A reader forwarded me exciting news about lidocaine and positive results for CFS. The common term often used today is “Fake News”.  in many cases, the less severe “Misleading News” could be used. I prefer to use “hopeful news” – because the writing paints a future hope that may somehow be realized (and with 20 years seeing these hopes too often disappointed).

The article was in Spanish and is here. An english version on ProHealth states

• “These results demonstrate that lidocaine injections reduce clinical fatigue of CFS patients significantly more than placebo, suggesting an important role of peripheral tissues for chronic fatigue. Future investigations will be necessary to evaluate the clinical benefits of such interventions.”

The actual study (full text is here). In reading any articles we look for things demonstrated:

• To have statistical significance (CFS symptoms vary from day to day — was the change seen just happenstance? )
• How many were positive results? negative results? no result?
• How many items were measured and how?
  • Self-evaluation is very prone to suffer from placebo effects. Sugar pills improve many conditions!

Let us quote from the article:

“Fatigue ratings of CFS patients decreased significantly more after lidocaine compared to saline injections (p = 0.03). In contrast, muscle injections reduced pain, depression, and anxiety (p < 0.001), but these changes were not statistically different between lidocaine and saline (p > 0.05). ”

Ouch, fatigue rating — means self-perception. Lidocaine is a pain killer which is known to work. Reduction of pain usually results in less fatigue. Saline solution is not a pain killer. The alternative should have been an equivalent pain killing drug. Bad design! You may be testing pain killers not lidocaine!

The slight of hand is claiming “reduced pain, depression, and anxiety” — which BOTH saline and lidocaine did.  Saline doing short term pain relief etc is documented in this post with the main mechanism being improvement of blood flow (an anticoagulant effect). There was no difference between lidocaine, a saline solution and I suspect almost any anticoagulant — even plain aspirin. Another poor design choice. They claimed “This study used a parallel group, double-blind, placebo-controlled design.” Unfortunately, there was no placebo! Saline solution impacts CFS patients positively – Jen Brae can definitely confirm that in her own experience.

Some method notes:

• “Ratings of overall fatigue, pain, and mood were obtained before and 30 min after the muscle injections” — so the conclusion is valid for exactly 30 minutes after injection. Whether there is any significant change the next day or week was not measured (or was not reported).
• “that lidocaine was only more effective than saline in increasing mechanical pain thresholds at the shoulders but not at any other location.”
• They cited using tables from a “Cohen” but there is no citation in the reference for a Cohen. Third party tables not done on CFS patients are very suspect — the metabolism of drugs by CFS patients can be very different than that of normal patients.
• There was no breakdown of individual responses. “Averages” can be very deceitful (especially with small studies). A few very good responders can result in a major increase of the average. It may work for 10% and do nothing for 90%.
• “The blood samples were immediately sent to the laboratory for analysis.” There was no mention of the results … did any lab results changed?
• “These results demonstrate that lidocaine injections reduce clinical fatigue of CFS patients significantly more than placebo, suggesting an important role of peripheral tissues for chronic fatigue. Future investigations will be necessary to evaluate the clinical benefits of such interventions.” There was no Placebo…
  • “the injections you are going to receive contain either a local anesthetic or an inert substance”.  This is false — saline solution is not inert.

Bottom Line

Many readers forward me latest studies and ask for an analysis and comments. Why me?

• I do not suffer from brain fog
• I have been reading medical journals since I was 15 (part of a special enrichment program)
• I have worked as a professional statistician and know how to take apart a study
• I have been a high school general science teacher (and also chemistry and physics at College level)

This post tries to give a framework for less brain-fogged individual to work from (and hopefully challenge my readings and conclusion based on published evidence studies).

View of this Study

The people doing the study constructed it poorly. There is evidence that they are not well familiar with all of the prior related studies for CFS. There should have been scatter gram showing for individuals the before and after values for each measurement.

Should CFS patients ask for this based on the evidence in this study? No — the effect may last for only 30 minutes, one could easily speculate that common aspirin could have the same or better effect.

Let us look at stuff cited in an interview…

“Los investigadores anotaron que los hallazgos sugieren que los músculos y otros tejidos periféricos están involucrados en la fatiga crónica. Concluyeron que las inyecciones de lidocaína ayudaron a bloquear la señalización anómala de los metabolitos musculares.”

“The researchers noted that the findings suggest that muscles and other peripheral tissues are involved in chronic fatigue. They concluded that injections of lidocaine helped block abnormal signaling of muscle metabolites.”

They produced no lab results showing “abnormal signaling of muscle metabolites” before the injections or a change after the injections….  “Show me the beef! (evidence)”