COMSAE 107 (Latest )
Complete Questions and 100% Correct
Answers (Verified Pass)
1. A 55-year-old man presents with weakness in his right upper extremity.
Examination reveals loss of sensation over the lateral forearm and thenar
eminence, and weakened elbow flexion. Which nerve root is most likely
affected?
A. C5
B. C6
C. C7
D. C8
Answer: B. C6
Rationale: The C6 nerve root corresponds to the biceps reflex, sensation over the
lateral forearm and thumb (thenar eminence), and contributes to elbow flexion and
wrist extension. C5 would show shoulder abduction weakness, C7 triceps/wrist
flexion, C8 finger flexion.
,2. A 34-year-old woman has a benign tumor compressing the facial nerve in the
internal acoustic meatus. Besides the muscles of facial expression, which
other function would likely be affected?
A. Hearing only
B. Taste from the anterior two-thirds of the tongue
C. Taste from the posterior one-third of the tongue
D. Palatal elevation
Answer: B. Taste from the anterior two-thirds of the tongue
Rationale: The facial nerve (CN VII) carries taste fibers from the anterior two-thirds
of the tongue via the chorda tympani. Hearing would be affected if CN VIII was
involved, and palatal elevation is controlled by CN X.
3. A patient presents with weakness in shoulder abduction and difficulty raising
the arm above the head. Which nerve root is most likely affected?
A. C5
B. C6
C. C7
D. C8
Answer: A. C5
Rationale: The C5 nerve root innervates the deltoid muscle, which is primarily
responsible for shoulder abduction. C5 also contributes to the biceps reflex and
sensation over the lateral arm.
,4. A patient has weakness in wrist extension. Which nerve root is most likely
affected?
A. C5
B. C6
C. C7
D. C8
Answer: B. C6
Rationale: Wrist extension is primarily a C6 function. The classic C6 motor test is
wrist extension and elbow flexion, with sensory distribution over the thumb and
lateral forearm.
5. A patient presents with weakness in elbow extension and wrist flexion.
Which nerve root is most likely affected?
A. C5
B. C6
C. C7
D. C8
Answer: C. C7
Rationale: The C7 nerve root is responsible for elbow extension (triceps) and wrist
flexion. The triceps reflex tests C7 integrity.
, 6. A patient has weakness in finger flexion. Which nerve root is most likely
affected?
A. C5
B. C6
C. C7
D. C8
Answer: D. C8
Rationale: The C8 nerve root is responsible for finger flexion. C8 also contributes to
hand intrinsic muscle function.
7. Fasciculations are indicative of which type of lesion?
A. Upper motor neuron (UMN)
B. Lower motor neuron (LMN)
C. Both UMN and LMN
D. Neither
Answer: B. Lower motor neuron (LMN)
Rationale: Fasciculations are spontaneous contractions of motor units and are a
hallmark of lower motor neuron lesions. UMN lesions typically present with
spasticity, hyperreflexia, and upgoing plantar reflexes.
8. A patient presents with a lesion in the internal capsule. Which of the
following findings would be expected?
Complete Questions and 100% Correct
Answers (Verified Pass)
1. A 55-year-old man presents with weakness in his right upper extremity.
Examination reveals loss of sensation over the lateral forearm and thenar
eminence, and weakened elbow flexion. Which nerve root is most likely
affected?
A. C5
B. C6
C. C7
D. C8
Answer: B. C6
Rationale: The C6 nerve root corresponds to the biceps reflex, sensation over the
lateral forearm and thumb (thenar eminence), and contributes to elbow flexion and
wrist extension. C5 would show shoulder abduction weakness, C7 triceps/wrist
flexion, C8 finger flexion.
,2. A 34-year-old woman has a benign tumor compressing the facial nerve in the
internal acoustic meatus. Besides the muscles of facial expression, which
other function would likely be affected?
A. Hearing only
B. Taste from the anterior two-thirds of the tongue
C. Taste from the posterior one-third of the tongue
D. Palatal elevation
Answer: B. Taste from the anterior two-thirds of the tongue
Rationale: The facial nerve (CN VII) carries taste fibers from the anterior two-thirds
of the tongue via the chorda tympani. Hearing would be affected if CN VIII was
involved, and palatal elevation is controlled by CN X.
3. A patient presents with weakness in shoulder abduction and difficulty raising
the arm above the head. Which nerve root is most likely affected?
A. C5
B. C6
C. C7
D. C8
Answer: A. C5
Rationale: The C5 nerve root innervates the deltoid muscle, which is primarily
responsible for shoulder abduction. C5 also contributes to the biceps reflex and
sensation over the lateral arm.
,4. A patient has weakness in wrist extension. Which nerve root is most likely
affected?
A. C5
B. C6
C. C7
D. C8
Answer: B. C6
Rationale: Wrist extension is primarily a C6 function. The classic C6 motor test is
wrist extension and elbow flexion, with sensory distribution over the thumb and
lateral forearm.
5. A patient presents with weakness in elbow extension and wrist flexion.
Which nerve root is most likely affected?
A. C5
B. C6
C. C7
D. C8
Answer: C. C7
Rationale: The C7 nerve root is responsible for elbow extension (triceps) and wrist
flexion. The triceps reflex tests C7 integrity.
, 6. A patient has weakness in finger flexion. Which nerve root is most likely
affected?
A. C5
B. C6
C. C7
D. C8
Answer: D. C8
Rationale: The C8 nerve root is responsible for finger flexion. C8 also contributes to
hand intrinsic muscle function.
7. Fasciculations are indicative of which type of lesion?
A. Upper motor neuron (UMN)
B. Lower motor neuron (LMN)
C. Both UMN and LMN
D. Neither
Answer: B. Lower motor neuron (LMN)
Rationale: Fasciculations are spontaneous contractions of motor units and are a
hallmark of lower motor neuron lesions. UMN lesions typically present with
spasticity, hyperreflexia, and upgoing plantar reflexes.
8. A patient presents with a lesion in the internal capsule. Which of the
following findings would be expected?
