Anandan, SRajendran, SSKumar, JPShajee, DS.2025-05-092025-05-092024-06Anandan S, Rajendran SS, Kumar JP, Shajee DS.. A rare cause for delirium: COPE syndrome . Indian Journal of Case Reports. 2024 Jun; 10(6): 176-1782454-13032454-129Xhttps://imsear.searo.who.int/handle/123456789/243595Calcium-alkali syndrome (CAS) (Milk alkali syndrome) is the third most common cause of hypercalcemia. The triad of hypercalcemia, metabolic alkalosis, and variable renal failure constitutes this syndrome. Here, we report a case of CAS in a female with post-thyroidectomy hypoparathyroidism who presented with delirium due to hypercalcemic encephalopathy. CAS can occur even after decades of normocalcemia in hypoparathyroidism, and regular monitoring of calcium levels is required.Calcium alkali syndromeCalcium citrate malateCope syndromeHypoparathyroidismHypercalcemiaMetabolic alkalosisMilk alkali syndromeJournal ArticleIndiaConsultant Neurologist, Department of Neurology, St. Joseph Hospital, Anchal, Kerala, IndiaConsultant Neurologist, Department of Neurology, Welcare Hospital, Kochi, Kerala, IndiaResident, Department of Neurology, St. Joseph Hospital, Anchal, Kerala, IndiaResident, Department of Neurology, St. Joseph Hospital, Anchal, Kerala, India