Recurrent leukoencephalopathy with microhemorrhages: gradient-echo MRI study diagnostic value in CNS primary angiitis.

Diagnosis of primary angiitis of the central nervous system (PACNS) is difficult in relation to variability in its clinical manifestations and absence of specific signs in neuroimaging. A young patient presented with a recurrent encephalopathic clinical course. T2 and fluid-attenuated inversion recovery-magnetic resonance imaging (FLAIR-MRI) showed hyperintense lesions in the cerebral white matter suggesting demyelination. Those lesions decreased or even disappeared after treatment with steroids and immunoglobulins. In echo gradient MRI (T2*-MRI), there were permanent cortical-subcortical petechial hypointense lesions (microhemorrhages). Definite diagnosis was established after cerebral biopsy. Intravenous cyclophosphamide was administrated with no new relapses in more than 18 months of follow-up. In a compatible clinical course, the finding of petechial hemorrhages in T2*-WI could play an important role in early diagnosis of PACNS.