dlark

Firewatcher, I have central partial diabetes insipidus, orthostatic intolerance (specifically Low-flow POTs), Chronic Fatigue Syndrome (CFS) and a partially empty sella. I do believe there is an overlap within these conditions and there is some interrelation. For instance Chronic Fatigue Syndrome (CFS) is often accompanied with orthostatic intolerance. Also low blood volume falls in there somewhere and problems with ADH being shut down. If you want to read more information on this go to the Lyndonville news archives http://www.pediatricnetwork.org/lyndonvillenews/index.htm , and select articles such as July 1999: Relationship Between Neurally Mediated Hypotension and CFS , July 1999: Circulating Blood Volume , March 2000: Evaluating Blood Volume Studies - Some Thoughts, May 2000: Orthostatic Intolerance: An Introduction . These articles are written by Dr. David Bell, a well known and well respected CFS specialist. As for my diagnoses of partial central diabetes insipidus, it was not a clear cut textbook case nor was it easy to come by. Prior to the DI diagnosis and DDAVP tabs, I was drinking 6-8QTs water daily, always thirsty, and constantly using the bathroom. Without my water, headaches and lightheadness were worse etc. as well as my irritability. My excessive drinking started in October 2004 if not before and it wasn?t until the summer 2007 that a diagnosis of partial diabetes insipidus was made and I started taking DDAVP tabs. In February 2007, I had an initial consultation with Dr. Bell. He suspected diabetes insipidus and recommended to my doctors that I have a water deprivation test. He also recommended other testing such as a total circulating blood volume test by the Cr-51 method. In April 2007, I had a water deprivation test. Although the endocrinologist?s office who preformed this water deprivation test told me it was normal, it was not. After being cut off from food and liquids including water since the night before, my serum vassopressin (ADH) levels both at 8:18AM and 1:21PM the day of the test were <0.5 pg/mL. 0.5 pg/mL is the limit of detection at the lab where the tests were preformed. I had some ability to concentrate my urine. In June 2007, I had my pediatric endocrinologist review the water deprivation results and he ordered from a different lab additional serum and urine osmolalities and serum ADH after overnight fast from food and liquids including water since ~7:30PM. The results from samples collected around 9:50AM were ADH was <0.8 pg/mL (ref. interval 0.0-4.7), my serum osmolality was 295 mOsmol/kg (ref. Interval 275-295) and my urine osmolality was 396 mOsmol/kg (ref interval reads After 12hr fluid restriction: >850). At this lab for ADH the limit of detection is 0.8 pg/mL. I had had a 14 hours + of no fluids and food , my urine osmolality was low. In April 2007, I also had my first total circulating blood volume test by the Cr-51 method. My plasma volume was decreased at 21.4 ml/kg (Normal 30-45 ml/kg). The Cr-51 blood volume results really added to the picture and made things clearer that I had problems related to conserving and holding onto water and it made sense that a the lack of sufficient ADH played a role. Since July 2007, I?ve been taking DDAVP tablets and since April 2008, I?ve also been on Florinef (fludrocortisone) tablets. Overall these medications have been helpful and made life a little easier. Initially, getting used to DDAVP and adjusting to it was not easy and took some time. At this point on the DDAVP and Florinef, I?m drinking about 2QTs water per a day. I?ve had additional Cr-51 blood volume testing now (I believe I have 3 sets of results now) and my plasma volume is still low (19.5 ml/kg on 8/2008) and we are still trying to work on increasing my plasma volume. Since my medical history is quite extensive and the results numerous, I?ll stop here for now. If you have any questions, please post and I?ll do my best to answer them. Hope this information is helpful and I hope you get some explanations and answers from Vanderbilt.