{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,1,29]],"date-time":"2026-01-29T22:35:34Z","timestamp":1769726134297,"version":"3.49.0"},"reference-count":68,"publisher":"Journal of Neurosurgery Publishing Group (JNSPG)","issue":"19","license":[{"start":{"date-parts":[[2025,11,10]],"date-time":"2025-11-10T00:00:00Z","timestamp":1762732800000},"content-version":"unspecified","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by-nc-nd\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["J Neurosurg Case Lessons"],"published-print":{"date-parts":[[2025,11,10]]},"abstract":"<jats:sec>\n                    <jats:title>BACKGROUND<\/jats:title>\n                    <jats:p>Fourth ventricular ependymomas are rare glial neoplasms that commonly present with obstructive hydrocephalus, headache, and cerebellar symptoms. Ornithine transcarbamylase deficiency (OTCD), the most common urea cycle disorder, typically presents in infancy but may remain latent until triggered by physiological stressors such as surgery.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>OBSERVATIONS<\/jats:title>\n                    <jats:p>A 59-year-old right-handed previously healthy woman presented to the emergency department with subacute nonspecific neurological symptoms. Initial imaging showed a large mass centered along the inferior aspect of the fourth ventricle with extrusion through the foramina of Luschka and Magendie and into the foramen magnum. She underwent a posterior fossa craniectomy for tumor resection without any intraoperative complications. The focus shifted in the postoperative period to managing emerging hyperammonemia. Complications, including cerebral edema, status epilepticus, and recurrent hyperammonemia, revealed an undiagnosed metabolic condition.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>LESSONS<\/jats:title>\n                    <jats:p>This case describes a novel presentation of late-onset OTCD triggered by posterior fossa craniectomy for resection of a fourth ventricular ependymoma\u2014an association not previously reported in the literature. It emphasizes the importance of maintaining an index of suspicion for metabolic disorders in the setting of postoperative hyperammonemia. Future steps should focus on early testing of ammonia levels in patients with unexplained neurological decline to be proactive with multidisciplinary management.<\/jats:p>\n                    <jats:p>\n                      <jats:ext-link xmlns:xlink=\"http:\/\/www.w3.org\/1999\/xlink\" ext-link-type=\"uri\" xlink:href=\"https:\/\/thejns.org\/doi\/10.3171\/CASE25324\">https:\/\/thejns.org\/doi\/10.3171\/CASE25324<\/jats:ext-link>\n                    <\/jats:p>\n                  <\/jats:sec>","DOI":"10.3171\/case25324","type":"journal-article","created":{"date-parts":[[2026,1,29]],"date-time":"2026-01-29T11:12:01Z","timestamp":1769685121000},"source":"Crossref","is-referenced-by-count":0,"title":["Fatal ornithine transcarbamylase deficiency presentation postresection of fourth ventricle ependymoma: illustrative case"],"prefix":"10.3171","volume":"10","author":[{"given":"Annika S.","family":"Witt","sequence":"first","affiliation":[{"name":"Department of Neurosurgery, University of Colorado School of Medicine, Aurora, Colorado"},{"name":"University of Colorado School of Medicine, Aurora, Colorado"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Luis","family":"Cava Prado","sequence":"additional","affiliation":[{"name":"Department of Neurosurgery, University of Colorado School of Medicine, Aurora, Colorado"},{"name":"University of Colorado School of Medicine, Aurora, Colorado"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Robert","family":"Neumann","sequence":"additional","affiliation":[{"name":"Department of Neurosurgery, University of Colorado School of Medicine, Aurora, Colorado"},{"name":"University of Colorado School of Medicine, Aurora, Colorado"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Jason","family":"Weedman","sequence":"additional","affiliation":[{"name":"Department of Neurosurgery, University of Colorado School of Medicine, Aurora, Colorado"},{"name":"University of Colorado School of Medicine, Aurora, Colorado"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Ross","family":"Moseley","sequence":"additional","affiliation":[{"name":"University of Colorado School of Medicine, Aurora, Colorado"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Pavan","family":"Guttipatti","sequence":"additional","affiliation":[{"name":"University of Colorado School of Medicine, Aurora, Colorado"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Timothy H.","family":"Ung","sequence":"additional","affiliation":[{"name":"Department of Neurosurgery, University of Colorado School of Medicine, Aurora, Colorado"},{"name":"University of Colorado School of Medicine, Aurora, Colorado"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1754","reference":[{"issue":"2","key":"bib1","series-title":"J Neurooncol","first-page":"341","article-title":"Surgical resection of fourth ventricular ependymomas: case series and technical nuances","volume":"130","author":"Winkler","year":"2016","unstructured":"Winkler EABirk HSafaee MSurgical resection of fourth ventricular ependymomas: case series and technical nuances. J Neurooncol. 2016;130(2):341-349."},{"issue":"5","key":"bib2","series-title":"Oper Neurosurg","first-page":"e189","article-title":"Resection of ependymomas infiltrating the fourth ventricular floor: anatomosurgical and stimulation mapping techniques","volume":"22","author":"Sharma","year":"2022","unstructured":"Sharma PSefcikova VSanders BSoumpasis CWaraich MSamandouras G.Resection of ependymomas infiltrating the fourth ventricular floor: anatomosurgical and stimulation mapping techniques. Oper Neurosurg. 2022;22(5):e189-e197."},{"issue":"1","key":"bib3","series-title":"J Neurosurg Pediatr","first-page":"52","article-title":"Fourth ventricle tumors in children: complications and influence of surgical approach","volume":"27","author":"Toescu","year":"2020","unstructured":"Toescu SMSamarth GHorsfall HLFourth ventricle tumors in children: complications and influence of surgical approach. J Neurosurg Pediatr. 2020;27(1):52-61."},{"issue":"8","key":"bib4","series-title":"Paediatr Anaesth","first-page":"937","article-title":"Patient and operative factors associated with unanticipated intensive care admission and outcomes following posterior fossa decompressions in children: a retrospective study","volume":"32","author":"Benzon","year":"2022","unstructured":"Benzon HATantoco ALonghini APatient and operative factors associated with unanticipated intensive care admission and outcomes following posterior fossa decompressions in children: a retrospective study. Paediatr Anaesth. 2022;32(8):937-945."},{"issue":"5","key":"bib5","series-title":"J Genet Genomics","first-page":"181","article-title":"Genotype-phenotype correlations in ornithine transcarbamylase deficiency: a mutation update","volume":"42","author":"Caldovic","year":"2015","unstructured":"Caldovic LAbdikarim INarain STuchman MMorizono H.Genotype-phenotype correlations in ornithine transcarbamylase deficiency: a mutation update. J Genet Genomics. 2015;42(5):181-194."},{"issue":"8","key":"bib6","series-title":"Children (Basel)","first-page":"1368","article-title":"Diagnostic and management issues in patients with late-onset ornithine transcarbamylase deficiency","volume":"10","author":"Ibrahim","year":"2023","unstructured":"Ibrahim MSGold JIWoodall AYilmaz BSGissen PStepien KM.Diagnostic and management issues in patients with late-onset ornithine transcarbamylase deficiency. Children (Basel). 2023;10(8):1368."},{"issue":"4","key":"bib7","series-title":"Clin Liver Dis (Hoboken)","first-page":"198","article-title":"Hepatic manifestations of urea cycle disorders","volume":"18","author":"Strong","year":"2021","unstructured":"Strong AGold JGold NBYudkoff M.Hepatic manifestations of urea cycle disorders. Clin Liver Dis (Hoboken). 2021;18(4):198-203."},{"issue":"5","key":"bib8","series-title":"BMJ Case Rep","first-page":"e255793","article-title":"Corticosteroid-induced hyperammonaemic encephalopathy in a woman with late-onset ornithine transcarbamylase deficiency","volume":"17","author":"McCormick","year":"2024","unstructured":"McCormick BJRitchie LVPorter IE.Corticosteroid-induced hyperammonaemic encephalopathy in a woman with late-onset ornithine transcarbamylase deficiency. BMJ Case Rep. 2024;17(5):e255793."},{"key":"bib9","series-title":"Clin Neurol Neurosurg","first-page":"108260","article-title":"Sensory ataxic polyneuropathy unmasking late-onset urea cycle defect","volume":"240","author":"Kanth","year":"2024","unstructured":"Kanth RKAgrawal NPatel PSensory ataxic polyneuropathy unmasking late-onset urea cycle defect. Clin Neurol Neurosurg. 2024;240:108260."},{"key":"bib10","series-title":"Am J Case Rep","first-page":"e937658","article-title":"Late-onset ornithine transcarbamylase deficiency complicated with extremely high serum ammonia level: prompt induction of hemodialysis as the key to successful treatment","volume":"23","author":"Yamamoto","year":"2022","unstructured":"Yamamoto SYamashita SKakiuchi TLate-onset ornithine transcarbamylase deficiency complicated with extremely high serum ammonia level: prompt induction of hemodialysis as the key to successful treatment. Am J Case Rep. 2022;23:e937658."},{"issue":"2","key":"bib11","series-title":"J Forensic Sci","first-page":"813","article-title":"Late-onset of ornithine transcarbamylase deficiency: a rare medical examiner case","volume":"67","author":"Gitto","year":"2022","unstructured":"Gitto LFuller CECalleo VJTawil MThach RRevercomb C.Late-onset of ornithine transcarbamylase deficiency: a rare medical examiner case. J Forensic Sci. 2022;67(2):813-819."},{"issue":"7","key":"bib12","series-title":"Ann Hematol","first-page":"857","article-title":"Ornithine transcarbamylase (OTC) deficiency based on a hemizygous p.R277W mutation causing life-threatening hyperammonemic crisis during treatment for Hodgkin\u2019s lymphoma","volume":"90","author":"Ritter","year":"2011","unstructured":"Ritter EHusain RAHinderhofer KOrnithine transcarbamylase (OTC) deficiency based on a hemizygous p.R277W mutation causing life-threatening hyperammonemic crisis during treatment for Hodgkin\u2019s lymphoma. Ann Hematol. 2011;90(7):857-859."},{"issue":"20","key":"bib13","series-title":"Neurology","first-page":"e146","article-title":"Teaching NeuroImages: ornithine transcarbamylase deficiency revealed by a coma in a pregnant woman","volume":"85","author":"Bailly","year":"2015","unstructured":"Bailly PNoury JBTimsit SBen Salem DB.Teaching NeuroImages: ornithine transcarbamylase deficiency revealed by a coma in a pregnant woman. Neurology. 2015;85(20):e146-e147."},{"issue":"12","key":"bib14","series-title":"Gynecol Endocrinol","first-page":"1052","article-title":"Ornithine transcarbamylase deficiency diagnosed in pregnancy","volume":"27","author":"Celik","year":"2011","unstructured":"Celik OBuyuktas DAydin AAcbay O.Ornithine transcarbamylase deficiency diagnosed in pregnancy. Gynecol Endocrinol. 2011;27(12):1052-1054."},{"issue":"6","key":"bib15","series-title":"Hepatology","first-page":"1413","article-title":"A novel two-nucleotide deletion in the ornithine transcarbamylase gene causing fatal hyperammonia in early pregnancy","volume":"24","author":"Schimanski","year":"1996","unstructured":"Schimanski UKrieger DHorn MStremmel WWermuth BTheilmann L.A novel two-nucleotide deletion in the ornithine transcarbamylase gene causing fatal hyperammonia in early pregnancy. Hepatology. 1996;24(6):1413-1415."},{"issue":"1","key":"bib16","series-title":"Gastroenterology","first-page":"282","article-title":"Hyperammonemic coma due to parenteral nutrition in a woman with heterozygous ornithine transcarbamylase deficiency","volume":"109","author":"Felig","year":"1995","unstructured":"Felig DMBrusilow SWBoyer JL.Hyperammonemic coma due to parenteral nutrition in a woman with heterozygous ornithine transcarbamylase deficiency. Gastroenterology. 1995;109(1):282-284."},{"issue":"1","key":"bib17","series-title":"BMC Neurol","first-page":"118","article-title":"Ammonia and coma\u2014a case report of late onset hemizygous ornithine carbamyltransferase deficiency in 68-year-old female","volume":"20","author":"Marquetand","year":"2020","unstructured":"Marquetand JFreisinger PLindig TEuler SGasser MOverkamp D.Ammonia and coma\u2014a case report of late onset hemizygous ornithine carbamyltransferase deficiency in 68-year-old female. BMC Neurol. 2020;20(1):118."},{"issue":"2","key":"bib18","series-title":"J Hepatol","first-page":"292","article-title":"Adult-onset ornithine transcarbamylase (OTC) deficiency unmasked by the Atkins\u2019 diet","volume":"52","author":"Ben-Ari","year":"2010","unstructured":"Ben-Ari ZDalal AMorry AAdult-onset ornithine transcarbamylase (OTC) deficiency unmasked by the Atkins\u2019 diet. J Hepatol. 2010;52(2):292-295."},{"issue":"10","key":"bib19","series-title":"Intensive Care Med","first-page":"1922","article-title":"Acute hyperammonemic encephalopathy in adult onset ornithine transcarbamylase deficiency","volume":"34","author":"Panlaqui","year":"2008","unstructured":"Panlaqui OMTran KJohns AMcGill JWhite H.Acute hyperammonemic encephalopathy in adult onset ornithine transcarbamylase deficiency. Intensive Care Med. 2008;34(10):1922-1924."},{"issue":"7","key":"bib20","series-title":"Intern Med","first-page":"937","article-title":"Hyperammonemia in a woman with late-onset ornithine transcarbamylase deficiency","volume":"58","author":"Koya","year":"2019","unstructured":"Koya YShibata MSenju MHyperammonemia in a woman with late-onset ornithine transcarbamylase deficiency. Intern Med. 2019;58(7):937-942."},{"issue":"1","key":"bib21","series-title":"J Med Case Rep","first-page":"134","article-title":"Valproate-induced hyperammonemia\u2014uncovering an underlying inherited metabolic disorder: a case report","volume":"12","author":"Mehta","year":"2018","unstructured":"Mehta STayabali SLachmann R.Valproate-induced hyperammonemia\u2014uncovering an underlying inherited metabolic disorder: a case report. J Med Case Rep. 2018;12(1):134."},{"issue":"5","key":"bib22","series-title":"BMJ Case Rep","first-page":"e241429","article-title":"Valproate-induced fatal acute hyperammonaemia-related encephalopathy in late-onset ornithine transcarbamylase deficiency","volume":"14","author":"Kazmierski","year":"2021","unstructured":"Kazmierski DSharma NO\u2019Leary KOchieng P.Valproate-induced fatal acute hyperammonaemia-related encephalopathy in late-onset ornithine transcarbamylase deficiency. BMJ Case Rep. 2021;14(5):e241429."},{"issue":"5","key":"bib23","series-title":"BMJ Case Rep","first-page":"e238023","article-title":"Status epilepticus secondary to hyperammonaemia: a late presentation of an undiagnosed urea cycle defect","volume":"14","author":"Beddoes","year":"2021","unstructured":"Beddoes PNerone GTai C.Status epilepticus secondary to hyperammonaemia: a late presentation of an undiagnosed urea cycle defect. BMJ Case Rep. 2021;14(5):e238023."},{"issue":"6","key":"bib24","series-title":"J Neurol Neurosurg Psychiatry","first-page":"813","article-title":"Late onset heterozygous ornithine transcarbamylase deficiency mimicking complex partial status epilepticus","volume":"69","author":"Bogdanovic","year":"2000","unstructured":"Bogdanovic MDKidd DBriddon ADuncan JSLand JM.Late onset heterozygous ornithine transcarbamylase deficiency mimicking complex partial status epilepticus. J Neurol Neurosurg Psychiatry. 2000;69(6):813-815."},{"issue":"3","key":"bib25","series-title":"Rev Neurol (Paris)","first-page":"296","article-title":"Diagnosis of ornithine transcarbamylase deficiency secondary to p.Leu301Phe mutation in an adult patient","volume":"168","author":"Morel","year":"2012","unstructured":"Morel NCorne CAquaviva CBesson G.Diagnosis of ornithine transcarbamylase deficiency secondary to p.Leu301Phe mutation in an adult patient. Rev Neurol (Paris). 2012;168(3):296-297."},{"issue":"1","key":"bib26","series-title":"Hematology","first-page":"2265187","article-title":"Adult presentation of ornithine transcarbamylase deficiency: a possible cause of hyperammonemia after high-dose chemotherapy and stem cell transplantation","volume":"28","author":"Tsykunova","year":"2023","unstructured":"Tsykunova GKristensen EStray-Pedersen AAdult presentation of ornithine transcarbamylase deficiency: a possible cause of hyperammonemia after high-dose chemotherapy and stem cell transplantation. Hematology. 2023;28(1):2265187."},{"issue":"5","key":"bib27","series-title":"J Korean Med Sci","first-page":"556","article-title":"Hyperammonemia in a patient with late-onset ornithine carbamoyltransferase deficiency","volume":"27","author":"Choi","year":"2012","unstructured":"Choi DELee KWShin YTNa KR.Hyperammonemia in a patient with late-onset ornithine carbamoyltransferase deficiency. J Korean Med Sci. 2012;27(5):556-559."},{"issue":"1","key":"bib28","series-title":"Arch Neurol","first-page":"126","article-title":"Ornithine transcarbamylase deficiency presenting as encephalopathy during adulthood following bariatric surgery","volume":"64","author":"Hu","year":"2007","unstructured":"Hu WTKantarci OHMerritt JLOrnithine transcarbamylase deficiency presenting as encephalopathy during adulthood following bariatric surgery. Arch Neurol. 2007;64(1):126-128."},{"issue":"1","key":"bib29","series-title":"Ann Emerg Med","first-page":"104","article-title":"Late-onset presentation of ornithine transcarbamylase deficiency in a young woman with hyperammonemic coma","volume":"41","author":"Gaspari","year":"2003","unstructured":"Gaspari RArcangeli AMensi SLate-onset presentation of ornithine transcarbamylase deficiency in a young woman with hyperammonemic coma. Ann Emerg Med. 2003;41(1):104-109."},{"issue":"1","key":"bib30","series-title":"Neth J Med","first-page":"25","article-title":"Bizarre behavior and decreased level of consciousness in an adult patient","volume":"77","author":"Van Son","year":"2019","unstructured":"Van Son JRietbroek RCVaz FMHollak CEM.Bizarre behavior and decreased level of consciousness in an adult patient. Neth J Med. 2019;77(1):25-28."},{"issue":"8","key":"bib31","series-title":"Med J Aust","first-page":"418","article-title":"Fatal late-onset ornithine transcarbamylase deficiency after coronary artery bypass surgery","volume":"186","author":"Chiong","year":"2007","unstructured":"Chiong MABennetts BHStrasser SIWilcken B.Fatal late-onset ornithine transcarbamylase deficiency after coronary artery bypass surgery. Med J Aust. 2007;186(8):418-419."},{"key":"bib32","series-title":"Biochem Pharmacol","first-page":"116034","article-title":"Mitochondrial targets in hyperammonemia: addressing urea cycle function to improve drug therapies","volume":"222","author":"Moedas","year":"2024","unstructured":"Moedas MFSim\u00f5es RJMSilva MFB.Mitochondrial targets in hyperammonemia: addressing urea cycle function to improve drug therapies. Biochem Pharmacol. 2024;222:116034."},{"key":"bib33","article-title":"Hyperammonemia","author":"Ali","unstructured":"Ali RNagalli S.Hyperammonemia. In: StatPearls. Accessed December 1, 2024. https:\/\/www.ncbi.nlm.nih.gov\/books\/NBK557504\/"},{"issue":"4","key":"bib34","series-title":"Pediatrics","first-page":"e1072","article-title":"Late-onset ornithine transcarbamylase deficiency: treatment and outcome of hyperammonemic crisis","volume":"133","author":"Bergmann","year":"2014","unstructured":"Bergmann KRMcCabe JSmith TRGuillaume DJSarafoglou KGupta S.Late-onset ornithine transcarbamylase deficiency: treatment and outcome of hyperammonemic crisis. Pediatrics. 2014;133(4):e1072-e1076."},{"issue":"2","key":"bib1","series-title":"J Neurooncol","first-page":"341","article-title":"Surgical resection of fourth ventricular ependymomas: case series and technical nuances","volume":"130","author":"Winkler","year":"2016","unstructured":"Winkler EABirk HSafaee MSurgical resection of fourth ventricular ependymomas: case series and technical nuances. J Neurooncol. 2016;130(2):341-349."},{"issue":"5","key":"bib2","series-title":"Oper Neurosurg","first-page":"e189","article-title":"Resection of ependymomas infiltrating the fourth ventricular floor: anatomosurgical and stimulation mapping techniques","volume":"22","author":"Sharma","year":"2022","unstructured":"Sharma PSefcikova VSanders BSoumpasis CWaraich MSamandouras G.Resection of ependymomas infiltrating the fourth ventricular floor: anatomosurgical and stimulation mapping techniques. Oper Neurosurg. 2022;22(5):e189-e197."},{"issue":"1","key":"bib3","series-title":"J Neurosurg Pediatr","first-page":"52","article-title":"Fourth ventricle tumors in children: complications and influence of surgical approach","volume":"27","author":"Toescu","year":"2020","unstructured":"Toescu SMSamarth GHorsfall HLFourth ventricle tumors in children: complications and influence of surgical approach. J Neurosurg Pediatr. 2020;27(1):52-61."},{"issue":"8","key":"bib4","series-title":"Paediatr Anaesth","first-page":"937","article-title":"Patient and operative factors associated with unanticipated intensive care admission and outcomes following posterior fossa decompressions in children: a retrospective study","volume":"32","author":"Benzon","year":"2022","unstructured":"Benzon HATantoco ALonghini APatient and operative factors associated with unanticipated intensive care admission and outcomes following posterior fossa decompressions in children: a retrospective study. Paediatr Anaesth. 2022;32(8):937-945."},{"issue":"5","key":"bib5","series-title":"J Genet Genomics","first-page":"181","article-title":"Genotype-phenotype correlations in ornithine transcarbamylase deficiency: a mutation update","volume":"42","author":"Caldovic","year":"2015","unstructured":"Caldovic LAbdikarim INarain STuchman MMorizono H.Genotype-phenotype correlations in ornithine transcarbamylase deficiency: a mutation update. J Genet Genomics. 2015;42(5):181-194."},{"issue":"8","key":"bib6","series-title":"Children (Basel)","first-page":"1368","article-title":"Diagnostic and management issues in patients with late-onset ornithine transcarbamylase deficiency","volume":"10","author":"Ibrahim","year":"2023","unstructured":"Ibrahim MSGold JIWoodall AYilmaz BSGissen PStepien KM.Diagnostic and management issues in patients with late-onset ornithine transcarbamylase deficiency. Children (Basel). 2023;10(8):1368."},{"issue":"4","key":"bib7","series-title":"Clin Liver Dis (Hoboken)","first-page":"198","article-title":"Hepatic manifestations of urea cycle disorders","volume":"18","author":"Strong","year":"2021","unstructured":"Strong AGold JGold NBYudkoff M.Hepatic manifestations of urea cycle disorders. Clin Liver Dis (Hoboken). 2021;18(4):198-203."},{"issue":"5","key":"bib8","series-title":"BMJ Case Rep","first-page":"e255793","article-title":"Corticosteroid-induced hyperammonaemic encephalopathy in a woman with late-onset ornithine transcarbamylase deficiency","volume":"17","author":"McCormick","year":"2024","unstructured":"McCormick BJRitchie LVPorter IE.Corticosteroid-induced hyperammonaemic encephalopathy in a woman with late-onset ornithine transcarbamylase deficiency. BMJ Case Rep. 2024;17(5):e255793."},{"key":"bib9","series-title":"Clin Neurol Neurosurg","first-page":"108260","article-title":"Sensory ataxic polyneuropathy unmasking late-onset urea cycle defect","volume":"240","author":"Kanth","year":"2024","unstructured":"Kanth RKAgrawal NPatel PSensory ataxic polyneuropathy unmasking late-onset urea cycle defect. Clin Neurol Neurosurg. 2024;240:108260."},{"key":"bib10","series-title":"Am J Case Rep","first-page":"e937658","article-title":"Late-onset ornithine transcarbamylase deficiency complicated with extremely high serum ammonia level: prompt induction of hemodialysis as the key to successful treatment","volume":"23","author":"Yamamoto","year":"2022","unstructured":"Yamamoto SYamashita SKakiuchi TLate-onset ornithine transcarbamylase deficiency complicated with extremely high serum ammonia level: prompt induction of hemodialysis as the key to successful treatment. Am J Case Rep. 2022;23:e937658."},{"issue":"2","key":"bib11","series-title":"J Forensic Sci","first-page":"813","article-title":"Late-onset of ornithine transcarbamylase deficiency: a rare medical examiner case","volume":"67","author":"Gitto","year":"2022","unstructured":"Gitto LFuller CECalleo VJTawil MThach RRevercomb C.Late-onset of ornithine transcarbamylase deficiency: a rare medical examiner case. J Forensic Sci. 2022;67(2):813-819."},{"issue":"7","key":"bib12","series-title":"Ann Hematol","first-page":"857","article-title":"Ornithine transcarbamylase (OTC) deficiency based on a hemizygous p.R277W mutation causing life-threatening hyperammonemic crisis during treatment for Hodgkin\u2019s lymphoma","volume":"90","author":"Ritter","year":"2011","unstructured":"Ritter EHusain RAHinderhofer KOrnithine transcarbamylase (OTC) deficiency based on a hemizygous p.R277W mutation causing life-threatening hyperammonemic crisis during treatment for Hodgkin\u2019s lymphoma. Ann Hematol. 2011;90(7):857-859."},{"issue":"20","key":"bib13","series-title":"Neurology","first-page":"e146","article-title":"Teaching NeuroImages: ornithine transcarbamylase deficiency revealed by a coma in a pregnant woman","volume":"85","author":"Bailly","year":"2015","unstructured":"Bailly PNoury JBTimsit SBen Salem DB.Teaching NeuroImages: ornithine transcarbamylase deficiency revealed by a coma in a pregnant woman. Neurology. 2015;85(20):e146-e147."},{"issue":"12","key":"bib14","series-title":"Gynecol Endocrinol","first-page":"1052","article-title":"Ornithine transcarbamylase deficiency diagnosed in pregnancy","volume":"27","author":"Celik","year":"2011","unstructured":"Celik OBuyuktas DAydin AAcbay O.Ornithine transcarbamylase deficiency diagnosed in pregnancy. Gynecol Endocrinol. 2011;27(12):1052-1054."},{"issue":"6","key":"bib15","series-title":"Hepatology","first-page":"1413","article-title":"A novel two-nucleotide deletion in the ornithine transcarbamylase gene causing fatal hyperammonia in early pregnancy","volume":"24","author":"Schimanski","year":"1996","unstructured":"Schimanski UKrieger DHorn MStremmel WWermuth BTheilmann L.A novel two-nucleotide deletion in the ornithine transcarbamylase gene causing fatal hyperammonia in early pregnancy. Hepatology. 1996;24(6):1413-1415."},{"issue":"1","key":"bib16","series-title":"Gastroenterology","first-page":"282","article-title":"Hyperammonemic coma due to parenteral nutrition in a woman with heterozygous ornithine transcarbamylase deficiency","volume":"109","author":"Felig","year":"1995","unstructured":"Felig DMBrusilow SWBoyer JL.Hyperammonemic coma due to parenteral nutrition in a woman with heterozygous ornithine transcarbamylase deficiency. Gastroenterology. 1995;109(1):282-284."},{"issue":"1","key":"bib17","series-title":"BMC Neurol","first-page":"118","article-title":"Ammonia and coma\u2014a case report of late onset hemizygous ornithine carbamyltransferase deficiency in 68-year-old female","volume":"20","author":"Marquetand","year":"2020","unstructured":"Marquetand JFreisinger PLindig TEuler SGasser MOverkamp D.Ammonia and coma\u2014a case report of late onset hemizygous ornithine carbamyltransferase deficiency in 68-year-old female. BMC Neurol. 2020;20(1):118."},{"issue":"2","key":"bib18","series-title":"J Hepatol","first-page":"292","article-title":"Adult-onset ornithine transcarbamylase (OTC) deficiency unmasked by the Atkins\u2019 diet","volume":"52","author":"Ben-Ari","year":"2010","unstructured":"Ben-Ari ZDalal AMorry AAdult-onset ornithine transcarbamylase (OTC) deficiency unmasked by the Atkins\u2019 diet. J Hepatol. 2010;52(2):292-295."},{"issue":"10","key":"bib19","series-title":"Intensive Care Med","first-page":"1922","article-title":"Acute hyperammonemic encephalopathy in adult onset ornithine transcarbamylase deficiency","volume":"34","author":"Panlaqui","year":"2008","unstructured":"Panlaqui OMTran KJohns AMcGill JWhite H.Acute hyperammonemic encephalopathy in adult onset ornithine transcarbamylase deficiency. Intensive Care Med. 2008;34(10):1922-1924."},{"issue":"7","key":"bib20","series-title":"Intern Med","first-page":"937","article-title":"Hyperammonemia in a woman with late-onset ornithine transcarbamylase deficiency","volume":"58","author":"Koya","year":"2019","unstructured":"Koya YShibata MSenju MHyperammonemia in a woman with late-onset ornithine transcarbamylase deficiency. Intern Med. 2019;58(7):937-942."},{"issue":"1","key":"bib21","series-title":"J Med Case Rep","first-page":"134","article-title":"Valproate-induced hyperammonemia\u2014uncovering an underlying inherited metabolic disorder: a case report","volume":"12","author":"Mehta","year":"2018","unstructured":"Mehta STayabali SLachmann R.Valproate-induced hyperammonemia\u2014uncovering an underlying inherited metabolic disorder: a case report. J Med Case Rep. 2018;12(1):134."},{"issue":"5","key":"bib22","series-title":"BMJ Case Rep","first-page":"e241429","article-title":"Valproate-induced fatal acute hyperammonaemia-related encephalopathy in late-onset ornithine transcarbamylase deficiency","volume":"14","author":"Kazmierski","year":"2021","unstructured":"Kazmierski DSharma NO\u2019Leary KOchieng P.Valproate-induced fatal acute hyperammonaemia-related encephalopathy in late-onset ornithine transcarbamylase deficiency. BMJ Case Rep. 2021;14(5):e241429."},{"issue":"5","key":"bib23","series-title":"BMJ Case Rep","first-page":"e238023","article-title":"Status epilepticus secondary to hyperammonaemia: a late presentation of an undiagnosed urea cycle defect","volume":"14","author":"Beddoes","year":"2021","unstructured":"Beddoes PNerone GTai C.Status epilepticus secondary to hyperammonaemia: a late presentation of an undiagnosed urea cycle defect. BMJ Case Rep. 2021;14(5):e238023."},{"issue":"6","key":"bib24","series-title":"J Neurol Neurosurg Psychiatry","first-page":"813","article-title":"Late onset heterozygous ornithine transcarbamylase deficiency mimicking complex partial status epilepticus","volume":"69","author":"Bogdanovic","year":"2000","unstructured":"Bogdanovic MDKidd DBriddon ADuncan JSLand JM.Late onset heterozygous ornithine transcarbamylase deficiency mimicking complex partial status epilepticus. J Neurol Neurosurg Psychiatry. 2000;69(6):813-815."},{"issue":"3","key":"bib25","series-title":"Rev Neurol (Paris)","first-page":"296","article-title":"Diagnosis of ornithine transcarbamylase deficiency secondary to p.Leu301Phe mutation in an adult patient","volume":"168","author":"Morel","year":"2012","unstructured":"Morel NCorne CAquaviva CBesson G.Diagnosis of ornithine transcarbamylase deficiency secondary to p.Leu301Phe mutation in an adult patient. Rev Neurol (Paris). 2012;168(3):296-297."},{"issue":"1","key":"bib26","series-title":"Hematology","first-page":"2265187","article-title":"Adult presentation of ornithine transcarbamylase deficiency: a possible cause of hyperammonemia after high-dose chemotherapy and stem cell transplantation","volume":"28","author":"Tsykunova","year":"2023","unstructured":"Tsykunova GKristensen EStray-Pedersen AAdult presentation of ornithine transcarbamylase deficiency: a possible cause of hyperammonemia after high-dose chemotherapy and stem cell transplantation. Hematology. 2023;28(1):2265187."},{"issue":"5","key":"bib27","series-title":"J Korean Med Sci","first-page":"556","article-title":"Hyperammonemia in a patient with late-onset ornithine carbamoyltransferase deficiency","volume":"27","author":"Choi","year":"2012","unstructured":"Choi DELee KWShin YTNa KR.Hyperammonemia in a patient with late-onset ornithine carbamoyltransferase deficiency. J Korean Med Sci. 2012;27(5):556-559."},{"issue":"1","key":"bib28","series-title":"Arch Neurol","first-page":"126","article-title":"Ornithine transcarbamylase deficiency presenting as encephalopathy during adulthood following bariatric surgery","volume":"64","author":"Hu","year":"2007","unstructured":"Hu WTKantarci OHMerritt JLOrnithine transcarbamylase deficiency presenting as encephalopathy during adulthood following bariatric surgery. Arch Neurol. 2007;64(1):126-128."},{"issue":"1","key":"bib29","series-title":"Ann Emerg Med","first-page":"104","article-title":"Late-onset presentation of ornithine transcarbamylase deficiency in a young woman with hyperammonemic coma","volume":"41","author":"Gaspari","year":"2003","unstructured":"Gaspari RArcangeli AMensi SLate-onset presentation of ornithine transcarbamylase deficiency in a young woman with hyperammonemic coma. Ann Emerg Med. 2003;41(1):104-109."},{"issue":"1","key":"bib30","series-title":"Neth J Med","first-page":"25","article-title":"Bizarre behavior and decreased level of consciousness in an adult patient","volume":"77","author":"Van Son","year":"2019","unstructured":"Van Son JRietbroek RCVaz FMHollak CEM.Bizarre behavior and decreased level of consciousness in an adult patient. Neth J Med. 2019;77(1):25-28."},{"issue":"8","key":"bib31","series-title":"Med J Aust","first-page":"418","article-title":"Fatal late-onset ornithine transcarbamylase deficiency after coronary artery bypass surgery","volume":"186","author":"Chiong","year":"2007","unstructured":"Chiong MABennetts BHStrasser SIWilcken B.Fatal late-onset ornithine transcarbamylase deficiency after coronary artery bypass surgery. Med J Aust. 2007;186(8):418-419."},{"key":"bib32","series-title":"Biochem Pharmacol","first-page":"116034","article-title":"Mitochondrial targets in hyperammonemia: addressing urea cycle function to improve drug therapies","volume":"222","author":"Moedas","year":"2024","unstructured":"Moedas MFSim\u00f5es RJMSilva MFB.Mitochondrial targets in hyperammonemia: addressing urea cycle function to improve drug therapies. Biochem Pharmacol. 2024;222:116034."},{"key":"bib33","article-title":"Hyperammonemia","author":"Ali","unstructured":"Ali RNagalli S.Hyperammonemia. In: StatPearls. Accessed December 1, 2024. https:\/\/www.ncbi.nlm.nih.gov\/books\/NBK557504\/"},{"issue":"4","key":"bib34","series-title":"Pediatrics","first-page":"e1072","article-title":"Late-onset ornithine transcarbamylase deficiency: treatment and outcome of hyperammonemic crisis","volume":"133","author":"Bergmann","year":"2014","unstructured":"Bergmann KRMcCabe JSmith TRGuillaume DJSarafoglou KGupta S.Late-onset ornithine transcarbamylase deficiency: treatment and outcome of hyperammonemic crisis. Pediatrics. 2014;133(4):e1072-e1076."}],"container-title":["Journal of Neurosurgery: Case Lessons"],"original-title":[],"link":[{"URL":"https:\/\/thejns.org\/view\/journals\/j-neurosurg-case-lessons\/10\/19\/article-CASE25324.xml","content-type":"text\/html","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/thejns.org\/downloadpdf\/journals\/j-neurosurg-case-lessons\/10\/19\/article-CASE25324.xml","content-type":"text\/html","content-version":"vor","intended-application":"syndication"},{"URL":"https:\/\/thejns.org\/downloadpdf\/journals\/j-neurosurg-case-lessons\/10\/19\/article-CASE25324.xml","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,1,29]],"date-time":"2026-01-29T11:12:01Z","timestamp":1769685121000},"score":1,"resource":{"primary":{"URL":"https:\/\/thejns.org\/view\/journals\/j-neurosurg-case-lessons\/10\/19\/article-CASE25324.xml"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2025,11,10]]},"references-count":68,"journal-issue":{"issue":"19"},"URL":"https:\/\/doi.org\/10.3171\/case25324","relation":{},"ISSN":["2694-1902"],"issn-type":[{"value":"2694-1902","type":"electronic"}],"subject":[],"published":{"date-parts":[[2025,11,10]]}}}