Information from: “Personal Communication on Laos Sign Languages” . James Woodward. (2015)
There are two sign languages in Laos - 1) Original Laos Sign Language which is close to Original Chiang Mai Sign Language, and 2) (modern) Laos Sign Language which is heavily influenced by Thai Sign Language which is heavily influenced by American Sign Language.
Information from: “Glottolog 2.3” . Hammarström, Harald & Forkel, Robert & Haspelmath, Martin & Nordhoff, Sebastian (2014)
Information from: “Ethnologue: Languages of the World, 17th Edition (2013)” . Paul M. Lewis; Gary F. Simons; and Charles D. Fennig · Dallas, Texas: SIL International