Background and Purpose-Activation of the sympathetic nervous system, which leads to elevation of circulating catecholamines, is implicated in the genesis of cerebral vasospasm and cardiac aberrations after subarachnoid hemorrhage. To this juncture, sympathetic nervous testing has relied on indirect methods only. Methods-We used an isotope dilution technique to estimate the magnitude and time course of sympathoadrenal activation in 18 subarachnoid patients. Results-Compared with 2 different control groups, the patients with subarachnoid hemorrhage exhibited an approximately 3-fold increase in total-body norepinephrine spillover into plasma within 48 hours after insult (3.2Ϯ0.3 and 4.2Ϯ0.7 versus 10.2Ϯ1.4 nmol/L; PϽ0.05 versus both). This sympathetic activation persisted throughout the 7-to 10-day examination period and was normalized at the 6-month follow-up visit. Conclusions-The present study has established that massive sympathetic nervous activation occurs in patients after subarachnoid hemorrhage. This overactivation may relate to the well-known cardiac complications described in subarachnoid hemorrhage. (Stroke. 2000;31:901-906.)

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The aim of this study is to monitor excitatory amino acids (EAAs) in the extracellular fluids of the brain and to characterize regional neuronal damage in a new experimental model for brain injury, in which rabbits were exposed to 180-260 krad/s2 rotational head acceleration. This loading causes extensive subarachnoid hemorrhage, focal tissue bleeding, reactive astrocytosis, and axonal damage. Animals were monitored for intracranial pressure (ICP) and for amino acids in the extracellular fluids. Immunohistochemistry was used to study expression of the gene c-Jun and apoptosis with the terminal deoxynucleotidyl transferase nick-end labeling (TUNEL) technique. Extracellular glutamate, glycine, and taurine increased significantly in the hippocampus within a few hours and remained high after 24 h. Neuronal nuclei in the granule layers of the hippocampus and cerebellum were positive for c-Jun after 24 h. Little immunoreactivity was detected in the cerebral cortex. c-Jun-positive neuronal perikarya and processes were found in granule and pyramidal CA4 layers of the hippocampus and among the Purkinje cells of the cerebellum. Also some microglial cells stained positively for c-Jun. TUNEL reactivity was most intense at 10 days after trauma and was extensive in neurons of the cerebral cortex, hippocampus, and cerebellum. The initial response of the brain after rotational head injury involves brain edema after 24 h and an excitotoxic neuronal microenvironment in the first hour, which leads to extensive delayed neuronal cell death by apoptosis necrosis in the cerebral cortex, hippocampus and cerebellum.

Cerebral vasospasm is the major cause of delayed ischemia in patients with subarachnoid haemorrhage (SAH). The Fisher grading scale has been used to predict patients in risk of developing vasospasm. Improved radiological techniques and treatment may have changed the relevance of the Fisher scale. We have now evaluated the Fisher scale, Hunt and Hess and age in relation to outcome in patients with SAH. Eighty- three patients were admitted with SAH during two years, and 84 aneurysms were treated in 78 patients. The Glasgow outcome score (GOS) within 3 months were as follows; GOS 1 (19%), GOS 2 (2%), GOS 3 (11%), GOS 4 (9%), GOS 5 (59%). There was a significant correlation between both the Fisher grading scale, Hunt and Hess scale and outcome. Age was not correlated to the Fisher grading scale or the Hunt and Hess scale. Age was also not correlated to outcome in our patients. Despite the correlation to outcome both Hunt and Hess and the Fisher grading scale had a limited predictive value of outcome due to a low specificity and/or sensitivity.