CT Diagnosis of Cerebral Venous Thrombosis: Importance of the First Examination for Fast Treatment

Deep cerebral venous system involvement in patients with cerebral sinus thrombosis. A proposal of neuroradiological score systems useful for clinical assessment

PURPOSE

To develop a neuroradiological score in patients with deep cerebral venous thrombosis (DCVT), capable of assessing extension of intracranial changes and venous occlusion at diagnosis; to assess the relationship between neuroradiological and clinical features at follow-up.

MATERIAL AND METHODS

In 14 patients with DCVT, we developed 2 score systems on non-enhanced and contrast-enhanced CT: Intracranial Imaging Score (IIS) and Venous Occlusion Imaging Score (VOIS). ISS considers parenchymal venous strokes, hemorrhage, mass effect, and hydrocephalus; VOIS evaluates unilateral or bilateral venous occlusion extension. Modified Rankin Scale (mRS) and vessel recanalization status were assessed at follow-up.

RESULTS

At diagnosis, higher IIS was related to bilateral venous thrombosis involvement (p 0,02; r:0,60), but parenchymal strokes were not related to venous occlusion extension (unilateral or bilateral) (p > 0,05). Moreover, the symptoms' onset time did not correlate with the severity scores (p > 0,05). At follow-up, 8 out of 14 patients showed good clinical outcomes with complete recanalization and neurological improvement, 1 patient showed a poor neurological outcome, whereas 5 patients died within 1 week. Positive correlations were found between IIS and mRS (p 0,003, r = 0,73), between IIS and vessels' recanalization status (p 0,002, r = 0,75), and between vessels' recanalization status and mRS (p < 0,001, r = 0,98).

CONCLUSION

Neuroradiological scores may enhance diagnostic accuracy, and they may have a predictive significance. In patients with DCVT, although intracranial involvement was not influenced by symptoms' onset time or extension of venous occlusion, clinical outcome was related to both intracranial involvement and venous recanalization state. Collateral venous drainage status may counterbalance the thrombotic process improving prognosis.

How to Distinguish between Venous and Arterial Strokes and Why?

Cerebral venous infarct is considered to be rare (0–5% of all strokes). In some cases venous infarcts with no specific signs on conventional CT or MR study are not diagnosed due to incomplete examination. A venous infarct more often (63%) than an arterial (15%) infarct is accompanied by hemorrhage (primary or secondary in the early period) and a high risk of hemorrhage should be a contraindication to intravenous thrombolysis. Consequently, the definition of the kind of a stroke should lead to different therapeutic tactics. Using MR and CT angiographic and perfusion techniques in the urgent examination of patients with an infarct, considering time necessary for the “time window”, can lead to exact diagnosis and fewer complications.