My Max had a similar ongoing tremor. It has disappeared in the last several years. I'm not sure what made it go away - acupuncture, chiropractic care, or antibiotic treatment (doxycycline for possible tick diseases) are high on the list for helping to resolve it. I'm sure laser therapy or the like might help too.
He does have ongoing neck issues. I make sure that I use no collars or head harness on him, or front clip harnesses, I use a harness that looks like this:
http://www.cleanrun.com/index.cfm?fu...roduct_ID=1771