Extrapontine myelinolysis in a 4 year old with diabetic ketoacidosis

Extrapontine and central pontine myelinolysis (EPM/CPM) are rare events in pediatric neurology but can have devastating consequences. They are most commonly associated with rapid correction of hyponatremia but have been reported in other situations as well. This condition is relatively more common in adult neurology, not surprisingly, as alcoholism and associated malnutrition are often predisposing conditions. There have been few case reports in children with regards to this. We describe a 4-year old who presented with focal neurological deficits in the setting of diabetic ketoacidosis and the ensuing underlying osmotic imbalances. The patient made a remarkable recovery with no deficits of note-cognitive or motor. To our knowledge this is the youngest case reported so far of EPM in a child with diabetic ketoacidosis. The history of the condition, early animal experiments, clinicopathologic correlates, previous case reports and other scenarios in which this unusual event can occur are discussed--though the exact pathogenesis of this condition still remains unclear. We hope to bring to the attention of clinicians caring for children in the acute care setting, the importance of gradual correction of serum osmolality to reduce morbidity and mortality.     

Cell volume regulation: a review of cerebral adaptive mechanisms and implications for clinical treatment of osmolal disturbances: II

Cerebral cell volume regulatory mechanisms are activated by sustained disturbances in plasma osmolality. Acute hypernatremia causes a predictable shrinkage of brain cells due to the sudden imposition of a plasma-to-cell osmolal gradient. However, during chronic hypernatremia cerebral cell volume is maintained close to the normal range as a result of the accumulation of electrolytes and organic osmolytes including myo-inositol, taurine, glutamine, glycerophosphorylcholine, and betaine. The increased cytosolic level of these molecules is generally accomplished via increased activity of sodium (Na⁺)-dependent cotransport systems. The slow dissipation of these additional osmotically active solutes from the cell during treatment of hypernatremia necessitates gradual correction of this electrolyte abnormality. Acute hyponatremia leads to cerebral cell swelling and severe neurological dysfunction. However, prolonged hyponatremia is associated with significant reductions in brain cell electrolyte and organic osmolyte content so that cerebral cell volume is restored to normal. While acute hyponatremia can be treated with the administration of moderate doses of hypertonic saline in order to control seizure activity, chronic hyponatremia should be corrected slowly in order to prevent subsequent neurological deterioration. If the rate of correction exceeds 0.5 mmol/l per hour, or if the total increment in serum [Na⁺] exceeds 25 mmol/l in the first 48 h of therapy, then there is an increased risk of the development of cerebral demyelinating lesions. Chronic hyperglycemia activates the brain cell volume regulatory adaptations in the same manner as hypernatremia. Therefore, during the treatment of diabetic ketoacidosis, it is imperative to restore normoglycemia gradually in order to prevent the occurrence of cerebral edema. It is possible that excessive administration of electrolyte-free solutions and high doses of insulin may increase the risk of this complication. While there are some data to suggest that brain cell size is disturbed during acute uremia, additional work is necessary to clarify the role of cerebral cell volume regulation during acute and chronic uremia.     

迟发性维生素K缺乏性颅内出血患儿血浆心钠素与低钠血症的关系

目的探讨迟发性维生素K缺乏性颅内出血患儿心钠素(ANP)水平变化与低钠血症的关系及其临床意义。方法应用放射免疫分析技术检测108例颅内出血患儿不同病程的血浆ANP水平,同时检测血清钠的含量,选取25例健康同龄儿作为对照。结果(1)颅内出血急性期血浆ANP水平均高于对照组(P<0·05);昏迷组患儿ANP升高更明显(P<0·01);(2)颅内出血患儿血浆ANP与血清钠水平呈负相关(γ=-0·748,P<0·05)。结论(1)迟发性维生素K缺乏性颅内出血患儿血浆ANP水平反映脑损伤严重程度;(2)ANP参与迟发性维生素K缺乏性颅内出血患儿低钠血症的形成过程。     

Decreased serum sodium levels predict symptomatic vasospasm in patients with subarachnoid hemorrhage

Background: Symptomatic vasospasm is a major cause of morbidity and mortality in subarachnoid hemorrhage patients. Hyponatremia and dehydration due to natriuresis after subarachnoid hemorrhage are related to symptomatic vasospasm. Therefore, most institutions are currently targeting euvolemia and eunatremia in subarachnoid hemorrhage patients to avoid complications. We retrospectively investigated the predictors of symptomatic vasospasm with respect to water and sodium homeostasis, while maintaining euvolemia and eunatremia after subarachnoid hemorrhage. Methods: We monitored changes in serum sodium levels, serum osmolarity, daily sodium intake, daily urine volume, and daily water balance for 14 days after subarachnoid hemorrhage. Outcomes were assessed using the modified Rankin scale at 1 month after subarachnoid hemorrhage. Results: Among 97 patients, 27 (27.8%) had symptomatic vasospasm. Patients with symptomatic vasospasm were older than those without symptomatic vasospasm; the occurrence of symptomatic vasospasm affected outcomes. Serum sodium levels were sequentially significantly decreased, but within the normal range from 1 day before the occurrence of symptomatic vasospasm. Serum osmolarity of the spasm group was lower than that of the non-spasm group. Conclusions: Symptomatic vasospasm occurs more often in older patients and affects outcomes. A decrease in serum sodium levels occurs a day before symptomatic vasospasm. This observation may help predict symptomatic vasospasm.     

脑梗死并发低钠血症与营养相关因素的分析

目的:分析脑梗死病人低钠血症的发生情况以及与营养相关因素的关系,旨在提高临床综合治疗效果。方法:对240例脑梗死病人,于入院后第2天清晨空腹抽取静脉血,检测血清钠、血红蛋白、总蛋白、清蛋白、C-反应蛋白和淋巴细胞计数,并进行统计学分析。结果:240例脑梗死病人发生低钠血症者为61例,占25.42%。低钠组病人血清总蛋白、清蛋白、血红蛋白、淋巴细胞计数均明显低于血钠正常组,C-反应蛋白显著高于血钠正常组(P<0.05)。脑梗死病人血清钠与总蛋白、清蛋白、血红蛋白和C-反应蛋白之间具有明显相关性(P<0.05)。结论:脑梗死病人低钠血症与机体营养不良因素密切相关,在纠正低钠血症的同时,要加强病人营养支持,从而提高临床综合治疗的效果。     

渗透性脱髓鞘综合征的临床分析

摘 要： 目的了解渗透性脱髓鞘综合征（ODS）的发病机制、诊断、治疗和预防方法。方法报告11例ODS患者，并结合文献进行分析。结果10例患者有明显低钠血症；发病诱因包括药源性3例，营养不良3例，肝移植术后、脑挫裂伤、垂体微腺瘤、糖尿病肾病和妊娠剧吐各1例。存在严重呕吐或进食量极少的患者7例。神经系统表现包括不同程度意识障碍，假性球麻痹，四肢瘫痪，眼球活动障碍，闭锁综合征，精神症状，震颤或手足徐动等不自主运动，肌张力齿轮样增高等帕金森样症状等。头颅MRI显示桥脑或双侧豆状核、尾状核头、丘脑等桥外部位脱髓鞘。单纯CPM 3例，单纯EPM 2例，CPM合并EPM 6例。治疗后10例好转，1例病情获稳定。结论ODS的发病与脑内渗透压平衡失调有关，各种原因引起的低钠血症及其快速纠正容易诱发，临床表现可为单纯CPM、EPM或二者合并存在。随着头颅MRI的应用，可使该病早期诊断，其预后明显改善。避免快速纠正低钠血症是预防的主要措施。