An increased pulsatility index in transcranial Doppler sonography is associated with Shiga-toxin-related encephalopathy in hemolytic uremic syndrome.

In patients with HUS-N, TCD showed only slightly increased blood flow velocities of basal brain arteries ( table 1 ). However, the mean resistance index (RI) and in particular the mean pulsatility index (PI) were significantly increased in patients with HUS-N, compared to HUS patients without neurological symptoms (mean PI/RI 1.11/0.62 vs. PI/RI 0.72/0.48, p ! 0.001, Mann Whitney U test; table 1 ). The abnormalities declined after 6 days, corresponding to clinical improvement ( table 1 ).