Electrical Currents for Pain Control Flashcards
What is pain?
an experience based on a complex interaction of physical and psychological processes. It has been defined as an unpleasant sensory and emotional experience associated with actual or potential tissue damage or described in terms of such damage
What are the 2 types of pain according to time?
acute and chronic
What is acute pain described as?
The response to immediate noxious stimulus
Acute pain can last for how long?
up to 6 months
When is pain considered chronic?
When it persists past what is considered “normal”
Chronic pain results in a decreased production of what?
opiods
Nociceptive receptors respond to what?
noxious mechanical, chemical, or thermal stimuli associated with ongoing tissue damage
What are some examples of nociceptive pain?
- arthritis
- ischemia
- cancer
- chronic pancreatiti
What does neuropathic pain result from?
PNS or CNS dysfunction without ongoing tissue damage
What is a common characteristic of chronic pain patients?
they are sleep deprived
What is referred pain?
Pain felt at a location distant from its source
What are the 3 things in which pain can be referred from?
- A nerve to its area of innervation
- One area to another derived from the same dermatome
- One area to another derived from the same embryonic segment
Compare and contrast cutaneous and visceral pain sensations
Cutaneous pain is sharp and well localized, whereas visceral pain is experienced as a deep ache
Where do the liver and gallbladder refer pain to?
The right shoulder and neck
Where do the lung and diaphragm refer pain to?
The left shoulder and neck
Describe the path pain takes to the cerebral cortex
- nociceptive receptors transmits signals to A-delta and unmyelinated C fibers
- these nociceptors (when activated) release neuropeptides which convert the original stimulus into electrical activity in the form of action potentials in a process called transduction
- an action potential propagates along the afferent nerves toward the spinal cord
- this afferent neuron synapses with a second order neuron in the dorsal horn of the spinal cord
- if the painful stimulus is not able to be inhibited, the stimulus travels to the thalamus, then the cortex
What can abnormal sympathetic activation result in?
excessive vasomotor or sweating reactions known as Complex Regional Pain Syndrome
What are the sensory changes associated with Complex Regional Pain Syndrome?
- allodynia (pain provocation to normally painless stimulus)
- hypo-/hyperalgesia (decrease/increase sensitivity to pain)
- hypo-/hyperesthesia (decrease/increase sensitivity to touch)
What are the tropic changes associated with Complex Regional Pain Syndrome?
skin, hair, and nail changes
What are the autonomic changes associated with Complex Regional Pain Syndrome?
- swelling/edema
- sweating
What are the motor changes associated with Complex Regional Pain Syndrome?
- weakness
- contractures
- atrophy
What are the 2 systems in which pain can be modulated?
- Gate control theory of pain
- Endogenous opioid system
What are specifics of pain a PT must assess?
- Location
- Quality
- Severity
- Timing
- Factors that make it better or worse
- The setting in which it occurs
- Associated manifestations
- How it affects a person’s activities, function, and participation
How does conventional TENS modulate pain?
It is worn at all times to control pain through sensory modulation
Conventional TENS is characterized by ___-duration pulse and ___ frequency
short (50-80 μs)
high (100-150 pps)
What should the amplitude be adjusted to for conventional TENS?
Adjusted to produce comfortable sensation without a muscle contraction
What nerve fibers does conventional TENS activate?
A-beta sensory nerves
How does low-rate TENS modulate pain?
It induces the secretion of endorphines and opiods and it may also elicit a motor response
Low-rate TENS is characterized by ___-duration pulse and ___ frequency
long (100-300 μs)
low (2-10 pps)
What should the amplitude be adjusted to for low-rate TENS?
Strong enough to elicit a small muscle contraction
What nerve fibers does low-rate TENS activate?
motor and A-delta nociceptive nerves
How long after treatment is low-rate TENS effective?
4-5 hours
Low-rate TENS application should be no longer than 45 minutes, why?
to avoid delayed-onset muscle soreness
Why is e-stim used after ACL reconstruction or TKA surgery?
to increase strength
Why is e-stim used in osteoarthritis, RA, and patellofemoral syndrome
to reduce pain and swelling
Burst Mode TENS utilizes the same mechanism as ___-rate TENS
low
Induces the secretion of endorphines and opiods
How does electroacupuncture work?
Electrodes are placed on the skin overlying acupuncture points to promote endorphin release
What type of waveform can be used for pain modulation?
Pulse-biphasic or interferential
What must the carrier frequency be in order to do IFC?
2500 Hz
