A 72-year-old man comes to his primary care provider because of double vision and headache. He says these symptoms developed suddenly last night and have not improved. He has had type 2 diabetes mellitus for 32 years and essential hypertension for 19 years for which he takes metformin and lisinopril. His last recorded A1c was 9.4%. He has smoked 10 to 15 cigarettes a day for the past 35 years. Family history is significant for chronic kidney disease in his mother. Vital signs reveal a temperature of 36.9 °C (98.42°F), blood pressure of 137/82 mm Hg, and pulse of 72/min. On examination, there is ptosis of the right eye and it is deviated down and out. Visual acuity is not affected in either eye. Which of the following cranial nerves is most likely impaired in this patient?
Q72
A 75-year-old woman is brought to the physician by her daughter for a 4-month history of increasing difficulty recognizing her friends and family. She has had to rely on recognizing haircuts, gait, and voices because she cannot remember their faces. Neurologic examination shows that she is able to recognize objects and name facial features such as the eyes and nose. On mental status examination, she is alert and has no deficits in cognition or short-term memory. An MRI of her head shows an inhomogeneous 2-cm mass with perifocal edema in her brain. Which of the following brain regions is most likely affected?
Q73
A 72-year-old man is brought to your office by his daughter due to concern over recent behavioral changes. Over the last several months he has had increasing difficulty with remembering recent events. She mentions that he is embarrassed due to a new inability to control urination. His medical history is significant for hypertension and insomnia. His medications include alprazolam and hydrochlorothiazide. On physical exam, he is oriented to time and place and thinks his daughter is exaggerating; however, when asked to recall 3 items, the patient refuses to continue the mental status exam. He has 5/5 strength bilaterally. He walks in short strides by sliding his feet across the floor. Which of the following would you expect to see in this patient?
Q74
A patient with a known spinal cord ependymoma presents to his neurologist for a check up. He complains that he has had difficulty walking, which he attributes to left leg weakness. On exam, he is noted to have 1/5 strength in his left lower extremity, as well as decreased vibration and position sensation in the left lower extremity and decreased pain and temperature sensation in the right lower extremity. Which of the following spinal cord lesions is most consistent with his presentation?
Q75
A 52-year-old man is brought to the emergency department while on vacation with a history of sudden onset vertigo and difficulty walking. He was in normal health since starting his vacation a week ago, but today he is suffering from a loss of balance, mild headache, and has had 5–6 episodes of vomiting over the last few hours. He denies fever, neck pain, head trauma, weakness, and diplopia. Past medical history is significant for hypertension and dyslipidemia. His medications include valsartan and atorvastatin, but he missed several doses since leaving for this trip. Blood pressure is 198/112 mm Hg, the heart rate is 76/min, the respiratory rate is 16/min, and the temperature is 37.0°C (98.6°F). The patient is awake and oriented to time, place, and person. Extraocular movements are within normal limits. Muscle strength is normal in all 4 extremities. An urgent head CT is ordered and shown in the picture. What additional clinical features would be expected in this patient?
Q76
A 5-year-old boy who recently emigrated from Nigeria is brought to the emergency department because of a 2-day history of lower leg weakness, swallowing difficulty, and drooling of saliva. He has not yet received any childhood vaccinations. Two days after admission, the patient develops shortness of breath. Pulse oximetry shows an oxygen saturation of 64%. Despite resuscitative efforts, the patient dies of respiratory failure. At autopsy, examination of the spinal cord shows destruction of the anterior horn cells. Neurological examination of this patient would have most likely shown which of the following findings?
Neuroanatomy US Medical PG Practice Questions and MCQs
Question 71: A 72-year-old man comes to his primary care provider because of double vision and headache. He says these symptoms developed suddenly last night and have not improved. He has had type 2 diabetes mellitus for 32 years and essential hypertension for 19 years for which he takes metformin and lisinopril. His last recorded A1c was 9.4%. He has smoked 10 to 15 cigarettes a day for the past 35 years. Family history is significant for chronic kidney disease in his mother. Vital signs reveal a temperature of 36.9 °C (98.42°F), blood pressure of 137/82 mm Hg, and pulse of 72/min. On examination, there is ptosis of the right eye and it is deviated down and out. Visual acuity is not affected in either eye. Which of the following cranial nerves is most likely impaired in this patient?
A. Facial nerve
B. Optic nerve
C. Oculomotor nerve (Correct Answer)
D. Abducens nerve
E. Trochlear nerve
Explanation: ***Oculomotor nerve***
- The patient's presentation of **ptosis** (due to paralysis of the **levator palpebrae superioris** muscle) and the eye being **deviated down and out** (due to paralysis of most extraocular muscles except the superior oblique and lateral rectus) are classic signs of **oculomotor nerve (CN III) palsy**.
- Given the patient's history of **poorly controlled diabetes** and **hypertension**, microvascular ischemia is a common cause of CN III palsy that typically spares the pupil due to its superficial location.
*Facial nerve*
- Dysfunction of the **facial nerve (CN VII)** primarily affects **facial muscle movements**, leading to symptoms like facial drooping, inability to close the eye, or difficulty with smiling.
- It does not cause double vision, ptosis, or specific eye deviation patterns.
*Optic nerve*
- The **optic nerve (CN II)** is responsible for **vision (visual acuity)** and transmits visual information from the retina to the brain.
- Impairment would lead to vision loss or specific visual field defects, but not double vision, ptosis, or oculomotor abnormalities as described.
*Abducens nerve*
- The **abducens nerve (CN VI)** innervates the **lateral rectus muscle**, which is responsible for **abducting the eye** (moving it outward).
- A lesion would cause the eye to be **adducted at rest** and lead to **horizontal double vision**, especially when looking towards the affected side, which is different from "down and out" deviation.
*Trochlear nerve*
- The **trochlear nerve (CN IV)** innervates the **superior oblique muscle**, which is responsible for **intorsion, depression, and abduction of the eye**.
- Palsy typically causes **vertical double vision** that is worse when looking down and is often compensated by a head tilt away from the affected side, not ptosis or a "down and out" position.
Question 72: A 75-year-old woman is brought to the physician by her daughter for a 4-month history of increasing difficulty recognizing her friends and family. She has had to rely on recognizing haircuts, gait, and voices because she cannot remember their faces. Neurologic examination shows that she is able to recognize objects and name facial features such as the eyes and nose. On mental status examination, she is alert and has no deficits in cognition or short-term memory. An MRI of her head shows an inhomogeneous 2-cm mass with perifocal edema in her brain. Which of the following brain regions is most likely affected?
A. Right posterior superior temporal cortex
B. Right superior parietal cortex
C. Right ventral occipitotemporal cortex (Correct Answer)
D. Left posterior parietal cortex
E. Left hippocampus
Explanation: ***Right ventral occipitotemporal cortex***
- The inability to recognize familiar faces, despite being able to identify facial features and objects, is characteristic of **prosopagnosia**.
- **Prosopagnosia** is most commonly associated with damage to the **fusiform gyrus**, located in the right ventral occipitotemporal cortex, also known as the fusiform face area.
*Right posterior superior temporal cortex*
- This region is primarily involved in **auditory processing** and **language comprehension** (Wernicke's area in the dominant hemisphere), not facial recognition.
- Damage here might lead to **auditory agnosia** or receptive aphasia, which are not described.
*Right superior parietal cortex*
- The superior parietal cortex is involved in **spatial awareness**, **attention**, and integrating sensory information.
- Lesions here could cause **neglect syndromes** or difficulties with spatial tasks, not specific facial recognition deficits.
*Left posterior parietal cortex*
- The left posterior parietal cortex plays a role in **praxis**, **arithmetic**, and certain aspects of **language**.
- Damage to this area is often associated with Gerstmann syndrome (acalculia, agraphia, finger agnosia, left-right disorientation), which is not evident here.
*Left hippocampus*
- The hippocampus is crucial for **memory formation** and recall, particularly **episodic memory**.
- Lesions in this area would primarily result in **anterograde amnesia** or difficulties with new memory acquisition, not isolated facial recognition deficits.
Question 73: A 72-year-old man is brought to your office by his daughter due to concern over recent behavioral changes. Over the last several months he has had increasing difficulty with remembering recent events. She mentions that he is embarrassed due to a new inability to control urination. His medical history is significant for hypertension and insomnia. His medications include alprazolam and hydrochlorothiazide. On physical exam, he is oriented to time and place and thinks his daughter is exaggerating; however, when asked to recall 3 items, the patient refuses to continue the mental status exam. He has 5/5 strength bilaterally. He walks in short strides by sliding his feet across the floor. Which of the following would you expect to see in this patient?
A. Depigmentation of the substantia nigra pars compacta
B. Convex hemorrhage that does not cross suture lines
C. Atrophy of the caudate and putamen
D. Distortion of corona radiata fibers (Correct Answer)
E. Atrophy of the subthalamic nucleus
Explanation: ***Distortion of corona radiata fibers***
- The patient's symptoms of **memory decline**, **urinary incontinence**, and **gait disturbance** (magnetic gait) form the classic triad of **normal pressure hydrocephalus (NPH)**.
- In NPH, the enlarged ventricles cause **stretching and distortion of the periventricular white matter tracts**, including the ascending and descending fibers of the **corona radiata**, which leads to the characteristic neurological symptoms.
*Depigmentation of the substantia nigra pars compacta*
- This is a hallmark pathological finding in **Parkinson's disease**, characterized by the loss of **dopaminergic neurons** in the substantia nigra.
- While gait disturbance (shuffling gait) can occur in Parkinson's, the presenting symptoms of **urinary incontinence** and prominent memory decline are not typical primary features, and the gait description is more suggestive of NPH.
*Convex hemorrhage that does not cross suture lines*
- This describes an **epidural hematoma**, typically resulting from **head trauma** and often associated with rupture of the **middle meningeal artery**.
- The clinical presentation is usually acute with signs of increased intracranial pressure, rather than the chronic, progressive symptoms described in the patient.
*Atrophy of the caudate and putamen*
- This is a characteristic finding in **Huntington's disease**, a neurodegenerative disorder.
- Huntington's typically presents with **chorea** (involuntary movements), psychiatric disturbances, and cognitive decline, which do not align with the patient's primary symptoms of gait disturbance and incontinence.
*Atrophy of the subthalamic nucleus*
- Atrophy of the subthalamic nucleus is not a distinct primary disorder associated with the patient's constellation of symptoms.
- The subthalamic nucleus plays a role in motor control, and damage to it can cause **hemiballismus**, which is not described here.
Question 74: A patient with a known spinal cord ependymoma presents to his neurologist for a check up. He complains that he has had difficulty walking, which he attributes to left leg weakness. On exam, he is noted to have 1/5 strength in his left lower extremity, as well as decreased vibration and position sensation in the left lower extremity and decreased pain and temperature sensation in the right lower extremity. Which of the following spinal cord lesions is most consistent with his presentation?
A. Anterior cord syndrome
B. Posterior cord syndrome
C. Syringomyelia
D. Right-sided Brown-Sequard (hemisection)
E. Left-sided Brown-Sequard (hemisection) (Correct Answer)
Explanation: ***Left-sided Brown-Sequard (hemisection)***
- This syndrome is characterized by **ipsilateral loss of motor function (weakness)** and **proprioception/vibration sensation** below the lesion, along with **contralateral loss of pain and temperature sensation**.
- The patient's left leg weakness, decreased vibration/position sensation in the left lower extremity, and decreased pain/temperature sensation in the right lower extremity perfectly match a **left-sided hemisection of the spinal cord**.
*Anterior cord syndrome*
- This syndrome results in **bilateral motor paralysis** and bilateral loss of **pain and temperature sensation** below the level of the lesion.
- However, **proprioception** and **vibration sense** are typically preserved, which contrasts with the patient's presentation of ipsilateral loss of these senses.
*Posterior cord syndrome*
- This rare syndrome primarily affects the **dorsal columns**, leading to bilateral loss of **vibration and proprioception** below the lesion.
- **Motor function** and **pain/temperature sensation** are largely preserved, which is inconsistent with the patient's significant motor weakness and contralateral pain/temperature loss.
*Syringomelia*
- This condition involves a fluid-filled cavity (syrinx) within the spinal cord, often causing a **cape-like distribution of pain and temperature loss** (crossing the midline) due to damage to the **decussating spinothalamic fibers**.
- While it can cause weakness, the distinct **ipsilateral proprioceptive loss** and **contralateral pain/temperature loss** seen in this patient are not typical for syringomyelia.
*Right-sided Brown-Sequard (hemisection)*
- A right-sided Brown-Sequard syndrome would present with **right-sided weakness** and **loss of proprioception/vibration sensation**, along with **left-sided loss of pain and temperature sensation**.
- This is the **opposite of the patient's presentation** of left-sided weakness and ipsilateral proprioceptive loss.
Question 75: A 52-year-old man is brought to the emergency department while on vacation with a history of sudden onset vertigo and difficulty walking. He was in normal health since starting his vacation a week ago, but today he is suffering from a loss of balance, mild headache, and has had 5–6 episodes of vomiting over the last few hours. He denies fever, neck pain, head trauma, weakness, and diplopia. Past medical history is significant for hypertension and dyslipidemia. His medications include valsartan and atorvastatin, but he missed several doses since leaving for this trip. Blood pressure is 198/112 mm Hg, the heart rate is 76/min, the respiratory rate is 16/min, and the temperature is 37.0°C (98.6°F). The patient is awake and oriented to time, place, and person. Extraocular movements are within normal limits. Muscle strength is normal in all 4 extremities. An urgent head CT is ordered and shown in the picture. What additional clinical features would be expected in this patient?
A. Inability to speak fluently
B. Right-sided visual field loss
C. Right-sided neglect
D. Inability to comprehend commands
E. Inability to perform repetitive alternating movements (Correct Answer)
Explanation: ***Inability to perform repetitive alternating movements***
- The CT scan image shows a **hypodense lesion in the right cerebellar hemisphere**, which strongly suggests a **cerebellar infarct**.
- **Dysdiadochokinesia** (inability to perform rapid alternating movements) is a classic sign of cerebellar dysfunction, along with ataxia, vertigo, and nystagmus.
- This aligns perfectly with the patient's presentation of **sudden onset vertigo, difficulty walking, and loss of balance**.
- Other expected cerebellar signs include intention tremor, dysmetria, and scanning speech.
*Inability to speak fluently*
- **Broca's aphasia** (non-fluent speech) results from damage to the **dominant (usually left) frontal lobe**, specifically Broca's area.
- This does not align with the imaging findings of a **right cerebellar lesion**.
- The patient is awake and oriented, which is consistent with preserved language function.
*Right-sided visual field loss*
- **Homonymous hemianopsia** results from lesions in the **contralateral visual pathways** (optic tract, lateral geniculate nucleus, optic radiations, or occipital cortex).
- Right-sided visual field loss would require a **left cerebral hemisphere lesion**, not a right cerebellar lesion.
- The patient has normal extraocular movements and denies diplopia, further excluding visual pathway involvement.
*Right-sided neglect*
- **Hemispatial neglect** is most commonly associated with lesions in the **non-dominant (typically right) parietal lobe**.
- While the lesion is right-sided, cerebellar lesions cause **coordination and balance deficits**, not spatial awareness or attention problems.
*Inability to comprehend commands*
- **Wernicke's aphasia** (impaired comprehension) results from damage to the **dominant (usually left) superior temporal gyrus**.
- This is not consistent with a right cerebellar lesion.
- The patient is awake and oriented to time, place, and person, indicating intact comprehension.
Question 76: A 5-year-old boy who recently emigrated from Nigeria is brought to the emergency department because of a 2-day history of lower leg weakness, swallowing difficulty, and drooling of saliva. He has not yet received any childhood vaccinations. Two days after admission, the patient develops shortness of breath. Pulse oximetry shows an oxygen saturation of 64%. Despite resuscitative efforts, the patient dies of respiratory failure. At autopsy, examination of the spinal cord shows destruction of the anterior horn cells. Neurological examination of this patient would have most likely shown which of the following findings?
A. Sensory loss
B. Positive Babinski sign
C. Hyporeflexia (Correct Answer)
D. Myoclonus
E. Pronator drift
Explanation: ***Hyporeflexia***
- The destruction of **anterior horn cells** in the spinal cord is characteristic of **poliomyelitis**, a disease that primarily affects **lower motor neurons**.
- Lower motor neuron lesions lead to symptoms like **flaccid paralysis**, **weakness**, and **hyporeflexia** (diminished or absent reflexes).
*Sensory loss*
- Poliomyelitis specifically targets **motor neurons** and typically spares **sensory pathways**, meaning sensory function remains intact.
- Therefore, **sensory loss** is not a characteristic finding in poliomyelitis.
*Positive Babinski sign*
- A positive Babinski sign (**upgoing plantar reflex**) is indicative of an **upper motor neuron lesion** affecting the **corticospinal tract**.
- Since poliomyelitis involves lower motor neurons, a positive Babinski sign would not be expected.
*Myoclonus*
- **Myoclonus** refers to brief, involuntary twitching of a muscle or a group of muscles, often associated with disorders affecting the **cerebellum**, **brainstem**, or **cortex**.
- It is not a typical neurological finding in **poliomyelitis**, which primarily causes muscle weakness and paralysis.
*Pronator drift*
- **Pronator drift** is a sign of **upper motor neuron weakness** affecting the **contralateral corticospinal tract**, particularly in the arm.
- As **poliomyelitis** is a **lower motor neuron disease**, pronator drift would not be expected as a primary finding.
