Hyperammonemia in a case of herpes simplex and anti-N-methyl-d-aspartate receptor encephalitis

• Published in: Brain & development (Tokyo. 1979) 2019-08, Vol.41 (7), p.634-637
• Main Authors: Ko, Jung Min, Kim, Woo Joong, Kim, Soo Yeon, Lee, Jun Hwa, Chae, Jong Hee, Kim, Ki Joong, Lim, Byung Chan
• Format: Article
• Language: English
• Subjects: Amino Acid Metabolism, Inborn Errors; Anti-N-methyl-d-aspartate receptor encephalitis; Anti-N-Methyl-D-Aspartate Receptor Encephalitis - complications; Anti-N-Methyl-D-Aspartate Receptor Encephalitis - metabolism; Anti-N-Methyl-D-Aspartate Receptor Encephalitis - physiopathology; Autoantibodies; Encephalitis, Herpes Simplex - complications; Female; Herpes Simplex - complications; Herpes Simplex - physiopathology; Herpes simplex encephalitis; Humans; Hyperammonemia - complications; Hyperammonemia - physiopathology; Infant; Lysinuric protein intolerance; Receptors, N-Methyl-D-Aspartate - immunology
• ISSN: 0387-7604; 1872-7131
• DOI: 10.1016/j.braindev.2019.03.013

Herpes simplex encephalitis (HSE) is a widely accepted risk factor for anti N-methyl-d-aspartate receptor (NMDAR) encephalitis. Association of inherited metabolic disease has never been reported in a patient with HSE and anti-NMDAR encephalitis. Herein, we report a case of pediatric HSE complicated by development of anti-NMDAR encephalitis; this patient showed subsequent recurrent, unexplained episodes of encephalopathy associated with hyperammonemia. The patient was diagnosed with lysinuric protein intolerance (LPI), a rare inborn metabolic disorder. Although it would be difficult to make conclusions regarding the casual link of HSE and anti-NMDAR encephalitis with LPI from a single case, there have been many reports that autoimmune diseases and immunologic abnormalities are frequently associated with LPI. Thus, we speculate that LPI may contribute to the development of anti-NMDAR encephalitis following HSE.