Neurologic Anatomy Review Practice Questions

30 multiple-choice questions on Neurologic anatomy review for paramedic and EMT students, from Chapter 19 (Neurologic Emergencies). Read each question, pick your answer, then tap Show answer to check it and read the explanation.

30 practice questions

1. A 66-year-old has sudden vertigo and keeps veering to the right. His right hand overshoots when he touches your finger, but his strength is equal on both sides. Where is the lesion most likely?

   1. A. Left cerebellar hemisphere
   2. B. Left frontal motor cortex
   3. C. Right cerebellar hemisphere
   4. D. Right occipital lobe cortex
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   Answer: C. Right cerebellar hemisphere

   Each cerebellar hemisphere coordinates movement on the same side of the body, so right-sided limb ataxia with normal strength points to the right cerebellar hemisphere. A left cerebellar lesion would make the left limbs clumsy. A lesion of the left motor cortex causes right-sided weakness, not pure incoordination, and the occipital cortex handles vision rather than coordination.

2. A 70-year-old has sudden double vision. His left eye cannot turn outward, and his right arm and leg are weak. What does this combination of findings most suggest?

   1. A. A brainstem lesion
   2. B. A right cerebral hemisphere stroke
   3. C. A left cerebral hemisphere stroke
   4. D. A peripheral nerve injury
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   Answer: A. A brainstem lesion

   A cranial nerve deficit on one side with arm and leg weakness on the other side ('crossed' findings) localizes to the brainstem, where cranial nerve nuclei sit next to motor tracts that have not yet crossed. A stroke in either cerebral hemisphere causes weakness and facial findings on the same side of the body, and a single peripheral nerve injury cannot weaken an eye muscle and the opposite limbs together.

3. A 72-year-old keeps bumping into door frames on her left. She has normal strength and speech, but in both eyes she cannot see objects on her left side. Which artery is most likely blocked?

   1. A. Left posterior cerebral artery
   2. B. Right posterior cerebral artery
   3. C. Right anterior cerebral artery
   4. D. Left middle cerebral artery branch
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   Answer: B. Right posterior cerebral artery

   Loss of the same half of the visual field in both eyes (homonymous hemianopia) without weakness points to the visual (occipital) cortex on the opposite side, which the posterior cerebral artery supplies. A left posterior cerebral artery occlusion would cause right-sided field loss. The anterior cerebral artery supplies the medial frontal lobe and leg motor area, and a left middle cerebral artery stroke causes right-sided weakness and aphasia.

4. A patient with a slowly enlarging brain tumor asks why it did not hurt until recently. Which explanation is most accurate?

   1. A. Brain tissue has no pain receptors
   2. B. The tumor blocked pain fibers early
   3. C. The skull absorbs pressure painlessly
   4. D. Steroids masked the pain until now
   Show answer

   Answer: A. Brain tissue has no pain receptors

   The brain tissue itself has no pain receptors. Headache from a mass comes from stretching or pressure on pain-sensitive structures such as the dura, the large blood vessels and the cranial nerves, which often happens only once the mass is large or pressure rises. A tumor does not block pain fibers early, the rigid skull makes pressure harder rather than easier to tolerate, and steroids reduce swelling but do not explain a painless early course.

5. A woman with weeks of worsening headache and swelling of the optic discs now cannot move her right eye outward. Her pupils are equal and reactive. What best explains the eye finding?

   1. A. A right oculomotor nerve compressed by herniation
   2. B. A right-sided Horner syndrome from dissection
   3. C. Raised pressure stretching the sixth nerve
   4. D. Weakness of the right facial nerve
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   Answer: C. Raised pressure stretching the sixth nerve

   The abducens nerve (CN VI) moves the eye outward and has a long course inside the skull, so raised intracranial pressure can stretch it and cause a 'false localizing' palsy on either side. Oculomotor (CN III) compression causes a dilated pupil and a down-and-out eye, which she does not have. Horner syndrome causes ptosis and a small pupil, and the facial nerve moves the face, not the eye.

6. A 52-year-old has a sudden severe headache. Her right eyelid droops, the right eye rests down and out, and the right pupil is dilated. She is alert. What is the most concerning cause?

   1. A. Bell palsy affecting the right facial nerve
   2. B. An aneurysm pressing on the third nerve
   3. C. Horner syndrome from an apical lung tumor
   4. D. Myasthenia gravis with weak eye muscles
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   Answer: B. An aneurysm pressing on the third nerve

   The oculomotor nerve (CN III) lifts the eyelid, turns the eye up, down and inward, and constricts the pupil. A third nerve palsy with a dilated pupil and sudden headache suggests compression by an expanding posterior communicating artery aneurysm, which can rupture and needs emergency care. Bell palsy affects facial muscles, Horner syndrome gives a small rather than a dilated pupil, and myasthenia does not affect the pupil.

7. After surgery on the left side of his neck, a patient's tongue deviates toward the left when he sticks it out. Which nerve is most likely injured?

   1. A. Right hypoglossal nerve (CN XII)
   2. B. Left hypoglossal nerve (CN XII)
   3. C. Left facial nerve (CN VII)
   4. D. Left glossopharyngeal nerve (CN IX)
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   Answer: B. Left hypoglossal nerve (CN XII)

   Each hypoglossal nerve powers the muscles that push the tongue forward on its own side. When one side is weak, the stronger side pushes the tongue toward the weak side, so a left hypoglossal injury makes the tongue deviate to the left. A right-sided injury would push it to the right. The facial nerve moves the face, and the glossopharyngeal nerve carries sensation from the throat rather than moving the tongue.

8. Why does a right cerebral hemisphere stroke typically cause left-sided weakness?

   1. A. The cerebellum reverses signals
   2. B. Motor tracts cross in the corpus callosum
   3. C. Motor tracts cross in the internal capsule
   4. D. Motor tracts cross in the medulla
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   Answer: D. Motor tracts cross in the medulla

   Most corticospinal (motor) fibers decussate at the pyramids of the medulla, so each hemisphere controls movement on the opposite side of the body. The corpus callosum connects the two hemispheres to each other but does not carry motor fibers down to the opposite side, and in the internal capsule the motor fibers are still running down on their own side. The cerebellum coordinates movement on its own side rather than reversing signals.

9. After cardiac arrest with prolonged low blood pressure, a patient can move his hands and legs but cannot lift either arm at the shoulder. Which explanation fits best?

   1. A. Bilateral middle cerebral artery emboli
   2. B. Guillain-Barre syndrome after the arrest
   3. C. Injury to both brachial plexuses during CPR
   4. D. Low flow where two artery territories meet
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   Answer: D. Low flow where two artery territories meet

   Severe hypotension starves the border zones (watershed areas) between the anterior and middle cerebral artery territories first. These zones control the shoulders and upper arms, which produces bilateral proximal arm weakness, sometimes called 'man in a barrel.' Emboli to both middle cerebral arteries would cause face and arm weakness with aphasia or neglect. Guillain-Barre develops over days and starts in the legs, and CPR does not typically injure both brachial plexuses.

10. The circle of Willis is best described as:

    1. A. An arterial ring at the brain base
    2. B. A venous sinus draining the cortex
    3. C. A fluid space around the spinal cord
    4. D. A protective layer of the meninges
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    Answer: A. An arterial ring at the brain base

    The circle of Willis connects the anterior (carotid) and posterior (vertebrobasilar) circulations, providing potential collateral flow if one vessel is occluded.

11. Which artery supplies most of the lateral surface of the cerebral hemisphere and is the most commonly occluded in stroke?

    1. A. Anterior cerebral artery
    2. B. Posterior cerebral artery
    3. C. Basilar artery
    4. D. Middle cerebral artery
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    Answer: D. Middle cerebral artery

    The middle cerebral artery supplies the lateral frontal, parietal, and temporal lobes, including motor and language areas of the face and arm. It is the most common site of ischemic stroke.

12. Occlusion of the anterior cerebral artery would most likely cause weakness that is greatest in the:

    1. A. Contralateral face
    2. B. Contralateral leg
    3. C. Ipsilateral arm
    4. D. Ipsilateral leg
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    Answer: B. Contralateral leg

    The anterior cerebral artery supplies the medial frontal and parietal lobes, where the motor area for the leg is represented, so weakness is greatest in the contralateral leg. Face and arm weakness points to the middle cerebral artery, and hemisphere strokes cause contralateral rather than ipsilateral weakness because the motor tracts cross in the medulla.

13. The vertebral arteries join to form which vessel?

    1. A. Internal carotid artery
    2. B. Basilar artery
    3. C. Middle cerebral artery
    4. D. Anterior communicating artery
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    Answer: B. Basilar artery

    The two vertebral arteries unite at the pons to form the basilar artery, which supplies the brainstem, cerebellum, and via the posterior cerebral arteries, the occipital lobes.

14. A patient has a weak, wasted right hand with fine twitching under the skin and reduced reflexes in that arm. Where is the problem most likely located?

    1. A. The lower motor neuron
    2. B. The upper motor neuron
    3. C. The cerebellar hemisphere
    4. D. The basal ganglia
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    Answer: A. The lower motor neuron

    Lower motor neuron damage (anterior horn cell, nerve root or peripheral nerve) causes weakness with muscle wasting, fasciculations and reduced reflexes. Upper motor neuron damage in the brain or spinal cord causes weakness with increased tone, brisk reflexes and a Babinski sign. Cerebellar disease causes incoordination with normal strength, and basal ganglia disease causes tremor, rigidity or abnormal movements.

15. A 74-year-old on apixaban had an epidural catheter removed after surgery yesterday. She now has severe back pain and her legs are becoming weak and numb. What should you suspect?

    1. A. A bleed compressing the spinal cord
    2. B. A urinary tract infection with sepsis
    3. C. A lumbar muscle spasm after surgery
    4. D. A pulmonary embolism with low perfusion
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    Answer: A. A bleed compressing the spinal cord

    A spinal epidural hematoma can follow epidural catheter placement or removal, especially in a patient taking an anticoagulant. Sudden back pain followed by progressive leg weakness and numbness means the cord or nerve roots are being compressed, and outcome depends on rapid decompression. Infection, muscle spasm and pulmonary embolism do not explain progressive weakness and numbness of both legs.

16. A 61-year-old asks the same questions every few minutes and cannot remember anything new, yet knows his name and has a normal neurologic exam. Hours later he is back to normal. What is the most likely diagnosis?

    1. A. Wernicke encephalopathy
    2. B. Psychogenic amnesia
    3. C. A prolonged absence seizure
    4. D. Transient global amnesia
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    Answer: D. Transient global amnesia

    Transient global amnesia causes sudden loss of the ability to form new memories, with repetitive questioning and preserved identity and alertness, and it resolves within 24 hours. These patients still need evaluation because stroke and seizure can mimic it. Wernicke encephalopathy brings ataxia and eye movement problems, psychogenic amnesia often involves loss of personal identity, and absence seizures last only seconds.

17. During repair of an aortic aneurysm, a patient's spinal cord loses part of its blood supply. Afterward he cannot move his legs or feel pain in them, but he can feel vibration and the position of his toes. What best explains this pattern?

    1. A. Compression of the cauda equina roots
    2. B. A complete cord transection at T10
    3. C. A stroke in both cerebral hemispheres
    4. D. Infarction of the front of the cord
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    Answer: D. Infarction of the front of the cord

    The anterior spinal artery supplies the front two-thirds of the cord, which carries the motor tracts and the pain and temperature pathways. The dorsal columns, which carry vibration and position sense, get a separate posterior supply and are spared. A complete transection would remove all sensation, cauda equina compression causes saddle numbness and bladder problems with reduced reflexes, and bilateral cerebral strokes would not spare vibration in this pattern.

18. A 30-year-old has burned his hands several times without noticing. He cannot feel pain or temperature across his shoulders and arms, but touch and vibration are normal. What is the most likely cause?

    1. A. A small stroke in the left parietal lobe
    2. B. Carpal tunnel syndrome in both wrists
    3. C. A fluid cavity in the cervical cord
    4. D. A peripheral neuropathy from diabetes
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    Answer: C. A fluid cavity in the cervical cord

    A syrinx (syringomyelia) in the center of the cervical cord first damages the pain and temperature fibers that cross in front of the central canal, causing a cape-like loss over the shoulders and arms while touch and vibration, carried in the dorsal columns, are spared. A parietal stroke affects one side of the body, carpal tunnel syndrome causes numbness of the thumb and fingers, and a diabetic neuropathy starts in the feet and affects all sensations.

19. Shining a light in a patient's right eye makes both pupils constrict. Shining it in the left eye makes neither pupil constrict. What is the most likely problem?

    1. A. Left oculomotor nerve damage
    2. B. Left optic nerve damage
    3. C. Right optic nerve damage
    4. D. Pontine hemorrhage
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    Answer: B. Left optic nerve damage

    The optic nerve carries the light signal in, and both oculomotor nerves carry the constriction signal out to both pupils. Because light in the right eye constricts both pupils, both oculomotor nerves work, so the failure to respond to light in the left eye means the left optic nerve is not sending the signal. A left oculomotor lesion would leave the left pupil unreactive from either side, a right optic nerve lesion would fail when the right eye is lit, and a pontine hemorrhage causes pinpoint pupils.

20. Facial droop involving the lower face with forehead sparing suggests a lesion of the:

    1. A. Facial nerve (peripheral)
    2. B. Trigeminal nerve branch
    3. C. Brain (central lesion)
    4. D. Cerebellar hemisphere
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    Answer: C. Brain (central lesion)

    The forehead receives input from both hemispheres, so a central lesion such as a stroke spares the forehead. Bell palsy, a peripheral CN VII lesion, involves the entire half of the face.

21. After a lymph node biopsy in the side of his neck, a patient cannot shrug his left shoulder well and has trouble raising his arm overhead. Which nerve was most likely injured?

    1. A. Left spinal accessory nerve (CN XI)
    2. B. Left hypoglossal nerve (CN XII)
    3. C. Left phrenic nerve (roots C3 to C5)
    4. D. Left facial nerve (CN VII)
    Show answer

    Answer: A. Left spinal accessory nerve (CN XI)

    The spinal accessory nerve (CN XI) runs superficially across the side of the neck and powers the trapezius and sternocleidomastoid muscles, so injury during neck surgery causes a weak shoulder shrug and difficulty raising the arm overhead. The hypoglossal nerve moves the tongue, the phrenic nerve powers the diaphragm, and the facial nerve moves the face.

22. A 50-year-old has neck pain that shoots into his right arm, with numbness of the thumb and index finger. Moving his neck makes it worse. He has no chest pain and normal speech. What is the most likely cause?

    1. A. A right hemisphere ischemic stroke
    2. B. An inferior wall myocardial infarction
    3. C. A compressed cervical nerve root
    4. D. Carpal tunnel syndrome of the wrist
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    Answer: C. A compressed cervical nerve root

    Neck pain that radiates down one arm in a nerve root distribution, with numbness of the thumb and index finger and worsening on neck movement, fits a compressed C6 nerve root (cervical radiculopathy). A right hemisphere stroke would weaken the left side without neck pain. An inferior wall myocardial infarction can refer pain to the arm, but cardiac pain is not reproduced by neck movement and does not cause dermatomal numbness, and carpal tunnel syndrome causes hand numbness without neck pain.

23. The basic functional cell of the nervous system that transmits impulses is the:

    1. A. Astrocyte
    2. B. Schwann cell
    3. C. Microglial cell
    4. D. Neuron
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    Answer: D. Neuron

    Neurons conduct electrical impulses. Astrocytes, Schwann cells, and microglia are supporting (glial) cells.

24. The chemical released at a synapse to transmit a signal to the next cell is a:

    1. A. Circulating hormone
    2. B. Electrolyte ion
    3. C. Neurotransmitter
    4. D. Myelin protein
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    Answer: C. Neurotransmitter

    Neurotransmitters such as acetylcholine, norepinephrine, and GABA cross the synaptic cleft and bind receptors on the next cell.

25. A 62-year-old smoker with lung cancer has weak hips and shoulders and a dry mouth. His grip is weak at first but grows stronger when he squeezes repeatedly. What is the most likely disorder?

    1. A. Myasthenia gravis
    2. B. Guillain-Barre syndrome
    3. C. Amyotrophic lateral sclerosis
    4. D. Lambert-Eaton syndrome
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    Answer: D. Lambert-Eaton syndrome

    Lambert-Eaton syndrome is an autoimmune disorder, often linked to small cell lung cancer, in which antibodies reduce acetylcholine release at the nerve terminal. It causes proximal weakness, dry mouth and other autonomic signs, and strength briefly improves with repeated effort. Myasthenia gravis gets worse with repeated use. Guillain-Barre causes ascending weakness without improvement on effort, and amyotrophic lateral sclerosis (ALS) causes wasting and fasciculations without autonomic signs.

26. A 27-year-old woman has 2 days of blurred vision in her right eye, with pain when she moves the eye and colors that look washed out. What is the most likely diagnosis?

    1. A. Retinal detachment
    2. B. Migraine aura
    3. C. Optic neuritis
    4. D. Acute glaucoma
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    Answer: C. Optic neuritis

    Optic neuritis is inflammation and demyelination of the optic nerve, common in young women and often the first sign of multiple sclerosis. It causes vision loss over hours to days, pain with eye movement and faded color vision. Retinal detachment is painless with flashes, floaters or a curtain. A migraine aura lasts under an hour, and acute angle-closure glaucoma causes a red, hard, painful eye with halos and vomiting.

27. A 70-year-old with hypertension suddenly loses feeling over the entire left side of his face, arm and leg. His strength, speech and vision are normal. Where is the small stroke most likely?

    1. A. Left thalamus
    2. B. Right thalamus
    3. C. Right cerebellum
    4. D. Left frontal lobe
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    Answer: B. Right thalamus

    The thalamus relays sensation from the opposite side of the body to the cortex, so a small lacunar infarct in the right thalamus can cause pure sensory loss over the whole left side with no weakness. A left thalamic stroke would affect the right side. A cerebellar stroke causes incoordination rather than numbness, and a left frontal stroke causes right-sided weakness or speech problems.

28. A 68-year-old has taken metoclopramide daily for months. Over several weeks she has developed a shuffling gait, stiffness and slow movements. What is the most likely cause?

    1. A. Normal pressure hydrocephalus
    2. B. Drug-induced parkinsonism
    3. C. Acute dystonic reaction
    4. D. Serotonin syndrome
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    Answer: B. Drug-induced parkinsonism

    Metoclopramide and antipsychotics block dopamine receptors, and long-term use can cause parkinsonism with slowness, rigidity and a shuffling gait that often improves after the drug is stopped. Normal pressure hydrocephalus causes gait change with incontinence and memory loss. An acute dystonic reaction is a sudden muscle spasm within hours to days, and serotonin syndrome develops quickly with clonus, fever and agitation.

29. A 72-year-old gets pain, numbness and heaviness in both legs after walking a few blocks. It eases when he sits or leans forward on a shopping cart, and his foot pulses are normal. What is the most likely cause?

    1. A. Blockage of the arteries to the legs
    2. B. Narrowing of the lumbar spinal canal
    3. C. A deep vein thrombosis
    4. D. Diabetic peripheral neuropathy
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    Answer: B. Narrowing of the lumbar spinal canal

    Lumbar spinal stenosis causes neurogenic claudication: leg pain, numbness or weakness with walking or standing that eases with sitting or bending forward, because flexion widens the spinal canal. Arterial (vascular) claudication eases with simply standing still and comes with weak pulses. A deep vein thrombosis causes a swollen, painful leg at rest, and diabetic neuropathy causes constant numbness rather than walking-related symptoms.

30. Why does the brain tolerate interruption of blood flow so poorly?

    1. A. It cannot use oxygen efficiently
    2. B. It stores almost no oxygen or glucose
    3. C. It stores excess lactate inside neurons
    4. D. Its vessels are unable to dilate
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    Answer: B. It stores almost no oxygen or glucose

    The brain uses about 20% of the body's oxygen but stores almost none and very little glucose, so neurons begin to fail within seconds and irreversible injury starts within minutes of ischemia. The brain uses oxygen very efficiently, it does not store lactate (lactate builds up only during ischemia), and its vessels can dilate through autoregulation; the problem is the lack of reserves.