2011 final

Question 1

The following audiogram represents the air and bone conduction of both ears in a female with hearing problem. Which structure is likely to be affected?

O : air conduction in right ear
< : bone conduction in right ear
] : air conduction of left ear
square : bone conduction of left ear

• Left auditory nerve
• Right auditory nerve
• Left middle ear
• Right middle ear

Answer 1

• Left auditory nerve

Question 2

If the left corticobulbar fibers were injured, which side of the face will be affected?

• The right lower side
• The left lower side
• The entire left side

Answer 2

• The right lower side

Note: this is equivalent to injury of the upper motor neurons supplying the motor nucleus of the facial nucleus

Question 3

Which nucleus receives fibers from the cortex of the flocculonodular lobe?

• The vestibular nucleus
• The fastigial nucleus

Answer 3

• The vestibular nucleus

Question 4

Where does the corticospinal tract run in the crus cerebri of the midbrain?

• Middle two third
• Medial one sixth
• Lateral one third

Answer 4

• Middle two third

Note: the order of fibers running in the crus cerebri from medial to lateral is: frontopontine, croticospinal, corticonuclear, temporopontine

Question 5

Which nucleus receives signals regarding touch and pressure from the face?

Answer 5

Main sensory nucleus of trigeminal

Question 6

Which of the following is likely to be injured due to fracture of the floor of the orbit?

Answer 6

Inferior oblique muscle

Question 7

Which of the following cranial nerves carries the efferent fibers for the pupillary light reflex?

• III
• II

Answer 7

• III

Question 8

Which of the following innervates the inner surface of the tympanic membrane?

Answer 8

Glossopharyngeal nerve

Question 9

Which wall separates the middle ear from the dura?

Answer 9

Tegmental wall

Question 10

Which wall of the middle ear has the round and oval windows?

Answer 10

Labyrinthine wall

Question 11

Damage to which of the following structures causes unilateral deafness?

• Cochlear nucleus
• Inferior colliculus
• Lateral lemniscus

Answer 11

• Cochlear nucleus

Question 12

Where is the primary auditory area located?

Answer 12

Superior temporal gyrus

Question 13

Which of the following represents a correct sequence of structures involved in the primary circuit of the basal ganglia?

Answer 13

Globus pallidus to thalamus

Question 14

Injury to which of the following structures can cause retrograde neurodegeneration of the amygdala?

Answer 14

Stria terminalis

Question 15

Stimulation of which of the following structures can result in excitation of the mammillary bodies?

Answer 15

Fornix

Question 16

Which nucleus receives fibers carried by the glossopharyngeal nerve
regarding taste sensations?

Answer 16

Nucleus tractus solitaries

Question 17

Which of the following functional areas is present in the wall of the calcarine sulcus?

• Primary visual area
• Secondary visual area

Answer 17

• Primary visual area

Question 18

Which of the following tracts are most likely to be injured due to damage to the most anterior part of the internal capsule?

Answer 18

Corticospinal tract

Question 19

Damage to which of the following nuclei results in pupil dilation?

Answer 19

Edinger-westphal nucleus

Question 20

Which of the following can cause hydrocephalus?

Answer 20

Aqueduct stenosis

Question 21

Which of the following is responsible for feedback regulation of body weight?

Answer 21

Leptin

Question 22

Which of the following is released in response to thirst?

Answer 22

Vasopressin

Question 23

Which of the following is responsible for stopping the feeding drive?

Answer 23

Amylin

Question 24

What do the waves on EEG represent?

• EPSPs and IPSPs of the dendrites of cortical neurons
• EPSPs and IPSPs of the dendrites of thalamic neurons
• Action potentials of the cortical neurons

Answer 24

• EPSPs and IPSPs of the dendrites of cortical neurons

Question 25

Which of the following correctly represents the sensorymotor hierarchy in the higher cortical centers?

Answer 25

Posterior association area -> anterior association area -> premotor area -> primary motor area

Question 26

Which of the following only fires if a motor action is required?

Answer 26

Anterior association area

Question 27

What maintains the tone of smooth muscles of the arterioles in the brain?

Answer 27

The partial pressure of CO2 in tissues

Question 28

Which of the following modulates the effect of norepinephrine by increasing its activity?

Answer 28

Co-release of ATP

Question 29

Which of the following is correct regarding the receptor potential? * It is proportional to the strength of the stimulus * Frequency coded

Answer 29

• It is proportional to the strength of the stimulus Note: receptor potential is also called generator potential; action potential, on the other hand, is frequency coded

Question 30

What is the difference between rods and cones?

Answer 30

Type and distribution of the pigments

Question 31

How does dopamine exert its effect in the basal ganglia?

Answer 31

It activates the direct circuit

Question 32

Together with the basal ganglia, which of the following is involved in the selection of movements due to external cues?

Answer 32

Lateral premotor area

Question 33

Epilepsy can result from damage of the medial temporal lobe. What can mediate that damage?

Answer 33

Excitotoxicity

Question 34

Stepping on a sharp object causes flexion of the leg on that side. What happens to the leg on the other side?

Answer 34

An excitatory interneuron synapses with the motor neuron innervating the extensor muscle of the leg on the other side

Question 35

Which of the following is involved in walking in a constant speed?

Answer 35

Polysynaptic reflex

Question 36

Which of the following is involved in preventing someone from falling when being suddenly pushed from the back? * Feedback mechanism * Monosynaptic reflex

Answer 36

• Feedback mechanism

Question 37

Which of the following is involved in learning how to play piano?

Answer 37

Cerebellar synaptic plasticity

Question 38

Which of the following truly describes the function of the basal ganglia? * Inhibits inappropriate programs of movemets * Initiates movements through a connection with the prefrontal cortex

Answer 38

• Inhibits inappropriate programs of movemets

Question 39

Which deficiency is associated with subacute combined degeneration of the spinal cord?

Answer 39

Vitamin B12 deficiency

Question 40

Genetic defect of which of the following underlies hereditary spastic paraplegia? * Anterograde retrograde transport * Rho signaling system

Answer 40

• Anterograde retrograde transport

Question 41

Which of the following brain tumors commonly occurs in children in the posterior cranial fossa?

Answer 41

Pilocytic astrocytoma

Question 42

What can present with gelatinous or fibrinous exudate usually at the base of the brain?

Answer 42

Tuberculous meningitis

Question 43

In which condition are round or oval eosinophilic cytoplasmic inclusions found in the brain stem and cerebellum?

Answer 43

Rabies

Question 44

A 77 year old male with dementia and cognitive disability died. On autopsy, his brain was atrophied and showed extracellular amyloid plaques and intracellular tangles of tau protein histologically. What is the likely pathology?

Answer 44

Alzheimer's disease

Question 45

A 68 year old male with a history of rigidity and tremors passed away, and his brain showed hypopigmentation and loss of melanin in the substantia nigra. What is the likely pathology?

Answer 45

Parkinsons disease

Question 46

Multiple sclerosis is an autoimmune disease that is associated with demyelinating plaques. Where are those plaques most commonly located?

Answer 46

Periventricular region

Question 47

A 35 year old female developed a sudden headache associated with hemorrhage in the subarachnoid space. A lumbar puncture revealed numerous red blood cells. What is the likely cause?

Answer 47

Ruptured berry aneurysm

Question 48

Rupture of which of the following structures is associated with subdural hematoma?

Answer 48

Communicating veins

Question 49

What can be a consequence of a mutation affecting the potassium channels in the presynaptic membrane?

Answer 49

Increase in the flux of calcium

Question 50

Which disease is characterized by abnormally expanded CTG repeats from 50 to 2000 repeats (normal from 5 to 30)?

Answer 50

Myotonic dystrophy

Question 51

Which condition result from a mutation in an ion channel protein?

Answer 51

Epilepsy

Question 52

Release of which of the following mediators results in neuronal apoptosis in ischemia-reperfusion injury?

Answer 52

Cytochrome c

Question 53

What is the function of peroxisomes in brain cells?

Answer 53

Alpha oxidation of fatty acids

Question 54

How is Alzheimer's disease different from prion disease?

Answer 54

There is no infectious form of Alzheimer's disease

Question 55

How does the presence of VV alleles in prion gene reduce the probability of acquiring prion disease?

Answer 55

It reduces the binding between the normal and abnormal forms of prion protein

Question 56

Which of the following elements is associated with the amyloid plaques in Alzheimer's disease?

Answer 56

Aluminum

Question 57

A doctor is willing to generally anesthetize a patient, but he wanted him to respond to simple commands and questions and to be in a state of sedation and analgesia at the same time. Which combination of drugs would be given?

Answer 57

Doperidol and fentanyl

Question 58

What is the mechanism of action of lidocaine at normal doses?

Answer 58

It blocks voltage-gated sodium channels

Question 59

Which drug acts by inhibiting GABA transaminase and increasing the activity of glutamate decarboxylase?

Answer 59

Valproic acid

Question 60

Which drug has a narrow spectrum of activity and blocks T calcium channels?

Answer 60

Ethosuxemide

Question 61

Tolerance to which of the following effects doesn’t develop with the repeated use of benzodiazepines?

Answer 61

Anxiolytic effect

Question 62

A patient complained to his doctor that he suffers from insomnia. However, once he falls asleep, he can sleep for 6 hours. Which drug can be given to this patient?

Answer 62

Zolpidem Note: zolpidem is used for sleep-onset insomnia

Question 63

Which drug has an on-off effect?

Answer 63

Levodopa

Question 64

Which drug is a muscarinic antagonist?

Answer 64

Benzotropine

Question 65

Which of the following accurately describes the action of morphine on different sites?

Answer 65

Inhibits adenyl cyclase, closes calcium channels, opens potassium channels

Question 66

What chemoprophylaxis would you give a non-pregnant woman who has been in contact with a case of meningococcal meningitis? * Rifampicin for 2 days * Ceftriaxone for two days

Answer 66

• Rifampicin for 2 days

Question 67

Which of the following is a risk factor for acquiring streptococcus pneumoniae meningitis?

Answer 67

Sickle cell disease

Question 68

A 43 year old female with multiple sclerosis was found to have bilateral gaze paresis, intention tremor, bilateral dysmetria, abnormal heel to chin test, in addition to ataxic gait. Which of the following best describes her condition?

Answer 68

Pancerebellar disease

Question 69

A heavy alcohol drinker develops ataxia. Which of the following structures is most likely to be affected?

Answer 69

Superior vermis Note: alcohol selectively damages superior part of the cerebellar vermis

Question 70

Occlusion of which of the following arteries typically brings about lateral medullary (Wallenberg) syndrome?

Answer 70

Vertebral artery

Question 71

A patient was found to have partial ptosis, and his left pupil was smaller than the right one. Which of the following best describes his condition?

Answer 71

Horners syndrome

Question 72

A patient presented with horizontal diplopia. His right eye was pushed outward and downward. He couldn’t elevate or adduct his eye, and his eyelid was droopy while the pupil was normal. What is the likely diagnosis?

Answer 72

Left oculomotor nerve palsy

Question 73

A patient presented with horizontal diplopia on looking to the right. He couldn’t abduct his right eye. What is the likely diagnosis?

Answer 73

Right abducent nerve palsy

Question 74

Which of the following is associated with segmental demyelination?

Answer 74

Muscle weakness and decreased deep tendon reflexes

Question 75

Which of the following is true regarding poliomyelitis?

Answer 75

Associated with muscle paralysis, muscle atrophy, and absent deep tendon reflexes

Question 76

What is the most sensitive imaging technique used to detect cerebrovascular accident?

Answer 76

CT scan

Question 77

Which of the following nuclear imaging techniques is used to diagnose patients with cerebral ischemia?

Answer 77

HMPAO Tec99 with acetazolamide infusion

Question 78

What can the improvement of diagnostic imaging in stroke cause an apparent increase in?

Answer 78

In incidence and prevalence of stroke