Chapter 7 Workbook Questions

Question 1

Exerting pressure on the skin with a monofilament

Using this test method, what type of perception is being tested?

Answer 1

Tactile threshold

Question 2

Gentle poking with a pin, interspersed with light touches with the blunt end of the pin

Using this test method, what type of perception is being tested?

Answer 2

Sharp, fast pain

Question 3

Light touching of two points on the skin using smaller distances between the points until the points cannot be distinguished as separate points

Using this test method, what type of perception is being tested?

Answer 3

Two-point discrimination

Question 4

Light touching of both sides of the body simultaneously

Using this test method, what type of perception is being tested?

Answer 4

Bilateral simultaneous touch

Question 5

Drawing a line (using a dull point) on the patient’s skin

Using this test method, what type of perception is being tested?

Answer 5

Directional cutaneous kinesthesia

Question 6

Name the test that applies electrical stimulation to the skin over a peripheral nerve and then records the resulting electrical activity from the skin over the upper cervical region or from the scalp over the primary somatosensory cortex.

Answer 6

Applying electrical stimulation to the skin over a peripheral nerve and then recording the resulting electrical activity from the skin over the upper cervical region or from the scalp over the primary somatosensory cortex measures somatosensory-evoked potentials.

Question 7

Name the test that uses electrical stimulation of the skin over a peripheral nerve and then records the electrical activity from the skin over another point along the same peripheral nerve.

Answer 7

Electrically stimulating the skin over a peripheral nerve and then recording the electrical activity at another point along the same peripheral nerve measures nerve conduction velocity.

Question 8

Why does peripheral demyelination often affect proprioception and vibratory sense more severely than temperature discrimination?

Answer 8

Peripheral demyelination most severely affects the large diameter, heavily myelinated axons (Ia, Ib, II), resulting in diminished or absent proprioception and vibratory sense.

Question 9

Painful eruptions occur on the skin in a unilateral single-dermatome distribution.

What is the most likely cause of the this dysfunction?

Answer 9

Varicella zoster

Question 10

All sensations (except proprioception from the face) are lost from the right side of the face and body. All sensations are intact on the left side of the face and body.

What is the most likely cause of the this dysfunction?

Answer 10

Lesion in the left posterolateral region of the rostral pons or the midbrain

Question 11

All sensations bilaterally are completely lost below the L2 dermatome. (Sensation in the L1 dermatome is intact, and sensation is impaired in the L2 dermatome.)

What is the most likely cause of the this dysfunction?

Answer 11

Complete transection of the spinal cord

Question 12

Pain and temperature sensation are lost from the left side of the face, combined with the loss of pain and temperature sensation from the right side of the body; all other sensations remain intact.

What is the most likely cause of the this dysfunction?

Answer 12

Lesion in the left posterolateral medulla or lower pons

Question 13

Conscious proprioception, two-point discrimination, and vibration sense are lost bilaterally below the T10 dermatome; all other sensations remain intact.

What is the most likely cause of the this dysfunction?

Answer 13

Lesion to the dorsal column of the spinal cord

Question 14

Sensory extinction is the:
A. Inability to recognize any sensations consciously
B. Loss of conscious proprioception
C. Same as astereognosis
D. Awareness of stimuli on only one side of the body when both sides of the body are simultaneously stimulated
E. Inability to localize a pinprick on one side of the body

Answer 14

D: In cases of sensory extinction (also called sensory inattention), the loss of sensation is only evident when symmetrical body parts are tested bilaterally.

Question 15

The role of enkephalins in the spinal cord is:
A. To decrease release of substance P from the primary afferent
B. To hyperpolarize spinal interneurons in the pain pathway
C. To stimulate non-nociceptive interneurons of the dorsal horn
D. A and B
E. A, B, and C

Answer 15

D: Enkephalins bind with receptor sites on both the primary afferents and interneurons of the pain system. Enkephalin binding depresses the release of substance P and hyperpolarizes the interneurons, thus inhibiting the transmission of nociceptive signals.

Question 16

When the raphespinal tract is active, which neurotransmitter is released at the axon terminal in the dorsal horn of the spinal cord?
	A. Norepinephrine
	B. Gamma-aminobutyric acid (GABA)
	C. Dopamine
	D. Substance P
	E. Serotonin

Answer 16

E: When the rostral ventromedial medulla is electrically stimulated, the raphespinal tracts (i.e., the axons projecting to the spinal cord) release the neurotransmitter, serotonin, in the dorsal horn, inhibiting the tract neurons via enkephalin interneurons and thus interfering with the transmission of nociceptive messages.

Question 17

Which of the following is(are) part of the fast-descending neuronal system for pain inhibition?
	A. Rostral ventromedial medulla
	B. Periaqueductal gray
	C. Locus coeruleus
	D. A, B, and C
	E. None of the above

Answer 17

D: The brainstem areas that provide intrinsic antinociception form a neuronal descending system, arising in the following: rostral ventromedial medulla, periaqueductal gray (PAG) in the midbrain, and locus coeruleus in the pons.

Question 18

The locus coeruleus is located in which one of the following?
	A. Spinal cord dorsal horn
	B. Medulla
	C. Pons
	D. Midbrain
	E. Cerebral cortex

Answer 18

C: The locus coeruleus is located in the pons.

Question 19

Nonnarcotic analgesics, which decrease the synthesis of prostaglandins

Where is the action of this method of pain inhibition located?

Answer 19

Periphery

Question 20

Stimulation of opioid receptors and descending inhibition

Where is the action of this method of pain inhibition located?

Answer 20

Periaqueductal gray, raphe nuclei, and locus coeruleus

Question 21

Hormonal regulation

Where is the action of this method of pain inhibition located?

Answer 21

Hypothalamus, pituitary gland, and adrenal medulla

Question 22

Inhibitory interneurons, which release enkephalins or dynorphins

Where is the action of this method of pain inhibition located?

Answer 22

Dorsal horn of the spinal cord

Question 23

Expectations, distraction, placebos, and excitement

Where is the action of this method of pain inhibition located?

Answer 23

Cerebral cortex

Question 24

Why is the identification of referred pain important in physical therapy practice?

Answer 24

Identifying referred pain is important in physical therapy to ensure appropriate treatment, since referred pain is most often associated with inflammation or irritation of visceral tissue. The patient must be directed to the appropriate practitioner for diagnosis and treatment.

Question 25

Why is distinguishing between acute and chronic pain essential?

Answer 25

Therapists must distinguish between acute and chronic pain because the causes of acute and chronic pain are different, thereby requiring different treatment approaches. Modalities and soft-tissue treatments associated with acute pain are often not effective or appropriate for the treatment of chronic pain.

Question 26

How is a quick screening for somatosensory impairments performed?

Answer 26

For a quick screening, proprioception and vibration are tested in the fingers and toes, and pinprick sensation is tested on the limbs, trunk, and face.

Question 27

What are the important limitations of sensory testing?

Answer 27

Somatosensory evaluations require conscious awareness and cognition and thus do not evaluate how somatosensation is used in movement.

Question 28

What signs and/or symptoms indicate that a thorough somatosensory evaluation should be performed?

Answer 28

Complaints of abnormal sensations or sensory loss, skin lesions that are not painful, and/or localized weakness or atrophy indicate that thorough sensory testing is required.

Question 29

What precautions are essential to ensure valid results of somatosensory testing?

Answer 29

The subject must be prevented from seeing the stimuli during testing, the subject must understand the testing and its purpose, and prediction about stimuli must be prevented by irregular timing of stimuli and by varying the stimuli (e.g., randomly presenting dull vs. sharp stimuli).

Question 30

How is a sensory nerve conduction study performed?

Answer 30

An electrical current delivered to a surface electrode stimulates the distal distribution of a peripheral nerve. Surface electrodes placed along the course of the peripheral nerve record the electrical potential evoked in the nerve.

Question 31

A patient describes sponatneous tingling and prickling in both feet. What clinical term corresponds to this description?

Answer 31

Spontaneous tingling and prickling indicate paresthesia.

Question 32

How can a clinician distinguish between sensory ataxia and cerebellar ataxia?

Answer 32

In sensory ataxia, conscious proprioception and vibratory sensation are impaired, and balance when standing with the feet together is worse with the eyes closed than when the eyes are open. In cerebellar ataxia, conscious proprioception and vibratory sensation are normal, and balance is poor when standing regardless of whether the eyes are open or closed.

Question 33

Which types of somatosensory information are usually most impaired by demyelination? why?

Answer 33

Conscious proprioception and vibratory sense typically are most impaired by demyelination, because the information travels in large-diameter axons that require heavy myelination.

Question 34

What sensory and motor losses occur with left hemisection of the spinal cord? Name the resulting syndrome

Answer 34

A left hemisection of the spinal cord causes loss of voluntary motor control combined with loss of position, vibration, and discriminative touch sensation below the level of the lesion on the left side of the body. Pain and temperature information is lost from the right side of the body, one or two dermatomes below the level of the lesion, because collaterals of the first-order proximal axons ascend and descend a few levels in the dorsolateral column (zone of Lissauer). This combination of signs indicates Brown-Séquard syndrome.

Question 35

what is varicella zoster?

Answer 35

Varicella-zoster is a viral infection of the dorsal root ganglion that causes inflammation of the sensory nerves and painful eruptions on the skin. It usually is limited to a single dermatome.

Question 36

Describe the sensory loss associated with a lesion in the left postlateral lower pons

Answer 36

A lesion in the left posterolateral lower pons would cause loss of pain and temperature information from the left face and the right side of the body. This pattern arises because nociceptive information from the left face travels in the left posterolateral pons, and nociceptive information from the body has crossed midline in the spinal cord.

Question 37

What is sensory extinction?

Answer 37

Sensory extinction is lack of awareness of the stimulus presented on one side of the body when stimuli are provided simultaneously to both sides of the body. If a stimulus is presented only on the affected side, the person is aware of the stimulus.

Question 38

How does the counterirritant theory explain the inhibition of pain messages caused by application of pressure to an injured finger?

Answer 38

According to the counterirritant theory, pressure on an injured finger stimulates mechanoreceptor afferents that facilitate enkephalin interneurons. Enkephalin released by the interneurons activates receptors on primary nociceptive afferents and interneurons that decrease the release of substance P by primary afferents and that hyperpolarize interneurons in the nociceptive pathway. Both these actions decrease the transmission of nociceptive information.

Question 39

An inability to sleep due to nociception is an example of what aspect of the pain experience: discriminative motivational-affective, or cognitive-evaluative?

Answer 39

The inability to sleep is part of the motivational/affective aspect of the pain experience. Nociception increases arousal, and thus inhibits sleep.

Question 40

List the origins of the three supraspinal analgesic symptoms

Answer 40

The three supraspinal antinociceptive systems originate in the rostral ventromedial medulla, periaqueductal gray, and locus coeruleus.

Question 41

How do narcotics induce the effects of the supraspinal analgesics?

Answer 41

Narcotics activate opiate receptors in the rostral ventromedial medulla, periaqueductal gray, and dorsal horn of the spinal cord. This activation inhibits nociceptive information by direct and interneuronal inhibition of neurons in the nociceptive pathways, decreasing transmission of nociceptive information.

Question 42

Name the levels of the antinociception model

Answer 42

I: Peripheral 
II: Dorsal Horn
III: Neuronal Descending
IV: Hormonal
V: Corticol