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. 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. 2. 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. 3. 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.

10. 4. 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

11. 5. 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 nucleus (C) Ventral trigeminothalamic tract (D) Trigeminal nerve (E) Ventral trigeminothalamic fibers

12. 6. 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

13. Case 4 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.

15. 7. If the elevation identified by the black arrow in the image above were to be damaged by a vascular lesion, tumor, or trauma, significant and demonstrable deficits would result. Which of the following specifies this elevation? (A) Arcuate eminence (B) Facial colliculus (C) Hypoglossal trigone (D) Vagal trigone (E) Vestibular area