A 9-year-old girl is brought to the emergency department by her parents due to severe headache, lethargy, and vomiting.  Her symptoms began a few weeks ago as mild intermittent headaches with fatigue and have progressively worsened.  CT scan of the head reveals a mass lesion, enlarged lateral and third ventricles, and a normal-sized fourth ventricle.  Which of the following is the most likely site of obstruction in this patient?

A 62-year-old man is brought to the office by his son due to memory impairment and frequent falls.  The patient has been living alone since the death of his wife a year ago.  His son, who is visiting from out of town, found his father in poor living conditions.  The patient was forgetful and did not know the location of various items in his house, where he has lived for more than 20 years.  His gait is also unsteady, and he had had several falls.  The son says his father has always been “a drinker” and may have been drinking more recently.  The patient is indifferent to his son’s concerns and says he feels fine.  Vital signs are within normal limits.  On physical examination, bilateral lateral gaze palsy and nystagmus are present.  Muscle strength and deep tendon reflexes are normal, but the gait is ataxic.  On memory testing, he recalls 0 out of 3 objects after 5 minutes.  A lesion of which of the following labeled structures on a normal brain MRI is most specifically associated with this patient’s current condition?

A 65-year-old man is brought to the emergency department after he suddenly became unresponsive at home.  On arrival, paramedics found him pulseless with ventricular fibrillation.  After 10 minutes of cardiopulmonary resuscitation, the patient regains spontaneous circulation.  In the hospital, he is intubated and placed on mechanical ventilation.  His vitals remain stable.  A therapeutic hypothermia protocol is initiated.  After 72 hours following rewarming, he remains comatose with fixed and dilated pupils.  There is no direct or consensual pupillary response to light.  MRI of the brain reveals diffuse loss of grey-white matter differentiation with sulcal effacement.  Damage to which of the following areas of the brain is the most likely cause of this patient’s pupillary findings?

A 57-year-old man is brought to the emergency department following a generalized tonic-clonic seizure.  His wife reports that he has no history of seizures.  However, she says that he has been complaining of intermittent headaches, memory loss, and vision disturbances for the past 2 weeks.  Brain imaging shows a solitary mass within the right temporal lobe.  Which of the following visual field defects (areas of vision loss in black) is most likely present in this patient?

A 34-year-old man comes to the clinic with a 3-week history of difficulty hearing.  He finds it increasingly difficult to tolerate everyday sounds.  He also complains of ear pain and often avoids public places as a result.  The patient has no past medical history and takes no medications.  Injury to which of the following cranial nerves is most likely responsible for his condition?

A 67-year-old woman with a known history of lung cancer comes to the office due to hoarseness and difficulty swallowing.  She has no disturbances in vision or hearing.  On examination, there is loss of the gag reflex on the left side; when the patient is prompted to say “ah,” the uvula deviates to the right side.  Her left shoulder is drooped and strength is reduced during left shoulder shrug testing.  Chest x-ray shows a right lower lobe lung mass and several osteolytic rib lesions.  MRI of the head also demonstrates multiple lesions consistent with metastasis.  A lesion involving which of the following anatomical structures is most likely responsible for this patient’s symptoms?

A 51-year-old woman comes to the office because it feels like the right side of her face has been getting heavier for the past 12 hours.  Medical history is significant for type 2 diabetes mellitus.  Physical examination reveals asymmetry of her face when she smiles, puffs out her cheeks, raises her eyebrows, and tries to close her eyes tightly.  There is also effacement of the right nasolabial fold, and her lips are drawn toward the left side.  The remainder of the neurologic examination is normal.  Which of the following additional findings is most likely associated with this patient’s condition?

A 66-year-old, right-handed man is brought to the emergency department due to left-sided numbness and weakness.  The patient woke with left-hand clumsiness that rapidly progressed to profound left-sided weakness, affecting the left arm more than the left leg.  He has a history of hypertension and has smoked a pack of cigarettes daily for the past 40 years.  Blood pressure is 175/90 mm Hg and pulse is 82/min and regular.  Neurologic examination reveals impaired touch discrimination in the left arm with left facial weakness sparing the forehead, 2/5 muscle strength in the left upper limb, and 4/5 muscle strength in the left lower limb.  Right-sided strength and visual field examinations are normal.  Which of the following labeled arteries is most likely occluded in this patient?

A 5-year-old boy has developed persistent food-seeking behavior over the past few months.  His mother initially thought that the boy was undergoing a growth spurt, but despite how much she fed him he never seemed satisfied.  He has gained more than 4.5 kg (10 lb).  The patient has also started complaining of a headache and nausea in the morning.  His physical examination is significant for BMI of 32 kg/m².  Temperature is 37.2 C (99 F), blood pressure is 100/70 mm Hg, pulse is 92/min, and respirations are 16/min.  His pediatrician becomes concerned about possible central nervous system involvement.  This patient’s food-seeking behavior could be explained by a lesion causing impairment of which hypothalamic nucleus?

A 65-year-old man comes to the emergency department due to acute-onset slurred speech.  He also has right-sided weakness but denies any trauma, headache, or loss of consciousness.  His medical problems include hypertension and type 2 diabetes mellitus.  The patient has smoked 1 pack of cigarettes daily for 20 years.  Neurologic examination shows right-sided lower facial droop with sparing of the forehead muscles.  Motor strength is 3/5 on the right and 5/5 on the left with a Babinski response on the right.  There is also dysmetria and dysdiadochokinesia involving his right upper and lower extremities.  MRI of the brain reveals an acute lacunar infarct in the brainstem, as shown in the image below.

Which of the following cranial nerves exits the brainstem closest to the level affected by this patient’s stroke?

A 38-year-old man is brought to the office for evaluation of behavioral changes.  His wife says the patient has had frequent outbursts of anger, depressive mood, and insomnia.  The patient recently lost his job as a machine operator because of lack of focus and poor memory.  Over the past several years, he also has had involuntary, jerky, nonpurposeful movements of the extremities and face that have progressively worsened.  These abnormal movements are present while he is awake but not during sleep.  His 55-year-old mother has similar abnormal body movements and is at a nursing home with dementia.  Which of the following labeled regions of a normal brain is likely to be most affected by this patient’s disease process?

A 43-year-old, right-handed woman is evaluated in the clinic for progressively worsening neurologic symptoms.  The patient has a history of diabetes mellitus and hyperlipidemia for which she takes metformin and a statin.  She has no history of head trauma or seizures.  The patient occasionally drinks wine but does not use tobacco or illicit drugs.  Her mother has a history of migraine headaches.  A brain MRI is obtained and is shown in the image below:

This patient is most likely to have which of the following additional findings?

A 66-year-old man is undergoing a procedure to control chronic throat pain due to Eagle syndrome, a condition frequently caused by a misshapen or elongated styloid process.  During the procedure, the styloid process is trimmed surgically.  However, the left glossopharyngeal nerve is accidentally transected.  Which of the following is most likely to be seen as a result of this patient’s nerve injury?

A 56-year-old woman is brought to the emergency department with sudden onset of headache and partial loss of vision.  She has a 3-year history of atrial fibrillation.  Physical examination shows a visual field defect involving the black areas illustrated below.

This patient most likely has occlusion of which of the following arteries?

A 23-year-old woman has an acute attack of optic neuritis.  She has a history of relapsing-remitting multiple sclerosis.  An MRI of her brain reveals an area of demyelination involving the right optic nerve.  Which of the following is most likely to be found on examination of both eyes?

A 26-year-old previously healthy man is brought to the emergency department following a motorbike accident.  He is found to have a maxillofacial injury.  His condition is stabilized, and surgical repair is performed.  While recovering, the patient develops difficulty chewing food.  On examination, the jaw deviates to the right side when the patient is instructed to open his mouth.  The nerve that has been injured in this patient exits the skull through which of the following foramina?

A 46-year-old man comes to the office with left upper limb weakness and numbness.  He has had chronic neck pain since being involved in a motor vehicle collision 4 years ago.  He has no other medical problems.  Neurological evaluation reveals that the tendon reflex shown in the image below is absent.  Reflexes in the right upper extremity and both lower extremities are normal.

Imaging studies reveal degenerative changes in the spine causing mild spinal cord compression.  Which of the following spinal segments is most likely affected in this patient?

A 28-year-old woman, gravida 1 para 1, is seen in the clinic a week after spontaneous vaginal delivery.  The delivery was performed under epidural analgesia and complicated by a prolonged second stage of labor.  Since delivery, the patient has had frequent episodes of fecal incontinence, as well as mild perineal pain that is relieved by ibuprofen and opioid analgesics.  She reports no other medical conditions, and her pregnancy was otherwise uncomplicated.  On examination, a healing perineal laceration shows no signs of infection.  Digital anorectal examination reveals decreased anal sphincter tone and loss of the anal wink reflex.  Bilateral lower extremity reflexes are 2+ with normal tone.  Which of the following is the most likely cause of this patient’s fecal incontinence?

A 54-year-old Caucasian male dies from a progressive neurological disorder.  A brain section of the patient is shown below.

Which of the following corresponds to the structure with cystic degeneration (black arrow)?

A 65-year-old man is brought to the emergency department due to an acute change in mental status.  The patient was having dinner with his family when he suddenly had difficulty using his fork and appeared confused.  Other medical conditions include type 2 diabetes mellitus, hyperlipidemia, and hypertension.  The patient is a high school calculus teacher and has a 40-pack-year smoking history.  Blood pressure is 180/98 mm Hg and pulse is 98/min and regular.  On physical examination, the patient is well oriented, answers questions appropriately, and has no motor, sensory, or visual deficits.  He is unable to add simple numbers such as 17 plus 9; he is also unable to recognize or distinguish his fingers.  Which of the following brain areas is most likely affected in this patient?

A 68-year-old woman comes to the emergency department due to sudden-onset double vision that started immediately after she woke up.  The patient notices that her vision worsens when looking to the right.  She has no headache, weakness, or numbness.  The patient has a prolonged history of hypertension, hyperlipidemia, and type 2 diabetes mellitus.  Blood pressure is 160/90 mm Hg and pulse is 86/min and regular.  Neurologic examination, including visual acuity, is normal with the exception of the ocular findings shown in the image below.

A lesion involving which of the following structures is most likely causing the observed ocular findings in this patient?

A 36-year-old woman comes to the office due to firm, nontender swelling of her right cheek for the past 4 months.  The patient has had no fever, runny nose, sore throat, or cough.  She drinks a glass of wine with dinner on most nights but does not use tobacco.  Physical examination shows fullness of the preauricular space on the right side.  An MRI of the region identifies a 2.2-cm mass in the right parotid gland, and a follow-up core needle biopsy shows the lesion to be neoplastic.  If left untreated, this patient is most likely to develop which of the following?

A 30-year-old man comes to the emergency department due to severe headache and neck pain following a motor vehicle collision.  The patient has no blurry or double vision, dizziness, slurred speech, numbness, or weakness.  Neuroimaging is unremarkable except for evidence of a right transverse foramina fracture at the level of C2.  The patient is placed in a cervical collar and admitted to the hospital.  While undergoing further evaluation, he suddenly develops dizziness, right-sided facial numbness, and hoarseness.  Temperature is 36.7 C (98.1 F), blood pressure is 160/90 mm Hg, pulse is 80/min, and respirations are 12/min.  Neurologic examination shows partial ptosis and miosis of the right eye, as well as nystagmus.  Hearing is intact bilaterally.  There is reduced sensation to pain and temperature on the right side of the face and the left side of the body.  The patient is ataxic and displays past-pointing with his right hand on finger-to-nose testing.  Vascular imaging will most likely reveal an acute dissection in which of the following arteries?

A 72-year-old man is brought to the emergency department due to involuntary movements of his right arm that started several hours ago.  He was watching television when his arm “threw the remote control across the room.”  His past medical history is significant for long-standing hypertension and diabetes mellitus.  The patient does not use alcohol, tobacco, or illicit drugs.  Physical examination shows wild, large-amplitude, flinging movements affecting the proximal muscles of his right arm.  Which of the following areas of the brain is most likely injured in this patient?

A 35-year-old man comes to the office due to a painful tongue sore.  For the past 2 weeks he has had a fever and has experienced myalgias and arthralgias.  He has no known medical problems.  The patient works as a driver for a local delivery service.  He had unprotected sex with a stranger approximately 1 month ago.  Physical examination shows a rash over his trunk and cervical lymphadenopathy.  An ulcer is located on the median sulcus of the tongue and is 2 cm anterior to the foramen cecum.  Blood is drawn for an HIV test.  The pain sensation from his ulcer is most likely carried by which of the following nerves?

A 53-year-old man comes to the emergency department due to severe lower back pain.  The patient’s back pain started 2 weeks ago without any preceding trauma and has been keeping him awake at night.  The pain has acutely worsened over the past 2 days and is not relieved with over-the-counter pain medications.  His vital signs are within normal limits.  Examination shows low back pain that is worse with back flexion and raising of the legs; it radiates into his left leg.  Pinprick in the perianal area does not cause rapid contraction of the anal sphincter.  The rest of the neurologic examination is normal.  Which of the following nerve roots is most likely to be involved in this patient’s condition?

A 55-year-old, right-handed man comes to the emergency department due to recent onset of severe, throbbing, right-sided headache and double vision.  His medical history includes poorly controlled hypertension and chronic tobacco use.  Neurologic examination shows that he is awake, alert, and oriented and can follow commands.  Visual fields and optic fundi are normal.  The position of the right eye is down and out with ipsilateral ptosis, and the right pupil is dilated and nonreactive to both light and accommodation.  Left eye examination is normal.  Based on this patient’s neurologic deficits, CT angiography of the head is most likely to reveal an aneurysm arising from which of the following locations in the image below?

A 59-year-old man comes to the office due to diplopia and a drooping right eyelid.  His symptoms began a day earlier and have since worsened.  Physical examination shows a dilated right pupil that is nonreactive to both light and accommodation.  There is vertical and horizontal diplopia.  When the patient is asked to stare straight ahead, the right eye is directed inferiorly and laterally with respect to the left eye.  MRI of the brain reveals an aneurysm involving the right posterior communicating artery.  Which of the following muscles is most likely to remain functionally intact in this patient?

A 53-year-old man comes to the office due to double vision.  The patient lives in a two-story house and has had difficulty walking down stairs because he sees duplicates of every step and doesn’t “know which ones are real.”  He does not have significant problems walking up stairs.  The patient is also frustrated because he has trouble reading certain things, such as the morning newspaper and work-related documents.  He has had no eye trauma, headache, focal weakness, or numbness.  The patient has a history of hypertension and type 2 diabetes mellitus.  He exercises regularly and does not use tobacco, alcohol, or illicit drugs.  A lesion affecting which of the following structures is most likely responsible for this patient’s visual symptoms?

A 62-year-old man comes to the office reporting double vision.  He first noticed mild difficulty focusing his eyes about 3 weeks ago, and his symptoms have progressively worsened.  The patient’s other medical problems include metastatic prostate cancer.  On neurologic examination, he is unable to adduct his left eye, and stimulation of the left cornea does not elicit a corneal reflex.  A lesion involving which of the following anatomical structures is most likely responsible for this patient’s symptoms?

A 26-year-old woman comes to the office due to several weeks of pain and muffled hearing in the left ear, along with a sensation of jaw clicking when chewing food.  The patient has had episodic headaches and left-sided facial pain for several years that is worse when moving her jaw.  She also has been told that she grinds her teeth while asleep.  On examination, the patient is unable to fully open her mouth and reports pain with passive movement of the jaw.  The external auditory canal and tympanic membrane are normal.  A disorder affecting pterygoid muscle contractility is suspected.  Involvement of which of the following nerves is most likely contributing to this patient’s ear symptoms?

A 22-year-old man is brought to the emergency department after a bar fight during which he received a knife wound to his neck.  The patient is in moderate distress but is alert and can follow commands.  Vital signs are stable.  Neurologic examination shows right-sided hemiplegia.  Loss of proprioception and vibratory sensation is present below the C8 dermatome on the right side.  On the left side, there is loss of pain and temperature sensation below the T2 dermatome.  MRI of this patient’s spine will most likely reveal which of the following?

A 55-year-old man comes to the office due to progressive headaches over the past 2 months.  The headaches are throbbing, often associated with nausea, and worsen whenever the patient coughs or bears down during a bowel movement.  Medical history is significant for episodic migraine without aura.  MRI of the brain with gadolinium reveals a cystic mass, as shown in the image below:

Which of the following findings is most likely to be seen on physical examination of this patient?

A 68-year-old man is evaluated for visual loss in the left eye that resolved spontaneously within several hours.  The patient has a history of hypertension, type 2 diabetes mellitus, coronary artery disease, and ischemic cardiomyopathy.  He has smoked a pack of cigarettes daily for the past 40 years.  Physical examination reveals a left carotid bruit but no neurologic deficits.  A carotid duplex ultrasound shows 85% stenosis of the left internal carotid artery, and carotid angiography with stenting is performed.  During the procedure, atherosclerotic debris embolize to the artery shown (white arrow) on the cerebral magnetic resonance angiogram below.

Which of the following actions is most likely to be impaired in this patient as a result of the embolization?

A 62-year-old man comes to the office with left arm clumsiness.  Physical examination reveals motor weakness involving the left arm and leg.  The patient’s speech is slurred, and there is drooping of the left lower face.  On passive flexion of the left arm, there is initial resistance followed by a sudden release of tension as flexion is continued.  A lesion affecting which of the following brain structures is most likely responsible for this patient’s condition?

A 62-year-old woman comes to the emergency department due to difficulty walking that started 3 hours ago.  The patient also cannot feel anything on the right side of her body.  She has a history of hypertension and diabetes mellitus, and has smoked a pack of cigarettes daily for the past 30 years.  The patient’s father had a myocardial infarction at age 60.  Physical examination shows loss of touch, temperature, and vibratory sensation affecting the entire right side of the body.  Sensation is also diminished over the right side of the face.  Muscle strength is 5/5 throughout.  Speech, vision, and hearing tests are normal.

Item 1 of 2

This patient most likely experienced a stroke affecting which of the following brain structures?

Item 2 of 2

The patient was diagnosed with a pure sensory stroke and received appropriate treatment.  Her symptoms improved, and she returned home to live with her daughter after a few weeks of physical rehabilitation.  Five years later, the patient dies of a large myocardial infarction.  On autopsy, there are two 5- to 6-mm cavities in the deep structures of her brain filled with clear fluid.  Which of the following processes is most likely responsible for the patient’s brain findings?