A 13-year-old boy has headaches and vomiting for 2 months. He cannot look upwards, his pupils react poorly to light but constrict on near vision, and attempts at upward gaze produce convergence-retraction nystagmus. MRI shows a mass in the pineal region with hydrocephalus. Which region is being compressed?

Dorsal midbrain at the pretectal area

Oculomotor nerve in the cavernous sinus

Abducens nucleus in the lower pons

Medial longitudinal fasciculus in the pons

A 66-year-old man had a stroke 2 months ago that left him with numbness of the whole right side of the body. He now has a constant burning pain on the right side, and even light touch from his clothes is very unpleasant. Power is normal. MRI shows an old infarct in the lateral part of the left thalamus. Which arteries were most likely occluded?

Thalamogeniculate branches of the posterior cerebral artery

Paramedian branches of the basilar artery in the pons

Recurrent artery of Heubner from the anterior cerebral artery

Lateral lenticulostriate branches of the middle cerebral artery

A 62-year-old smoker has aching in the left arm when he chops vegetables, and twice he has felt giddy with blurred vision while working with that arm. The left radial pulse is weak and delayed; BP is 102/70 mmHg in the left arm and 146/86 mmHg in the right. Duplex scanning shows reversed flow in the left vertebral artery. Where is the narrowing?

Left subclavian artery, proximal to the vertebral origin

Left subclavian artery, distal to the vertebral origin

Origin of the left vertebral artery

A 67-year-old man has sudden vertigo, vomiting, ringing and deafness in the right ear, and cannot close his right eye or smile on the right. He has right limb ataxia and loss of pain and temperature over the right face and the left side of the body. Which artery is most likely occluded?

Right anterior inferior cerebellar artery

Right posterior inferior cerebellar artery

Paramedian branches of the basilar artery

Right superior cerebellar artery

Brainstem, cerebral blood supply and stroke syndromes

16 NEET-PG practice questions on Brainstem, cerebral blood supply and stroke syndromes, part of Anatomy. The first 16 are below; the first 5 with answers and explanations (tap Show answer after you have chosen), the rest in Learn with a free account.

Question 1 · Medium
A 62-year-old hypertensive man has sudden vertigo, vomiting and hoarseness, with difficulty swallowing. Examination shows left ptosis with a small left pupil, loss of pain and temperature on the left face and right side of the body, and left limb ataxia. Damage to which structure explains his hoarseness and dysphagia?
1. ANucleus tractus solitarius
2. BDorsal motor nucleus of vagus
3. CNucleus ambiguus
4. DHypoglossal nucleus
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Answer: C · Nucleus ambiguus
Crossed sensory loss (ipsilateral face, contralateral body), ipsilateral Horner syndrome and ipsilateral ataxia is the lateral medullary (Wallenberg) syndrome, from occlusion of the vertebral artery or its posterior inferior cerebellar branch. The nucleus ambiguus supplies the muscles of the pharynx and larynx through the glossopharyngeal and vagus nerves, so its infarction causes hoarseness, dysphagia and a reduced gag. The spinal trigeminal nucleus and tract explain the facial loss, and the spinothalamic tract the body loss. Swallowing must be assessed before oral feeding because aspiration is a common complication.
- A: The nucleus tractus solitarius handles taste and visceral sensation, not voice.
- B: The dorsal motor nucleus is parasympathetic to viscera and does not move the larynx.
- D: The hypoglossal nucleus is medial; its damage (medial medullary syndrome) deviates the tongue.
Question 2 · Medium
A 13-year-old boy has headaches and vomiting for 2 months. He cannot look upwards, his pupils react poorly to light but constrict on near vision, and attempts at upward gaze produce convergence-retraction nystagmus. MRI shows a mass in the pineal region with hydrocephalus. Which region is being compressed?
1. AOculomotor nerve in the cavernous sinus
2. BAbducens nucleus in the lower pons
3. CMedial longitudinal fasciculus in the pons
4. DDorsal midbrain at the pretectal area
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Answer: D · Dorsal midbrain at the pretectal area
Upgaze palsy, light-near dissociation of the pupils and convergence-retraction nystagmus form the dorsal midbrain (Parinaud) syndrome. A pineal tumour presses on the pretectal area and superior colliculi, which contain the centres for vertical gaze and the pretectal nucleus of the pupillary light reflex. The near response uses a more ventral pathway, so it survives. The same tumour narrows the cerebral aqueduct, which explains the hydrocephalus.
- A: A cavernous sinus lesion of the third nerve causes ptosis and a down-and-out eye.
- B: An abducens nucleus lesion causes horizontal gaze palsy.
- C: An MLF lesion causes internuclear ophthalmoplegia with failure of adduction, not upgaze palsy.
Question 3 · Hard
A 66-year-old man had a stroke 2 months ago that left him with numbness of the whole right side of the body. He now has a constant burning pain on the right side, and even light touch from his clothes is very unpleasant. Power is normal. MRI shows an old infarct in the lateral part of the left thalamus. Which arteries were most likely occluded?
1. AThalamogeniculate branches of the posterior cerebral artery
2. BParamedian branches of the basilar artery in the pons
3. CRecurrent artery of Heubner from the anterior cerebral artery
4. DLateral lenticulostriate branches of the middle cerebral artery
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Answer: A · Thalamogeniculate branches of the posterior cerebral artery
Hemisensory loss followed weeks later by spontaneous burning pain and allodynia on the same side is the thalamic pain (Dejerine-Roussy) syndrome, from an infarct of the ventral posterolateral nucleus of the thalamus. This part of the thalamus is supplied by the thalamogeniculate branches of the posterior cerebral artery, so the lesion is in the opposite (left) thalamus. Normal power shows the internal capsule and corticospinal tract were spared. Drugs such as amitriptyline or gabapentinoids are used for the central pain.
- B: Pontine paramedian branches cause hemiplegia, not a thalamic pain syndrome.
- C: Heubner's artery supplies the caudate head and anterior limb of the internal capsule.
- D: Lenticulostriate arteries supply the putamen and internal capsule; their infarct causes weakness.
Question 4 · Hard
A 62-year-old smoker has aching in the left arm when he chops vegetables, and twice he has felt giddy with blurred vision while working with that arm. The left radial pulse is weak and delayed; BP is 102/70 mmHg in the left arm and 146/86 mmHg in the right. Duplex scanning shows reversed flow in the left vertebral artery. Where is the narrowing?
1. ALeft subclavian artery, distal to the vertebral origin
2. BLeft subclavian artery, proximal to the vertebral origin
3. CBrachiocephalic trunk
4. DOrigin of the left vertebral artery
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Answer: B · Left subclavian artery, proximal to the vertebral origin
This is the subclavian steal syndrome. With a block in the first part of the left subclavian artery, before the vertebral artery arises, pressure in the distal subclavian falls, and blood flows up the right vertebral artery to the basilar junction and down the left vertebral artery to supply the arm. Exercising the arm increases the steal and causes vertebrobasilar symptoms such as giddiness and blurred vision. A block distal to the vertebral origin would cause arm claudication but no reversal of vertebral flow.
- A: A narrowing beyond the vertebral origin cannot reverse vertebral flow.
- C: Brachiocephalic disease affects the right arm and right vertebral and carotid arteries.
- D: A stenosis of the vertebral artery itself reduces, but does not reverse, its flow.
Question 5 · Medium
A 67-year-old man has sudden vertigo, vomiting, ringing and deafness in the right ear, and cannot close his right eye or smile on the right. He has right limb ataxia and loss of pain and temperature over the right face and the left side of the body. Which artery is most likely occluded?
1. ARight posterior inferior cerebellar artery
2. BRight anterior inferior cerebellar artery
3. CParamedian branches of the basilar artery
4. DRight superior cerebellar artery
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Answer: B · Right anterior inferior cerebellar artery
Lower motor neuron facial palsy and deafness on the same side, with ipsilateral ataxia and crossed loss of pain and temperature, place the lesion in the lateral part of the lower pons: the lateral pontine (AICA) syndrome. The AICA supplies the facial nucleus, vestibular and cochlear nuclei, the middle cerebellar peduncle and the spinal trigeminal tract, and usually gives the labyrinthine artery to the inner ear. The facial palsy and deafness separate it from the lateral medullary (PICA) syndrome. Paramedian basilar branches supply the medial pons and cause hemiplegia.
- A: PICA occlusion spares the facial nucleus and hearing.
- C: Paramedian basilar branches cause contralateral hemiplegia, not deafness.
- D: Superior cerebellar artery occlusion affects the upper pons and cerebellum without facial palsy or deafness.
Question 6 · Easy
A 61-year-old diabetic man in the medicine OPD has a drooping right eyelid, with the right eye turned down and out and a dilated right pupil. He also has weakness of the left arm and leg and of the lower left face. Where is the lesion?
1. ARight ventral pons
2. BLeft ventral midbrain
3. CRight ventral midbrain
4. DRight dorsal midbrain
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Question 7 · Easy
A 56-year-old man with untreated hypertension for 15 years collapses at a wedding with sudden left hemiplegia. CT shows a haematoma centred on the right putamen and extending to the internal capsule. Rupture of which vessels most likely caused it?
1. ARecurrent artery of Heubner
2. BThalamoperforating arteries
3. CLateral lenticulostriate arteries
4. DPericallosal artery branches
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Question 8 · Medium
Residents discuss a 66-year-old man with a lacunar infarct in the internal capsule and list four statements: 1. The posterior limb carries corticospinal fibres for the opposite arm and leg. 2. The genu carries corticonuclear fibres. 3. The retrolentiform part carries the optic radiation. 4. The anterior limb lies between the thalamus and the lentiform nucleus. Which statements are correct?
1. A1, 2 and 3 only
2. B1 and 2 only
3. C1, 2 and 4 only
4. D2, 3 and 4 only
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Question 9 · Medium
A 70-year-old right-handed man in a stroke unit has weakness of the left face and arm more than the left leg. He leaves food on the left side of his plate, shaves only the right side of his face and insists nothing is wrong with his left arm. His speech is fluent and he understands well. Which artery is most likely occluded?
1. ALeft middle cerebral artery
2. BRight anterior cerebral artery
3. CRight middle cerebral artery
4. DRight posterior cerebral artery
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Question 10 · Easy
A 68-year-old woman has sudden weakness and numbness of the right leg, with only mild weakness of the right arm and normal face and speech. Her family says she has become apathetic and has been wetting herself since the attack. Which artery is most likely occluded?
1. ALeft middle cerebral artery
2. BLeft posterior cerebral artery
3. CRight anterior cerebral artery
4. DLeft anterior cerebral artery
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Question 11 · Medium
A 63-year-old smoker has sudden weakness of the right arm and leg with the face spared. On protrusion his tongue deviates to the left and the left half of the tongue is wasted a few weeks later. Vibration and joint position sense are lost on the right side of the body; pain and temperature are normal. Occlusion of which artery best explains this?
1. AAnterior spinal artery
2. BSuperior cerebellar artery
3. CPosterior inferior cerebellar artery
4. DAnterior inferior cerebellar artery
Answer and explanation in LearnFree account
Question 12 · Medium
A 59-year-old man with diabetes and hypertension wakes with weakness of the left face, arm and leg, all to the same degree. He has no sensory loss, no visual field defect, and his speech and understanding are normal. MRI shows a small deep infarct. Where is it most likely to be?
1. ARight medullary pyramid
2. BPosterior limb of the right internal capsule
3. CRight ventral posterolateral thalamus
4. DLateral part of the right precentral gyrus
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Question 13 · Hard
A 55-year-old woman develops sudden vertigo, hiccups and an unsteady gait. The right pupil is small with a slight ptosis, the right arm and leg are ataxic, and pain and temperature are lost over the right face and the left trunk and limbs. MRI shows an infarct in the right lateral medulla. Consider: 1. The small pupil and ptosis follow damage to descending sympathetic fibres. 2. The loss over the left body follows damage to the lateral spinothalamic tract. 3. Her tongue would deviate to the right on protrusion. 4. The facial loss follows damage to the spinal trigeminal nucleus and tract. Which are correct?
1. A1, 2 and 4 only
2. B1 and 4 only
3. C1, 2, 3 and 4
4. D1 and 2 only
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Question 14 · Medium
A 47-year-old woman has had a severe headache behind the left eye for 3 days. The left upper lid droops, the left eye rests down and out, and the left pupil is dilated and does not react to light. The rest of the neurological examination is normal. An aneurysm at which site is most likely?
1. AAnterior communicating artery
2. BJunction of internal carotid and posterior communicating arteries
3. CTip of the basilar artery
4. DBifurcation of the middle cerebral artery
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Question 15 · Medium
A 58-year-old man is brought to casualty unable to move any limb or speak. He is fully alert, answers questions by blinking and can look up and down on command, but cannot move his eyes to either side. Which artery is most likely occluded?
1. AAnterior spinal artery
2. BBoth posterior cerebral arteries
3. CBasilar artery
4. DLeft vertebral artery
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Question 16 · Medium
A 64-year-old woman notices she keeps bumping into things on her left. Perimetry shows a left homonymous hemianopia, but the central few degrees of vision on the left are preserved. MRI shows an infarct in the right occipital lobe. What best explains the preserved central vision?
1. AThe occipital pole also receives MCA branches
2. BThe anterior choroidal artery supplies the calcarine cortex
3. CMacular fibres bypass the lateral geniculate body
4. DMacular fibres run in Meyer loop in the temporal lobe
Answer and explanation in LearnFree account

Brainstem, cerebral blood supply and stroke syndromes

A 67-year-old man has sudden vertigo, vomiting, ringing and deafness in the right ear, and cannot close his right eye or smile on the right. He has right limb ataxia and loss of pain and temperature over the right face and the left side of the body. Which artery is most likely occluded?

A 61-year-old diabetic man in the medicine OPD has a drooping right eyelid, with the right eye turned down and out and a dilated right pupil. He also has weakness of the left arm and leg and of the lower left face. Where is the lesion?

A 56-year-old man with untreated hypertension for 15 years collapses at a wedding with sudden left hemiplegia. CT shows a haematoma centred on the right putamen and extending to the internal capsule. Rupture of which vessels most likely caused it?

A 68-year-old woman has sudden weakness and numbness of the right leg, with only mild weakness of the right arm and normal face and speech. Her family says she has become apathetic and has been wetting herself since the attack. Which artery is most likely occluded?

A 59-year-old man with diabetes and hypertension wakes with weakness of the left face, arm and leg, all to the same degree. He has no sensory loss, no visual field defect, and his speech and understanding are normal. MRI shows a small deep infarct. Where is it most likely to be?

A 47-year-old woman has had a severe headache behind the left eye for 3 days. The left upper lid droops, the left eye rests down and out, and the left pupil is dilated and does not react to light. The rest of the neurological examination is normal. An aneurysm at which site is most likely?

A 58-year-old man is brought to casualty unable to move any limb or speak. He is fully alert, answers questions by blinking and can look up and down on command, but cannot move his eyes to either side. Which artery is most likely occluded?

A 64-year-old woman notices she keeps bumping into things on her left. Perimetry shows a left homonymous hemianopia, but the central few degrees of vision on the left are preserved. MRI shows an infarct in the right occipital lobe. What best explains the preserved central vision?