Manifestations and characteristics of congenital adrenal hyperplasia-associated encephalopathy

Background: This study aimed to clarify the characteristics of acute encephalopathic episodes in patients with congenital adrenal hyperplasia (CAH), which we termed "CAH-associated encephalopathy (CAHE).". Methods: This retrospective study was conducted using a questionnaire as a nationwide survey of patients with CAH with acute encephalopathy and related episodes. Results: Fifteen patients were recruited on the bases of clinical data that supported a diagnosis of CAHE. Fourteen patients displayed seizures at onset, and 12 patients exhibited refractory seizures. Deep coma lasting >24 h was noted in 12 patients. Neuroimaging studies revealed some heterogeneous features. Diffuse or focal edematous lesions in the cerebrum, which produce high signal intensity on diffusion-weighted magnetic resonance imaging or low density on computer tomography, were found in the acute period in all 15 patients. In the chronic period, 14 patients survived, 11 of whom had some degree of neurological sequelae. Moreover, various degrees of cerebral shrinkage were observed in 11 of 14 surviving patients. Surprisingly, there were no abnormal neuroimaging findings in the basal ganglia, brainstem, and cerebellum in any patient. Conclusion: Our results indicated that patients with CAH have a risk of developing CAHE, and thus, they should be followed closely because not only status epilepticus or deep coma but also minor symptoms, such as fever and nausea, may lead to CAHE. Because CAHE may feature some heterogeneous encephalopathic episodes, further validation is needed to clarify its etiology.