Application of transcranial Doppler in subarachnoid hemorrhage.

Transcranial Doppler (TCD) was dynamically performed on 25 patients with subarachnoid hemorrhage (SAH) before and after treatment. In the first 4 days of clinical course, 3 cases demonstrated elevated intracranial pressure (ICP), 6 cases showed stenosis of blood vessels, and 16 cases gave normal findings. At 7-14 days of clinical course, 20 cases showed vascular spasm or narrowing, 4 cases imparted normal findings and 1 patient died of elevated ICP. After the third TCD performed on the 20th day of the clinical course, 5 cases showed mean blood flow velocities (Vm) below normal values, indicating poor cerebral perfusion, 9 cases still had Vm above normal levels, 10 cases yielded completely normal findings. In conclusion, TCD conducted at different phases of SAH can not only demonstrate the functional and pathological status of cerebral blood vessels following SAH, but also reflect the outcome of clinical features. It is very helpful in the evaluation of the causes and the prognosis of SAH.