They might have resulted in a persistent -NAO pattern, but the little ice age period likely wasn't driven by Atmospheric circulation. I studied this period extensively in college, and it was more of a perfect series of dominoes falling to cause the event. Tropical volcanic forcing likely led to a few years of increasing ice cap volume which altered Ocean patterns, especially the formation of North Atlantic Deep Water. This reduced heat transport into the North Atlantic which would have then led to persistent changes in atmospheric circulation, such as a semi-permanent -NAO. The sunspot minimum likely increased the staying power of this phenomena, acting as a reinforcement of sorts.