SUMMARY OF THE DIFFERENT TYPES OF ELECTRICAL STIMULATION

TES  

If you are told by your doctor to do NIGHTTIME e-stim on your child - this is the one! and this is the ONLY one that can be done overnight.

The unit that is FDA approved for nighttime use in children is the BMR NT2000-TES. It has built-in safeguards to prevent injury if an electrode falls off or gets wet (or other circumstances).  And it has a lock button to make it difficult for a child to turn the level up or down.

• TES = threshold electrical stimulation (e-stim)

• this type of e-stim produces NO muscle contraction
  it only brings blood flow (and growth hormones) to innervated but atrophied muscles

• treats the weakest muscles  ("disuse muscle atrophy")

• long term commitment of 3-4 years, then a break, then another 3-4 years at puberty

• worn at night while the body and brain are in a rested state for growth & repair

• for anyone two years and older (only because of the space needed between the
  electrodes - the younger ones just don't have enough space for placement)

• surface electrodes

• treats motor fields

• very soft feeling - like a quiet vibration (EXCEPT for a child with serious sensory integration issues)

NMES      

if you are told by your doctor to do DAYTIME e-stim on your child - this is the one!
                 
Many therapists also concur that the BMR NT2000-NMES unit is the most comfortable unit to use on a child.  The NMES unit (BMR NT2000) can be purchased through Rehabilicare at 1-800-343-0488.
This unit does NOT have the safeguards built into it for nighttime e-stim usage.  It is strictly to be used during the day for short amount s of time with adult supervision and while doing specific therapy. Other units that children seem to do well with is the EMPI NMES unit (don't have a number on it though) and other higher end units.

• neuromuscular electrical stimulation (also called NMES, EMS or ES)

• produces active muscle contraction

• augments exercise

• muscle strengthening

• surface electrodes

• provides functional re-education

• "Fittest Fibers Fire First"

• daytime treatment only for short intervals

• treats motor points

• works by depolarizing nerve

 TENS      

If you are interested in doing e-stim for pain relief purposes - this is the one! But it's not used for children under the age of 12.

• transcutaneous electrical nerve stimulation

• primarily used for temporary pain relief

• surface electrodes

• daytime treatment only - and NOT done with children

 FES        

This is for creating "electrically controlled" functional movement (this is what Christopher Reeves [rest his soul] used when he did his "walking exercises")

• functional electrical stimulation

• active muscle contraction

• computer or therapist sequenced activation

• produces functional movement

• implanted or surface electrode

TES

What Is TES?

TES is "Threshold Electrical Stimulation".  It is a type of electrical stimulation that is used at night while the patient is sleeping.  The goal of TES is to increase blood flow and growth hormone to atrophied muscles.  It is used in conjunction with physical and/or occupational therapies. It strengthens the muscles which in turn will improve the individual's functional abilities.  TES was developed by Dr. Karen Pape at the Magee Clinic in Toronto, Canada in 1989.  

The BMR 2000-TES machine is the only unit that is FDA approved for nighttime usage on children  it has many safety features / including automatic shutdowns if an electrode falls off or if the child pees, and a lock button that will make it hard for a child to change the settings.

How It Works

By stimulating the targeted muscle at night, there will be increased blood flow, and therefore, more nutrients (growth hormone) delivered to it. This allows for the atrophied muscles to repair themselves and grow. Under the microscope there is an increased amount of regrowth after treatment with TES. This new growth takes about three to six months. After that time increased muscle strength and improved functional abilities can be seen.

Who Should Use It

The individual must have a definite diagnosis of muscle atrophy but the muscle must be innervated. It is important that the family be motivated because this is a daily program administered at home.

Contraindications

Contraindications for TES include pregnancy and implanted devices such as pacemakers. Obese individuals require careful consideration as it is difficult for the stimulation current to penetrate fat tissue. Caution should also be taken in an individual with seizure disorders. The seizures should be well controlled before starting this program. TES does not cause or exacerbate seizures, but it is always recommended that seizures be controlled before any new treatment is begun. It is also important to note that while TES will augment current treatments, it cannot prevent or replace surgical intervention.

Complications

There are no known permanent, undesirable side effects to TES. There are some transient side effects. The incorrect placement of electrodes can actually increase spasticity. Stimulating at an intensity that is too high can result in muscle aches. The above two side effects will subside within a few days of stopping the treatments. Rarely there have been reports of skin irritation from the electrodes. Occasionally when an electrode is old and the sticky layer is moldy (hard to tell) - the child may get a fungal growth (redness).  When this happens, TES is stopped until the skin irritation is gone and a new electrode should be used.  Normal skin irritation is more likely to occur if the individual has a sun burn or skin lesion (such as chicken pox). It is recommended that treatment be suspended while such lesions heal.

Results

Three to six months after starting TES, an increase in muscle bulk is apparent. In the following months functional changes can be seen.  Some parents report that their children sleep better through the night when they use the TES and others whose children have severe sensory integration issues report that their child can't stand it even for a moment! It would be great if you could borrow a unit from your therapist to see how your child will react to it before making the big purchase.

The use of TES is relatively new; therefore, research material is limited. One criticism of the TES program is that the majority of research has been done by Dr. Pape. However, as TES becomes more popular, other centers have begun formal research studies.

Source: The Center For Functional Restoration, The Hyman-Newman Institute for Neurology and Neurosurgery, Beth Israel Medical Center, Singer Division, New York, NY

NMES (ES, EMS)

What is NMES?

NMES is "neuro-muscular electrical stimulation".   NMES is used for the relaxation of muscle spasms, increasing range of motion, reduction and prevention of muscle atrophy, reeducation of muscles and increasing local blood circulation, for relief from minor pain (joint pains, muscle aches, etc) and stress, to strengthen muscles, improve overall appearance, and enhance your physical training.  When we hear of kids with bpi getting e-stim during therapy - this is what they are getting.

NMES uses electrical current to stimulate your muscles through passive exercise.  By placing the pair of pads on a particular muscle group, your muscles respond to the impulses that are generated by contracting and relaxing rhythmically as instructed by you through the unit. When a muscle contracts as a result of a unique EMS/TENS signal, the chemical changes taking place within the muscles are similar to those associated with voluntary contraction in "normal exercising". These chemical reactions which result from muscle contractions utilizes glycogen, fat and other nutrients stored in the muscle. These resulting series of muscle contractions will enable an individual to tone, strengthen, and combat flabbiness while improving contour.

WORKING WITH THE BMR NT 2000 NMES UNIT

These are the parameters we were given by one of our bpi specialist docs:
Frequency 35
Pulse Width  - we started at 130 and now we are at 200
Contraction 10
Relaxation 14
Ramp Up 4
Ramp Down 4
RX Treatment Time - 15 minutes

TO USE THE UNIT:

first define the placements - you can treat two areas at the same time - the unit will alternate first one then the other..... (this is one of the option settings - look in the manual to see how to change it if you just want to treat one area...)

The set of wires contains two sets of leads... a lighter set and a darker set. Each set has a dark lead and a light lead. The dark lead is the ACTIVE, the light lead is the INACTIVE.

The ACTIVE lead goes on the electrode that is placed on the motor point. The INACTIVE lead goes on the electrode - which can be placed almost anywhere- it just completes the circuit. It is usually also put on the muscle or in that area.

The motor point is where the nerve enters the muscle belly. It's the point that causes the contraction. (print off the finger tip trick)

Now that you have the electrodes on - put on the lead wires correctly...double check to make sure that you have sets matching and leads where they should be.

click the wires into the unit.

Turn the unit on
set the program to 0 (automatic I think on mine)

Now look at the two buttons on the front.... this is what brings the electricity into the muscle.... the left button is lighter - this powers the light set of wires....the right button is darker - this powers the darker set of wires.

Slowly start increasing the "volume".... ask your child to feel for the butterfly kisses. They'll tell you. Keep it really low and very short lived for the first time - you don't want to scare them off.  In time you'll be able to raise it up higher as they get used to it.

As the machine is working - it will be alternating between the two sites...
the deal is to watch the machine to know when it's working each section - and have the child do an exercise that causes that same muscle to contract.

It's great brain information for him to move the muscle in the same direction that the unit is making him move.

The unit will beep at 15 minutes and shut off.

When you remove the electrodes - use water... dip your fingers in a cup of water and wet the underside of the electrode - keep on dipping to wet the goopy part - it will easily slip off this way.

Also - here is a TRICK to find motor points!  This works really great especially since our kids motor points might be placed differently due to muscle transfers, muscle size (smaller), etc.

1. Put the INACTIVE lead (light pin connector) on the child's arm (anywhere below where the motor point should be)

2. Put the ACTIVE lead (dark pin connector) on the palm of your hand - yes yours!

3. Turn the unit on and pump up the "volume" on that side until it's about 10-20.  Do you feel it in your finger?

4. Touch where you think the motor point will be with the index finger of the hand that has the electrode on it.  When you find the actual motor point, the muscle will respond and contract.  You will feel the muscle tense and rise up to your finger.  Remember to watch the machine to see when that side is "working".  

THIS WORKS EVERY TIME!!

Remember that if you are not putting the electrode on the motor point - you are not stim'ing the muscle correctly.

Resources

ARTICLES:

Electrical Stimulation In Children, L. Michaud, Physical Medicine & Rehab: State of the Art Reviews, Volume 14, No. 2, June, 2000.  

Therapeutic Electrical Stimulation:  The Past, The Present, The Future, K. Pape, Network, A Bi-monthly Publication of the Neuro-Developmental Treatment Association, July/August 1996

Neuromuscular Approach to the Motor Deficits of Cerebral Palsy:  A Pilot Study, K. Pape, S. Kirsch, A. Galil, J. Boulton. A. White, M. Chipman,  Journal of Pediatric Orthopaedics 13:628-633m 1993 Raven Press, Ltd, New York

Initial Experience With Home Therapeutic Electrical Stimulation For Continence In the Myelomeningocele Population, A.  Balcom, M. Wiatrak, T. Biefeld, K. Rauen, P. Langenstroer, The Journal Of Urology, 1997 by American Urological Association, Inc.

Continence Following Electrical Stimuluation and EMG Biofeedback in a Teenager With Imperforate Anus, S. Kirsch, B. Shandling, S. Watson, R. Gilmour, K. Pape, 1992, Magee Clinic, Toronto, Canada

Developmental Apraxia Arising From Neonatal Brachial Plexus Palsy, T. Brown, C. Cupido, H. Scarfone, K. Pape, V. Calea, A. McComas, reprints available by contacting Alan J. McComas, Division of Neurology (Room 4U1), McMaster University Medical Centre, 1200 Main Street West, Hamilton, Ontario, Canada L8N 3Z5.

Electrical Stimulation and Biofeedback Techniques and Continence, W. Kaplan, I. Richards, C. Durkee, M. Plummer, A. Balcorn, T. Biefeld, Dialogues in Pediatric Urology, Volume 21, Number 9, September 1998.

Therapeutic Electrical Stimulation (TES) For The Treatment of Disuse Muscle Atrophy in Cerebral Palsy, K. Pape, Pediatric Physical Therapy, 1997

Clinical Perspective:  Use of Sensory Level Electrical Stimulation in the Physical Therapy Management of a Child with Cerebral Palsy, S. Beck, Pediatric Physical Therapy, 1997

The Diplegic Child: Evaluation & Management:  M. Sussman, 1991, American Academy of Orthopaedic Surgeons, 6300 North River Road, Rosemont, IL  60018

BOOKS:

Introduction to Surface Electromyography (1998) by Jeffrey R. Cram & Glenn S. Kasman with Jonathan Holz (Aspen Publishers, Inc.). If anyone is interested in ordering the volume it is at 800-638-8437 (http://www.aspenpub.com)

Clinical Electrophysiology (1995)by Andrew J. Robinson and Lynn Snyder-Mackler. Publisher is Williams & Wilkins. 

Electrical Stimulation: Enhancement of Muscle Function, An American Physical Therapy Association Anthology (1993). This volume includes research articles, mostly from the 1980s, investigating efficacy of NMES. 

PRACTICAL INFORMATION ABOUT PURCHASING & USING A TES UNIT

STEP ONE:

Contact your specialist and get two prescriptions and one letter:  

(1)  prescription for the unit - the BMR2000-TES (should be specific as this is the only machine FDA approved for TES nightime use with children) ....and 99 months for the usage.  Here is a form (pdf file) for durable medical equipment prescription that your doctor can use.   

(2)  prescription for the therapist for initial evaluation and re-evaluations once a quarter for 99 months or more.   Get two or more original copies of this prescription (in case you need to change therapists)

(3)  Letter of Medical Necessity -  Your specialist must write why this particular therapy is medically necessary and how no other therapy works the same way with the same results - state how long the child will be using the unit and how much percentage improvement the child might get from it - also what negative issues  (results from NOT doing the TES) the child will avoid by doing this therapy.  Here is the lingo for for children with brachial plexus injuries:  "nighttime neuromuscular stimulation to treat disuse muscle atrophy secondary to brachial plexus injury"

The insurance codes are as follows:

Diagnosis:  Disuse Muscle Atrophy 728.2

Equipment:

BMR 2000-TES Unit:    E0745
Electrodes:  A4556
Lead Wires:  A4557
Batteries:  E1399

STEP TWO:

Contact TASCnetwork (info@tascnetwork.net)  to get a listing of certified TES therapists in your area.  (www.tascnetwork.net)

Call the therapists and find one who has training and experience in brachial plexus electrode placements.  Here are some questions you may want to ask:

(1)  what date did you take your TES certification course?  did you learn the brachial plexus placements at this course?
(2)  which insurances are you covered by?
(3)  do you have experience helping families get TES covered by insurance?
(4)  how many children do you currently have using TES?  what types of diagnoses do they have?
(5)  how many kids with bpi are you using TES on?  how many of them have had surgery ?
(6)  what kind of results have you noted? after how long?   
(7)  can you explain to me how TES works - why is it worn at night - how long will my child's treatment be?

STEP THREE:

INSURANCE COVERAGE:

Call your insurance company to find out if they will cover it and if not - what the appeals process is, etc.  

If you don't have a case manager - now is a good time to get one.  If they send this to an outside expert for an evaluation and it is still denied, you are entitled to get a copy of this expert's report.  Sometimes the expert's report is favorable but someone in the insurance company denies it anyway - it is your right to find out why.  "What research have you done and what is your denial based on?"

Post something on the www.ubpn.org message board to see if other families who have your insurance company got approved or not.  This is a good way to network and find out what they had to do to get approval.

STEP FOUR:

ORDERING THE UNIT:

800-963-4325 Rehabilicare

ORDERING THE SUPPLIES:

Electrodes can be ordered through the National Medical Alliance. They are DME's that sell the Axelgaard electrodes.    

CLICK HERE FOR THE LIST (PDF FILE) OF COMPANIES THAT SELL AXELGAARD ELECTRODES.

Other suppliers are:
800-963-4325 Rehabilicare
800-458-3210 another supplier of Axelgaard electrodes

I suggest that for you initial try-out period, you order 2 sets of different kinds of electrodes, and one extra set of wires - always have extra wires on hand. Although not shown below - we seem to do well with the Pals silver electrodes. But every child is different because every child's skin is different - humidity in the home is different - sweat is different, etc.

white electrodes are the foam ones (1.5" circle and 1X4" rectangle)
the white ones have the wires and leads

brown electrodes are carbon ones (1.5" square and 1X6" rectangle)
the carbon ones have raised connectors that are part of it

this is one of Maia's placements - vertical back and triceps
dark blue is active (closest to the spine and closest to the head)
we're still using the goop layer so we are also taping to keep them on

(this is only for information only - please follow the strategies

About the goop layer:  The goop layer - dries out easily or gets too moist easily.  You can moisten them with your finger tip (dipping into water and spreading the water on) or you can spray them with water and put them in a zip lock bag and they will rehydrate.  Sometimes I just put a couple of drops of water in the zip lock bag and that keeps them nice and moist or put a tiny piece of damp paper towel in there.  

If the edges get dry and the middle is thick and goopy - you can actually let it all dry out - and then re-wet them and it will re-gel uniformly.  It's actually pretty cool stuff.  You stop using the electrode when the goop degrades and doesn't cover the whole electrode or you can try out TAC GELor TENSIVE.  You can probably purchase both of those items locally - you need to check with a medical supply house that deals with electrical stimulation systems.  

Tac Gel or Tensive is a very inexpensive electrode glue.  It is used in geriatric cases where the skin is very frail.  Put your electrode on a wet paper towel until the goop layer is really hydrated - it will slide off.  Wash it with a wet paper towel (on the side you will glue) and dry it off.  Put a very, very thin layer of Tac Gel on the electrode and let it dry for 1-2 minutes.... then put it on the skin and press it down for a minute or so.

When you remove the electrode, you will need to wash the skin well to remove the glue (wipe works fine) and you will also need to clean off the electrode immediately (don't let the Tac Gel dry on!).  Your carbon electrodes will last a very long time using Tac Gel. (sometimes even a year!)

You can certainly use the goop layer on the electrode until it's done and then pull it off and use Tac Gel.  Tac Gel is also more sanitary because you are cleaning it off and putting  a new layer on each time - no mold or fungus...no dead skin embedded into the goop - no sweat in the goop.  Makes sense doesn't it?  But some kids will get a reaction to Tac Gel so ask whoever you are buying it from to give you a sample tube first.

EASY REMOVAL OF THE ELECTRODE:  Here is the pain-free method to remove electrodes:  Keep a bowl of water nearby.  Wet your finger and wet the corner of the electrode (underneath).  Wet your finger again and now wet a little more underneath the electrode - you will see how it separates from the skin easily.  Keep on wetting your finger and then wetting the electrode and within just a few more seconds the electrode will be off.  Simple, pain-free and no hassles!

About humidity and skin types:  There is no rhyme of reason to how this works.  Maia has severe eczema and dry skin.  So what we do is towel dry her arm after her bath and apply the electrodes and we tape them with Nexcare tape products (we use Advanced Holding).  She uses the carbon electrodes.  There is this equation of how humid the room is versus how dry your child's skin is versus many other possibilities that will define what will work for you or not work for you.  It's going to take a while to figure this out for your child... so just be patient.  We all have to go through this transitionary period.  With Maia - when I remove the electrodes, I wash her with a diaper wipe, then I coat the whole area with Eucerin cream to moisturize it during the day and it's fine for the night.  We have also used a long sleeve organic cotton t-shirt that works well in holding electrodes on instead of the tape.  We get the shirts at http://www.kidsnatureonline.com/store/page14.html.  The shirt they have are organic cotton and they shrink down so that you have a tight fitting shirt that is extremely long lasting.  It works really well actually.   Some other parents have reported good results with vetwrap (but be aware of the compression aspects of this tape) and some parents use ace wraps (same compression problem).

Warm / humid climates and electrodes:  The goop layer can get moldy.  This hard to tell because the goop is clear and it is against a dark brown carbon electrode.  If your electrode smells in anyway than take a closer look at the gel layer - it might be moldy.  You can pull it off and wash off the electrode and use TAC GEL as a replacement.  (yuck mold!)  Our first tip that our goop was moldy was a rash that Maia had where her electrodes were...and it smelled. Gross!  We also learned from a friend who has a biracial child that a fungal infection may show up as a lightening of the skin.  We were told from the experts that they should throw away those electrodes and use a different placement until it cleared up.  SO IT'S GOOD TO HAVE AN ALTERNATE PLACEMENT!

WIRES:  You will need to order an extra set of wires because they fail, too.   They will fail faster if you tape such that the wire lead looks like it's popping up.   Wires will fail because as the child sleeps the wires will get pulled here and there.  They do have a 6 month warranty, but you should have an extra one on hand in case of failure....you don't want to stop treatment for a whole week waiting for a new set of wires to come in.  

BATTERIES:

Regular Batteries:  Eveready batteries fit perfectly in the TES unit casing.   Duracell's are smaller - but you can tape the bottom so they will fit better.  No problem.  They say that the batteries will last for 7 days but we haven't gotten one yet to last more than 4 days - but then again Maia sleeps for 11 hours so that might be the difference.  Have your friends save you battery coupons - 5 years is a long time, 2 batteries a week!!  I wonder if you can go directly to Eveready and get a medical discount or buy in bulk?  A friend uses the new titanium batteries and says that they actually do last for 7 days - but locally are also double in cost -- so get those coupons and look for those sales.

Rechargeable Batteries: We ordered the rechargeable battery and charger from TASCnetwork and we did not have luck with it because it did not have a tester included and the battery needed to be completely discharged first and we didn't know how to do that.  The battery failed after 3 tries with it so we gave up on it.

I received an email from a dear friend whose child also does TES and she told me about what she does for the rechargeable batteries....  She bought a recharger from Radio Shack - it drains the batteries automatically before it recharges them.  Nickel Metal Hydride batteries do not have to be drained first and they say that they last for 500 rechargings.  Nickel Cadmium batteries do have to be drained first.   She said to buy two batteries so that you always have one waiting in the wings fully charged.

2003 update:  they make high speed chargers now!! so it might be worth a try!

USING THE UNIT:

Talk to your child about it first.  We call it the "sticky" machine and the tape is "happy tape" and we sing a song about it and well you get the drill....  Becoming part of the TES program requires a great commitment from both parent and child.  The child will have to know that it is an every night thing - so you have to really do it every night from day one.  Update (Maia at age five):  Maia knows that the Sticky machine brings more blood (food) to her arm to make it stronger. So when she eats dinner, I say, "Oh Maia, what's your army going to eat tonight when the sticky machine is on? and Maia will answer,  "Yay yay - my armie is going to get macaroni and cheese! Come on Mommy - let's get stickies on !!"

Wash and dry the skin to make sure there's no residue of soap or cream or dirt, etc.  We always did this after a bath, so Lou would always blow dry Maia's arm, too.  By the way - because Maia has very dry skin, when we take the electrodes off, I wash her arm with a washcloth and then apply a thick layer of Eucerin cream and put on a long sleeve shirt to hold the cream in for a while.  This is working well.

There are two sets of electrodes - your therapist will show you exactly where they should be placed.  There is a light blue set and a dark blue set (wire colors).  Then the connectors on the lead wires are either dark blue or white. The dark blue always goes closest to the head (proximal).  If you are using carbon electrodes, put the wire leads in their holes BEFORE you place the electrodes on the child.  If you are using foam electrodes, it doesn't matter.  Put them on, tape them down (if you choose to use tape) and you're a go.  Have the child wear a long sleeve shirt to bed - covers all the electrodes.  And then you can turn the unit on, set the current and push the lock button. 

What do you do with the machine now?  Well I am a stickler for safety in a crib - so in my mind I tried to envision how this unit and long wire was going to work.  You can't keep it on the crib mattress because the child will turn, the wires will come loose and it's just too exposed.  Some therapists recommend putting the unit in a puppet and leaving that on the crib but you still have wires hanging out and what if the child twists and turns. Doesn't seem safe to me.  So I am making fanny packs now.... I use flannel and cotton batting cloth inbetween the layers and have a soft fanny pack with velcro on the belt.  The wires stay intact, the fanny pack is comfortable and it's a working solution. If you are interested in one of my Auntie Franny's Flannel Fannies go to www.flannelfannypacks.com . Maia's fanny pack has certainly helped her succeed in this nightly process. I have MANY kinds of fabric - here are just 3 of them...

We also got Maia involved in turning the machine on and setting the current - although I have her push the minus buttons and not the positive buttons.  She thinks she is doing it, when she's really not - but she really loves the involvement in her own treatment. I like that, too.  We talk about how the "sticky machine" will make her arm stronger and we thank it and kiss all the electrodes goodnight and tell them to do a lot of good work while Maia is asleep.  In the morning when we take it off, I congratulate the stickies for staying on all night and doing such good work.

The child needs to wear the unit for at least 5 hours per night, maximum 12 hours.  Every 4th night they can have a night off, but we keep on going as long as Maia is ok with it.  Somehow Maia is much better with just using them 6 nights in a row with a night off for weekend. It's confusing when you do every 4th night.

Update: at age 9, I put Maia's electrodes on and Maia takes care of everything else herself...she plugs it in, she sets the unit, and locks it, puts it in her fanny pack and off she goes...... <sigh> ahhh they do grow up!

MISCELLAENOUS BUT IMPORTANT INFORMATION:

How do you know what to set the machine to?  You need to set it to a comfortable level.  Since you are probably not sure about how much sensation your child has, test it out on the unaffected arm.  When they make a grimace turn it down until they can't feel it.  So for example if they grimace and squelch at a 6, then turn it down to a 4.  Then you can see if they can handle a 5 or not.  They'll let you know.  Try it on yourself - sleep with it to see what it's like. Just remember that your setting will be different from your child's setting - you are not going to feel it the same way - no two people feel it the same way - with or without injury. So that means don't compare two children either.

When you put the TES on - the body will become used to it and adapt to it, sometimes within seconds.  I'm telling you this so that if you try it out and this happens, here's the explanation.  Also - if you do not feel the current at one level - note that when you go to sleep, your body becomes more sensitive to it - so you might feel it then.  This could very well be one of the reasons why a child's sleep may be disrupted if they use TES.  But most children sleep really good with TES on.... like an automobile ride vibration.

How far away do the electrodes have to be?  2-3 finger widths.  

My personal perspective:  Don't do anything to your kid until you experience it yourself.   Want to understand TES?  Get a unit and sleep with it.  Work out all the bugs before your kid gets it.  Want to figure out what NMES machine to purchase? Try them out yourself.  I say the same thing about alternative practitioners.  Don't send your kid to a chiropractor unless you've had at least a month experience with them for yourself.  Same with acupuncturists or homeopaths or anyone else.   Is it scary for you?  Yeah - that's good - feel the fear.  Your kids feel it 100 X worse!  Once you do it yourself, you'll have a better understanding of what's going on and of the bigger picture.  You will also come to understand your child much better and have more patience when behavioral issues pop up.  At least that's been my experience.  Oh, what our kids go through!

If there are any other questions - just ask and I'll try my best to answer.  Good luck!