Road Maps: Spinal Cord Flashcards
1
Q
- Cutting a dorsal root of a spinal nerve may result in:
A. Hypotonia in skeletal muscles innervated by the cut root
B. Fasciculations in skeletal muscles innervated by the cut root
C. Reversed cutaneous reflexes in skin over the denervated muscle
D. Anterograde degeneration of axons in the spinothalamic tract
E. A loss of all touch, vibration, and pressure sensations ipsilateral to and below the lesion
A
A. Hypotonia in skeletal muscles innervated by the cut root
2
Q
2. A neurological exam of your patient reveals a loss of vibratory sense in the lower limb on the right, weakness and hyperactive reflexes in the lower limb on the right, and a loss of pain and temperature that begins below the T8 dermatome on the left. Where is the lesion? A. T6 spinal cord segment on the right B. T8 spinal cord segment on the right C. T10 spinal cord segment on the right D. T8 spinal cord segment on the left E. T6 spinal cord segment on the left
A
A. T6 spinal cord segment on the right
3
Q
3. Your patient complains that he burned his hand on his portable heater but did not feel the stimulus. The patient also notes that he has difficulty using either hand. You note that the patient has no response to pinprick in skin of either hand, arm, or shoulder and a bilateral wasting of intrinsic hand muscles. You suspect that the pa- tient has: A. Syringomyelia B. Multiple sclerosis C. Poliomyelitis D. Brown-Séquard syndrome E. Amyotrophic lateral sclerosis
A
A. Syringomyelia
4
Q
- A tumor pressing against the dorsal funiculus of the spinal cord at lumbar levels has caused neurological deficits. Your patient might have:
A. A bilateral loss of pain and temperature sensations from sacral dermatomes
B. Altered vibratory sense in the lower limbs
C. A loss of protopathic sensations from thoracic dermatomes
D. Bilateral spastic weakness in the lower limbs
E. A loss of reflexes in the upper limbs
A
B. Altered vibratory sense in the lower limbs
5
Q
- The spinal cord has been hemisected at spinal cord segment C5. You might expect retrograde chromatolysis to occur:
A. In dorsal root ganglia contralateral and below the lesion
B. In lamina I of the dorsal horn contralateral to and below the lesion
C. In lamina V of the dorsal horn ipsilateral to and below the lesion
D. In the precentral gyrus ipsilateral to the lesion
E. In Clarke’s nucleus contralateral to and below the lesion
A
B. In lamina I of the dorsal horn contralateral to and below the lesion
6
Q
- Your patient has received a painful wound.
All of the following neural structures are active in the suppression of pain except:
A. Neurons in the periaqueductal gray of the midbrain
B. Neurons in lamina II
C. Neurons in the brainstem
D. Medial division dorsal root fibers
E. Neurons in lamina V
A
E. Neurons in lamina V
7
Q
7. A weight lifter is attempting to set a new personal best in competition. As the lifter attempts to raise the weight to his chest by flexing his forearms at the elbow, he sud- denly drops the weight to the floor. Which neurons were excessively stimulated and caused the lifter to drop the weight? A. Renshaw cells B. Lateral reticulospinal tract neurons C. Gamma motor neurons D. Class Ib afferent neurons E. Class II afferent neurons
A
D. Class Ib afferent neurons
8
Q
8. You are evaluating your adult patient’s muscle strength and muscle stretch reflexes. Which of the following would be expected in a normal motor exam? A. A positive Romberg sign B. Absent abdominal reflexes C. A grade of 2+ for reflexes D. A grade of muscle strength of 3/5 E. Clonus
A
C. A grade of 2+ for reflexes
9
Q
- A construction worker falls off a ladder and fractures a vertebra. A neurological exam conducted 2 weeks after the accident reveals that the individual has a complete hemi- section of the right side of the spinal cord at T5. In this patient, you might expect a pain and temperature loss:
A. In the upper and lower limbs on the left
B. In all dermatomes below T7 on the left
C. In the T3 dermatome on the right
D. Below the T5 dermatome on the right
E. That is caused by degeneration of dorsal root ganglion cells below T7 on the left.
A
B. In all dermatomes below T7 on the left
10
Q
- A construction worker falls off a ladder and fractures a vertebra. A neurological exam conducted 2 weeks after the accident reveals that the individual has a complete hemi- section of the right side of the spinal cord at T5. You would expect a spastic weakness in this patient to be:
A. Ipsilateral to and below the level of the lesion
B. Ipsilateral to and above the level of the lesion
C. Observed before the onset of spinal shock
D. Contralateral to and below the level of the lesion
E. Bilateral to and at the level of the lesion
A
A. Ipsilateral to and below the level of the lesion
11
Q
11. A newborn infant has difficulty sucking, swallowing, or breathing and has flaccid weakness in the limbs. What kind of motor disorder might the patient have? A. Poliomyelitis B. Amyotrophic lateral sclerosis C. Werdnig-Hoffmann disease D. Guillain-Barré syndrome E. Myasthenia gravis
A
C. Werdnig-Hoffmann disease
12
Q
- The anterior spinal artery has been occluded at the point where it supplies the midthoracic segments of the spinal cord. What might you expect your patient to have?
A. Spastic weakness of both upper limbs
B. Altered touch sensations in both lower limbs
C. Hyporeflexia in both lower limbs
D. Bilateral degeneration of LMNs in the ventral horns of the lumbar spinal cord
E. Bilateral Babinski signs
A
E. Bilateral Babinski sign
The Anterior Spinal artery supplies the ventrolateral parts of the cord, including the corticospinal tracts and the spinothalmic tracts. Below the level of the lesion at mid thoracic levels, the patient may have a bilateral spastic paresis and Babinski signs and a bilateral loss of pain and temperature.
13
Q
13. An anesthetic has been administered to a patient. Which fibers will be anesthetized first? A. Class Ib fibers B. A-delta fibers C. Gamma motor neurons D. Preganglionic autonomic axons E. C fibers
A
E. C fibers
14
Q
14. Your patient has suffered trauma to the spinal cord. During a period of spinal shock, what might you expect to observe in the patient? A. Hyperactive reflexes below the lesion B. Flaccid weakness below the lesion C. A spastic bladder D. A clasp knife reflex E. A Babinski sign
A
B. Flaccid weakness below the lesion
A patient with an initial period of spinal shock after spinal cord trauma, has flaccid paralysis below the lesion is replaced by a spastic weakness and other signs associated with a lesion of axons of UMNs (choices A, D and E) and a spastic bladder (choice C)
15
Q
- A tumor is beginning to compress the right side of the spinal cord at the C3 spinal cord segment and is impinging on the corticospinal and spinothalamic tracts. What might you expect to observe first in the patient?
A. Alteration of pain and temperature sensations from the left upper limb
B. Alteration of pain and temperature sensations from the left lower limb
C. Spastic weakness of the left upper limb
D. Spastic weakness of the left lower limb
E. Bilateral loss of pain and temperature sensations from sacral dermatomes
A
B. Alteration of pain and temperature sensations from the left lower limb
The crossed pain and temperature information from sacral and lumbar dermatomes is conveyed by laterally placed spinothalmic axons at cervical spinal cord levels and is the first of the choices given to be compressed by the tumor.
16
Q
- Which of the following diseases or lesions is incorrectly matched with a location where neuronal cell bodies might show degeneration or retrograde changes as a result of the disease process?
A. Tabes dorsalis/neurons in dorsal root ganglia
B. Poliomyelitis/neurons in lamina IX
C. Syringomyelia/neurons in lamina II
D. Brown-Séquard syndrome/neurons in dorsal root ganglia
E. Lesion of the dorsal spinocerebellar tract/Clarke’s nucleus
A
The answer is C. the crossing spinothalmic axons compressed by the syrinx arise from Laminae I and V. Laminae II neurons receive C fiber input and act to suppress pain.
17
Q
17. A Navy officer who recently retired from active duty overseas develops sharp pains in both legs, altered vibratory and pressure sensations in both legs, and an increased ten- dency to urinate. When he walks out to get the morning newspaper, his gait is un- steady. Strength is 5/5 in both lower limbs, but the Achilles tendon reflexes are graded as 1 bilaterally. Plantar stimulation yields a flexor response. An evaluation of cranial nerves reveals that the patient’s pupils constrict in response to a near stimulus but not in response to light. What might the patient have? A. Poliomyelitis B. Amyotrophic lateral sclerosis C. Tabes dorsalis D. Syringomyelia E. Vitamin B12 deficiency
A
The answer is C. Tabetic patients commonly have the 3 “P’s”, parathesia result from impaired vibration and position sense in the lower limbs. The radiating pain result from hypersensitivity of the small-diameter A-delta and class C pain and temperature dorsal roots. Polyuria or urine retention may also be evident. Patients with tabes dorsal is may also have Argyll Roberston pupils, which accommodate, but are unreactive, to light.
18
Q
- A Navy officer who recently retired from active duty overseas develops sharp pains in both legs, altered vibratory and pressure sensations in both legs, and an increased ten- dency to urinate. When he walks out to get the morning newspaper, his gait is un- steady. Strength is 5/5 in both lower limbs, but the Achilles tendon reflexes are graded as 1 bilaterally. Plantar stimulation yields a flexor response. An evaluation of cranial nerves reveals that the patient’s pupils constrict in response to a near stimulus but not in response to light. What else might your neurological exam of the patient in Question 17 reveal?
A. Wasting of lower limb muscles
B. Patient will sway back and forth with eyes closed
C. Horner’s syndrome
D. A central canal syrinx
E. Absence of abdominal and cremasteric reflexes
A
B. Patient will sway back and forth with eyes closed
19
Q
- You are a pathologist examining a spinal cord acquired during an autopsy. You sec- tion the cord and stain the sections with a myelin stain. Which of the following would you normally expect to observe in a stained section?
A. The least amount of staining in the white matter would be in Lissauer’s tract.
B. Dorsal and ventral roots would be unstained.
C. The class C fibers in the spinothalamic tracts would be unstained.
D. The lateral division of the dorsal root would be more heavily stained than the medial division of the dorsal root.
E. The axons in the fasciculus gracilis would be more heavily stained than those in the fasciculus cuneatus.
A
The answer is A. The least amount of staining in the white matter would be in Lissauer’s tract because this tract contains thinly myelinated A-delta fibers and class C fibers. Both dorsal and ventral roots would be stained, the medial division would stain more heavily than the lateral division, the dorsal columns would stain equally, and there are no class C fibers in the spinothalmic tracts.
20
Q
- A middle-aged man develops motor weakness in both the upper and lower limbs. The thenar eminences of both hands appear to have atrophied, and the biceps and triceps tendon reflexes are diminished. In the weak lower limbs, the muscle stretch reflexes are brisk. There are no sensory deficits. Which of the following conclusions might be made?
A. The patient may have suffered from an occlusion of the anterior spinal artery
at cervical spinal cord levels.
B. The patient has Brown-Séquard syndrome.
C. The patient has Werdnig-Hoffmann syndrome.
D. The patient has Guillain-Barré syndrome.
E. The patient has amyotrophic lateral sclerosis.
A
E. The patient has amyotrophic lateral sclerosis.
21
Q
MATCHING PROBLEMS Questions 21–30: Fiber match Match the following fiber types with their function or descriptive feature. Choices (each choice may be used once, more than once, or not at all): A. A-delta fibers B. A-beta fibers C. C fibers D. Ia fibers E. Gamma motor neurons F. Alpha motor neurons G. Preganglionic autonomic axons H. Postganglionic autonomic axons I. More than one choice in A–H is correct 21. Fibers in a dorsal root that are most susceptible to anesthesia.
A
C. C fibers
22
Q
MATCHING PROBLEMS Questions 21–30: Fiber match Match the following fiber types with their function or descriptive feature. Choices (each choice may be used once, more than once, or not at all): A. A-delta fibers B. A-beta fibers C. C fibers D. Ia fibers E. Gamma motor neurons F. Alpha motor neurons G. Preganglionic autonomic axons H. Postganglionic autonomic axons I. More than one choice in A–H is correct 22. Fibers associated with the modalities of burning pain and warmth.
A
C. C fibers
23
Q
MATCHING PROBLEMS Questions 21–30: Fiber match Match the following fiber types with their function or descriptive feature. Choices (each choice may be used once, more than once, or not at all): A. A-delta fibers B. A-beta fibers C. C fibers D. Ia fibers E. Gamma motor neurons F. Alpha motor neurons G. Preganglionic autonomic axons H. Postganglionic autonomic axons I. More than one choice in A–H is correct 23. Fibers that make muscle spindles more sensitive to stretch.
A
E. Gamma motor neurons
