Helena Komnene of Greece - Parentage Unknown

Helena, the widow of Yuri Dolgorukiy, grand prince of Kiev, moved to Constantinople after her husband's death. This has led some scholars to theorize that perhaps she was Byzantine. But there is no documentary evidence for this, and certainly no evidence to identify her as the daughter of Isaak Leo Komnenos, Sebastokrator of the Byzantine Empire

Here is what Medlands has to say:
"m secondly [HELENA] [Komnene], daughter of --- (-[1183]). Baumgarten cites one secondary source which discusses "the probability" that the second wife of Prince Iurii was of Byzantine origin, suggesting her possible name on a subsequent page[774]. Although the date of his second marriage is not known, the timing suggests that his wife may have belonged to the Komnenos family if she was indeed of Byzantine origin. Sturdza states that she was the daughter of Isaakios Komnenos cæsar, but the primary source on which this might be based has not yet been identified. She adopted the name OLGA in Russia."
http://fmg.ac/Projects/MedLands/RUSSIA,%20Rurik.htm#IuriiVladimirov...

I suggest that we cut the connection between Helena and Isaakios, since there is no real evidence behind this connection.