What are the sleep symptoms of anti-iglon5 antibody-related encephalopathy and what specialist treats this condition?

There is an article with more information and citations which may be helpful to you: https://www.jneurology.com/articles/anti-iglon5-syndrome-what-we-know-so-far-a-non-systematic-review.html Please check with the Neurologists in Boston, who may be more familiar with the condition.

This is a very rare condition with perhaps 60 total cases reported, majority in Europe. The sleep disorder most commonly is a REM sleep disorder, which involves thrashing about with arms and legs while asleep. Most commonly, this is associated with movement disorders such as Parkinson's disease or Lewy Body Disease.