the method of afferent nerve fiber stimulation designed to control pain through various mechanisms ?
TENS
what type of current do TENS units use?
pulsed current of asymmetrical, biphasic, square/rectangular or triangular/spike waveform
nocioceptors receive noxious stimuli thru what kind of fibers?
A delta (acute)
C fibers (chronic)
pain stimuli then go where after they are received?
spinal cord
after the pain stimuli reach the spinal cord what are the next progressions?
spinal cord--substania gelinousa neurons in grey area--reticular formation--thalamus--somatosensory cortex
pain is based on an imbalance of excitatory and inhibitory input to the T cells located within the spinal cord
desribes what?
gait control theory of pain
excitatory input in gate controlled theory comes from what fibers?
A delta, C-fiber afferent fibers
inhibitory input in gate controlled theory comes from what fibers?
A-beta non-nocioceptive afferents
when the gate is open what happens?
excitatory is greater than inhibitory
= PAIN
the gate is closed what happens?
inhibitory is greater than excitatory
NO PAIN
morphine induced analgesia
describes what type of pain control?
endogenous opiate system
opiate receptors ____release of substance P from _____ fiber terminals and ______pain transmission
decrease
C-fiber
depress
what does substance P do?
excites pain transmitting neurons located in the spinal cord
what do chemicals like Beta endorphine do to opiate receptors?
inhibit pain
Sensory pain management specifics
mode of TENS:
current:
mechanism for action:
what it does to fibers:
conventional, modulation, SD
HVPC
gait theory
stimulate A beta afferent to inhibit T cells
Motor pain management specifics
mode of TENS:
current:
mechanism for action:
what it does to fibers:
low frequency, burst
HVPC
endorphins for analgesia
stimulates deeper afferent nerves which cause release of beat endorphine from hypothalamus and pituitary gland
nerve block pain management specifics:
mode of TENS:
what it does to fibers:
brief intense
decrease conduction along A delta and C fibers durng stimulation which blocks AP of nocioceptors
can produce an incrase of K which inhibits Na transport and conductance
sensory stimulation:
amplitude
phase/pulse duration
frequency
duration tx
duration of analgesia after tx
pins and needles/tingling
50-125 microsecs
50-110 pps
20-60 mins
short duration of analgesia
motor stimulation:
amplitude
phase/pulse duration
frequency
duration of tx
analgesia after tx
muscle twitch
200-500 microsecs
1-5 pps
30-60 mins
long last analgesia
noxious level:
amplitude
phase/pulse duration
frequency
duration of tx
analgeisa after tx
painful sensation
less than 1 msec
1-5 pps or less than 100 bps
few seconds to minutes
analgesia lasts long
nerve block:
amplitude
phase/pulse duration
frequency
duration of tx
analgesia after tx
maximum paresthesia
250 microsecs
110 pps
15 mins
short analgesia none to few mins
Contraindications of TENS (4)
pacemakers
pregnancy
over carotid sinus , laryngeal/pharyngeal muscles
while operating heavy machinery
advantages of conventional mode TENS
comfy
fast acting
used with acute and chronic
can use it 24 hours
disadvantages of conventional TENS
short acting analgeisa affect
based on chemical mechanism of action
adaptation to stimulus is common therefore you need to increase amplitude or pulse duration
advantages of modulation mode TENS
comfy
fast acting
used for acute and chronic
can use 24 hours
decreased nerve adaptation
disadvantages of modulation mode of TENS
analgesic effects are rarely felt after treatment has stopped
constant changing stimulation can be annoying
strength duration mode of TENS: mechanism
amplitude will decrease % while the pulse duration increases % to main a certain strength of stimulation
advantages of SD TENS
comfy
fast acting
used for acute/chronic conditions
can use for 24 hours
decreased nerve adaptation
disadvantages of SD TENS
analgesia is limited to time of stimulation
advantages of low frequency TENS
longer lasting analgesia following treatment due to the 2-6 hour half life of beta endorphine
adaptation to stimulus is slight, requiring only minimal adjustment of amplitude and pulse duration
disadvantages of low frequency TENS
motor response required to activate this mechanism--some patients may not get to this level
not good for very acute conditions
motor response may limit functional activities while undergoing stimulus
stimulation is decreased to 1 hour
onset of analgesia is delayed 20-30 mins
advantages of burst mode TENS
longer lasting analegisa due to the 2-6 hour half life of beta endorphine
adaptation to stimulus is slight
more comfortable than low frequency
disadvantages of burst mode TENS
motor response is required to activate this mechanism--some people can't get to that point
not good for very acute conditions
motor response may limit the functional activites of the pt during treatment
stimulation is limited to 1 hour
onset of analgesia is about 20-30 mins after treatments
advantages of nerve block TENS
comfy
very fast onset of analgesia
can be used on extremely acute conditions
disadvantages of TENS
fast return to normal sensation when tx is done
not effective for chronic pain because tx sessions are only 15 mins
treatment best when placed over superficial peripheral nerves
higher intensities can be annoying
the use of ultrasound and electrical stimulating currents in combination to provide analgesia and reduce the effectiveness of the pain-spasm cycle.
US and E-stim combo
what is the most common condition that US and e stim combo is used for?
myofascial trigger points
US:
frequency
1 MHz for deep structures
3 MHz for superficial structures
US:
duty cycle
20% pulsed for nonthermal effects
100% continuous for thermal effects
US:
Intensity
acute: less than .5 W/cm2
subacute .5-1.3 W/cm2
chronic 1.3-3.0 W/cm2
US indications:
soft tissue shortening
subacute/chronic conditions
can be used for muscle gaurding or trigger points
can be used for wound healing
Contraindications of US
decreased arterial circulation
bleeding
do not use over eyes or abdomen if pregnant
do not use if pt has cancer
E stim for chronic condition:
intensity-
frequency-
pulse width/duration-
local visible muscle contraction
1-4 Hz
200-500ms, wide pulse width
E stim for acute conditions:
intensity-
frequency-
pulse width/duration
comfortable sensation below motor stimulation level
50-110 Hz
50-125 ms, narrow pulse width
advantages of US and E-stim combo
increase efficacy of both
US can provide a theraml effect in addition to the analgesia of the e stim
can be used to treat a variety of conditions
disadvantages of US and E stim combo
not scientifically founded
TENS like device used to deliver electrical stimuli to accomplish a variety of therapeutic purposes. Different from other methods delievering e-stim because of the waveform of the current and the voltage of the generator
HVPC
high voltage pulsed current
waveform form shape characteristics
twin spike monophasic pulsed current
rise immediately, fall exponentially
phase duration of HVPC
50-100 microsecs
pulse duration of HVPC
up to 200 microsecs
duration of A beta fibers
20 microsecs
duration of A delta fibers
450 microsecs
duration of C fibers
1500 microsecs
fixed characteristics of HVPC that cannot be changed
voltage-
0-500 V other e stim uses mA
skin resistance less than 100,000 (upside down horsehoe looking symbol)
when current goes thru resistance voltage decreases and energy decreases
clinical uses of HVPC
pain modulation
tissue healing
muscle re-ed
edema control
muscle strengthening
HVPC frequency for:
sensory vs motor
sensory: 80-125 Hz
motor-1-5 Hz
HVPC intensity
sensory vs motor
0-500 V
comfortable sensation below motor threshold (for sensory level)
muscle twitch (motor)
HVPC dosage:
intensity
pulse duration
duration
treatment frequency
comfortable sensation below motor response (sensory) and muscle twitch (motor)
100-200 microsecs
30-60 mins
1-2x day
advantages of HVPC
short pulse duration-no electrochemical effects
high voltage-bypasses skin impedence
disadvantages of HVPC
short pulse duration
cannot stimulate denervated muscle
cannot perform iontophoresis
acupuncture, motor or trigger points, many of these points are located at the same anatomical site
specific points
most utilized, though not always placed at the appropriate source of pain, effective post surgery, placing electrodes close to incisions
painful region
placing electrodes according to _______can be a useful method of focusing on specific spinal levels
dermatomes
by placing electrodes beside specific vertebrae or between the spinous processes, localized vertebral column pain can be alleviated
spinal cord segment
some ______nerves such as ulnar nerve have superficial points that are readily accessible for stimulation (not to be confused with dermatomes)
peripheral nerves
directly stimulating the nerve plexus itself can be beneficial although the brachial plexus is the only one which can be stimulated superficially. other can be stimulated by percutaneous methods
nerve plexus
described as lines which have anatomical counterparts through which pain is transmitted. pathways may be useful when pain is diffuse and extensive
linear pathways
these methods use all the other guidelines but often employ multiple electrodes. examples include dual-channel placement, bilateral placement, contralateral placement etc
alternative methods
treatment technique that uses medium frequency currents
interferential current
2 channel stimulators producing a sinusoidal, symmetrical, alternating current at frequencies of several thousand cycles per second on each channel
interferential current
what are the common frequencies of 2 unmodulated sine waves? (IFC)
200-500 Hz
frequency of resultant amplitude IFC can be _____ or _____
constant or variable
modulation/beat frequency of IFC
varies from 0-1000bps
sensory nerve stimulation for IFC (frequency and phase duration)
frequency 4000 Hz
125msec phase duration
motor nerve stimulation for IFC (frequency and phase duration)
frequency 2000 HZ
250msec phase duration
Purposes of IFC
pain relief
deep tissue currents
increased blood flow to deeper tissues
reduces edema
decreases muscle spasm
How does IFC work?
2 currents cross
nerve fibers receive max stimulation
each beat is amplitude modulated
stimulated fibers do not accommodate
at greater than 50 bps and low amplitudes, pain relief is achieved in 2 ways
-stimulating large afferent fibers
-interfering with ascending transmission of pain impulses
with stimuli of constant amplitude and frequencies greater than 1000 Hz, successive stimuli prevent the nerve from repolarizing.. This temporary nerve member depolarization is known as _________.
Wedensky inhibition
What ist he effect of the Wedensky inhibition?
responsibile for the decreased sensation under the electrodes---only occurs with unmodulated current
reciprocal scanning of IFC through an arc of 45d. This allows the current to perfuse through a greater volume of tissue then if this option was not selected
Scanning
frequency modulation that prevents adaptation
sweeping
a mode in which the 2 currents are mixed within the machine to produce an amplitude-modulated frequency output. mode only uses 2 electrode
premodulation
0-10 bps is good for...?
amplitude enough to produce small pulsating muscle contractions, may relieve pain
30-50 bps is good for...?
results in tetany of the muscle, may be able to modulate the contractions, but may not be effective for muscle strengthening
greater than 50 bps is good for...?
low amplitudes, pain relief
advantages of IFC
low impedence when crossing the skin
targets deeper sites
more comfy low amplitude current delivered thru skin with higher amplitude delievered to deeper structures
disadvantages of IFC
current is highest directly under electrodes so patient may not be able to perceive the stimulation at the targest site
research is sparse
TENS is just effective
indications for IFC
pain relief
muscle exercise for
increased blood flow
muscle relaxation
edema reduction
relief of urinary stress incontinence
contraindications of IFC
pacemakers
pregnancy
stimulation over eyes, mucousal membranes
cardiac diseases
IFC for chronic pain:
frequency
sweep
time
intensity
frequency; 3-5 Hz
sweep: on
time: 20-30 mins
intensity: mild twitching
IFC for subacute pain
frequency
sweep
time
intensity
frequency: 1-150 Hz
sweep: on
time: 20-30 mins
intensity: sub contraction/pt comfort zone
IFC for acute pain-
frequency
sweep
time
intensity
frequency: 80-120 Hz
sweep: on
time: 20-30mins
intensity: sub contraction/pt comfort zone
IFC for hyper acute pain
frequency
sweep
time
intensity
frequency: greater than 1000 Hz (nerve block)
sweep: N/A
time: 8-10 mins
intensity: patient comfort zone
responses to IFC
tingling under electrodes
skin should show no change in color and in integrity
tx ineffective :rearrange electrodes or use scanning feature for change in amplitude
form of neuromodulation that uses noxious input to control pain
hyperstimulation
noxious level stiumlation for pain improvement is the application of electrotherapeutic currents to produce a painful stimulus in or remote from the pain sit
hyperstimulation
what mechanism of action does hyperstimulation use?
endorphins
do endogenous opiates increase/decrease patients pain threshold with hyperstim?
increases
what is a noxious level stimulation that causes a quick onset of pain modulation called?
hyperstimulation analgesia
T/F hyperstim is used as a first approach? explain
FALSE--used after adaptation to sensory stimulation
T/F Hyperstimulation is MOTOR stimulation? explain
FALSE! hyperstim is noxious stimulation
mechanism of hyperstim
relieves pain thru proposed brainstem neurochemical mechanism that exerts descending inhibitory control at spinal cord level
what do small pain fibers excite when a noxious stimuli hits them?
reticular formation
information from the reticular formationt then excites what?
PAG with high opioid concentration
the raphe nucleus is high in what NT
serotonin
ultimately, what is the overall mechanism of hyperstim?
intense stimulation activates small diameter nerve fibers to block pain
where is noxious level stimulation applied?
areas with no motor nerve fibers
how is hyperstim different from other analgesia mechanisms?
patient is required to perceive stimulus as painful
effectiveness can be felt after a few mins or a few points
small little points are more effective than large electrodes
disadvantages of hyperstim
unpleasant noxious stim--patients may not be able to tolerate it
indications for hyperstim
pain control
headaches, RSD, trigger point syndromes
scar tissue
chronic intractable pain
joint pain
phantom pain
contraindications of hyperstim
pacemaker
cardiac disease
children
pregnancy
skin irritation
precautions of hyperstim
muscular stiffness treatment often not effective until 10mins or later
low frequency of hyperstim
1-5 pps
high frequency of hyperstim
80-100 pps
frequency of hyperstim
1-2 times a day for initial pain then progressing to 3-5 times a week
phase/pulse duration for hyperstim
250 microsec to 10 milisecs
pulse rate of hyperstim
1-4 pps
amplitude of hyperstim
maximum tolerable level of noxious input
intensity of hyperstim
noxious sensation
duration of treatment of hyperstim
each point is 30-60secs
duration of analgesia of hyperstim
very long, lasts for hours
how many points at a time can you treat for a hyperstim patient?
20 points
where are electrodes placed in hyperstim?
right over pain sight to generate the best response
measure the distance between the 2 creases of the IP joints of the patients flexed middle finger = ?
equivalent to 1 inch
CUN
width of patients 4 fingers =?
3 CUN
what type of fibers does hyperstim affect?
unmyelinated C fibers
what type of duty cycle does hyperstim have?
50%
what type of current does hyperstim have?
monopolar pulsed DC
parameters for neuroprobe system 4
pulse rate
stim time
output intensity
treatment area
pulse rate- 4 Hz monopolar
stim time-15-45 secs
output intensity-maximal patient tolerance
treatment area-trigger points
tender points will become ____ during treatment....be prepared to reduce the current intensity
hypersensitization
non-pathological point or points which respond immediately to treatment generally ______during stimulation. be prepared to increase intensity to maintain hyperstim
adaptation
these points have very low pain thresholds and should be used for follow up TENS application
hyperactivity
about 5% of patients treated in this mode will experience more pain following stimulation. you should still continue future treatments
increased pain
where should the patient experience tingling?
under electrodes and in problem area
what is the ultimate goal for all modes of TENS?
pain relief
______occupy the position of an acupuncture site
acupoints
what are the different techniques of acupuncture?
manual needling and twisting
electrical acupuncture
heavy needling
what types of substances are released by acupuncture?
enkephalin
dynorphin
beta-endorphins
what effects do low intensity, high frequency electroacupuncture produce?
endorphin mechanism
slow onset analgesia
long lasting results
cumulative effect
acupuncture for pain control
2 Hz of stim and 100 Hz of stim plus the release of enkephalin, dynoprhin and beta endorphin allow for powerful analgesic effect
deficiency of energy or decrease in response; treatment should be tonifying (warming, weak stimulation) moxibustion etc
emptiness
abundance of energy or increase in response; treatment should be dispersing (microbleeding, strong stimulation) acupuncture etc
fullness
channel/pathway through which energy flows=
meridian
how many meridians are there?
12
what are meridians commonly used for?
GI issues and myocarditis
pt has organ dysfunction and corresponding distal meridian points are found to have increase pain threshold and differ in heat sensitivity and EP ===?
Akabane Phenomenon
Ryodoraku literally translates into?
good...electroconductive....line
one point along each Ryodoraku provides average electroconductive value for all points on the same Ryodoraku (so just have to measure 1 point instead of 12) ===?
representative measuring point (RMP)
tonification points excite in ____% of cases but sedate in ___% not perfect
80% excite
20% sedate
the point that has a higher electro-permeability (EP) than the surrounding area
reactive electro permeability points (REPP)
REPP is measured at how many volts?
12 V
conductivity at REPP is related to _____ activity/excitability
sympathetic
depolarization is by ________ (sympathetic/parasympathetic)
sympathetic
polarization is by ______(sympathetic/parasympathetic)
parasympathetic
Pts with higher lower REPP averages have _______(hyperstate/hypostate) ANS
hyperstate
Pts with lower REPP averages tend to have _____(hyperstate/hypostate) ANS
hypostate
hyperstate ANS includes what?
hot weather, youth, acute disease
hypostate ANS includes what?
cold weather, eldery, chronic
readings of electrical acupuncture are affected by?
perspiration
scarring
dermatitis
meals
recent treatments
medications
electroacupuncture uses what type of current?______changes peripheral polarization in tissues and therefore has a strong analgesic effect
DC
describe the mirror image of electroacupuncture
peripheral afferent stimuation travels to spinal cord and is sent back out bilaterally
detecting electrode is....? (anode/cathode)
anode
dispersion electrode is.....? (anode/cathode)
cathode
neurometer current reading
200 microA
intensity of neurometer
12 V
duration of neurometer
7 sec, continue until muscles relax to stimulation
