Although there was a significant decrease in midline shift after craniectomy, this did not translate into decompressive craniectomy demonstrating a beneficial effect on patient outcome.

Thermal-diffusion flowmetry represents a promising method for the bedside monitoring of patients with SAH to detect symptomatic vasospasm. This is of major clinical interest for patients with high-grade SAH, who often cannot be assessed neurologically.

Critically elevated intracranial pressure (ICP) represents the most important cause of morbidity and mortality in patients suffering from severe traumatic brain injury (TBI) and is a serious complication after subarachnoid hemorrhage (SAH). Thus new strategies for the control of ICP are required. Based on the evidence available hypertonic saline solution (HSS) may be a promising approach. It was therefore the aim of the present study to evaluate in a prospective manner the effects of HSS on ICP and cerebral perfusion pressure (CPP) in patients with therapy-resistant elevation of ICP. A total of 48 bolus infusions of HSS (7.5%, 2 ml kg-1 b.w.; infusion rate 20 ml min-1) were given intravenously (range 1-15 per patient) to 10 patients (age 41 +/- 6 years) with TBI and SAH. Only patients with ICP > 25 mmHg not responding to standard ICP-management protocol and plasma sodium (Na+) concentration < 150 mmol l-1 were included in the study. Within the first hour after HSS application, ICP decreased from 33 +/- 9 mmHg to 19 +/- 6 mmHg (p < 0.05) and further to 18 +/- 5 mmHg at the time of maximum effect (98 +/- 11 min post bolus). Decrease of ICP was accompanied by a rise of CPP from 68 +/- 11 mmHg to 79 +/- 11 mmHg (p < 0.05) after 1 h and further to 81 +/- 11 mmHg at the time of maximum effect. Plasma Na+ concentration was 141 +/- 6 mmol l-1 before and 143 +/- 5 mmol l-1 1 h after HSS bolus. Corresponding values for plasma osmolality were 302 +/- 11 and 308 +/- 12 mOsm l-1. When the ICP lowering effect was transient, subsequent HSS bolus was necessary 163 +/- 54 min after previous dosing. The present results indicate that repeated bolus application of HSS (7.5% NaCl, 2 ml kg-1 b.w.) is an effective measure to decrease ICP which is otherwise refractory to standard therapeutic approaches. Whether or not the therapy scheme is also suited as primary measure for the control of ICP remains to be established.

Background: The best revascularization strategy for moyamoya disease (MMD) remains unknown. Our aim was to characterize angiographic revascularization effects of a bilateral standardized revascularization approach, consisting of superficial temporal artery (STA)-middle cerebral artery (MCA) bypass and encephalomyosynangiosis (EMS) on one hemisphere and single EMS on the contralateral hemisphere of each patient, and to compare the effects of both revascularization strategies on cerebral hemodynamics. Methods: In 30 patients (18 females/12 males, age 8–63 years), standardized revascularization was performed. Digital subtraction angiography was performed preoperatively and at 7 days, 6 months and 12 months postoperatively. STA-MCA and EMS functions were graded I (poor), II (medium) or III (extensive) according to angiographic aspects. In 20 patients, cerebrovascular reserve capacity (CVRC) was assessed pre- and postoperatively (at 12 months) using xenon CT. Results: After 12 months, STA-MCA/EMS function was grade 1 in 40/40%, grade 2 in 27/26%, and grade 3 in 27/10% of hemispheres, respectively. Twelve months after surgery, single EMS showed grade I in 37%, grade II in 27%, and grade III in 20% of hemispheres. Combined revascularization improved CVRC significantly compared to preoperative measurement (preoperative: 16.5 ± 34.6% vs. postoperative: 60.8 ± 64.22%; p < 0.05). Single EMS did not improve CVRC significantly (preoperative: 21.8 ± 35.9% vs. postoperative: 34.8 ± 63.0%; p < 0.05). Conclusions: Combined and indirect revascularization may be successfully applied in a bilateral standardized approach. STA-MCA/EMS is superior to single EMS in restoring CVRC in adult MMD patients.

Background and Purpose-The purpose of this study was to investigate the effect of nicardipine prolonged-release implants (NPRIs) on cerebral vasospasm and clinical outcome after severe subarachnoid hemorrhage. Methods-Thirty-two patients with severe subarachnoid hemorrhage and undergoing aneurysm clipping were included into this single center, randomized, double-blind trial. Sixteen patients received NPRIs implanted into the basal cisterns in direct contact to the exposed proximal blood vessels; in 16 control patients, the basal cisterns were opened and washed out only without leaving implants. Angiography was performed preoperatively and at day 8Ϯ1. Computed tomography imaging was analyzed for the incidence of territorial infarcts unrelated to surgery. Patient outcome was assessed using the modified Rankin and National Institute of Health Stroke scales. Results-The incidence of angiographic vasospasm in proximal vessel segments was significantly reduced after implantation of NPRIs (73% control versus 7% NPRIs). Significant differences occurred also for the majority of distal vessel segments. Computed tomography scans revealed a lower incidence of delayed ischemic lesions (47% control versus 14% NPRIs). The NPRI group demonstrated more favorable modified Rankin and National Institute of Health Stroke scales as well as a significantly lower incidence of deaths (38% control versus 6% NPRIs). Conclusions-Implantation of NPRIs reduces the incidence of cerebral vasospasm and delayed ischemic deficits and improves clinical outcome after severe subarachnoid hemorrhage. Key Words: nicardipine prolonged-release implants Ⅲ SAH Ⅲ stroke Ⅲ vasospasm C erebral vasospasm remains one of the most serious complications after aneurysmal subarachnoid hemorrhage (SAH). Over the past decades, several pharmacological approaches have been investigated for the prevention of cerebral vasospasm. Among those, the most prominent is the use of voltage-gated calcium channel antagonists such as nimodipine and nicardipine. Experimental data support the concept that voltage-gated calcium channel antagonists are capable of preventing cerebral vasospasm if administered in high enough doses to the vessel wall. 1 However, when administered intravenously or orally, the doses necessary to exert maximum pharmacological effect cannot be achieved as a result of the side effects of the drug. [2][3][4] Recently, this limitation in the delivery of voltage-gated calcium channel antagonists has been overcome by the introduction of nicardipine prolonged-release implants (NPRIs). These nicardipine-loaded polymers are implanted into the basal cisterns in close contact to the proximal cerebrovascular system at the time of aneurysm clipping and release the drug over 14 days. Thereby, nicardipine is delivered locally at a high and constant concentration to the cerebral blood vessel wall, at the same time avoiding systemic side effects.The initial preclinical and clinical experiences with NPRIs have been promising and have failed to show toxicity. [2][3][4] In a re...

Background and Purpose-It remains controversial whether the intra-arterial administration of papaverine (IAP) is effective in reversing vasospasm-associated cerebral hypoperfusion after aneurysmal subarachnoid hemorrhage. The aim of the present study was to continuously assess regional cerebral blood flow (rCBF) during and after IAP with the use of quantitative, bedside thermal diffusion flowmetry. Methods-Eight patients with cerebral vasospasm after subarachnoid hemorrhage (mean flow velocity Ͼ120 cm/s; angiographic vessel constriction Ͼ33%; hemispheric cerebral blood flow [CBF] Ͻ32 mL/100 g per minute) were prospectively entered into the study. Before IAP, thermal diffusion microprobes were implanted into the white matter of each affected vascular territory (nϭ10) for rCBF monitoring. During and after IAP (300 mg papaverine/50 mL saline over 1 hour), mean arterial blood pressure, intracranial pressure, cerebral perfusion pressure, thermal diffusion rCBF (TD-rCBF), and cerebrovascular resistance (CVR) were recorded continuously. Results-IAP significantly increased TD-rCBF from 7.3Ϯ1.6 to 37.9Ϯ6.6 mL/100 g per minute (meanϮSEM), indicating reversal of cerebral hypoperfusion. This TD-rCBF response was dependent on the degree of cerebral vasospasm and reduced perfusion within the vascular territory. Long-term analysis of TD-rCBF, however, demonstrated that this beneficial effect of IAP on cerebral hypoperfusion was only transient: within 3 hours after treatment, TD-rCBF and CVR returned to baseline values. Furthermore, a lack of correlation between transcranial Doppler sonography and thermal diffusion flowmetry suggested that transcranial Doppler sonography is not suited for CBF-based neuromonitoring after IAP. Conclusions-IAP is not effective in permanently reversing cerebral hypoperfusion in patients with cerebral vasospasm.The need to validate alternative therapeutic strategies that seek to improve cerebral perfusion in vasospasm warrants continued development of CBF-based neuromonitoring strategies. (Stroke. 2001;32:498-505.)

Fibrinogen concentration influences mechanical and functional properties of the clot. The purpose of the present study was to identify threshold concentrations of fibrinogen resulting in relevant changes in whole blood clot elastic modulus and platelet contractile force, as well as plasma prothrombin time and activated partial thromboplastin time. We measured clot elastic modulus, platelet contractile force, and other hemostasis parameters in whole blood samples from 552 patients admitted to a surgical intensive care unit. Platelet contractile force and clot elastic modulus were measured using the Hemodyne apparatus. Fibrinogen levels were between less than 0.10 and 9.44 g/l, with a mean of 2.41 g/l. Mean platelet count was 203 x 10(9) l(-1), with a range of 16 x 10(9) l(-1) to 682 x 10(9) l(-1). High levels of fibrinogen result in improved mechanical stability and improved interaction of platelets with the fibrin network. Clot elastic modulus and platelet contractile force are correlated positively with plasma fibrinogen concentration. However, there was no threshold concentration or ceiling effect concerning the mechanical properties of the clots. In contrast, clotting time assays such as prothrombin time, thrombin time, or activated partial thromboplastin time are influenced by the fibrinogen concentration only at levels below 1 g/l. In linear regression analysis, clot elastic modulus was mainly influenced by fibrinogen concentration (F = 185.4, P < 0.0001), whereas platelet contractile force was influenced by fibrinogen (F = 197.0, P < 0.0001) and platelet count (F = 104.7, P < 0.0001). The present data show that 1 g/l is a threshold fibrinogen concentration for an effect on coagulation assays such as prothrombin time, thrombin time, or activated partial thromboplastin time, but increasing fibrinogen concentrations above this level results in further continuous improvement of mechanical properties of the whole blood clot.

Controlled lumbar cerebrospinal fluid drainage significantly reduces refractory intracranial hypertension. The danger of transtentorial or tonsillar herniation is minimized by considering lumbar drainage in the presence of discernible basilar cisterns only.