PUTAMINAL PETECHIAL HEMORRHAGE AS THE CAUSE OF CHOREA - A NEUROIMAGING STUDY

Objectives - A hyperintense putamen on either CT or MRI as a finding a ssociated with chorea has occasionally been described and is almost al ways associated with non-ketotic hyperglycaemia. The cause of the hype rintensity of the striatum in these images is still controversial. Som e reports have found that calcification was responsible whereas others have advocated petechial haemorrhage as the cause. The purpose of thi s study was to determine whether hyperintense striata are caused by pe techial haemorrhage or calcification, with the sequential imaging chan ges. Subjects and methods - Five patients presenting with an acute ons et of either hemichorea or generalised chorea and showed either unilat eral or bilateral hyperdense striatum on the initial CT were assessed. Neuroimaging studies including sequential CT and MRI examinations and detailed biochemical tests were performed. Results - Three patients h ad pronounced hyperglycaemia and the other two patients had no biochem ical abnormalities. In all patients, the first CT scans, performed wit hin two weeks of the onset of chorea, showed a high density over the s triatum contralateral to the chorea, which diminished or disappeared t wo months later. T1 weighted imaging disclosed hypersignal intensities over the striatum contralateral to the chorea on admission which dimi nished two months later. T2 weighted imaging at two months showed hypo signal intensity changes corresponding to the area with hypersignal ch anges on T1 weighted images, implying haemosiderin deposition. Conclus ion - Based on the evolution of clinical manifestations and the findin gs of neuroimaging, putaminal petechial haemorrhage might be a new ent ity causing either hemichorea or generalised chorea.