Radiological and histological changes following cerebral venous sinus thrombosis in a rat model

Cerebral venous sinus thrombosis (CVST) is an important cause of stroke in young especially after pregnancy. We induced CVST in rat by topical application of ferric chloride over the exposed superior sagittal sinus (SSS) and pathological changes were monitored on days 1, 2 and 7. Thrombus weight was estimated and H&E staining was performed for comparison with MRI data. T2 weighted signal changes were present in all the study group rats. T2 hyper intensity decreased over the time. In study group, the apparent diffusion coefficient (ADC) was decreased by 31.94% on day 1 compared to the controls. There was 15.5% increase in the ADC value on day 2 compared to day 1 which reached almost equal to control value on day 7. On histological evaluation, neuronal necrosis and cellular infiltration were observed in cortical region after thrombosis. The early decrease in ADC could be attributed to cytotoxic edema that precedes vasogenic edema indicated by normalization of ADC and a decreased T2 hyper intensity. In conclusion, ferric chloride induced CVST in the rat produces cytotoxic edema in early stage followed by vasogenic edema which is related to recanalization of the superior sagittal sinus.