Carmilla Thank you for the information on CO cause of PD.You may remember me mentioning this before as I do not chat very often but read everything sent in. I too am researching into this but I was exposed to domestic gas whilst helping in a suicide rescue that was about 8 years before I was diagnosed with Pernicious anaemia and excaema vitiligo followed then PD.at same time as testing positive ANA and later followed hypothyroiditis all autoimmune disorders????????I feel that the CO altered the balance in the Haemoglobin some way or another I am not very technical but am gathering as much info. as possible. Would be pleased to hear from any one with anything revelant. have a happy day Margaret