Chapter 35

A neurologic assessment of the somatosensory function of the body is often necessary for diagnostic information. How is this assessment done?

Testing the integrity of spinal segmental nerves

Using surgery to relieve severe, intractable pain has been successful to a degree. What can surgery be used for when a person is in pain?

block transmission of phantom limb pain

The purpose of acute pain is to serve as a ---- system.

warning

---- sensations is discriminated by 3 types of receptors: cold receptors, warmth receptors, and pain receptors.

Thermal

Guarding

protective rigidity reflex

In describing the ideal analgesic, what factors would be included?

- inexpensive - have minimal adverse effects - effective

What is phantom limb, and what are some of the theories postulated to explain its presence?

- is that the end of a regenerating nerve becomes trapped in the scar tissue of the amputation site - proposed that these afferents show increased sensitivity to innocuous mechanical stimuli and to sympathetic activity and circulating catecholamines - moves the source of phantom limb pain to the spinal cord, suggesting that the pain is due to the spontaneous firing spinal cord neurons that have lost their normal sensory input from the body - the pain is caused by changes in the flow of signals through somatosensory areas of the brain

It is often necessary to assess a client's pain. What factors would you assess when assessing pain?

- nature and severity of pain - location and radiation of pain

What are the 3 orders of sensory system organization?

-1st order: transmit sensory information from the periphery to the CNS -2nd order: communicate with various reflex networks and sensory pathways in the spinal cord and travel directly to the thalamus - 3rd order: relay information from the thalamus to the cerebral cortex

What are the types of sensory information that can be perceived by our sensory receptors?

-discriminative touch: required to identify the size and shape of objects and their movement across the skin - temperature sensation - sense of movement of the limbs and joints of the body - nociception or pain

The ability to discriminate the location of a somesthetic stimulus is called ---- and is based on the sensory field in a dermatome innervated by an afferent neuron.

acuity

What type of information can be obtained from a single pinprick to the bottom of a patient's foot?

A pinpoint pressed against the skin of the sole of the foot that results in a withdrawal reflex and a complaint of skin pain confirms the functional integrity of the afferent terminals in the skin, the entire pathway through the peripheral nerves of the foot, leg, and thigh to the sacral (S1) dorsal root ganglion, and through the dorsal root into the spinal cord segment.

An 82-year-old woman is brought to the emergency department by ambulance from a local nursing home. The report from the accompanying staff member is that the client suffers from a physiologic dementia, and that 2 days ago she suffered a fall in the bathroom. The client denies pain but has been restless and agitate since the fall, and today she will not use her right arm. A. The caregiver asks the nurse how the health care team is going to assess this client's pain as the client cannot give them nay accurate information. What is the nurse's best response? B. The client is diagnosed with a fractured right ulna. She is taken to the operating room, where the arm is aligned and cast. When the client is ready for release back to the nursing home, the caregiver asks what can be done for the client's discomfort. What teaching would the nurse include at discharge?

A. It is difficult to assess pain and discomfort in someone suffering with dementia. B. Acetaminophen is the drug of choice to manage this client's discomfort. You can also place ice on the cast at the point of fracture for 20 minutes, each hour, to help reduce the discomfort.

What is known about the pathology of pain during migrainous headache?

Activation of the trigeminal sensory fibers may lead to the release of neuropeptides, causing painful neurogenic inflammation within the meningeal vasculature characterized by plasma protein extravasation, vasodilation, and mast cell degranulation.

---- is the absence of pain on noxious stimulation or the relief of pain without loss of consciousness.

Analgesia

Nociceptive stimulation that activates ---- ---- can cause a response known as neurogenic inflammation that produces vasodilation and an increased release of chemical mediators to which nociceptors respond.

C-fibers

---- headache is a type of primary neurovascular headache that typically includes severe, unrelenting, unilateral pain located, in order of decreasing frequency, in the orbital, retro-orbital, temporal, supraorbital, and infraorbital region.

Cluster

---- pain arises from superficial structures, such as the skin and subcutaneous tissues.

Cutaneous

---- ---- pain originates in deep body structures, such as the periosteum, muscles, tendons, joints, and blood vessels.

Deep somatic

Which of the following neurons transmits sensory information from the periphery to the CNS.

Dorsal root ganglion neurons

---- are endogenous opioid peptides that blunt pain sensations.

Endorphins

---- somatic afferent neurons have branches with widespread distribution throughout the body and with many distinct types of receptors that result in sensations such as pain, touch, and temperature.

General

One of the neurotransmitters between the nociceptive neurons and the dorsal horn neurons is a major excitatory neurotransmitter. What is this neurotransmitter?

Glutamate

In many sports injuries the athlete may be instructed to place heat on the injured area. What is the effect on pain originating from the injury?

Heat dilates blood vessels and increases local blood flow, which increases collagen extensibility. With there being an increase in local circulation can reduce the level of nociceptive stimulation by reducing local ischemia caused by muscle spasm or tension. It could also trigger the release of endogenous opioids.

What are the differences and similarities between migraine headaches with aura and migraine headaches without aura?

Migraine without aura is a pulsatile, throbbing, unilateral headache that typically lasts 1 to 2 days and is aggravated by routine physical activity.

---- is characterized by severe, brief, often repetitive attacks of lightning-like or throbbing pain.

Neuralgia

---- pain arises from direct injury or dysfunction of the sensory axons of peripheral or central nerves

Neurpathic

---- stimuli are objectively defined as stimuli of such intensity that they cause or are close to causing tissue damage.

Nociceptive

Which of the following will conduct injurious stimuli to alert the body of potential damage?

Nociceptors

Which tract in the spinal cord conducts the diffuse, dull, aching sensations that are associated with chronic and visceral pain?

Paleospinothalamic tract

When testing nociceptive stimuli to elicit a withdrawal reflex in the body, what stimuli are commonly used?

Pressure from a sharp object

How can the phenomena of referred pain be explained?

Referred pain is pain that is perceived at a site different from its point of origin but innervated by the same spinal segment. It is hypothesized that visceral and somatic afferent neurons converge on the same dorsal horn projection neurons.

---- somatic afferent neurons sense position and movement of the body.

Special

What is the gate control theory of pain?

The internuncial neurons involved in the gating mechanism are activated by large-diameter, faster-propagating fibers that carry tactile information. The simultaneous firing of the large-diameter myelinated and unmyelinated pain fibers.

The receptive endings of different afferent neurons can initiate ---- ---- to many forms of energy at high energy levels, but they usually are highly tuned to be differentially sensitive to low levels of a particular energy type.

action potentials

Chronic pain is difficult to treat. Cancer, a common cause of chronic pain, has been especially addressed by the World Health Organization (WHO). What has WHO created to assist clinicians in choosing appropriate anagesics?

an analgesic ladder for pain control

An ---- drug is a medication that acts on the nervous system to decrease or eliminate pain without inducing loss of consciousness.

analgesic

The ---- pathways provide for transmission of sensory information such as pain, thermal sensations, crude touch, and pressure that does not require discrete localization of signal source or fine discrimination of intensity.

anterolateral

Merkel disks

are responsible for giving steady-state signals that allow for continuous determination of touch against the skin

Perception

awareness of the stimuli, localization and discrimination of their characteristics, and interpretation of their meaning

A severe type of headache that occurs more frequently in men than women and is described as having unrelenting, unilateral pain located most frequently in the orbit is called what?

cluster headache

Type A fibers

convey cutaneous pressure and touch sensations, cold sensation, mechanical pain, and heat pain

Type C fibers

convey warm-hot sensation and mechanical and chemical as well as heat- and cold-induced pain sensation

The region of the body wall that is supplied by a single pair of dorsal root ganglia is called a ----

dermatone

Free nerve endings

detect touch and pressure

The ---- pathway is used for the rapid transmission of sensory information such as discriminative touch.

discriminative

Meissner corpuscles

elongated encapsulated nerve ending that is present in nonhairy parts of the skin

When giving pain medicine for acute pain, health care workers are reluctant to provide much needed opioid pain medicine. What is the major concern of health care workers when providing opioid pain relief?

fear of addiction

Ruffini end organs

found in joint capsules

Primary ---- describes pain sensitivity that occurs directly in damaged tissues.

hyperalgesia

Somatosensory experience can be divided into ----, a term used for qualitative, subjective distinctions between sensations such as touch, heat, and pain.

modalities

Migraine headaches affect millions of people worldwide. What are first-line agents for the treatment of migraine headaches?

naproxen sodium and metoclopramide

The faster-conducting fibers in the ---- tract are associated mainly with the transmission of sharp-fast pain information to the thalamus.

neospinothalamic

Which of the following types of pain is characterized by severe, brief, often repetitive pain?

neuralgia

The ---- theory proposes that the brain contains a widely distributed neural network that contains somatosensory, limbic, and thalamocortical components.

neuromatrix

Attention, motivation, past experience, and the meaning of the situation can influence the individual's reaction to ----

pain

When a peripheral nerve is irritated enough, it becomes hypersensitive to the noxious stimuli, which results in increased painfulness or hyperalgesia. Health care professionals recognize both primary and secondary forms of hyperalgesia. What is primary hyperalgesia?

pain sensitivity that occurs directly in damaged tissues

The ---- tract is a slower-conducting, multisynaptic tract concerned with the diffuse, dull, aching, and unpleasant sensations that commonly are associated with chronic and visceral pain.

paleospinothalamic

Through research, it was found that electrical stimulation of the midbrain ---- ---- regions produced a state of anaglesia that lasted for many hours.

periaqueductal gray

Primary somatosensory cortex

receives primary sensory information by way of direct projections from the thalamus

Polymodal receptors

respond to mechanical, thermal, and chemical stimuli

Hyperpathia

sensory threshold is raised

The experience of pain depends on both ---- stimulation and ----

sensory; perception

The ---- system is designed to provide the CNS with information related to deep and superficial body structures as contrasted to special senses such as sight and hearing.

somatosensory

Pacinian corpuscles

stimulated by rapid movements of the tissues and adapts within a few hundredths of a second

Phantom limb pain is a little understood pain that is difficult to treat, even though the client is experiencing severe pain. What are the treatments for phantom limb pain?

sympathetic blocks and hypnosis

The ---- system, which relays sensory information regarding touch, pressure, and vibration, is considered the basic somatosensory system.

tactile

A common cause of head pain is ---- ---- syndrome.

temporomandibular joint

The most common type of headache is ---- headache.

tension-type

Somesthesia

the perception of tactual, proprioceptive, or gut sensations

Pain ---- and tolerance affect an individual's response to a painful stimulus.

threshold

Type A alpha fibers

transmit information about muscle length and tendon stretch

Type B fibers

transmit information from cutaneous and subcutaneous mechanoreceptors

Children feel pain just as much as adults do. What is the major principle in pain management in the pediatric population?

treat on individual basis and match analgesic agent with cause and level of pain

Somatosensory information from the face and cranial structures is transmitted by the ---- sensory neurons, which function in the same manner as the dorsal root ganglion neurons.

trigeminal

Hair follicle end organs

unmyelinated fibers entwined around most of the length of the hair follicle that detect movement on the surface of the body

General ---- afferent neurons have receptors on various visceral structures that sense fullness and discomfort

visceral