Blood flow velocities in middle cerebral artery branches after subarachnoid hemorrhage.

In a prospective study, 55 patients were examined by transcranial duplex sonography (TCCS) after subarachnoid hemorrhage (SAH) to determine whether additional transcranial duplex examination on the middle cerebral artery M2 segments would aid in the examination of the MCA stem segment. The mean blood flow velocities and pulsatility index were correlated to the occurrence of delayed ischemic neurologic deficits (DIND). Out of 47 patients included, 21 did not experience any delayed deficit (group I), 15 did (group II), and in 11 the extent to which vasospasm contributed to a neurologic deficit was unclear (group III). The highest blood flow velocity and the greatest increase of mean blood flow velocity on 1 day were significantly higher in groups II and III both in M1 and in M2. In 10 patients in group II, where the onset day of DIND was known exactly, Doppler data indicating ischemia before or at the time of DIND were observed in nine. In eight patients, Doppler of the MCA stem alone would have provided enough information to recognize the risk of symptomatic vasospasm; in one patient, only the M2 Doppler gave an indication of ischemic complication. Transcranial duplex sonography may provide additional information to TCD by accurate delineation of M1/M2 vasospasm and therefore may help plan cerebral angiography and neurointerventional treatment.

[Neuro-monitoring using visual evoked potentials in comatose neurologic intensive care patients]. / Neuromonitoring mit visuell evozierten Potentialen bei komatösen neurologischen Intensivpatienten.

The application of visual evoked potentials (VEP) as a monitoring tool was studied in 40 comatose neurological intensive care patients. With increasing depth of coma, the number of detectable VEP components decreased. In deeply comatose patients, VEP were regularly displayed as a negative wave with a latency of app. 100 ms and an amplitude of app. 8 microV (N100). The administration of promethazine or flunitrazepam used as sedatives produced a decrease of amplitude and an increase of latency of N100 that was reversed within 30 or 60 min respectively. In 10 patients, in which intraventricular pressure (IVP) was measured continuously by means of an intraventricular catheter, it was found that increases of IVP produced a considerable decrease of the amplitude and area of N100; after reduction of the increased IVP, both parameters quickly recovered. These observations indicate that VEP may be a useful tool for neuro-monitoring in neurological intensive care patients.