WHEN THE classic clinical picture of hyperparathyroidism is present, the diagnosis is usually readily made. The most bizarre clinical pictures are produced when the calcium levels are extremely high, or, in other words, when the picture of calcium poisoning is present. This has been referred to as "parathyrotoxicosis."1 These are the cases that may result in sudden death and are definitely medical emergencies. We have had an opportunity to observe two such cases in which the primary manifestations were psychic. In both cases the mental disturbances produced such an unusual picture that the diagnosis was overlooked for several months. In one of these cases this delay led to almost disastrous consequences.
Although much has been written about hyperparathyroidism, comparatively little attention has been devoted to its effects on mental processes. For this reason, and since any toxic signs are danger signs in this disease, we thought it important to