Assessment of cerebral blood flow velocities in pre and post angiographic states with transcranial doppler.

The frequency of complications resulting from angiograms reported in the literature vary between 0.2-5 percent. This study was planned to determine the changes in cerebral blood flow velocity before and after angiography, using transcranial doppler in patients of subarachnoid hemorrhage (SAH) undergoing angiographies. Thirty patients with subarachnoid hemorrhage underwent transcranial doppler ultrasonography immediately before and after angiography. Nonionic water-soluble agents were used during the angiograms. The mean flow velocity (MFV) and pulsatility index (PI) at the M1 segment of both middle cerebral arteries was simultaneously measured. When the patients (11 male, 19 female, mean age+SD; 52.45+12.06) were compared according to changes in MFV and PI, pre and post-angiography, there was no statistical difference in MFV (p=0.51 and p=0.99, left and right side respectively), and in PI (p=0.48 and p=0.66) pre and post angiography. Although angiogram can be used to detect vasospasm in SAH, it can also be cause of vasospasm, partially due to the effect of the contrast agent on the cerebral arteries. This study proposes that the angiographic method is still safe and TCD can be used to follow up any possible changes in diameter of cerebral arteries before and after angiography.

Micro embolic signals in patients with cerebral ischaemic events.

The aim of this study was to evaluate the occurrence of micro embolic signals (MES) in patients with a cerebral ischaemia using transcranial doppler monitoring and to find out its diagnostic relevance. We prospectively performed bilateral multigated transcranial doppler monitoring from both middle cerebral arteries in 359 patients with an acute or recent (<4 weeks) cerebral ischaemic event, and in 182 control subjects without a cerebral ischaemic event. MES were analysed according to the standardised protocol. Patients with cerebral ischaemic events had a significantly higher (p<0.00001) rate of MES occurrence (31.8%) than control subjects (5.5%). MES were detected significantly higher in patients with partial or total anterior circulation infarcts (39.1%) than in those with lacunar infarcts (26.0%) or transient ischaemic attacks (27.3%). A correlation of MES and neuroimaging finding was also tried. TCD was found to have a predictive role in microemboli monitoring, predominantly in patients with large vessel territory infarction.