Thrombotic stroke in a child with diarrhea-associated hemolytic-uremic syndrome with a good recovery

Cerebral sinovenous thrombosis in pediatric hemolytic uremic syndrome

Hemolytic uremic syndrome (HUS) may result in thrombotic central nervous system complications. We present a child with diarrhea-associated HUS who developed new-onset focal seizures secondary to cerebral sinovenous thrombosis (CSVT). Her CSVT was treated with low-molecular-weight heparin. The patient's seizures were controlled with levetiracetam, and her HUS was managed supportively with hemodialysis. Repeat imaging nearly 6 months following presentation and initiation of anticoagulation demonstrated cerebral sinus enlargement and persistent intraluminal webbing. Anticoagulation was discontinued after 6 months, and she did not experience long-term gross neurologic sequelae. CSVT is a complication of HUS that has not been previously described. In this report, we summarize the thrombotic central nervous system complications of pediatric HUS.

Postoperative Symptomatic Cerebral Infarction in Pediatric Moyamoya Disease: Risk Factors and Clinical Outcome

BACKGROUND

Indirect bypass surgery is used to improve the hemodynamic status of pediatric patients with moyamoya disease (MMD). Symptomatic cerebral infarction during the early postoperative period may be the most frustrating complication. This study was conducted to investigate the factors associated with early postoperative symptomatic cerebral infarction.

METHODS

Between January 2000 and February 2014, we performed 1241 indirect bypass surgeries in 659 pediatric MMD patients. Symptomatic infarction during the early postoperative period was diagnosed in 63 operations in 61 patients.

RESULTS

The overall incidence of symptomatic cerebral infarction after indirect bypass surgery was 5.1%. The median age of the patients with postoperative infarction was 6 years (mean, 6.4 years; range, 1-15 years). The performance of 2 craniotomies in single operation was associated with a higher rate of cerebral infarction. Moreover, the incidence was higher in young patients (age <6 years) compared with older patients. In a matched analysis, an immediate postoperative hemoglobin level >13 g/dL was associated with decreased risk of infarction (odds ratio, 0.144; P = 0.003). Mutation of the methylenetetrahydrofolate reductase (MTHFR) gene occurred in a relatively high proportion of our infarction cohort.

CONCLUSIONS

Postoperative symptomatic infarctions can occur despite a unified surgical method and formulaic perioperative management protocol. Patient-centered factors, such as young age, genetic background of MTHFR, and certain medical conditions, including hyperthyroidism, renovascular hypertension, and hemolytic uremic syndrome, as well as management-related factors, including 2 craniotomies and low immediate postoperative hemoglobin level, could be risk factors for early postoperative symptomatic cerebral infarction.

Shiga Toxin/Verocytotoxin-Producing Escherichia coli Infections: Practical Clinical Perspectives

Escherichia coli strains that produce Shiga toxins/verotoxins are rare, but important, causes of human disease. They are responsible for a spectrum of illnesses that range from the asymptomatic to the life-threatening hemolytic-uremic syndrome; diseases caused by E. coli belonging to serotype O157:H7 are exceptionally severe. Each illness has a fairly predictable trajectory, and good clinical practice at one phase can be inappropriate at other phases. Early recognition, rapid and definitive microbiology, and strategic selection of tests increase the likelihood of good outcomes. The best management of these infections consists of avoiding antibiotics, antimotility agents, and narcotics and implementing aggressive intravenous volume expansion, especially in the early phases of illness.

Hemolytic uremic syndrome

The thrombotic microangiopathies include both hemolytic uremic syndrome (HUS) and thrombotic thrombocytopenic purpura (TTP). Although debate exists as to whether these are separate entities or a spectrum of disease, both result in the clinical picture of thrombocytopenia, hemolytic anemia, and varying degrees of renal and neurologic involvement. Etiology of HUS includes diarrheal infection due to Shiga toxin-producing bacteria, complement deficiency, pneumococcal infection, and cobalamin deficiency. In disease ascribed to TTP, the main etiologic factor is deficiency of an enzyme known as a disintegrin-like and metalloprotease with thrombospondin type 1 repeats, number 13 (ADAMTS-13). The clinical manifestations may vary, but neurologic involvement can be significant, with reports of hypertensive encephalopathy, seizures, thrombosis and infarct. In nondiarrheal forms of disease, recurrence may occur and clinical diagnosis is essential in order to provide a targeted therapy for the suspected etiology. Therapies include supportive care, cobalamin supplementation, as well as plasma infusion and exchange. End stage renal disease may result and transplantation is curative for some forms of the disease. More recent research focuses on targeted immunotherapy to prevent autoantibody prevention. As of yet, there is no one cure for these potentially devastating diseases, and diagnosis and treatment selection presents a challenge to the clinician.