Medical cannabis therapy is used extensively in Israel with approximately 2% of the population holding a license for medical cannabis.  The most common method of application in Israel is by smoking and the most common grade is THC20%:CBD4%.  The following investigation was undertaken in order to assess the effect of medical cannabis therapy on autonomic nervous system (ANS) balance and activation.  The assessment was performed using a CLA INSIGHT instrumentation.  The system evaluates three parameters: heart rate variability, skin conductivity and skin temperature.  An AI analysis comparing to several tens of thousands of prior measurements allows determination of two essential characteristics of the autonomic nervous system: 1. Degree of activation and 2. Sympathetic to parasympathetic balance.

Methods: 121 patients seeking treatment by medical cannabis at one of the authors clinic (DR) were assessed prior to therapy initiation and at least 3 months following therapy initiation. The degree of ANS activation and balance was measured as well as brief pain inventory questionnaire and Oswestry disability index.  

Results: BPI improvement average 6 grades after at least 3 months of therapy (p<0.001), ODI changed by 3 months by an average of 32% (p<0.01).  The change in ANS activity averged 22 points (100 max), and balance by 34 percent (p<0.01).  The correlation between BPI and ANS balance was high (R>0.9), the correlation between BPI and ANS activity was lower (R<0.7) though significant.  The same was true for ODI changes.

Conclusion: It appears that medical cannabis therapy using smoking T20:C4 strains appears to relieve in a consistent manner pain and disability related to chronic low back pain.  The mechanism of action appears to involve rebalancing of the autonomous nervous system activity and in particular vagus nerve activation leading to parasympathetic activation.  It is important to measure ANS activity and add interventions leading to ANS activation as it has been previously related to lack of spontaneous tissue repair.  The optimal therapy for chronic low back pain might involve a multimodality mind-body approach and ANS assessment can serve as an objective measure of treatment success.