Unit 5 Electrical Stimulation for Pain Flashcards
(41 cards)
What are the Charateristics of Acute Pain?
- Tissue damage, trauma, or infection
- Last less than 12 weeks (3 months)
- Sharp and easy to locate
- Acute deep-tissue pain from muscles, joints, or viscera can be diffuse and difficult to locate
What are the characteristics of Chronic Pain?
- 3 to 6 months or pain that persist beyond the normal time expected to heal injured tissues
- Central Sensitization, or the amplification of neural signaling with the CNS
- Dull, burning sensation
- Associated with physical, emotional, social and financial disability
Nociceptive Afferents
What are the Characteristics of A-delta Fibers?
- High threshold
- Myelinated
- Fast conducting (5-30 m/sec)
- Responds to high intensity heat, cold, and mechanical stimuli
- Generates fast/first pain with withdraw refelxes and sensations
- Associated with the precise location of noxious stimuli on the body
Nociceptor Afferents
What are the Characteristics of C-Fiber?
- High Threshold
- Unmyelinated
- Slow Conducting (0.5-2 m/sec)
- Responds to high intensity heat, cold, mechanical and chemical stimuli (polymodal)
- Generates slow/seconds pain sensations
- Assocaited with the prevention of further tissue damage
What is the Frequency for Transcutaneous Electrical Nerve Stimulation (TENS)?
- Low Frequeny: 1 to 120 Hz
What is the frequency of Interferential Current (IFC)?
- Median Frequency: 4000 Hz - 4100 Hz is the most common
With TENS, what are the different Modulation Parameters?
- C - Continuous: This set of therapy current remains constant for the duration of the therapy session
- B - Burst Mode: Short electrical pulses are generated, with intervals
- M - Modulation Mode: This set duration of the pulse width is slowly decreased and increased from the set
What are the 2 most common waveforms for TENS?
- Biphasic Symmetrical Pulse Current
- Asymmetrical Bophasic Balanced Pulsed Current
Modes of TENS
What are the Characteristics of Conventional TENS?
- Low Intensity = Comfortable tingling sensation
- High Frequency = 80 to 110 Hz
- Short Pulse Duration = 50 to 100 usec
Modes of TENS
What are the Characteristics for Acupuncture-Like TENS?
- High Intensity = Muslce Contraction
- Low Frequency = Less than 10 Hz
- Long Pulse Duration = 200 usec
Modes of TENS
What are the Characteristics of Burst Train TENS?
This is a combination of Conventional and Acupuncture-Like TENS
- Intensity = Produces muscle contraction
- High Frequency trains of pulse = 100 Hz
- Low-burst Frequency = Less than 10 Hz
Modes of TENS
What are the Characteristics of Brief Intense TENS?
- Intensity = High but tolerable
- High Frequency = 100 to150 Hz
- Long Pulse Duration = 150 to 250 Hz usec
What are the Common Parameters used for Pain Control with Conventional TENS?
- Frequency = 10 - 250 Hz
- Pulse Duration = ≤ 100 usec
- Amplitude/Intensity = Sensory Level
What are the Common Parameters used for Pain Control with Acupuncture-Like TENS?
- Frequency = < 10 Hz (1-4 Hz)
- Pulse Duration = 150 - 200 usec
- Amplitude/Intensity = Motor Level
What are the Common Parameters used for Pain Control with Burst Train TENS?
- Frequency = 100 Hz, delivered at 2 Hz
- Pulse Duration = 150 - 200 usec
- Amplitude/Intensity = Motor Level
What are the Common Parameters used for Pain Control with Brief, Intense TENS?
- Frequency = 100 -150 Hz
- Pulse Duration = 150 - 200 usec
- Amplitude/Intensity = Noxious Level
What are Commonly used Parameters with Conventional TENS with Acute Conditions?
- Waveform = Mono- or Biphasic pulsed current
- Pulse Frequency = 100-150 Hz
- Pulse Duration = 50 -80 usec
- Amplitude = mA to Maximum comfortable perception (or paresthesia). No or barely visible motor activity
- Duration = 20 - 30 min (Longer if Used During Activity)
What are Commonly used Parameters with Amplitude-Like TENS with Chronic Conditions?
- Waveform = Mono- or Biphasic pulsed current
- Pulse Frequency = 2 - 10 Hz
- Pulse Duration = 150 - 300 usec
- Amplitude = mA to visible muscle twitches
- Duration = 20 - 45 min
What is the Gate Control Theory?
Selective stimulation of the Large-diameter afferent fibers (A-beta) can result in a gating, or blocking, or noxious afferent input from small-diameter unmyelinated nopciceptive C-fibers and small myelinated A-delta fibers at the level of the Spinal Cord
Differentiation of Mixed Peripheral Nerve
What is the Function of A-Beta fibers? What is the diameter?
Touch and Pressure
- 5-12 um
This Activates Substantia Gelatinosa neurons
Differentiation of Mixed Peripheral Nerve
What is the Function of A-Delta fibers? What is the diameter?
Pain and Temperature
- 2-5 um
This Inhibits Substantia Geltinosa neurons
Differentiation of Mixed Peripheral Nerve
What is the Function of Dorsal Root (Type C) fibers? What is the diameter?
Pain
- 0.4 - 1.2 um
This Inhibits Substantia Geltinosa neurons
What is the Analgesic Mechanisms of Low-Frequency TENS?
Low-Frequency TENS (Less than 10Hz) triggers descending inhibatory pathways that include the ventrolateral periaqueductal gray (PAG) that sends projections to the rostal ventromedial medulla (RVM), which then projects to the spinal cord
What is the Analgesic Mechanisms of High-Frequency TENS?
- Increases the conentration of B-endorphins in the bloodsteam, CSF, and methinine encephalin in the CSF in human subjects
- Reduces glutamate and aspartate concentrations in the spinal cord dorsal horn by activating opioid (delta) receptors