Neurological involvement in children with E. coli O104:H4-induced hemolytic uremic syndrome.

Background: The aim of this study was to analyze the neurological involvement and outcome in pediatric patients with hemolytic uremic syndrome (HUS) during the 2011 epidemic caused by Escherichia coli O104:H4.

Methods: Clinical data and data from magnetic resonance imaging (MRI) scans and electroencephalography (EEG) during the acute phase of the disease and during follow-up at 3 and 6 months were analyzed in 50 patients. Twenty-five of these patients underwent neuropsychological testing (WISC IV) during follow-up.

Results: Neurological involvement (stupor or coma, seizures, visual disturbances, paresis, myocloni) was initially observed in 14/50 (28%) patients. One patient died. EEG abnormalities were more frequent in patients with neurological involvement than in those without (12/14 vs. 13/25, respectively). Cranial MRI scans were analyzed in nine patients with neurological involvement, of whom five showed abnormal findings. At the 3- and 6-month follow-ups, EEG abnormalities were found in 14/40 (35%) and 7/36 (19%) patients, respectively, whereas 28/42 (67%) and 17/39 (44%) patients, respectively, complained about on-going reduced performance. Neuropsychological testing showed a slightly lower global intelligence quotient in patients with neurological involvement versus those without (113.4 ± 2.8 vs. 119.4 ± 1.8, respectively).

Conclusions: Neurological involvement was frequent in our cohort. Accordingly, the incidence of pathological EEG findings was high, even in patients without clinical signs of neurological involvement. Nevertheless, major neurological sequelae were rare, and neuropsychological outcome was favorable after 6 months.