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Scientific Session IV: Impact of Neurosonology on Therapeutic Decisions
Author(s) -
Becker V.U.,
Hansen H.C.,
Brewitt U.,
Thie A.
Publication year - 1995
Publication title -
journal of neuroimaging
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.822
H-Index - 64
eISSN - 1552-6569
pISSN - 1051-2284
DOI - 10.1111/jon19955s2s78
Subject(s) - medicine , vasospasm , ischemia , anesthesia , stimulation , subarachnoid hemorrhage , cerebral blood flow , cardiology
To assess the impact of brain activation and subarachnoid haemorrhage (SAH) on flow velocity changes after visual stimulation, we examined 27 healthy controls ( 13 subjects examined with closed and opened eyes), 12 patients with SAH while eyes were kept open, 9 patients under general anesthesia without brain disease and 5 patients with vegetative state after brain injury. All subjects were examined with bilateral TCD monitoring of one PCA and contralateral MCA during rest (30s) and stimulation with 10 Hz flashlight (30s). Ten cycles of stimulation were averaged for estimation of the specific flow response (SFR), which was computed as percent increase of PCNMCA ratio. In controls, SFR was significantly higher with opened eyes (mean, 15.8%) than closed eyes (mean, 11.8%, p < 0.01, Wilcoxon test). SFR was significantly decreased in early stage of SAH (mean, 4,83%, p < 0.01) and normalized during course of disease. Four of 5 patients with abolished SFR suffered delayed ischemia due to vasospasm. Of 7 patients with preserved SFR, 5 had vasospasm by ultrasonic or angiographic criteria, but none had delayed ischemia. No SFR was observed in general anesthesia and apallic state. We conclude that vasoneuronal coupling depends on stimulus directed attention. Furthermore, abolished SFR in SAH might indicate a high risk of delayed ischemia due to vasospasm.