Laurie's Blogs.

And can I apply laser therapy and acupuncture on the same day?

A question came up on a veterinary rehab chat group about whether doing acupuncture and laser on the same day was appropriate.  The person who posed the question thought that she had heard that these therapies should be spaced at least a day apart.

One responder had posted that the reason one would want to space out the therapies would be to avoid transneuronal degeneration (TND).  Further discussion ensued and another responder gave a description, “…think of it as using up of the neurotransmitters and metabolic resources in the face of applied stimulation.  TND is a gradation of used up resources and decreasing appropriate nerve function and/or health.”

There were suggestions to monitor the pupillary light reflexes (PLR) to monitor for TND.  The PLRs can become delayed or asymmetrical.  One can also monitor respiratory rate (which may increase), or gut sounds (which may decrease), and on horses, observable patches of sweating may be noted.  Of course, the caveat is that in order to monitor PLR, or gut sounds, or respiratory rate, one needs to take note of the baseline when the animal first comes in / before treatment.

Clinically, the concern was that the treatment(s) could be rendered ineffective as well.  

To be honest, I had never heard of this!  I’m assuming nor have many of my physio colleagues either.  So, I headed over to Pubmed to look into transneuronal degeneration and laser, chiropractic, acupuncture, or physiotherapy.  Nothing.  I looked for ‘just’ transneuronal degeneration and 29 papers came up, but they did not apply to therapeutics at all.  They were more related to nerve sectioning, nerve lesions, cortical contusions, hemidecordication and other very serious lesions or man-made events for research purposes.

Wikipedia’s definition:  Transneuronal degeneration is the death of neurons resulting from the disruption of input from or output to other nearby neurons.  This still didn’t fit the description being given by and warned about by the practitioners on the chat group.

So, I next went to my library (i.e. MY personal library… I am a textbook whore).  Of my 4 human acupuncture books, all I found in regards to acupuncture and anything that could even be close to an adverse event that could appear to be a ‘using up of neurotransmitters and metabolic resources’ was syncope (fainting).  Two books referenced this.  

I then went to my animal textbooks and pulled out 6 books on veterinary acupuncture.  One text commented that some animals are reported to sleep for extended periods of time (up to 24 hours or even a week reported) following acupuncture.  This text went on to note that syncope is not reported following needling in animals, but that one author had witness a near collapse then recovery of a horse following the needing of a point in the cranial tibial muscle.  Sweating was noted to commonly occur in horses during acupuncture.  This textbook did not give any rationale for the phenomenon.  None of the textbooks noted the term transneuronal degeneration. 

So, I checked my three veterinary neurology books.  Nothing.  One book had a section on Neuronal Degeneration (systemic diseases).  

Then I dug through my human neurology text books and I found one that had a section on transneural degeneration.  In reading this text, I came to understand that TND was more a sequellae of 1) compression of a nerve, 2) anoxia, or 3) ischaemia.

It’s a long read, but I want to quote part of the text book (Functional Neurology for Practitioners of Manual Medicine):

“In neurons that have been exposed to a decreased frequency of synaptic activation a number of responses can be found in the neurons including:

•  Decreases in cellular immediate early gene responses;

•  Decreased in protein production;

•  Decreases in  cellular respiration;

•  Decreases in ATP synthesis;

•  Increases in resting membrane potential in initial stages;

•  Hyperpolarisation of membrane potential in the late stages of degeneration;

•  Increased free radical formation; and

•  Further inhibition of cellular respiration in the mitochondrial

All of these processes will contribute to the development of transmural degeneration (TND), which refers to a state of instability of the nerve cell as a result of changes in frequency of firing and/or fuel delivery to the cell.”

This description ‘sort of’ fits, but again the context seemed to be if a specific nerve was impacted by a pressure, force, tractioning, metabolic crisis.  Not a ‘using up of resources.’

To my way of thinking, acupuncture, as well as laser, or manual therapies, or other modalities tend to increase blood flow, draw in useful metabolites, and improve ‘fuel delivery’.  The place where I see ‘draining of resources’ to potentially occur is when we would uses NMES as a way to fatigue a muscle, because in that scenario we are specifically using up the available resources for localized nerve firing.

Okay… I felt like I was getting somewhere.  So I ventured onto the ‘google-verse’ and typed in Transneural degeneration “and chiropractic”, “and physiotherapy”, “and laser”, “and acupuncture”.  The only hits that came up were with chiropractic, written in chiropractor blogs and articles.  I went back to the Functional Neurology text book, and sure enough the author is a doctor of chiropractic.  I reread the sections on transneural degeneration and noted that there were no literature references for the phenomenon as described.  As such, I am leaning towards thinking that the use of this term to describe the decreased frequency of synaptic activation listed above is a colloquialism specific to chiropractic theory.  Furthermore it is not a term for using up all available metabolites via therapeutic interventions.

So, IF TND isn’t what happens when an animal gets sleepy with treatment and/or its pupillary light reflexes are altered, or its heart rate increases, or (if it’s a horse) a sweating is noted, then what is?

I went back to the phenomenon of syncope. Down the rabbit hole in ‘google-verse’, I began to search ‘mechanisms of acupuncture syncope’.  Here, I think, is the answer.  I presume it must be a vasovagal response.  Check out this chart below.  I found it on: https://www.syncopedia.org/vasovagal-syncope/ 

The third column has everything that has been described, sweating, pupillary dilation, increased heart rate, etc.  This answer explains what is seen AND is known to occur with acupuncture.  This answer makes more sense to me.

Now, fatigue after acupuncture isn’t necessarily a bad thing.  We know that most of our healing occurs when we are sleeping.  I have always presumed that this is the case when a patient is sleepy after an acupuncture, laser, physiotherapy, hydrotherapy, etc., session.  

Back to PubMed, I found research that showed that pre-exercise laser therapy resulted in decreasing exercise-induced oxidative stress and consequently enhancing athletic performance and improving postexercise recovery.  I couldn’t find anything there in regards to ‘causing fatigue’ or ‘inducing fatigue’, although I had heard of that back in the 90’s when I started to use laser therapy.  It might induce sleepiness by stimulating release of endorphins, serotonin, nitric oxide etc.

All in all.  Here are my take away points:

1)  The term ‘transneural / transneuronal degeneration’ in regards to neural tissue depletion seems to be chiropractic in origin.

2)  It seems to be unlikely that therapies such as laser therapy or acupuncture will cause neural tissue depletion to the extent that systemic autonomic nervous system effects are seen. (Nor is there evidence of such in research literature.)

3)  The autonomic nervous system events seen in some patients treated with acupuncture are more likely a vasovagal response (i.e. syncope).

4)  Laser therapy does not seem to incite a vasovagal response but could contribute to sleepiness after treatment.

5)  It is likely safe to apply laser therapy and acupuncture on the same day and/or simultaneously.

I always use laser and acupuncture simultaneously and have never had a deleterious effect.  Yes, some dogs will sleep after their sessions, more so older dogs.  This has always seemed to have a restorative effect, and the dogs seems to do wonderfully afterwards.

So, that’s what I searched.  That’s what I found.  That’s what I came to conclude.

I hope others find this helpful, and if you are in fervent disagreement, I wholeheartedly welcome the discussion and would love to read any articles that you might want to provide me as a source of enlightenment!

On that note,  have  great week ahead!

Cheers,  Laurie