct answer is option e, asprin

A common side effect of aspirin is dyspepsia. Although ramipril and atorvastatin can also cause some GI discomfort, the timing is important. The asprin would have been started following the TIA as secondary prevention of further cerebrovascular events.

Question 23

Sarah is a 68 year old lady who presented to the GP with indigestion for the last 8 weeks. She has not previously suffered with similar symptoms.

She has a past medical history of hypertension, hypercholesterolaemia and had a TIA 2 months ago.

Her regular medications include Ramipril, amlodipine, atorvastatin, clopidogrel and aspirin.

What is the mechanism of action of atorvastatin?

  1. Blocks HMG CoA reductase enzyme
  2. Agonists against peroxisome proliferator activated receptor (PPAR-alpha)
  3. Inhibits intestinal absorption of cholesterol
  4. Reduces VLDL synthesis in the liver
  5. Reduce hormone sensitive lipase activity in adipose tissue

The correct answer is option a, Blocks HMG CoA reductase enzyme

Atorvastatin falls into the category of statins which are HMG CoA reductase inhibitors. This then blocks conversion of HMG CoA to mevalonic acid. They also block cholesterol synthesis by upregulating LDL receptor synthesis and increasing LDL clearance from the plasma by the liver.
Option b,Agonists against peroxisome proliferator activated receptor (PPAR-alpha) describes the action of fibrates
Option c,Inhibits intestinal absorption of cholesterol describes the action of cholesterol absorption inhibitors
Option d,reduces VLDL synthesis in the liverdescribes the action of nicotinic acid
Option e, reduce hormone sensitive lipase activity in adipose tissue describes the action of nicotinic acid

Question 24

It is 5:30 pm when you go to see Mr Jones in A&E. He was brought into hospital by ambulance with his daughter, who found him with right-sided facial and arm weakness. He seemed confused and had difficulty speaking to her.

On further questioning, she said she found him at 4:30pm this afternoon and called the ambulance straight away. She said he lives alone and no one had seen him today but she spoke to him over the phone at around midday on her lunch break.

Which of the following treatments should not be commenced as part of stroke treatment and future prevention?

  1. Aspirin 300mg PO
  2. Alteplase IV
  3. Oxygen
  4. Clopidogrel 75mg PO
  5. Paracetamol

The correct answer is option 4, Alteplase IV

Thrombolysis would not be given as it has been > 4.5 hours since he was last known to be healthy.
Aspirin 300mg would be given as soon as a haemorrhagic stroke had been excluded.
Oxygen would be given to maintain sats > 95% unless he had COPD
Clopidogrel would be commenced 14 days after the event as an antithrombotic
Paracetamol could be given if the patient was in any pain

Question 25

Which of the following statements the pharmacology of warfarin is untrue?

  1. There is rapid absorption from the GI tract
  2. It Is metabolised by CYP450
  3. It has an immediate anticoagulant affect
  4. Low volume of distribution
  5. It interferes with clotting factors 2, 7, 9 and 10

The correct answer is option c, It has an immediate anticoagulant affect

Anticoagulant effect of warfarin takes 48-72 hours to develop and can actually cause a hyper-coagulabe state whist waiting for it to develop. This is why heparin is needed when starting warfarin. The other statements are all true.

Question 26

Which of these blood results is not common seen in familial combined hyperlipidaemia?

  1. Total cholesterol 6.5-10 mmol/L
  2. TG 2.3-6.0 can be higher
  3. Frequent low HDL-C
  4. Non-HDL-C/ApoB > 5
  5. VLDL-C/total TG ratio < 0.69

The correct answer is option d, Non-HDL-C/ApoB would be < 5.

Question 27

From the history given, which of these patient’s has no contraindications for thrombolysis?

  1. 67 y/o female with a history of alcohol abuse and oesophageal varices
  2. 82 y/o male who suffers from moderate hypertension, high cholesterol and T2DM, with a history of stroke
  3. 78 y/o male with a severe stroke 12 months ago
  4. 59 y/o female who’s stroke was witnessed by her husband. He said she made some jerky movements.
  5. 64 y/o male who had surgery for fractured neck of femur last week

The correct answer is option c, 78 y/o male with a severe stroke 12 months ago

Contraindications for thrombolysis are:

  • Condition with increased risk of bleeding
    • Oesophageal varices
    • Coag defects
    • Recent trauma/surgery
    • Aneurysm
  • Acute pancreatitis
  • Pericarditis/endocarditis
  • Sever hypertension
  • Convulsion w stroke
  • Diabetic w stroke Hx
  • Hyper/hypoglycaemia
  • Previous severe stroke in last 3 months

Question 28

A patient presents with a Total Anterior Circulation Stroke. What artery is most likely to be occluded?

  1. Anterior cerebral artery
  2. Middle meningeal artery
  3. Middle cerebral artery
  4. Posterior cerebral artery
  5. Internal carotid

The correct answer is option c, Middle cerebral artery

The middle cerebral artery is the largest and most direct branch of the internal carotid and therefore most subject to embolism.

Question 29

A 40 year old man called Dan has been brought into resus following a road traffic accident. When attempting to ask him questions, including his name, he simply groans and doesn’t open his eyes. When you assess for a response to pain, he moves away from the pain and opens his eyes.

What is Dan’s current GCS?

  1. 5
  2. 6
  3. 7
  4. 8
  5. 9

The correct answer is option d, GCS of 8

Eyes = 2 – Eyes open to pain but not to speech. Voice = 2 – No audible words are heard but he is still groaning. Motor = 4 – He withdraws from the pain by moving away, but he doesn’t localise to the pain using his hands

GCS = 4+2+2 = 8

Question 30

What does the following score on the Glasgow Coma Scale?

  • Eyes open when patient spoken to
  • Confused speech
  • Localises to pain
  1. 9
  2. 12
  3. 11
  4. 10
  5. 14

The correct answer is option b, GCS=12, E4, V4, M5

Question 31

Which one of the following best describes familial hypercholesterolaemia?

  1. Autosomal Dominant, Defective VLDL receptors, raised VLDL’s
  2. Autosomal Recessive, Defective LDL receptors, raised LDL’s
  3. Autosomal Dominant, Defective LDL receptors, raised LDL’s
  4. Autosomal Recessive, Defective ApoE receptors, raised VLDL’s
  5. Autosomal Dominant, Defective ApoE receptors, raised LDL’s

The correct answer is option c, Autosomal Dominant, Defective LDL receptors, raised LDL’s

Familial hypercholesterolaemia is characterised by a defective LDL receptor leading to high LDL’s. It is an autosomal dominant disease. It is important to be aware of as it can increase the CVD risk.

Question 32

Familial hypercholesterolaemia is known to cause xanthelasma, corneal arcus and tendon xanthoma’s. Where are most tendon xanthoma’s commonly found?

  1. Patellar tendon
  2. Achilles tendon
  3. Tendons of hands
  4. Biceps tendon
  5. Tendons of feet

The correct answer is option b, The Achilles tendon is the most common location.

Question 33

What type of lipoprotein increases the risk of atherosclerosis?

  1. HDL
  2. IDL
  3. VLDL
  4. LDL
  5. Chylomicrons

The correct answer is option d, LDL

HDL is Healthy (protective against atherosclerosis) and LDL is Lethal cholesterol plaque formation in peripheral arteries increases risk of cardiac disease and stroke. Although chylomucrons, VLDL and IDL do contribute to risk, this is indirect and LDL is the main risk factor for atherosclerosis is raised LDL

Question 34

What is the mechanism behind thrombolysis?

  1. Anticoagulant
  2. Antifibrinolytic
  3. Fibrinolysis
  4. Antiplatelet
  5. Fondaparinux

The correct answer is option c, Fibrinolysis

Thrombolysis targets the fibrin involved in a clot, hence C being the correct answer. Recombinant tissue plasminogen activator is administered. This converts plasminogen to plasmin which is the main enzyme responsible for clot breakdown. Fibrin is inevitably broken down as part of the clot breakdown.

Question 35

Complete the sentence below regarding thrombolysis in an ischaemic stroke:

Thrombolytic therapy should be administered within ___________________ from the onset of symptoms

  1. 2 hours
  2. 4 hours and 30 minutes
  3. 3 hours and 30 minutes
  4. 6 hours
  5. 5 hours and 30 minutes

The correct answer is option b, 4 hours and 30 minutes

Just need to know. 4.5 hrs is the limit for thrombolysis in an ischaemic stroke. After this time, the risk of heammorhage outweights any clinical benifit

Question 36

What lipoproteins is used in removing cholesterol from tissues?

  1. HDL
  2. IDL
  3. VLDL
  4. LDL
  5. Chylomicrons

The correct answer is option a, HDL

HDL’s transport cholesterol from peripheral tissues (e.g., atherosclerotic arteries) to the liver (reverse cholesterol transport), where it is excreted (e.g. via bile).
LDL’s transport cholesterol from the liver to peripheral tissues
VLDL’s transport hepatic triglycerides
IDL’s transport triglycerides
Chylomicrons transport cholesterol to the liver in the form of triglyceride depleted chylomicron remnants

Question 37

How do statins work in the treatment of hyperlipidaemia?

  1. Inhibition of cholesterol reabsorption in the brush border enterocytes
  2. Binds to bile acid in the intestines, therefore reducing bile acid reabsorption
  3. Increases lipoprotein lipase activity, which increases LDL and triglyceride degradation and induces HDL synthesis
  4. Inhibition of HMG-CoA reductase
  5. Contains omega 3 fatty acids which help to inhibit triglyceride synthesis

The correct answer is option 4, Inhibition of HMG-CoA reductase

d- Statins – HMG CoA reductase – HMG-CoA is involved in the production of cholesterol in the liver. By inhibiting this enzyme, less cholesterol is produced. This is the most effective drug against hyperlipidaemia and is seen commonly in clinical practice.
Inhibition of cholesterol reabsorption in the brush border enterocytes is the mechanism of action of Ezetimibe
Binds to bile acid in the intestines, therefore reducing bile acid reabsorptionis the mechanism of action of bile acid resins
Increases lipoprotein lipase activity, which increases LDL and triglyceride degradation and induces HDL synthesis is the mechanism of action of fibrates
Omega 3 fatty acids aren’t used in statins but it has been shown to reduce triglycerides

Question 38

What clotting factors does warfarin target?

  1. II, VII, X, VIII
  2. X, XII, II, VII
  3. IX, X, VIII, II
  4. III, II, VII, IX
  5. II, X, IX, VII

The correct answer is option e, II, X, IX, VII

Warfarin targets Vit K dependent clotting factors – this includes 10, 9, 7 and 2 (Remembered by 1972). Then it’s just about recognising the numbers in roman numerals.

Question 39

What is the role of ‘tissue factor’ in the clotting process?

  1. Converts Prothrombin to Thrombin
  2. Stimulates the intrinsic pathway
  3. Converts fibrinogen to fibrin
  4. Involved in cross linking fibrin to the clot
  5. Stimulates the extrinsic pathway

The correct answer is option e, Stimulates the extrinsic pathway

Option e, Tissue factor is a protein found in sub-endothelial cells, which becomes exposed when the vessels are damaged. Tissue factor then binds to factor 7 (VII) to form Factor 7a (VIIa), which activates the extrinsic pathway.
Option a, The Prothrombinase complex – (Xa + Va + Calcium) is what converts prothrombin (II) to thrombin (IIa)
Option b, The intrinsic pathway is activated by exposed endothelial collagen
Option c, Thrombin is involved in the conversion of fibrinogen to fibrin
Option d, Factor 13a enables cross linking of the fibrin clot

Question 40

How does Haemophilia A affect clotting?

  1. Deficiency in Factor 9
  2. Defective Factor 9
  3. Deficiency in thrombin
  4. Deficiency in Factor 8
  5. Defective Factor 8

The correct answer is option d, deficency in factor 8

Haemophilia A is due to a deficiency in Factor 8. Haemophilia’s cause impaired clotting, which leads to haemorrhaging. Haemophilia A is more common and is treated with Recombinant Factor 8 in severe disease
Haemophilia B is due to a deficiency in Factor 9.
Thrombin deficency is not compatitble with life

Credits

  • 20-25 (Hollie Ross-Kenny, 3rd year),
  • 26-40 (William Madu, 4th year)