Headache Center, Neurology Department, G. Salvini Hospital, AO G. Salvini, Viale Forlanini, 121, 20200 Garbagnate Milanese (MI), Italy.
Neurol Sci. 2011 May;32 Suppl 1:S157-9. doi: 10.1007/s10072-011-0518-3.
An enzymatic abnormality of the urea cycle is a metabolic disorder occasionally seen in adults, but particularly in the puerperium. The main risk is acute hyperammoniemic encephalopathy, leading to psychosis, coma and even death if not diagnosed promptly and treated appropriately. Headache is frequent in the puerperium normally manifesting between 3 and 6 days after delivery. We describe here a 39-year-old woman, who 3 days after delivery presented diffuse tension-type headache and depression, followed by behavioral disorders, psychomotor agitation, epileptic seizures, and finally coma 2 days later. Pregnancy and normal delivery: routine blood chemistry findings, CT scan, MR imaging, angio-MR of the brain, and lumbar puncture were normal. EEG when seizures started, it showed diffuse slowing, as in the case of metabolic encephalopathy. This led us to assay blood ammonia, which was high at >400 mmol. Liver function and abdominal US were normal; hence, we suspected a urea cycle enzymatic abnormality, and requested for genetic tests. These confirmed a congenital primary metabolic deficiency of arginine succinate synthetase, with high citrullinemia (type II, adult form). Dialysis was started promptly, with initially iv arginine, then orally, plus medical therapy for the hyperammoniemia and a low protein diet; plasma ammonia dropped swiftly to normal, and her state of consciousness gradually improved until all the clinical symptoms had resolved. Ammonia assay should always be considered in the first few days of the puerperium in women with headache and behavioral disorders, to exclude an inborn deficiency of the urea cycle, which may have gone unnoticed until then.
尿素循环酶的异常是一种代谢紊乱，偶尔在成人中出现，但尤其在产褥期更为常见。主要风险是急性高氨血症性脑病，导致精神病、昏迷，甚至死亡，如果不及时诊断和适当治疗。头痛在产褥期很常见，通常在分娩后 3 至 6 天出现。我们在此描述一位 39 岁的女性，她在分娩后 3 天出现弥漫性紧张型头痛和抑郁，随后出现行为障碍、精神运动激越、癫痫发作，最终在 2 天后昏迷。妊娠和分娩：常规血液化学检查、CT 扫描、磁共振成像、脑血管磁共振成像和腰椎穿刺均正常。癫痫发作时的脑电图显示弥漫性减慢，类似于代谢性脑病。这导致我们检测血氨，结果发现血氨值>400mmol/L。肝功能和腹部超声正常；因此，我们怀疑存在尿素循环酶异常，并要求进行基因检测。这些检测结果证实存在精氨酸琥珀酸合成酶先天性原发性代谢缺陷，伴有高瓜氨酸血症（II 型，成人型）。迅速开始透析，最初静脉注射精氨酸，然后口服，同时进行高氨血症的药物治疗和低蛋白饮食；血浆氨迅速降至正常，她的意识状态逐渐改善，直至所有临床症状均已缓解。在产褥期头痛和行为障碍的女性中，应始终考虑进行氨检测，以排除尿素循环的先天性缺陷，这种缺陷在此之前可能未被发现。
