Department of Emergency and Critical Care Medicine, The University of Tokyo Hospital, Tokyo 113-8655, Japan.
Am J Emerg Med. 2013 Oct;31(10):1486-9. doi: 10.1016/j.ajem.2013.08.003. Epub 2013 Sep 3.
It is known that patients with convulsion often present hyperammonemia. The elevation of ammonia levels in convulsion is considered to occur along with extensive muscle contractions, but the details remain unclear. In emergency pathologies, such as cardiopulmonary arrest or hemorrhagic shock without muscle contraction, red blood cells are known to produce ammonia through acidosis, leading to hyperammonemia. A similar effect would be considered to be involved in idiopathic epileptic seizure patients as well.
We retrospectively analyzed the cases of epileptic seizure that were transported to the emergency medical care center of Ohta Nishinouchi Hospital and diagnosed by neurologist as idiopathic epileptic seizure or epilepsy due to cerebrovascular disorder. Forty-four patients were idiopathic epilepsy, and 8 had epilepsy due to cerebrovascular disorder. Those with hepatic encephalopathy, metabolic disorder, alcohol consumption, tumor, and patients taking oral valproic acid were excluded.
High ammonia levels (>35 μmol/L) were observed in 22 cases. Maximum ammonia level was 506 μmol/L. Significant differences were observed in the pH (r = 0.838, P < .0001) and base excess (BE) (r = 0.863, P < .0001), the values suggesting a strong negative correlation between the ammonia level and pH/BE.
Idiopathic epileptic seizures can present with prominent hyperammonemia with acidosis. Because high ammonia level in epileptic seizure was strongly correlated with pH and BE, we speculate that hyperammonemia is not only because of extensive muscle contractions but is also related to ammonia production in the red blood cells through acidosis like other emergency conditions.
众所周知，抽搐患者常伴有高血氨症。抽搐时血氨水平升高被认为与广泛的肌肉收缩有关，但具体机制尚不清楚。在心肺骤停或无肌肉收缩的失血性休克等紧急情况下，已知红细胞会通过酸中毒产生氨，导致高血氨症。同样的情况也被认为与特发性癫痫发作患者有关。
我们回顾性分析了被送往大平西野之内医院急救医疗中心并被神经科医生诊断为特发性癫痫发作或脑血管疾病引起的癫痫的癫痫发作病例。44 例为特发性癫痫，8 例为脑血管疾病引起的癫痫。排除肝性脑病、代谢紊乱、酒精摄入、肿瘤和服用口服丙戊酸钠的患者。
22 例患者血氨水平升高（>35 μmol/L），最高血氨水平为 506 μmol/L。血氨水平与 pH 值（r = 0.838，P <.0001）和碱剩余（BE）（r = 0.863，P <.0001）呈显著负相关，提示两者之间存在很强的相关性。
特发性癫痫发作可伴有明显的酸中毒高血氨症。由于癫痫发作时的高血氨水平与 pH 值和 BE 值呈强相关性，我们推测高血氨症不仅与广泛的肌肉收缩有关，还与红细胞通过酸中毒产生氨有关，这种情况类似于其他紧急情况。
