Cerebral imaging of CNS involvement in haemolytic uraemic syndrome

Objectives: Cerebral involvement occurs in app. 30% of children with haemolytic uraemic syndrome (HUS). We aimed to investigate the value of cerebral imaging.

Material and Methods: Retrospective analysis of medical records and imaging scans of children treated at our institution because of acute HUS from 1989 to June 2004.

Results: The records of 104 patients with HUS could be analyzed. Clinical signs of CNS involvement were present in 29 patients: altered consciousness in all (including coma in 9), epileptic seizures in 14. In 23 patients cerebral imaging studies were performed including cranial computed tomography (cCT) in 22, cCT and magnetic resonance imaging (MRI) in 11, MRI only in 1, diffusion weighted imaging (DWI) in 11. Follow-up studies were available in 17 patients. All 23 patients (9 male, 14 female) had diarrheoa associated HUS. Median age at onset of the disease was 31 m (9–131). 22 children were treated with peritoneal dialysis and 5 with plasmapheresis. Four patients died and 8 showed impaired neurological functions at the time of discharge. Abnormal cCT findings included hypodensities of the basal ganglia and thalami in 9, the deep white matter in 2, subcortical white matter in 5, haemorrhagic transformation in 2, and generalized oedema in 5. Abnormal MRI findings included abnormal signal intensities in the basal ganglia and thalami in 6, lesions of the fronto-parietal white matter in 4, signs of cortical infarction in 2, and infratentorial abnormalities in 2. DWI showed abnormal signal intensities in the fronto-parietal white matter with normal FLAIR in 4 patients. Both modalities were normal in an early examination in 2 patients but abnormal in a follow-up study in 1. Thalamic lesions and haemorrhagic transformation or T1 hyperintense basal ganglia appeared to be associated with poor prognosis.

Conclusions: Cerebral imaging shows a wide variety of supra- and infratentorial lesions in patients with CNS involvement during HUS. Different patterns can be demonstrated by different techniques possibly related to different pathophysiological mechanisms.