Electroanalgesia

Question 1

What does the Walla and Melzak Gate control theory state?

Answer 1

Wall and Melzak Gate Control theory - stimulation of large myelinated afferents with high frequency stimulation to “block” pain input

Question 2

What does low frequency stimulation stimulated the release of? What type of “effect” does it have?

Answer 2

Stimulation of release of endogenous opiates ( endorphins and enkephalins) with low frequency stimulation; Acupuncture effect

Question 3

What type of current is the TENS unit?

Answer 3

Pulsed current waveforms, often asymmetrical biphasic, unlike NMES which symmetrical biphasic

Question 4

Name 4 indicationrs for using Electroanalgesia?

Answer 4

1. acute and chronic pain syndromes - musculoskeletal , neurological pain
2. post operative pain
3. labor and delivery pain
4. prior to painful procedures

Question 5

Name 8 contraindications for using electroanalgesia

Answer 5

1. demand type cardiac pacemakers or other implanted stimulating devices
2. over eyes
3. over the carotid sinus
4. over the chest in the presence of cardiac dysfunction
5. in the presence of seizure disorders, avoid the head and neck area
6. with patients with cognitive impairment
7. over open wounds or compromised skin including friable skin
8. over areas in which movement is contraindicated if stimulating in a mode which creates visible muscle contractions

Question 6

Name 1 precaution for electranalgesia

Answer 6

pregnancy - can use for labor pain

Question 7

Name 2 types of modes for the TENS unit

Answer 7

1) Sensory-level mode

2) Motor-level mode

Question 8

Which TENS mode is high rate, conventional?

Answer 8

Sensory-level mode

Question 9

Which TENS mode is low rate, acupunture-like?

Answer 9

Motor-level mode

Question 10

For TENS unit, what is the main goal for sensory-level mode?

Answer 10

Stimulate large A sensory afferents

Question 11

What is the frequency used for sensory level mode? What is the most common?

Answer 11

50-200 pps, 100-150 is most common

Question 12

TENS-Where do you stimulate over?

Answer 12

Usually stimulate directly over the site or over anatomically related sites such as dermatomes , spinal cord root levels

Question 13

TENS-Electrodes can be placed over __ or “__” pain

Answer 13

Electrodes can be place over pain or “sandwiching” pain

Question 14

TENS unit-What is the goal of the motor-level mode?

Answer 14

Stimulate small un-myelinated A delta and C fibers along with motor efferents to stimulate muscles rhythmically

Question 15

TENS-What is the pulse duration and frequency fo the motor-level mode?

Answer 15

Pulse duration -> 100-200 microsec
Frequency -> very dependent on type of motor stimulation, but can be 2-10 pps with amplitude high enough to get a visible but not tetanic contraction

Question 16

TENS-What is the pulse duration for sensory-level mode?

Answer 16

20-100 micro sec

Question 17

TENS-Motor-level mode: What is burst (of pulse trains) mode (burst modulated pulsed currents)?

Answer 17

creates bursts of pulses at low repetitions (2 bursts per second)

Question 18

What type of waveform does IFC (interferential current) use?

Answer 18

sinusoidal polyphasic AC waveforms

Question 19

What are the 2 indications for IFC?

Answer 19

1) Electroanalgesia

2) Muscle stimulation (different parameters)

Question 20

What are the two frequencies usually used for IFC? What is it known as?

Answer 20

4000-5000 Hz to create an interference freq., known as beat freq.
Example:
Channel 1 - 4100 Hz
Channel 2 - 4000 Hz
Beat frequency - 100 Hz (this is the working frequency or the beat frequency )

Question 21

Name the 3 contraindications for IFC

Answer 21

1) Over metallic implants
2) Over excessive hair
3) Severe cardiopathies

Question 22

What type of electrode technique is used in IFC?

Answer 22

Quadripolar electrode technique - 4 crossed electrodes (2 electrodes on each of 2 channels) - the interference current is generated in the body

Question 23

In IFC, what does vector scan mean?

Answer 23

• amplitude of current is varied which increases the field
• can only be done with the quadripolar technique
• current is felt to move among and between the electrodes

Question 24

In IFC, name the 2 different types of beat frequencies

Answer 24

1. variable (sweep) - varies within a range (e.g. 1-15 bps, 80-150 bps)
2. constant - set at one unchanging beat frequency

Question 25

In IFC, the modes of application is similar to what? Name 3 how they are similar.

Answer 25

Modes of Application similar to TENS - conventional, acupuncture-like , or burst (sensory is most common)