To test the assumption that transcranial Doppler ultrasound (TCD) is able to detect and to monitor intracranial venous blood flow velocities in patients with confirmed cerebral venous thrombosis (CVT).
Prospective case study in 18 patients.
Inpatient neurologic service in a university hospital.
Subjects and Methods
Serial TCD examinations were performed in 18 consecutive patients with CVT (14 females, 4 males) aged 16 to 64 years (mean±SD, 36.8±13.1 years) during a mean follow-up ranging from 34 to 783 days (mean±SD, 201±185 days) between 1993 and 1997. Venous TCD was performed with a 2-MHz range-gated transducer.
Venous blood flow velocities were successfully measured in all patients. The highest measured velocities in the monitored intracranial venous vessels ranged from 20 to 150 cm/s (mean±SD, 58.9±38.8 cm/s), and the lowest were from 9 to 84 cm/s (mean±SD, 27.9±17.0 cm/s). Fifteen patients (83%) showed a decrease of velocities—2 of them after a transient increase during cessation of heparin therapy. The percentage of velocity decrease ranged from 34% to 73% (mean±SD, 56.4%±10.9%). A plateau phase, defined as no further decrease in velocities, was reached in these patients within 4 to 314 days (mean±SD, 59.9±73.7 days). Three patients (17%) showed no changes in velocities as defined by a limit of velocity variation of 30% during the course of CVT. High venous velocities were significantly associated with altered consciousness (P=.001). A nonsignificant relationship was observed with affliction of the superior sagittal sinus. No correlations were noted for onset of disease, initial motor deficits, and presence of bleeding. No predictive value was gained from analyzing the outcome in relation to absolute velocities or their decrease.
Serial TCD studies allow monitoring of venous hemodynamics and collateral pathways in patients with CVT. Normal venous velocities in serial measurements, however, do not exclude a diagnosis of CVT.