[Cerebral blood flow as a prognostic indication in subarachnoid hemorrhage]

Effect of a platelet-activating factor receptor antagonist, E5880, on cerebral vasospasm after aneurysmal subarachnoid hemorrhage--open clinical trial to investigate efficacy and safety

The efficacy and safety of a new platelet-activating factor receptor antagonist, E5880, were investigated for preventing cerebral vasospasm after subarachnoid hemorrhage (SAH) in 71 patients with SAH who underwent surgery for ruptured aneurysms within 3 days. Intravenous E5880 administration (300 micrograms or 1200 micrograms twice daily) was begun within 4 days and continued for 14 days. The incidence of symptomatic vasospasm, low-density area on computed tomography, and angiographic vasospasm was lower than in placebo groups in previous studies. Clinical outcome was favorable compared with previous studies. No clinically important adverse events were observed. These results suggest that E5880 is safe and effective in the treatment of patients with cerebral vasospasm due to SAH.

Anti-phospholipid antibodies and cerebral vasospasm following subarachnoid haemorrhage

Delayed ischaemic deficits due to cerebral vasospasm contribute to the high morbidity and mortality rates associated with subarachnoid haemorrhage. We evaluated the usefulness of measuring anti-phospholipid antibodies (aPLs) for prediction of the occurrence of symptomatic vasospasm and the outcome after subarachnoid haemorrhage. 32 consecutive patients with subarachnoid haemorrhage due to ruptured cerebral aneurysms were studied. They were admitted and operated on within 72 hours after the onset of subarachnoid haemorrhage. aPLs such as lupus anticoagulants, anti-cardiolipin IgG and anti-cardiolipin IgM were measured repeatedly after admission. Furthermore, platelet count, platelet aggregability and plasma platelet factor 4 were also measured. Eleven among the 32 patients (34.4%) showed positive in the examination for aPLs. Although aPLs could not predict symptomatic vasospasm, once symptomatic vasospasm occurred, patients with aPLs frequently demonstrated cerebral infarction and therefore their outcome was worse. aPLs were associated with a severe initial clinical grade and SAH grade on CT scan. Therefore it may explain the association of aPLs with worse outcome. aPLs were detected between 1 and 7 days. Four of 6 patients (67%) with aPLs became negative between 7 and 13 days after subarachnoid haemorrhage. The mechanism of transient aPLs is unclear but it is more likely to occur in the severer grade patients. The reduction in platelet count, the increased platelet aggregability, and the increased plasma platelet factor 4 concentration were also observed in aPLs-positive patients with symptomatic vasospasm.

"Head-shaking syndrome" neurological deterioration during continuous head-shaking as an adjunct to cisternal irrigation for clot removal in patients with acute subarachnoid haemorrhage

To prevent cerebral vasospasm after aneurysmal subarachnoid haemorrhage, cisternal irrigation has been reported to be more effective when combined with continuous head-shaking (head-shaking method). The present study was conducted to evaluate the safety and preventative effect for vasospasm in patients treated with the head-shaking method. Six of 17 patients managed postoperatively by the original head-shaking procedure developed neurological deterioration related to the method: two had intracranial haematoma (one with acute interhemispheric subdural haematoma, and the other with cerebellar haemorrhage), two had acute brain swelling, and two failed to show abnormal findings on computed tomography. These pathological processes may be suitably referred to as "head-shaking syndrome". Delayed ischaemic neurological deficits associated with low-density lesions on computed tomography were demonstrated in five patients (29%). From these observations, the head-shaking method may not be as safe as described in the original articles, and is critically evaluated in terms of its preventative effect for cerebral vasospasm.

Platelet-activating factor and antiphospholipid antibodies in subarachnoid haemorrhage

The purpose of this study was to measure plasma platelet-activating factor (PAF) concentration, PAF-acetylhydrolase activities, anti-phospholipid antibody (aPLs) titers, and platelet function in patients with subarachnoid haemorrhage (SAH) and to assess the association of these variables with the development of cerebral vasospasm. Thirty-two patients with SAH due to ruptured cerebral aneurysm were studied. Plasma PAF concentration, PAF-acetylhydrolase activity, platelet count and aggregability, and plasma factor 4 (PF4) concentrations were measured regularly until approximately 2 weeks after SAH. aPLs, including lupus anticoagulant and anti-cardiolipin IgG and IgM were measured within 3 days after SAH. Plasma PAF concentration in patients with SAH showed the highest value on the occasion during 5 to 9 days after SAH. The concentrations were higher in patients with infarction due to vasospasm than in patients without cerebral infarction on any occasions after SAH. Plasma PAF-acetylhydrolase activities did not change in patients, regardless of the presence of cerebral infarction after SAH. Increased platelet consumption and aggregability and higher concentrations of PF 4 were detected in patients with cerebral infarction and not in patients without cerebral infarction. The patients with cerebral infarction due to cerebral vasospasm had aPLs more frequently than the control volunteers. Our findings indicate that increased plasma PAF and aPLs may contribute to the pathogenesis of cerebral vasospasm after SAH.

Role of platelet function in symptomatic cerebral vasospasm following aneurysmal subarachnoid hemorrhage

To evaluate the role of platelet function in the pathogenesis of cerebral vasospasm, we compared sequential changes of platelet aggregability and beta-thromboglobulin and thromboxane B2 concentrations in blood samples from the internal jugular and peripheral vein of 13 patients with aneurysmal subarachnoid hemorrhage. Platelet function in blood from the internal jugular vein tended to be enhanced during days 0-1 but recovered to the normal range during days 2-4. After day 5, platelet function showed various patterns depending on the presence of symptomatic vasospasm. In patients without symptomatic vasospasm, sequential changes were relatively minor, with normal or slightly high values. Patients with symptomatic vasospasm already showed high platelet aggregability during the early stage of vasospasm. The concentration of beta-thromboglobulin increased several days after the onset of vasospasm, reaching 80 ng/ml or more in patients with a poor prognosis. Two of the five patients with symptomatic vasospasm showed markedly high concentrations of thromboxane B2 after day 8. These results suggest that vasospasm activates platelets and promotes aggregability and that the resulting increased tendency for thrombus formation may affect the patient's prognosis during the advanced stage.

Sequential changes of cerebral blood flow after aneurysmal subarachnoid haemorrhage

A total of 226 measurements of cerebral blood flow (CBF) were performed in 96 postoperative patients with aneurysmal subarachnoid haemorrhage (SAH). The global CBF was significantly reduced in the first week after SAH, and the extent of the CBF reduction was less in the patients with good outcome than in those with fair/poor outcome. The good outcome patients showed a progressive increase in CBF in the following 3 weeks. Although the CBF decreased further in the second week in some of those patients, it turned to a steady increase thereafter. On the other hand, in the fair/poor outcome patients CBF remained far below the normal control value for at least 3 months after SAH. When looking into the effect of age on CBF in the patients with good outcome, those in their thirties and forties had a significantly reduced CBF during the first 2 weeks, whereas in those in their fifties and sixties a significant reduction persisted for 3 months to 1 year after SAH. Management of the older patients needs special attention even if they are apparently in good clinical condition, since the CBF threshold to ischaemia is diminished.