1.
Examination of a patient revealed reduced pinprick and temperature sensation on the right side of the face, and the left side of the body. Where is the most likely location of the lesion?
Correct Answer
C. Right side of the medulla
Explanation
The most likely location of the lesion is the right side of the medulla. This is because the medulla is responsible for carrying sensory information from the face and body to the brain. The symptoms described, reduced pinprick and temperature sensation on the right side of the face and the left side of the body, suggest a lesion in the pathway that transmits these sensations from the right side of the medulla to the brain.
2.
A patient was brought to the hospital by his wife. On examination, he seemed unable to understand the questions that the doctor posed to him. Where is the most likely location of the lesion?
Correct Answer
E. Cerebral hemisphere
Explanation
The patient's inability to understand the questions posed by the doctor suggests a problem with language comprehension, which is typically associated with lesions in the cerebral hemisphere. The cerebral hemisphere is responsible for higher cognitive functions, including language processing. Lesions in this area can disrupt the connections between different regions involved in language comprehension, leading to difficulties in understanding spoken or written language.
3.
A patient noted that all the muscle on the left side of her face seemed to be paralyzed. Sensation was normal excepting an inability to taste on the left side of her tongue. Where is the most likely location of the lesion?
Correct Answer
D. Posterior fossa, left side
Explanation
The most likely location of the lesion is the posterior fossa on the left side. This is because the patient is experiencing paralysis of the muscles on the left side of her face, which suggests a problem with the facial nerve. The facial nerve, also known as cranial nerve VII, passes through the posterior fossa before exiting the skull and innervating the muscles of the face. Additionally, the patient's inability to taste on the left side of her tongue suggests involvement of the chorda tympani branch of the facial nerve, which also passes through the posterior fossa.
4.
A patient with a disease of myelin in the central nervous system presented with loss of vision in both eyes. Where is the most likely location of the lesion?
Correct Answer
A. Supratentorial
Explanation
The correct answer is Supratentorial. The patient's loss of vision in both eyes suggests a lesion in the central nervous system. The supratentorial region refers to the area above the tentorium cerebelli, which includes the cerebral hemispheres. Lesions in this region can affect the optic nerves or optic tracts, leading to visual disturbances.
5.
A patient presented with abnormal ocular movements and papillary dilatation of the right eye. Where is the most likely location of the lesion?
Correct Answer
B. Midbrain
Explanation
The midbrain is the most likely location of the lesion because it is responsible for controlling eye movements and pupil size. Abnormal ocular movements and papillary dilatation suggest dysfunction in the structures within the midbrain that regulate these functions. The thalamus, cerebellum, pons, and occipital lobe are not primarily involved in controlling ocular movements and pupillary dilation, making them less likely locations for the lesion.
6.
A patient is evaluated for his ocular movements. Which brain level/structure is being evaluated?
Correct Answer
A. Midbrain and pons
Explanation
The correct answer is Midbrain and pons. The question is asking which brain level or structure is being evaluated during the assessment of ocular movements. The midbrain and pons are responsible for controlling eye movements. The midbrain contains the superior colliculus, which helps coordinate eye movements, while the pons contains the pontine nuclei, which control horizontal eye movements. Therefore, evaluating ocular movements involves assessing the function of the midbrain and pons.
7.
A patient is evaluated for his muscles of facial expression? Which brain level/structure is being evaluated?
Correct Answer
B. Pons
Explanation
The correct answer is Pons. The pons is a structure located in the brainstem, specifically in the upper part. It is responsible for relaying signals between different parts of the brain, including the cerebrum and the cerebellum. In the context of evaluating the muscles of facial expression, the pons would be involved in coordinating the movement of these muscles and transmitting the necessary signals from the brain to the muscles.
8.
A patient is evaluated for the pupillary light reflex? Which brain level/structure is being evaluated?
Correct Answer
B. Midbrain
Explanation
The pupillary light reflex is controlled by the midbrain. This reflex involves the constriction of the pupil in response to light stimulation. The midbrain contains the Edinger-Westphal nucleus, which controls the parasympathetic pupillary reflex pathway. When light is detected by the retina, the signal is transmitted to the midbrain, which then sends signals to the muscles of the iris to constrict the pupil. Therefore, evaluating the pupillary light reflex involves assessing the function of the midbrain.
9.
Which of the following regulates the muscle tone?
Correct Answer
D. All of the above
Explanation
The correct answer is "All of the above". The cerebellum, descending motor pathways, and spinal reflex circuits all play a role in regulating muscle tone. The cerebellum helps to coordinate and fine-tune muscle movements, while descending motor pathways from the brain send signals to the muscles to control their tone. Spinal reflex circuits, on the other hand, are responsible for involuntary muscle contractions and maintaining muscle tone. Together, these three components work in harmony to regulate muscle tone.