Stroke is one of the most frequent complications of sickle cell disease (HbSS), occurring in 7-17% of children. Recent studies recognized more minor lesions on MRI, not associated with clinical signs on standard neurological examination, which however have been found to be a risk factor for developing stroke later. The aim of this study was to evaluate whether minor lesions observed on imaging could be associated with 'soft' neurological signs not detectable on conventional neurological examination. Fourteen children with HbSS were assessed with MRI, standard neurological examination and evaluation of 'soft' signs (Zurich Neuromotor Test) and motor function (Movement ABC). Eight of the 14 children scanned showed lesions on MRI but only 3 of the full cohort were abnormal on standard neurological examination. However, all of the eight children with MRI lesions also showed abnormal signs on at least one of the two tests (Zurich and Movement ABC). All the children with normal MRI were normal on all the tests performed. The sensitivity of Zurich Neuromotor Test and Movement ABC in the group of children with MRI lesions is 0.88 and 0.75, respectively, and increases to 1 when the two tests are used together. The specificity of both tests is 1 even when the tests are used separately.
Conclusion: Although the number of cases is small, 'soft' signs may reliably identify the presence of even minor MRI lesions, allow the evaluation of the global incidence of major and minor neurological signs and may also help to identify the population at risk for developing strokes. This population could then be closely monitored and benefit from early intervention.