1. Cases Neuroscience

3. 1. Which of the following structures is located at the irregularity indicated by the black arrow in the fissure shown in the image below? (A) Decussation of trigeminothalamic fibers (B) Exit of accessory nerve (C) Exit of phrenic nerve (D) Level of motor decussation (E) Level of sensory decussation

4. 2. The MRI of a 71-year-old woman reveals a defect in the territory served by the posterior inferior cerebellar artery. Which of the following combinations of structures is located within the territory of this vessel? (A) Anterolateral system + medial lemniscus (B) Hypoglossal nerve root + spinal trigeminal nucleus (C) Pyramid + anterolateral system (D) Spinal trigeminal tract + nucleus ambiguus (E) Vestibular nuclei + medial longitudinal fasciculus

5. 3. A 76-year-old man presents to the Emergency Department with the complaint of persistent headache. The examination reveals evidence of increased intracranial pressure (lethargy,nausea, headache). During the examination, the man loses consciousness, his blood pressure suddenly and dramatically increases and then precipitously drops, he has bradycardia, and then his heart rate ceases with respiration following a similar course, all within about 6 minutes. Which of the following regions of the brain contains centers that, if rapidly compromised, would give rise to this man’s sudden symptoms and catastrophic decline?

6. (A) Diencephalon/thalamus (B) Mesencephalon/midbrain (C) Metencephalon/pons (D) Myelencephalon/medulla (E) Telencephalon/cerebrum

7. 4. An 80 year old woman suddenly fell to the floor and was unable to rise. She found that her left arm and leg were paralyzed and her speech was “ slurred”. Neurologic examination some months later showed that she had a spastic paralysis of her left limbs with increased tone and exaggerated deep tendon reflexes. Motor examination of the face was normal, however upon protrusion, the tongue pointed toward her right side; the right side of her tongue was atrophic. The sensory exam indicated that pain and temperature was bilaterally normal from the body and face but there was loss of proprioception from the left lower extremity. Examination of other cranial nerves was normal.

8. 5. A 39 year old man awoke with a horizontal diplopia especially on right gaze. 5 days later, a Hess chart examination performed by an ophthalmologist showed paresis of the lateral rectus muscle. On admission 19 days after onset, the patient showed a mild paresis of the right abducens nerve and a subtle weakness of his left leg with moderate hyperreflexia in the left upper and lower limbs. Babinski’s reflex was positive and abdominal reflex was absent on the left side, no facial weakness or deviation of the tongue on protrusion was found. All other general and neurological exams were normal.

9. 6. A 45 year old woman with a history of hypertension experienced a brief "blackout". She had complained of severe headaches, nausea, dizziness and a roaring sound in the left ear during the previous day. She also had difficulty walking and called a cab to take her to the hospital. The physician found her mentally alert and communicative, the external auditory canals were clear and she was physically normal except for an elevated blood pressure of 165/105. Strength in her extremities was generally normal. Her speech was fluent and full of meaning though dysarthric. Nystagmus was present. There was a facial paralysis (upper and lower) on the left side which also had diminished sensation. There was impaired pain and temperature sense from the right side of the body. Hearing was diminished on the left side. On the left, the eye drooped and the pupil was constricted.

10. 7. A 59-year-old woman presents with a sudden onset of diplopia, and with ataxia and tremor, most noticeable on her right side. CT reveals a small hemorrhage in the area indicated in the image below. This woman’s signs and symptoms are most indicative of which of the following?

11. (A) Avellis syndrome (B) Benedikt syndrome (C) Claude syndrome (D) Foville syndrome (E) Weber Syndrome

12. 8. A 41-year-old man presents with the complaint of double vision and persistent headache. The history reveals that his symptoms have waxed and waned over the past several months, but over the last 2 weeks have become noticeably worse. The examination shows that his right eye is deviated slightly outward and the pupil responds slowly to light. An MRI reveals an aneurysm impinging on one of the structures indicated by the white outlines in the image below. Damage to which of the following structures would most likely explain this patient’s deficits? (A) A (B) B (C) C (D) D (E) E

13. A B C D E

14. 9. A 43-year-old woman complains to her primary care physician that she “can’t hear as well as I used to.” After a preliminary examination, she is referred to an audiologist who determines that the woman is not deaf in either ear, even though her perception of sounds and her ability to localize sound in space is altered. Which of the following midbrain structures might be affected to result in these changes? (A) Brachium conjunctivum (B) Crus cerebri (C) Inferior colliculus (D) Mesencephalic nucleus (E) Superior colliculus

15. 10. A 65 year old women suddenly remarked that she was seeing double and felt a weakness in his left arm and leg.Her husband noticed that her right eyelid was drooping. At the hospital, she was awake, oriented, and articulate. Her visual fields were normal but her right eye deviated to the right. On attempted lateral gaze to the left only the left eye responded; only the left eye constructed in response to light. Upon smiling, there was a minor weakness on the left. The gag, corneal, and jaw jerk reflexes were normal as were the sensory examinations of the face and body. Motor strength was normal in the extremities on the right but reduced on the left especially in the arm while there was a heightened biceps reflex and resistance to passive stretch.

16. 11. A 71-year-old man is brought to the Emergency Department from his home. He complains that his hand suddenly became numb; the physician notices that the man’s speech seems slightly slurred. The examination reveals weakness of the facial muscles on upper and lower aspects of his face on the left and a loss of pain and thermal sense on the left side of his face and right side of his body. Masticatory function is impaired, and his tongue does not deviate on attempted protrusion. The loss of pain and thermal sense on this man’s body indicates damage to which of the following? (A) Anterolateral system (B) Anterior white commissure (C) Medial lemniscus (D) Ventral posterolateral nucleus (E) Posterior limb, internal capsule

17. 12. The loss of pain and thermal sense on this man’s face indicates damage to which of the following? (A) Spinal trigeminal nucleus (B) Principal sensory trigeminal nucleus (C) Mesencephalic nucleus (D) Trigeminal nerve (E) Ventral trigeminothalamic fi bers

18. 13. Assuming that this is a vascular lesion (sudden onset), which of the following vessels would most likely be involved? (A) Anterior spinal artery (B) Circumferential branches of the basilar artery (C) Paramedian branches of the basilar artery (D) Posterior inferior cerebellar artery