Recommendation:
700-880 probes =
- 1.5-163 Joules (6 Joules average)
- 1-3 spots
- Frequency = 1x per day down to 1x per week
In 2016 Li et al. wrote a meta analysis of the treatment of carpal tunnel with LLLT. They referred to a lack of consensus on the effectiveness of LLLT and hence the need for the review. Like many areas that laser has been applied to the studies in the carpal tunnel often included other treatment methods and so the effectiveness of the laser alone was difficult to establish (laser can be used as a stand alone treatment but generally is given with exercises, ice, bracing etc.).
So what does laser do in carpal tunnel syndrome? Padua et al, (1998) and Rochkind et al. (1990) have shown that laser increases myelin production and reduces retrograde degeneration of motor neurons.
Other benefits include antiinflammatory effects, (Honmura et al. 1993) selective inhibition of nociceptive activation at peripheral nerves (Jarvis et al. 1990), increased ATP production and cellular respiration (Passarella 1989), and improvement of blood circulation to remove algesic substances (Lee, Wong, Mason. 1996).
But do these effects translate into real people? Weintraub (1997) said LLLT reversed CTS in 77% of cases. However, these studies were uncontrolled.
In more recent articles, some placebo-controlled studies have shown beneficial effects of LLLT on clinical and physiological parameters in the treatment of CTS.
- Naeser et al. 2002
- Bakhtiary, and Rashidy-Pour 2004
- Evcik et al. 2007
- Shooshtari et al. 2008
- Chang et al. 2008
- Dincer et al. 2009
However, these studies are not consistent because of different laser intervention protocols.
Studies with more tightly controlled parameters were used by Lin et al. (2016) showing positive results from LLLT in CTS:
- Yagci et al. 2009
- Tascioglu et al. 2012
- Rayegani et al. 2013
- Fusakul et al. 2014
Li et al. (2016) concluded that LLLT improved hand grip, VAS, and SNAP (long) after 3 months of follow-up for mild to moderate CTS.
Dosage for CTS treatment have varied but the wavelengths used are consistently 800nm (785-880nm). Energy per spot ranged from 2.7 J to 11 J and total energy ranged from 81-300 J. Anywhere between 2 to 5 spots of treatment were most common. Most common applications included above the transverse carpal ligament or along the median nerve. The average number of sessions given was 10 (most common 5x per week for 2 weeks) This is likely to fit in with a working week rather than for any other research reason.
Positive results were shown after the treatments in as little as 2 weeks lasting beyond 3 months.