-
Question 1
Incorrect
-
A 70-year-old man presents with right-sided hemiplegia and loss of joint position sense, vibratory sense, and discriminatory touch. Upon further physical examination, it was observed that her tongue deviates to the left-hand side. An MRI and CT scan was ordered and results showed that he was suffering a left-sided stroke.
Branches of which of the following arteries are most likely implicated in the case?Your Answer: Posterior spinal artery
Correct Answer: Anterior spinal artery
Explanation:Medial medullary syndrome is a form of stroke that affects the medial medulla of the brain. It is caused by a lesion in the medial part of the medulla, which is due to an infraction of vertebral arteries and/or paramedian branches of the anterior spinal artery.
It is characterized by contralateral paralysis of the upper and lower limb of the body, a contralateral decrease in proprioception, vibration, and/or fine touch sensation, paresthesias or less commonly dysesthesias in the contralateral trunk and lower limb, and loss of position and vibration sense with proprioceptive dysfunction. Ipsilateral deviation of the tongue due to ipsilateral hypoglossal nerve damage can also be seen.
-
This question is part of the following fields:
- Anatomy
- Central Nervous System
-
-
Question 2
Incorrect
-
Regarding aspirin at analgesic doses, which of the following statements is CORRECT:
Your Answer: The analgesic dose is smaller than the antiplatelet dose.
Correct Answer: It is contraindicated in patients with severe heart failure.
Explanation:Aspirin (at analgesic doses) is contraindicated in severe heart failure. Aspirin irreversibly inhibits cyclooxygenase (COX) enzymes resulting in decreased production of prostaglandins (which can lead to irritation of the gastric mucosa). The analgesic dose is greater than the antiplatelet dose, and taken orally it has a duration of action of about 4 hours. Clinical features of salicylate toxicity in overdose include hyperventilation, tinnitus, deafness, vasodilatation, and sweating.
-
This question is part of the following fields:
- Central Nervous System
- Pharmacology
-
-
Question 3
Correct
-
Which of the following is most likely to cause a homonymous hemianopia:
Your Answer: Posterior cerebral artery stroke
Explanation:A posterior cerebral stroke will most likely result in a contralateral homonymous hemianopia with macular sparing.
-
This question is part of the following fields:
- Anatomy
- Central Nervous System
-
-
Question 4
Correct
-
Which of the following statements is true about anterior cord syndrome?
Your Answer: There is preservation of proprioception
Explanation:Anterior cord syndrome is an incomplete cord syndrome that predominantly affects the anterior 2/3 of the spinal cord, characteristically resulting in motor paralysis below the level of the lesion as well as the loss of pain and temperature at and below the level of the lesion. The patient presentation typically includes these two findings; however, there is variability depending on the portion of the spinal cord affected. Other findings include back pain, or autonomic dysfunction such as hypotension, neurogenic bowel or bladder, and sexual dysfunction. The severity of motor dysfunction can vary, typically resulting in paraplegia or quadriplegia.
Proprioception, vibratory sense, two-point discrimination, and fine touch are not affected in anterior cord syndrome. These sensations are under the control of the dorsal column of the spinal cord, which is supplied by two posterior spinal arteries running in the posterior lateral sulci.
-
This question is part of the following fields:
- Anatomy
- Central Nervous System
-
-
Question 5
Correct
-
What type of visual field defect are you most likely to see in a lesion of the parietal optic radiation:
Your Answer: Contralateral homonymous inferior quadrantanopia
Explanation:A lesion of the parietal optic radiation will result in a contralateral homonymous inferior quadrantanopia.
A lesion of the temporal optic radiation will result in a contralateral homonymous superior quadrantanopia. -
This question is part of the following fields:
- Anatomy
- Central Nervous System
-
-
Question 6
Incorrect
-
The sensation produced by touching the arm with a vibrating tuning fork during a neurological examination is mediated by which of the following spinal tracts:
Your Answer: Lateral spinothalamic tract
Correct Answer: Posterior column
Explanation:Fine-touch, proprioception and vibration sensation are mediated by the posterior column-medial lemniscus pathway.
-
This question is part of the following fields:
- Anatomy
- Central Nervous System
-
-
Question 7
Incorrect
-
A 70-year-old woman presents with right-sided loss of pain and temperature sense on the body as well as left-sided loss of pain and temperature sense on the face. She also has complaints of vertigo, nausea, and tinnitus. Further examination of her cranial nerves suggest the presence of Horner's Syndrome. An MRI and CT scan was ordered and results showed that she is suffering from a left-sided stroke.
Branches of which of the following arteries are most likely implicated in the case?Your Answer: Anterior spinal artery
Correct Answer: Posterior inferior cerebellar artery
Explanation:Wallenberg syndrome is also known as lateral medullary syndrome and posterior inferior cerebellar artery syndrome. It is the most common posterior circulation ischemic stroke syndrome. The primary pathology of Wallenberg syndrome is occlusion of the posterior inferior cerebellar artery (PICA) or one of its branches.
It is characterized by vertigo with nystagmus, nausea and vomiting, and sometimes hiccups, dysphonia, dysarthria, and dysphagia often present with ipsilateral loss of gag reflex, ipsilateral ataxia with a tendency to fall to the ipsilateral side, pain and numbness with impaired facial sensation on the face, impaired taste sensation, and impaired pain and temperature sensation in the arms and legs.
-
This question is part of the following fields:
- Anatomy
- Central Nervous System
-
-
Question 8
Correct
-
What is the main mechanism of action of metoclopramide:
Your Answer: Dopamine antagonist
Explanation:Metoclopramide is a dopamine-receptor antagonist. Blockade of inhibitory dopamine receptors in the GI tract may allow stimulatory actions of ACh at muscarinic synapses to predominate. Metoclopramide also blocks dopamine D2-receptors within the chemoreceptor trigger zone (CTZ). At high doses, it is also thought to have some 5-HT3antagonist activity.
-
This question is part of the following fields:
- Central Nervous System
- Pharmacology
-
-
Question 9
Incorrect
-
Regarding codeine, which of the following statements is INCORRECT:
Your Answer: Codeine 240 mg is approximately equivalent to 30 mg of morphine.
Correct Answer: There is a reduced risk of toxicity in patients who are ultra-rapid metabolisers of codeine.
Explanation:Codeine phosphate is a weak opioid and can be used for the relief of mild to moderate pain where other painkillers such as paracetamol or ibuprofen have proved ineffective.Codeine is metabolised to morphine which is responsible for its therapeutic effects. Codeine 240 mg is approximately equivalent to 30 mg of morphine. The capacity to metabolise codeine can vary considerably between individuals; there is a marked increase in morphine toxicity in people who are ultra rapid metabolisers, and reduced therapeutic effect in poor codeine metabolisers. Codeine is contraindicated in patients of any age who are known to be ultra-rapid metabolisers of codeine (CYP2D6 ultra-rapid metabolisers).Codeine is also contraindicated in children under 12, and in children of any age who undergo the removal of tonsils or adenoids for the treatment of obstructive sleep apnoea due to reports of morphine toxicity.
-
This question is part of the following fields:
- Central Nervous System
- Pharmacology
-
-
Question 10
Correct
-
Regarding paracetamol, which of the following statements is CORRECT:
Your Answer: It has anti-pyretic action.
Explanation:Paracetamol is a non-opioid analgesic, similar in efficacy to aspirin, with antipyretic properties but no anti-inflammatory properties. It is well absorbed orally and does not cause gastric irritation. Paracetamol is a suitable first-line choice for most people with mild-to-moderate pain, and for combination therapy.
-
This question is part of the following fields:
- Central Nervous System
- Pharmacology
-
SESSION STATS - PERFORMANCE PER SPECIALTY
