1.
Dr Welke
You are seeing a patient with a tumor affecting the brainstem. The disorder has specifically attacked the nerve marked by the arrow. Name (i) the marked nerve and (ii) the nuclei associated with this nerve.
Correct Answer
A. Oculomotor nerve – oculomotor nucleus & Edinger-WestpHal nucleus
Explanation
The correct answer is the Oculomotor nerve – oculomotor nucleus & Edinger-Westphal nucleus. The oculomotor nerve controls the movement of the eye and is responsible for eye movements such as raising the eyelid and constriction of the pupil. The oculomotor nucleus is located in the midbrain and is responsible for controlling the muscles that move the eye. The Edinger-Westphal nucleus is also located in the midbrain and is responsible for controlling the muscles that constrict the pupil.
2.
A patient has a severe stroke in the artery marked in the below angiogram. As the physician you know (i) the name of the artery and (ii) the clinical syndrome that is produced by damage to this artery at the level of the midbrain.
Correct Answer
C. Posterior Cerebral Artery – Weber’s syndrome
Explanation
The correct answer is "Posterior Cerebral Artery – Weber’s syndrome." Weber's syndrome is caused by damage to the midbrain, specifically the cerebral peduncle, which is supplied by the posterior cerebral artery. This syndrome is characterized by a combination of symptoms including weakness or paralysis of the contralateral face and body, along with a cranial nerve III palsy (oculomotor nerve), resulting in a drooping eyelid and an outwardly turned eye.
3.
As a resident physician, you are examining a patient who has been in a major vehicular accident. You perform a series of tests and find a present Babinski sign when striking the left foot, a loss of touch in the left leg as well as a loss of pain in the right leg. These signs are indicative of which of the following:
Correct Answer
D. Brown-Sequard Syndrome
Explanation
The patient's symptoms of a present Babinski sign when striking the left foot, loss of touch in the left leg, and loss of pain in the right leg are indicative of Brown-Sequard Syndrome. This syndrome is characterized by damage to one side of the spinal cord, leading to a combination of motor and sensory deficits on opposite sides of the body.
4.
A research scientist is interested in creating a discrete lesion in the area marked below. According to the picture, he is also interested in affecting what region and side of the body?
Correct Answer
C. The lower limb on the right side of the subject
Explanation
Based on the picture provided, the research scientist is interested in creating a discrete lesion in the lower limb on the right side of the subject.
5.
Which of the following pairs of thalamic nuclei are both important in relaying motor information to the cortex?
Correct Answer
D. VA & VL
Explanation
VA (ventral anterior) and VL (ventral lateral) are both important thalamic nuclei in relaying motor information to the cortex. The VA nucleus receives input from the basal ganglia and cerebellum, while the VL nucleus receives input from the motor cortex. Both nuclei then project this information to the primary motor cortex, allowing for the execution of voluntary movements. Therefore, VA and VL are both involved in the relay of motor information to the cortex.
6.
The general purpose of the cerebellum is to evaluate the differences between motor intentions and actions and then adjust the operations of motor centers accordingly. Name the two inputs into the cerebellum that are critically important for this function.
Correct Answer
E. Sensory inputs and corollary motor discharge
Explanation
The cerebellum evaluates the differences between motor intentions and actions and adjusts motor centers accordingly. This process requires two inputs: sensory inputs, which provide information about the body's position and movement, and corollary motor discharge, which provides information about the motor commands being sent to the muscles. These inputs allow the cerebellum to compare the intended movement with the actual movement and make any necessary adjustments to ensure smooth and coordinated motor control.
7.
When considering primary motor cortex, you know that (i) neurons representing which of the following are located in the anterior paracentral lobule and (ii) are supplied by what blood vessel?
Correct Answer
C. Leg – Anterior Cerebral Artery
Explanation
Neurons representing the leg are located in the anterior paracentral lobule and are supplied by the anterior cerebral artery.
8.
A lesion to the structure marked by the arrow will produce what type of deficit. Be specific for left or right.
Correct Answer
C. A loss of pain and temperature sensation on the right side of the patient.
Explanation
A lesion to the structure marked by the arrow would result in a loss of pain and temperature sensation on the right side of the patient. This is because the structure marked by the arrow is likely involved in transmitting pain and temperature signals from the right side of the body to the brain. As a result of the lesion, these signals would not be able to reach the brain, leading to a loss of sensation specifically on the right side of the patient.
9.
Dr O’Donoghue
A 45-year old man presents to the Emergency Department in a state of coma. An MRI reveals a growing mass in his left temporal lobe. Brain tissue has been displaced through the tentorial notch and is now compressing which structure?
Correct Answer
A. Midbrain
Explanation
The correct answer is Midbrain. In this scenario, the growing mass in the left temporal lobe has caused brain tissue to be displaced through the tentorial notch. The tentorial notch is a narrow opening in the tentorium cerebelli, a structure that separates the cerebellum from the cerebral hemispheres. The midbrain is located above the tentorial notch, and when brain tissue is displaced through the notch, it can compress the midbrain. This compression can lead to neurological symptoms such as coma, as seen in the patient in this case.
10.
During a routine neurological examination of a 29-year old man, the physician gently taps the patellar tendon to activate the knee jerk reflex. The resulting reflex is within a normal range. Name (i) the type of reflex (ii) the sensory axon involved
Correct Answer
B. Monosynaptic reflex, Ia axon
Explanation
The correct answer is "Monosynaptic reflex, Ia axon." This is because the knee jerk reflex is a monosynaptic reflex, meaning it involves only one synapse in the neural pathway. The sensory axon involved is the Ia axon, which carries information from the muscle spindle to the spinal cord.
11.
A 25-year old footballer is rushed to the emergency room following a collision with a member of the opposition during a football game. His upper limbs are flexed and lower limbs are extended. Name (i) the type of rigidity and (ii) the level of the lesion.
Correct Answer
A. Decorticate; Above the midbrain
Explanation
The correct answer is "Decorticate; Above the midbrain". Decorticate rigidity refers to a posture characterized by flexion of the upper limbs and extension of the lower limbs. It is caused by damage to the corticospinal tract above the level of the midbrain. This type of rigidity indicates dysfunction in the cerebral hemisphere or internal capsule.
12.
A 36-year old woman experiences drooping of the facial muscles on the entire left side of her face (muscles above and below the eye). Given her symptoms, name (i) the site of the lesion and (ii) the side of the lesion.
Correct Answer
A. Facial nerve, left.
Explanation
The correct answer is Facial nerve, left. This is because the drooping of the facial muscles on the entire left side of the face suggests a lesion in the left facial nerve. The facial nerve is responsible for controlling the muscles of facial expression, and a lesion in this nerve can result in facial weakness or paralysis on the affected side.
13.
A 64-year old man is exhibiting wild flailing movements of his right upper and lower limb. An MRI reveals a small lesion in which structure?
Correct Answer
B. The left subthalamic nucleus
Explanation
The correct answer is the left subthalamic nucleus. The patient's symptoms of wild flailing movements of the right upper and lower limb are consistent with a condition called hemiballismus. Hemiballismus is often caused by a lesion in the contralateral subthalamic nucleus, leading to an imbalance in the basal ganglia circuitry. In this case, the lesion is in the left subthalamic nucleus, resulting in abnormal movements on the right side of the body.
14.
Dr. Salm
A 42-year old woman is suffering from late onset seizures. An MRI reveals clumps of gray matter near the ventricles in her brain. You know from your neuroanatomy that this is a result of failed migration of cortical neurons. Genetic testing would reveal a mutation in which gene?
Correct Answer
E. Filamin A
Explanation
The correct answer is Filamin A. Filamin A is a protein that plays a role in the migration of cortical neurons during brain development. Mutations in the Filamin A gene have been associated with a condition called periventricular nodular heterotopia, which is characterized by clumps of gray matter near the ventricles in the brain. This condition can lead to late onset seizures, as seen in the case of the 42-year old woman. Therefore, genetic testing would reveal a mutation in the Filamin A gene.
15.
Dr Martin
A baby girl presents with an abnormally wide high skull and a short occipitofrontal diameter. Which cranial suture most likely closed prematurely to cause this condition?
Correct Answer
B. Coronal
Explanation
Premature closure of the coronal suture can lead to a condition called craniosynostosis, which is characterized by an abnormally wide high skull and a short occipitofrontal diameter. The closure of the coronal suture restricts the growth of the skull in the transverse direction, resulting in the characteristic skull shape seen in this baby girl. The other sutures listed do not typically cause this specific presentation.
16.
A defect in ossification of skull bones leads to herniation of meninges and or brain tissue. Which of the following conditions includes CSF; meninges and brain?
Correct Answer
E. MeningoencepHalocele
Explanation
Meningoencephalocele is the correct answer because it is a condition that involves the herniation of both the meninges and brain tissue. This condition occurs due to a defect in the ossification of the skull bones, which allows the meninges and brain tissue to protrude through the skull. Meningocele, meningohydrocele, and rachischisis do not involve the herniation of brain tissue, while anencephaly involves the absence of a major portion of the brain.
17.
Dr Vigh
You have been asked to assess the neurological deficit that might exist in a patient diagnosed with cavernous sinus thrombosis. You will focus your examination on cranial nerves related to the sinus that includes all the following EXCEPT:
Correct Answer
B. Facial (CN VII)
Explanation
In cavernous sinus thrombosis, there is inflammation and blood clot formation in the cavernous sinus, which can lead to compression of the cranial nerves passing through this region. The cranial nerves that pass through the cavernous sinus include the oculomotor (CN III), trochlear (CN IV), abducens (CN VI), and ophthalmic division of the trigeminal nerve (CN V1). The facial nerve (CN VII) does not pass through the cavernous sinus and therefore would not be affected by the thrombosis.
18.
Which of the following layers of the scalp constitute the "danger" layer?
Correct Answer
D. Loose areolar tissue layer
Explanation
The "danger" layer of the scalp refers to the layer where infections or bleeding can easily spread to the brain. The loose areolar tissue layer is the correct answer because it is a potential space filled with loose connective tissue and blood vessels. This layer allows for easy movement of the scalp over the calvaria, but it also allows infections or bleeding to rapidly spread to the meninges and brain if not properly treated.
19.
A 20-year old man presents double vision after a car accident. The ER resident tests the eye muscle functions and find that the patient is unable to depress the abducted right eye (look down). Which muscle is not functioning properly?
Correct Answer
B. Inferior rectus
Explanation
obliques only raise and lower in the aDDucted position
20.
Dr Chaudhary
A young enthusiastic surgeon decided to incise an abscess in the middle of the posterior triangle of the neck on the right side. On making the incision, he found that the interior of the abscess was extensive, and he felt that he should explore more deeply. On recovering from the operation, the patient could no longer raise his hand above his head to comb his hair. Which of the following nerves is damaged during the operation?
Correct Answer
A. Accessory nerve
Explanation
The accessory nerve is responsible for innervating the trapezius muscle and sternocleidomastoid muscle, both of which are involved in raising the arm above the head. Damage to the accessory nerve during the operation would result in the patient's inability to raise his hand above his head to comb his hair.
21.
Dr Meisenberg
y-aminobutyric acid (GABA) is the most important inhibitory neurotransmitter in the brain. GABA suppresses anxiety, and a deficiency of GABA causes anxiety. You work for a secret service that wants to develop an anxiety-inducing drug for interrogations. The best strategy to accomplish this aim would be a drug that
Correct Answer
A. Inhibits glutamate decarboxylase
Explanation
glutamate is decarboxylated to form GABA
22.
Dr Sharma
The Romberg’s sign is positive in a patient who suffers from tertiary syphilis when
Correct Answer
E. The patient closes his or her eyes
23.
A 40 year old female is being interviewed for her complaint of feeling very sad. When her mental status is explored the patient reports that she feels suicidal. This finding demonstrates what feature of the interview?
Correct Answer
E. Content
Explanation
The correct answer is "Content". In this scenario, the patient's report of feeling suicidal is a specific piece of information provided during the interview, which falls under the content of the interview. The content refers to the specific details and information shared by the patient during the interview, while the other options (process, procedure, consideration, validation) are more related to the overall approach, structure, and analysis of the interview.
24.
Dr Coffin
With regards to the time course of normal neurodevelopment, what involves loss of neurons that is most active during childhood and adolescence that helps with brain restructuring?
Correct Answer
C. Competitive elimination
Explanation
Competitive elimination refers to the process of eliminating excess neurons and synapses in the brain during childhood and adolescence. This process helps with brain restructuring by refining and strengthening neural connections. It involves a competition among neurons and synapses for limited resources and survival, leading to the elimination of weaker connections and the strengthening of stronger ones. This process is crucial for shaping the neural circuitry and optimizing brain function during development.
25.
In the time course of signal transduction what can be activated after the binding of the first messenger that can lead to new protein synthesis?
Correct Answer
B. Genes
Explanation
After the binding of the first messenger in signal transduction, genes can be activated, leading to new protein synthesis. Genes contain the instructions for protein synthesis, and when activated, they initiate the process of transcription and translation, resulting in the production of new proteins. This activation of genes allows the cell to respond to the initial signal and adapt to the changing environment.