Adult-onset non-cirrhotic hyperammonemia (NCH) is a rare, but often fatal condition that can result in both reversible and irreversible neurological defects. Here we present five cases of adult-onset non-cirrhotic hyperammonemia wherein brain magnetic resonance spectroscopy (MRS) scans for cerebral glutamine (Gln) and myo-inositol (mI) levels helped guide clinical management. Specifically, we demonstrate that when combined with traditional brain magnetic resonance imaging (MRI) scans, cerebral Gln and mI MRS can help disentangle the reversible from irreversible neurological defects associated with hyperammonemic crisis. Specifically, we demonstrate that whereas an elevated brain MRS Gln level is associated with reversible neurological defects, markedly low mI levels are associated with a risk for irreversible neurological defects such as central pontine myelinolysis. Overall, our findings indicate the utility of brain MRS in guiding clinical care and prognosis in patients with adult-onset non-cirrhotic hyperammonemia.

成人发作的非肝硬化性高氨血症（NCH）是一种罕见的但通常致命的疾病，可能导致可逆和不可逆的神经功能缺损。在这里，我们介绍了5例成人发作的非肝硬化性高氨血症，其中脑磁共振波谱（MRS）扫描脑谷氨酰胺（Gln）和肌醇（mI）水平有助于指导临床管理。具体而言，我们证明，与传统的脑磁共振成像（MRI）扫描结合使用时，脑Gln和mI MRS可以帮助将可逆性疾病与与高氨血症危机相关的不可逆性神经系统疾病相分离。具体来说，我们证明，虽然脑MRS Gln水平升高与可逆性神经功能缺损有关，显着较低的mI水平与不可逆的神经系统缺陷（例如桥脑中枢髓鞘溶解）的风险有关。总体而言，我们的发现表明，脑MRS在指导成人非肝硬化性高氨血症患者的临床护理和预后方面具有实用性。