Mid 11th Century Byzantine Medallion

Byzantine Medallion, 11th Century AD Obv: Saint Nicholas [O AGIOS NIKOC] Rev: Virgin and Child [+KEROH(TH)TWCW/DOULI] 7.97g, 19.5mm Twice pierced and gold plated. Interesting piece. Both the inscription and the fact it was gold plated may suggests that it may have been a commemorative medallion for a special occasion. Holes seem to be modern and possibly used on cross or jewelry. Please feel free to comment if something more about this piece is known. Thanks