Hydrocephalus in cerebral venous thrombosis

Increased intracranial pressure is common in cerebral venous thrombosis (CVT), but hydrocephalus is rarely reported in these patients. We examined the frequency, pathophysiology and associated clinical manifestations of hydrocephalus in patients with CVT admitted to our hospital between 2000 and 2010 (prospectively since July 2006). Hydrocephalus was defined as a bicaudate index larger than the 95th percentile for age, and/or a radial width of the temporal horn of ≥5 mm. We excluded patients in whom hydrocephalus was caused by a disease other than CVT or if it was iatrogenic. 20 out of 99 patients with CVT had hydrocephalus. 6 patients with hydrocephalus were excluded from the analysis. Patients with hydrocephalus more often had focal neurological deficits (86 vs. 49 %, p = 0.02) and were more frequently comatose (43 vs. 16 %, p = 0.06), as compared to patients without hydrocephalus. Deep cerebral venous thrombosis (64 vs. 9 %, p < 0.001) and edema of the basal ganglia and thalami (64 vs. 4 %, p < 0.001) were more common in patients with hydrocephalus. Intraventricular hemorrhage was present in 1 patient with hydrocephalus, compared to none among patients without hydrocephalus (7 vs. 0 %, p = 0.15). Outcome at follow-up was worse in patients with hydrocephalus (mRS 0–1, 36 vs. 68 %, p = 0.02; mortality 29 vs. 9 %, p = 0.07). Hydrocephalus occurs more frequently in cerebral venous thrombosis than previously believed, especially in patients with deep cerebral venous thrombosis and edema of the basal ganglia. The presence of hydrocephalus is associated with a worse clinical outcome, but a direct causal relation is unlikely. Routine shunting procedures are not advisable.