1.
A female patient complains of difficulty swallowing, a loss of pain and temperature sensations from the left side of her body below the neck and from the right side of her face, At what level of the brainstem do you suspect the lesion to be?
Correct Answer
A. The right lateral medulla
Explanation
The patient's symptoms suggest a lesion in the right lateral medulla. The difficulty swallowing indicates involvement of the glossopharyngeal and vagus nerves, which are located in the medulla. The loss of pain and temperature sensations from the left side of the body below the neck suggests involvement of the spinothalamic tract, which also passes through the medulla. The loss of pain and temperature sensations from the right side of the face suggests involvement of the trigeminal nerve, which exits the pons. Therefore, the most likely location for the lesion is the right lateral medulla.
2.
You are a pathologist who has sectioned the brain and brainstem and are ready to examine a section of medulla. Which of the following would you expect to see at this level?
Correct Answer
B. Inferior olivary nucleus
Explanation
At the level of the medulla, the pathologist would expect to see the Inferior Olivary Nucleus. The Inferior Olivary Nucleus is located in the medulla and is involved in motor coordination and learning. It receives input from various parts of the brain and sends output to the cerebellum. This nucleus is important for coordinating movements and maintaining balance.
3.
A 62-year old male has sustained several injuries from a car accident. Upon administering a neurological examination, you suspect that the patient has damage to the right caudal medulla. Why do you think this?
Correct Answer
B. The patient's tongue deviates towards to right when you asked him to stick it out and his uvula deviates towards the left when you ask him to say, "aahhh".
Explanation
Based on the symptoms described, it is likely that the patient has damage to the right caudal medulla. The deviation of the tongue and uvula are indicative of damage to the cranial nerves, specifically the hypoglossal nerve (CN XII) and the vagus nerve (CN X), which are both located in the medulla. These nerves control the movement of the tongue and uvula. The other symptoms mentioned, such as hypertropia, loss of taste, anosmia, and facial pain, are not specific to damage in the right caudal medulla.
4.
A lesion at the level of the cerebral peduncle would affect descending fibers of the corticospinal tract. Disruption of these axons would result in which of the following?
Correct Answer
D. Positive Babinski sign
Explanation
A lesion at the level of the cerebral peduncle would affect the descending fibers of the corticospinal tract. The corticospinal tract is responsible for transmitting motor signals from the brain to the spinal cord. When the corticospinal tract is disrupted, it can result in a positive Babinski sign. A positive Babinski sign is characterized by the upward movement of the big toe and fanning out of the other toes when the sole of the foot is stimulated. This abnormal response indicates an upper motor neuron lesion, which can occur when there is damage to the corticospinal tract.
5.
A 23-year-old female suffers a discrete arterial infarct that affects the left spinal tract of V and the left spinal nucleus of V. What deficit would you expect to see in this patient?
Correct Answer
B. A loss of pain and temperature sense on the left side of the face.
Explanation
The left spinal tract of V and the left spinal nucleus of V are responsible for transmitting pain and temperature sensations from the face. Therefore, if these structures are affected, it would result in a loss of pain and temperature sense on the left side of the face.
6.
A 49-year old woman suffers a small infarct that affects only the medial lemniscus in the mid-pons on the right. What clinical deficit do you expect to see in this woman?
Correct Answer
C. A loss of touch and pressure sense below the neck on the left
Explanation
The medial lemniscus carries sensory information related to touch and pressure from the body below the neck to the brain. Therefore, a lesion affecting only the medial lemniscus on the right side would result in a loss of touch and pressure sense below the neck on the left side of the body.
7.
You are a pathologist who has sectioned the brain and brainstem and are ready to examine a section of midbrain. Which of the following would you expect to see at this level?
Correct Answer
C. Edinger-WestpHal nucleus
Explanation
At the level of the midbrain, the Edinger-Westphal nucleus is expected to be seen. This nucleus is responsible for controlling the pupillary light reflex and is located in the midbrain. The other options listed, such as the Rostral nucleus solitaries, Accessory nucleus, Spinal nucleus of V, and Inferior olivary nucleus, are not typically found at this level of the brain.
8.
A detailed neurological examination of a 52-year old male reveals the following: patient H5 alert to time, date and place and exhibits no disorders of speech or comprehension. Visual system testing, however, reveals a paralysis of upward gaze as well as a loss of the consensual pupillary light reflex. Such a constellation of symptoms could be due to a tumor at which location?
Correct Answer
D. Pineal gland
Explanation
A paralysis of upward gaze and loss of the consensual pupillary light reflex suggests dysfunction in the midbrain. The pineal gland is located in the midbrain and is responsible for regulating sleep-wake cycles. Tumors in the pineal gland can compress nearby structures, leading to these symptoms. Therefore, a tumor in the pineal gland could explain the constellation of symptoms observed in the patient.
9.
Which of the following 2" order neurons is involved with relaying touch & proprioceptive information to the somatosensory cortex from the face?
Correct Answer
A. Principal (main) sensory nucleus of V
Explanation
The Principal (main) sensory nucleus of V is involved with relaying touch and proprioceptive information to the somatosensory cortex from the face.
10.
A 60-year old man suffered from a right sided hemiplegia and right sided cerebellar ataxia. He could not abduct the left eye. Which of the following structures is involved?
Correct Answer
E. Left pons
Explanation
The left pons is involved in this case because it controls the movement of the left eye. The symptoms of right-sided hemiplegia and right-sided cerebellar ataxia suggest that there is damage to the left pons, which is responsible for controlling motor function on the opposite side of the body. This damage is likely causing the patient's inability to abduct the left eye.
11.
During a college football game, a player is "sacked" and carried off the field. A CT scan reveals a bone fragment lodged into the lateral aspect of his dorsal columns in the cervical spinal cord on the left side. Which of the following functions will most likely be affected given this patient's presentation?
Correct Answer
F. Touch, pressure, vibration of left arm
Explanation
The bone fragment lodged into the lateral aspect of the dorsal columns in the cervical spinal cord on the left side will most likely affect the sensory functions of the body. The dorsal columns are responsible for transmitting touch, pressure, and vibration sensations to the brain. Since the fragment is on the left side, it will specifically affect the sensations in the left arm. Therefore, the correct answer is touch, pressure, and vibration of the left arm.
12.
A 50-year old man present with complaint of double vision. While testing the patient's right eye movement during a cranial nerve test, the physician noted that the patient cannot elevate the adducted eye. Which of the following muscles is involved?
Correct Answer
E. Inferior oblique
Explanation
The correct answer is Inferior oblique. The patient's inability to elevate the adducted eye suggests weakness or dysfunction of the inferior oblique muscle. The inferior oblique muscle is responsible for elevating the eye when it is adducted (turned inward). Dysfunction of this muscle can result in double vision and difficulty with eye movement.
13.
A patient is found to be unable to dilate his pupil and has drooping left eyelid ptosis). Ptosis disappears when he looks up. What structure is damaged?
Correct Answer
C. Superior cervical ganglion
Explanation
The superior cervical ganglion is responsible for innervating the dilator muscle of the pupil, which is responsible for pupil dilation. In this case, the patient is unable to dilate his pupil, indicating that the superior cervical ganglion is damaged. Additionally, the drooping left eyelid (ptosis) disappearing when the patient looks up suggests that the oculomotor nerve, which controls the levator palpebrae superioris muscle responsible for lifting the eyelid, is intact. Therefore, the correct answer is the superior cervical ganglion.
14.
In a blow-out fracture of the orbit, the floor of the orbit is fractured. Which of the following movements of the eyeball is lost?
Correct Answer
D. Downward
Explanation
The floor of the orbit provides support for the eye and helps in controlling its movement. When the floor of the orbit is fractured, it can lead to impairment of certain movements of the eyeball. In particular, downward movement of the eyeball is often affected in blow-out fractures because the fracture may interfere with the function of the muscles and structures involved in this movement. Therefore, downward movement of the eyeball is the movement that is typically lost in blow-out fractures of the orbit where the floor is fractured.
15.
A 16-year-old teenager presents with complaint of double vision. The chief resident asked you to assess the functions of the extrinsic eye muscles. While testing the patient's left eye movement, you noted that the patient cannot depress the adducted eye. Which of the following muscles is involved?
Correct Answer
B. Superior oblique
Explanation
The superior oblique muscle is involved in the patient's inability to depress the adducted eye. The superior oblique muscle is responsible for depressing the adducted eye and rotating it medially. Dysfunction or weakness of this muscle can result in double vision and difficulty in moving the eye downwards when it is turned inward.
16.
A 20-year old man presents with double vision after a car accident. The ER resident tests the eye muscle functions and finds that the patient is unable to elevate the adducted right eye. Which muscle is not functioning properly?
Correct Answer
E. Inferior oblique
Explanation
The patient's inability to elevate the adducted right eye suggests dysfunction of the inferior oblique muscle. The inferior oblique muscle is responsible for elevating and abducting the eye. In this case, since the patient is unable to elevate the adducted right eye, it suggests that the inferior oblique muscle is not functioning properly.
17.
Which of the following layers of the scalp constitute the "danger" layer?
Correct Answer
A. Loose areolar tissue layer
Explanation
The "danger" layer of the scalp is the loose areolar tissue layer. This layer is highly vascularized and contains emissary veins that connect the scalp with the intracranial venous sinuses. Infections or trauma in this layer can easily spread to the meninges and brain, leading to potentially serious complications such as meningitis or brain abscess.
18.
At Pterion, which of the following bones does not articulate?
Correct Answer
C. Zygomatic
Explanation
The zygomatic bone does not articulate at the Pterion. The Pterion is a point on the side of the skull where four bones meet: the parietal, frontal, temporal, and sphenoid bones. The zygomatic bone, also known as the cheekbone, does not directly connect or articulate with the Pterion.
19.
An elderly patient developed fever and worsening headache a few days after sustaining a scalp laceration and subsequent infection due to a car accident. At the hospital the case was diagnosed as meningitis and superior sagittal sinus thrombosis. The attending physician suggested that infection to the sinus initially spread through one of the scalp layers. The scalp layer involved is:
Correct Answer
B. Areolar tissue
Explanation
The correct answer is Areolar tissue. Areolar tissue is a loose connective tissue that is found in the scalp. It contains a network of blood vessels and lymphatic vessels, making it a potential pathway for the spread of infection. In this case, the infection from the scalp laceration likely spread to the superior sagittal sinus through the areolar tissue layer.
20.
A 25-year-old woman sustains a head injury. A radiograph of the skull shows a fracture of the foramen ovale. Which of the following nerves would most likely be damaged by this event?
Correct Answer
D. Mandibular nerve
Explanation
A fracture of the foramen ovale would most likely damage the mandibular nerve. The mandibular nerve is a branch of the trigeminal nerve (cranial nerve V) and passes through the foramen ovale. It provides sensory innervation to the lower teeth, lower lip, and chin, as well as motor innervation to the muscles of mastication. Therefore, a fracture of the foramen ovale would likely result in sensory deficits and/or weakness in the muscles of mastication supplied by the mandibular nerve.