Objective: To report a rare case of Addison disease presenting with acute neurologic deterioration, and to discuss previous reports and illustrative clinical lessons drawn from the case.
Methods: We detail the clinical presentation and sequence of events leading to diagnosis of Addison disease in a 20-year-old man whose initial symptoms were those of acute neurologic deterioration.
Results: A 20-year-old man presented with acute, rapid neurologic deterioration. The patient required intubation, but his condition responded very well to mannitol and dexamethasone. Head computed tomography showed a fourth ventricle reduced in size and basal cistern effacement, changes consistent with mild cerebral edema. Primary adrenal insufficiency was diagnosed after a low morning cortisol concentration prompted a corticotropin-stimulation test and serum aldosterone measurement (undetectable). The diagnosis was almost missed because of suspected confounders of dexamethasone and etomidate use. Subsequently, the patient tested positive for anti-21- hydroxylase antibodies. Cerebral edema rarely occurs with Addison disease and is most likely secondary to hyponatremia. Diagnosis in such cases may be complicated by resuscitative therapies; however, low cortisol levels should always be thoroughly investigated. This patient's presentation was also unique in that he maintained a normal electrolyte profile despite hypoaldosteronism, a phenomenon that may be explained by enhanced mineralocorticoid activity of exogenous cortisol.
Conclusions: The diagnosis of primary adrenal insufficiency may not be suspected in the absence of classic hyperpigmentation and hyperkalemia, but should remain in the differential diagnosis of acute confusion. While the use of dexamethasone and etomidate in initial resuscitation can transiently suppress adrenal function, any unusually low cortisol level merits thorough investigation.