Motor Neuron Quiz

20 Questions | By BLACKMD | Updated: Nov 4, 2022 | Attempts: 3585

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Are you an expert in motor neurology? Test yourself right now with this motor neuron quiz here. Motor neurons are meant by a specialized type of brain cell called neurons, located within the spinal cord and the brain. There are two main subtypes. These two types are the upper motor neurons and the lower motor neurons. Here are some questions for your practice and a better understanding of motor neurology. Give your best shot!

Questions and Answers

1.

A 74-year-old woman was residing in a rehabilitation facility while recovering from an infection. She was doing well until one morning. She suddenly developed slurred speech and right-sided weakness. An emergency neurologist was consulted. Her medical history was notable for hypertension, coronary artery disease, and a recent onset of atrial fibrillation. Examination revealed weak movements of the right face with only mild forehead involvement. Decreased palate movement on the right and rightward tongue deviation. The neurologist suspected lacunar infarction, which was confirmed by MRI. Where is the possible localization?
- A.
  
  Left prefrontal gyrus medial part of the hemisphere
- B.
  
  Right Broca area with involvement of lower part of Brodmann area 4.
- C.
  
  Left posterior limb of the internal capsule
- D.
  
  Left genu of the internal capsule
- E.
  
  Right posterior limb and genu of the internal capsule
2.

Your elderly neighbor has difficulties in picking up his newspaper properly from his porch, and you have also noticed that he exhibits issues with correctly grasping his brandy glass when he invites you over for a drink. He told you that he has problems controlling the distance of his movements. You know this to be which of the following?
- A.
  
  Akinesia
- B.
  
  Dysdiadochokinesia
- C.
  
  Bradykinesia
- D.
  
  Dysphagia
- E.
  
  Dysmetria
3.

A 52-year-old woman who is unable to move her left leg visits your office. Sensory modalities in all of her limbs are retained and there appears to be no sign of weakness in any of her other limbs. In which of the following structures are the cell bodies of lower motor neurons innervating the lower limb located?
- A.
  
  Lamina I-VI
- B.
  
  Lamina VIII, IX
- C.
  
  Lamina X
- D.
  
  Lamina I, II
- E.
  
  Lamina III, IV
4.

A 24-year-old woman is rushed to the hospital following severe head injuries. She is displaying a specific rigidity that is a result of lesions rostral to the red nucleus. What symptoms is she displaying?
- A.
  
  Lower extremity weakness
- B.
  
  Weakness of the masticatory muscles
- C.
  
  Upper and lower limb extension
- D.
  
  Upper limb flexion and lower limb extension
- E.
  
  Deviation of the tongue on the protrusion
5.

A 34-year-old man is rushed to the emergency room from the site of a car accident. An MRI reveals a lesion at the level of the midbrain. His upper and lower limbs are extended. Name (i) the type of rigidity and (ii) the tract/tracts involved in the extension of the limbs.
- A.
  
  Decorticate; Rubrospinal tract
- B.
  
  Decorticate; Medial reticulospinal and lateral vestibulospinal tract
- C.
  
  Decerebrate; Rubrospinal and lateral vestibulospinal tract
- D.
  
  Decerebrate; Rubrospinal tract
- E.
  
  Decerebrate; Medial reticulospinal and lateral vestibulospinal tract
6.

A 22-year-old woman n is suffering from bilateral weakness of her lower limbs. Which of the following represents the most likely location of this lesion?
- A.
  
  A lesion rostral to the pyramidal decussation
- B.
  
  The left genu of the internal capsule
- C.
  
  The right posterior limb of the internal capsule
- D.
  
  A lesion caudal to the pyramidal decussation
- E.
  
  The right genu of the internal capsule
7.

Which of the following represents the fibers that fan out from the internal capsule into the white matter of the hemisphere?
- A.
  
  Cingulum
- B.
  
  Corona Radiata
- C.
  
  Genu of the corpus callosum
- D.
  
  Superior longitudinal fasciculus
- E.
  
  Uncinate fasciculus
8.

Damage to the efferent portion of the muscle spindle would involve which of the following fiber types?
- A.
  
  B fibers
- B.
  
  Aa fibers
- C.
  
  C fibers
- D.
  
  Ay fibers
- E.
  
  AB fibers
9.

A 54-year-old morbidly obese and hypertensive man is brought to the emergency department after experiencing the sudden onset of weakness in his left upper and lower extremities. CT shows an infarcted area in the medulla. Damage to which of the following tracts or fiber bundles of the medulla would most likely explain this deficit?
- A.
  
  Anterolateral system
- B.
  
  Corticospinal fibers
- C.
  
  Medial Lemniscus
- D.
  
  Rubrospinal tract
- E.
  
  Vestibulospinal fibers
10.

A 23-year-old man is brought to the emergency room from the site of an automobile collision. The neurological examination reveals weakness of the right lower extremity and a loss of pain and thermal sensations on the left side, beginning at the level of the umbilicus. CT shows a fracture of the vertebral column with the displacement of bone fragments into the vertebral canal. Damage to which of the following tracts would correlate with weakness of the lower extremity in this man?
- A.
  
  Left lateral corticospinal tract
- B.
  
  Reticulospinal fibers on the right
- C.
  
  Right lateral corticospinal tract
- D.
  
  Right rubrospinal tract
- E.
  
  Vestibulospinal fibers on the right
11.

Which of the following represents the most likely level of damage to the spinal cord resulting from the fracture to the vertebral column in this man?
- A.
  
  T6 on the left
- B.
  
  T8 on the left
- C.
  
  T8 on the right
- D.
  
  T10 on the left
- E.
  
  T10 on the right
12.

Based on their relative locations in the spinal cord, which of the following tracts or fiber bundles would most likely be involved In a lesion located in the immediate vicinity of the lateral corticospinal tract?
- A.
  
  Anterolateral system
- B.
  
  Anterior spinocerebellar tract
- C.
  
  Gracile fasciculus
- D.
  
  Medial longitudinal fasciculus
- E.
  
  Rubrospinal tract
13.

A 37-year-old man is brought to the emergency department with a severe head injury. Within a few hours, he is decerebrate (upper and lower extremities extended) and comatose. The extension of his extremities indicates a dominant input to extensor motor neurons through reticulospinal fibers/tracts. Which of the following most specifically describes the position of these activated fibers within the spinal cord?
- A.
  
  Anterolateral area (area of anterolateral system)
- B.
  
  Posterolateral area (area of lateral corticospinal tract)
- C.
  
  Posteriorcolumns
- D.
  
  Posterolateral (dorsolateraI)tract
- E.
  
  Intermediate zone
14.

A 47-year-old man is transported to the emergency department from the site of an automobile collision. The examination reveals a paralysis of both lower extremities. Which of the following most specifically identifies this clinical picture?
- A.
  
  Alternating hemiplegia
- B.
  
  Hemiplegia
- C.
  
  Monoplegia
- D.
  
  Quadriplegia
- E.
  
  Paraplegia
15.

A 57-year-old woman presents with the main complaint of difficulty speaking. The examination reveals that the woman's tongue deviates to the right on the attempted protrusion. When she says \\Ah," her soft palate elevates slightly on the left, and the uvula deviates to the same side. This combination of deficits most likely indicates a small lesion in which of the following?
- A.
  
  Crus cerebri on the right
- B.
  
  Genu of the internal capsule on the left
- C.
  
  Genu of the internal capsule on the right
- D.
  
  Lateral medulla on the right
- E.
  
  Medial medulla on the right
16.

A 70-year-old woman is brought to the emergency department by members of the volunteer fire department of a small town. She primarily complains of weakness. The examination reveals hemiplegia involving the left upper and lower extremities, sensory losses (pain, thermal sensations, and proprioception) on the left side of the body and face, and a visual deficit in both eyes. MRI shows an area of infarction consistent with the territory served by the anterior choroidal artery. The weakness of the extremities in this woman is most likely due to damage to which of the following?
- A.
  
  Corticospinal fibers on the left
- B.
  
  Corticospinal fibers on the right
- C.
  
  Somatomotor cortex on the right
- D.
  
  Thalamocortical fibers to the motor cortex on the right
- E.
  
  Thalamocortical fibers to the sensory cortex on the right
17.

A 57-year-old man presents with hoarseness. The neurological examination reveals a deviation of the uvula to the left on phonation, deviation of the tongue to the right on the protrusion, and weakness of the facial muscles around the mouth on the right. Which of the following would most likely also be seen in this man?
- A.
  
  Inability to turn his head to the left against resistance
- B.
  
  Inability to turn his head to the right against resistance
- C.
  
  Inability to shrug the right shoulder against resistance
- D.
  
  Weakness of the masticatory muscles on the left
- E.
  
  Weakness of the masticatory muscles on the right
18.

A 57-year-old obese man is brought to the emergency department by his wife. The examination reveals that cranial nerve function is normal, but the man has bilateral weakness of his lower extremities. He has no sensory deficits. MRI shows a small infarcted area in the general region of the cervical spinal cord-medulla junction. Which of the following represents the most likely location of this lesion?
- A.
  
  Caudal part of the pyramidal decussation
- B.
  
  Lateral corticospinal tract on the left
- C.
  
  Pyramids bilaterally
- D.
  
  Pyramid on the right
- E.
  
  Rostral part of the pyramidal decussation
19.

As a medical student, you are tapping the patellar tendon to activate the knee jerk reflex. The resulting reflex is within a normal range. Which sensory organ is activated in response to this stimulus?
- A.
  
  Golgi tendon organ
- B.
  
  Merkel cell
- C.
  
  Pacinian corpuscle
- D.
  
  Muscle spindle
- E.
  
  Ruffini ending
20.

A 79~year old man is experiencing peripheral nerve damage to his lower right limb. Which of the following is characteristic of lower motor neuron damage?
- A.
  
  Hyperreflexia
- B.
  
  Increased tone
- C.
  
  Hyporeflexia
- D.
  
  Spastic paralysis
- E.
  
  Increased muscle mass