Early identification of patients at risk for symptomatic vasospasm after aneurysmal subarachnoid hemorrhage

OBJECTIVE

To develop a scheme for early identification of individuals at risk for symptomatic vasospasm after subarachnoid hemorrhage (SAH).

DESIGN

Analysis of prospectively collected data from the placebo-treated group in a multicenter clinical trial.

SETTINGS

Fifty-four neurosurgical centers in North America.

MEASUREMENTS AND MAIN RESULTS

We identified independent predictors of symptomatic vasospasm using stepwise logistic regression analysis from demographic, clinical, laboratory, and neuroimaging characteristics of the participants. We developed a scoring system (symptomatic vasospasm risk index) based on a combination of these predictors. Out of 283 patients in the analysis (all treated with oral nimodipine), 93 (33%) developed symptomatic vasospasm within 14 days after SAH. There were four independent predictors of symptomatic vasospasm: thickness of subarachnoid clot on computed tomographic scan (odds ratio [OR], 4.1; 95% confidence interval [CI], 1.8-10.0); early rise in middle cerebral artery mean flow velocity (MCA-MFV), defined as a value > or =110 cm/sec recorded on or before post-SAH day 5 (OR, 1.9; 95% CI, 1.1-3.3), Glasgow Coma Scale score <14 (OR, 1.8; 95% CI, 1.1-3.1); and rupture of anterior cerebral or internal carotid artery aneurysm (OR, 1.9; 95% CI, 1.0-3.4). The probability of identifying patients who would develop symptomatic vasospasm (percentage of area under receiver operating characteristics curve +/- SEM) was higher with symptomatic vasospasm risk index (68%+/-8%) compared with thickness of clot (62%+/-8%; p = .08) or MCA-MFV (45%+/-7%, p < .05) criteria alone.

CONCLUSIONS

Patients at high risk for symptomatic vasospasm can be identified early in the course of SAH using a risk index. A risk index based on a combination of variables may represent a predictive paradigm superior to conventionally used criteria based on clot thickness or MCA-MFV criteria.

Early predictors of outcome in patients receiving hypervolemic and hypertensive therapy for symptomatic vasospasm after subarachnoid hemorrhage

OBJECTIVE

Symptomatic vasospasm after subarachnoid hemorrhage (SAH) is associated with a high incidence of permanent disability and death. For early identification of patients who are at risk for poor outcome, we determined the predictors of outcome in patients with symptomatic vasospasm after SAH.

DESIGN

We retrospectively determined the prognostic value of clinical characteristics and computed tomographic scan both at admission and at the time of initiation of hypervolemic and hypertensive therapy.

SETTINGS

Neurosciences critical care unit at a University hospital.

PATIENTS

A total of 70 consecutive patients who developed symptomatic vasospasm after SAH.

INTERVENTION

Treatment with oral nimodipine, hypervolemic therapy, and hypertensive therapy. Angioplasty and intra-arterial papaverine were used in patients with vasospasm resistant to standard treatment.

MEASUREMENTS AND MAIN RESULTS

Poor outcome, defined as Glasgow Outcome Scale Score of 3-5 at 2 months or discharge, was observed in 32 (46%) patients. In the logistic regression analysis, a Glasgow Coma Scale (GCS) score of < or =11 (odds ratio, 11.0; 95% confidence interval, 3.6-39.3) and hydrocephalus (odds ratio, 4.3; 95% confidence interval, 1.2-18.2) at the time of initiation of hypervolemic and hypertensive therapy were significantly associated with poor outcome. Poor outcome was observed in 91% of the patients who had both a GCS score of < or =11 and hydrocephalus compared with 15% of patients with a GCS score of >11 and no hydrocephalus at the time of initiation of hypervolemic and hypertensive therapy. A GCS score of < or =11 was also independently associated with length of intensive care unit stay (F ratio = 18.0; p = .0011) and hospital stay (F ratio = 9.2; p = .0034) after initiation of hypervolemic and hypertensive therapy.

CONCLUSIONS

The results of this study suggest that outcome in patients with symptomatic vasospasm can be effectively predicted by routinely available information, including GCS score at the time of initiation of hypervolemic and hypertensive therapy. This information can be used for selection and stratification of patients in future treatment studies of patients with symptomatic vasospasm.

Plasma endothelin concentrations after aneurysmal subarachnoid hemorrhage

OBJECT

The pathogenesis of cerebral vasospasm and delayed ischemia after subarachnoid hemorrhage (SAH) seems to be complex. An important mediator of chronic vasospasm may be endothelin (ET), with its powerful and long-lasting vasoconstricting activity. In this study the author investigated the correlation between serial plasma concentrations of ET and ischemic symptoms, angiographically demonstrated evidence of vasospasm, and computerized tomography (CT) findings after aneurysmal SAH.

METHODS

Endothelin-1 immunoreactivity in plasma was studied in 70 patients with aneurysmal SAH and in 25 healthy volunteers by using a double-antibody sandwich-enzyme immunoassay (immunometric) technique. On the whole, mean plasma ET concentrations in patients with SAH (mean +/- standard error of mean, 2.1 +/- 0.1 pg/ml) did not differ from those of healthy volunteers (1.9 +/- 0.2 pg/ml). Endothelin concentrations were significantly higher (p < 0.05) in patients who experienced delayed cerebral ischemia with fixed neurological deficits compared with those in other patients (post-SAH Days 0-5, 3.1 +/- 0.8 pg/ml compared with 2.1 +/- 0.2 pg/ml; post-SAH Days 6-14, 2.5 +/- 0.4 pg/ml compared with 1.9 +/- 0.2 pg/ml). Patients with angiographic evidence of severe vasospasm also had significantly (p < 0.05) elevated ET concentrations (post-SAH Days 0-5, 3.2 +/- 0.8 pg/ml; post-SAH Days 6-14, 2.7 +/- 0.5 pg/ml) as did those with a cerebral infarction larger than a lacuna on the follow-up CT scan (post-SAH Days 0-5, 3.1 +/- 0.8 pg/ml; post-SAH Days 6-14, 2.5 +/- 0.4 pg/ml) compared with other patients. Patients in whom angiography revealed diffuse moderate-to-severe vasospasm had significantly (p < 0.05) higher ET levels than other patients within 24 hours before or after angiography (2.6 +/- 0.3 compared with 1.9 +/- 0.2 pg/ml). In addition, patients with a history of hypertension or cigarette smoking experienced cerebral infarctions significantly more often than other patients, although angiography did not demonstrate severe or diffuse vasospasm more often in these patients than in others.

CONCLUSIONS

Endothelin concentrations seem to correlate with delayed cerebral ischemia and vasospasm after SAH. The highest levels of ET are predictive of the symptoms of cerebral ischemia and vasospasm, and ET may also worsen ischemia in patients with a history of hypertension. Thus, ET may be an important causal or contributing factor to vasospasm, but its significance in the pathogenesis of vasospasm remains unknown.

[A controlled, double-blind, randomized pilot clinical trial of nicardipine as compared with a placebo in patients with moderate or severe head injury]

INTRODUCTION

One of the factors involved in the occurrence of ischemic cerebral lesions following head injury is cerebral vasospasm. We analyze the effect of intravenous nicardipine on the prevention and treatment of posttraumatic cerebral vasospasm.

PATIENTS AND METHODS

We made a placebo-controlled, randomised, double-blind pilot study of the effect of nicardipine (intravenously 5 mg/hour for one week) on patients with moderate or severe head injury who presented with cerebral vasospasm, defined as an average Doppler flow velocity (DFV) of 100 cm/second or more. The main variable assessed was the evolution of the DFV and the secondary criteria were the evolution of the arterial blood pressure, coma scales, the findings on the Glasgow Coma Scale and the safety of the drug.

RESULTS

Eleven patients were included in each homogeneous group. The DFV was found to have become normal on the first day of treatment with nicardipine and on the third day with the placebo (p = 0.023). During the first day of treatment the percentage of cerebral hemispheres diagnosed as having suspected spasm was 11.1% for nicardipine and 64.3% for the placebo (p = 0.02881). The average time for recovery (DFV < 100 cm/second) was 3.33 days with the placebo and 1.22 days with nicardipine (p = 0.0039). The patients treated with nicardipine had 8.89 times more chance of recovery from vasospasm. The incidence of adverse effects was greater with the placebo (p = 0.014).

CONCLUSION

Nicardipine is effective in the reversal and prevention of increased Doppler flow velocity in patients with moderate or severe head injury.

Efficacy of transluminal angioplasty for the management of symptomatic cerebral vasospasm following aneurysmal subarachnoid hemorrhage

OBJECT

Transluminal angioplasty has become a widely used adjunct therapy to medical management of symptomatic cerebral vasospasm following subarachnoid hemorrhage (SAH). Despite anecdotal reports of universal, angiographically confirmed reversal of vasospasm and high rates of clinical improvement, no rigorous examination of the efficacy of this procedure has been conducted. In this study the authors assess the efficacy of the aforementioned procedure.

METHODS

Thirty-eight patients enrolled as part of the North American trial of tirilazad in aneurysmal SAH underwent transluminal angioplasty for symptomatic cerebral vasospasm. Fifty-three percent of these patients showed good recovery or moderate disability based on their 3-month Glasgow Outcome Scale score. Among the 38 patients who underwent angioplasty, the severity and type of vasospasm, use of papaverine in addition to balloon angioplasty, timing of treatment, and dose of study drug did not have an effect on the outcome. The results of their neurological examinations improved in only four of the 38 patients immediately after the procedure. A conditional logistic regression analysis was performed in which these patients were compared with individuals matched for age, sex, dose of study drug, admission neurological grade, and modified Glasgow Coma Scale score at the time of angioplasty. No effect on favorable outcomes was found for this procedure.

CONCLUSIONS

Transluminal cerebral angioplasty is very effective in reversing angiographically confirmed vasospasm, and anecdotal reports of its clinical utility are numerous. However, in this report the authors conclude that its superiority to medical management for symptomatic cerebral vasospasm is questionable.

[Posttraumatic vasospasm and its treatment with nimodipine]

The aim of our study was to compare the incidence and the time course of vasospasm as well as outcome of patients with tSAH. In group I there were 15 patients treated with nimodipine. Group II consisted of 20 patients in whom nimodipine was not used. All patients suffered from severe head injury, scored 8 points or less according to Glasgow Coma Scale. The initial CT scan revealed tSAH in all of them. Outcome was evaluated according to Glasgow Outcome Scale (GOS) three months after injury. Results were better (but not significantly) in patients in whom nimodipine was used, time course of vasospasm was less severe and follow-up CT scans did not reveal ischaemic infarcts connected with vasospasm.

[Diffusion imaging in asymptomatic focal vasospasm. Apropos of a case]

We report a case of an asymptomatic vasospasm with a focal, reversible apparent diffusion coefficient (ADC) decrease after a middle cerebral artery aneurysm rupture. This isolated decrease of ADC has not yet been reported in this pathological situation. It could be interesting to predict the risk of ischemic delayed complications of vasospasm.

Vasospasm after cranial base tumor resection: pathogenesis, diagnosis, and therapy

OBJECTIVE

Cerebral vasospasm is well known to occur after various cerebral neurosurgical events that cause subarachnoid hemorrhage. However, cerebral vasospasm can occur after cranial base tumor resection. We present a series of nine patients with angiographically evident vasospasm that was clinically symptomatic in eight of them.

METHODS

A total of 470 consecutive patients with cranial base tumors were operated in our institution between April 1993 and December 1996. Nine had evidence of cerebral vasospasm postoperatively (1.9% of the total population), of whom eight were asymptomatic. There were seven males and two females with an age range of 33 to 65 years (average 48.5 years). There were seven meningiomas, one chordoma, and one trigeminal schwannoma.

RESULTS

Vasospasm manifested clinically 1 to 30 days postoperatively in eight patients. Most patients were symptomatic within 7 days. In the ninth case, surgery was delayed when asymptomatic vasospasm was noted on an angiogram before second stage surgery. Symptoms included altered mental status in four patients, hemiparesis in three patients (one patient had both hemiparesis and altered mental status), and monoparesis in two patients. Factors that were found to correlate with a higher incidence of vasospasm were tumor size, total operative time, vessel encasement, vessel narrowing, and preoperative embolization. All eight patients with symptomatic vasospasm were treated with hypertensive, hypervolemic, hemodilutional (HHH) therapy. Five patients also underwent intraluminal angioplasty, in conjunction with papaverine in one case. One patient received intraarterial papaverine alone. Angiographic results were good in all patients. Significant clinical improvement was seen in six of the eight symptomatic cases.

CONCLUSION

Delayed neurological deterioration in a patient who has undergone cranial base tumor surgery not explained by an intracranial mass lesion should be promptly investigated with angiography. If vasospasm is diagnosed, it should be treated aggressively with hypertensive, hypervolemic, hemodilutional therapy and early angioplasty.

[The value of MRI for the diagnosis of meningeal hemorrhage during vasospasm]

Retrospectively, subarachnoidal hemorrhage can be misdiagnosed when the acute event did not bring the patient to medical attention, when clinical history is unclear and the CT scan is normal. Moreover, days after subarachnoid hemorrhage, cerebral vasospasm can result in neurological deficits that are indistinguishable from that produced by other causes of stroke. We report our experience with two patients who presented with symptoms of ischemia due to an arterial vasospasm that followed unrecognized rupture of an intracranial aneurysm. In both cases, CT scan failed to detect subarachnoid hemorrhage while MR detected the presence of signal changes in the subarachnoidal spaces associated with an ischemic stroke in one case. Neurological symptoms resolved completely after aneurysm treatment. MR can be a critical for the diagnosis of stroke secondary to vasospasm in order to prescribe an adapted treatment, avoid anticoagulant or thrombolytic therapy, and rapidly exclude the recently ruptured aneurysm to protect the patient from the risk of rebleeding.

[Neurological spectrum of pre-eclampsia and eclampsia]

Preeclampsia is a disorder specific to pregnancy which can affect all maternal organs. Cerebral involvement with the occurrence of convulsions is the defining factor for eclampsia. The most prominent signs of cerebral dysfunction include headache, hyperreflexia, visual disturbances, confusion and/or altered state of consciousness. Patients usually recover completely however some patients remain disabled due to cerebrovascular damage. Intracerebral and subarachnoidal hemorrhage are severe however rare complications of eclampsia. TCD investigations regularly find vasospasm in all great cerebral arteries. Reversible hypodense lesions in the white matter on early CT-scans and increased signal intensities on T2-weighted MRT images indicate local edema. The etiology of preeclampsia and eclampsia remains unknown and its current pathophysiology is still hypothetical. The clinical picture may best be explained by an endothelial dysfunction with increased vascular sensitivity to circulating pressure agents as well as by a structural endothelial lesion with fluid loss from the intravascular compartment.

Making sense out of jargon: a neurolinguistic and computational account of jargon aphasia

OBJECTIVE

To identify the cognitive and neuroanatomic bases of neologistic jargon aphasia with spared comprehension and production of written words.

METHODS

Detailed analysis of performance across experiments of naming, reading, writing, repetition, and word/picture matching by a 68-year-old woman (J.B.N.) served to identify which cognitive mechanisms underlying naming and word comprehension were impaired. J.B.N.'s impairments were then simulated by selectively "lesioning" a computer model of word production that has semantic, word form, and subword phonologic levels of representation (described by Dell in 1986).

RESULTS

In comprehension experiments, J.B.N. made far more errors with spoken word input than with written word or picture input (chi-square = 40-59; df = 1; p < 0.0001) despite intact auditory discrimination. In naming experiments (with picture, definition, or tactile input), J.B.N. made far more errors in spoken output relative to written output (chi-square = 14-56; df = 1; p < 0.0001). These selective impairments of spoken word processing were simulated by reducing connection strength between word-level and subword-level phonologic units but maintaining full connection strength between word-level and semantic units in Dell's model. The simulation yielded a distribution of error types that was nearly identical to that of J.B.N., and her CT and MRI scans showed a small subarachnoid hemorrhage in the left sylvian fissure without infarct. Cerebral angiogram showed focal vasospasm in sylvian branches of the left middle cerebral artery.

CONCLUSION

Focal left perisylvian dysfunction can result in a highly selective "disconnection" between word-level and subword-level phonologic representations manifest as neologistic jargon aphasia with intact understanding and production of written words.

Bedside detection of brain ischemia using intracerebral microdialysis: subarachnoid hemorrhage and delayed ischemic deterioration

OBJECTIVE

Intracerebral microdialysis has been demonstrated to be a useful method for detection of brain ischemia in experimental models and in patients. We have applied new mobile microdialysate analysis equipment that allows a bedside comparison of changes in neurochemistry with the neurological status of the patient. Ten patients with severe aneurysmal subarachnoid hemorrhage (that is, with a high risk of vasospasm and a high risk of subsequent ischemic deficits) were selected.

METHODS

Microdialysis catheters were inserted into the temporal and subfrontal cortex at the end of aneurysm surgery. Samples, collected hourly for 4 to 11 days, were analyzed immediately at the bedside for glucose, lactate, and glycerol and later for pyruvate and glutamate. The patients' neurological status was monitored constantly, and daily recordings of blood flow velocities were performed using transcranial Doppler sonography.

RESULTS

Concentrations of the measured substances varied widely. Individual analyses revealed that patients with uneventful clinical courses generally demonstrated low and stable levels of the different metabolites, and those with signs of cerebral ischemia demonstrated various patterns of neurochemical changes. Lactate and glutamate seemed to be sensitive markers of impending ischemia, and increased glycerol levels were associated with severe ischemic deficits. Obtaining the microdialysis data directly at the bedside seemed to be of great advantage when relating the values to other clinical findings.

CONCLUSION

Bedside intracerebral microdialysis monitoring of patients with subarachnoid hemorrhage and signs of delayed ischemia revealed dramatic changes in extracellular concentrations of glucose, lactate, and glycerol that could be directly correlated to the clinical status of the patients. These findings emphasize the potential of microdialysis in neurosurgical intensive care patients.

[Transient cortical blindness in EPH gestosis caused by cerebral vasospasm]

The pathogenesis of cortical blindness as a rare complication in severe preeclampsia is still unclear. The case of a women with postpartum blindness is reported in which CT and MRI initially showed cortical and subcortical edema in the parieto-occipital lobes. At this time cerebral angiography and transcranial color-coded sonography (TCCS) revealed widespread cerebral vasospasm. Mean blood flow velocities in the middle and posterior cerebral artery and carotid syphon initially reached 380 cm/s and normalized within 2 weeks. While the patient's vision improved rapidly, follow-up MRI disclosed ischemic lesions and petechial hemorrhage in the occipital cortex. This case provides rare documentation that transient blindness in patients with preeclampsia may result from parieto-occipital ischemia due to cerebral vasospasm. In such patients TCCS may be useful to detect vasospasm associated with preeclampsia/eclampsia.

The incidence of T2-weighted MR imaging signal abnormalities in the brain of cocaine-dependent patients is age-related and region-specific

BACKGROUND AND PURPOSE

Cocaine and its metabolites can produce vasospasm, and cocaine-dependent patients are at increased risk for stroke. Based on previous case reports, we hypothesized that the incidence of hyperintense brain lesions observed on T2-weighted MR images would also be increased in asymptomatic cocaine-dependent individuals.

METHODS

Sixty-two male "crack" (smoked) cocaine-dependent participants ranging in age from 25 to 66 years were compared with 116 normal male control participants ranging in age from 25 to 80 years. Those with histories of neurologic symptoms or illnesses were excluded. The severity of hyperintense lesions was rated on a 0- to 3-point scale, and ratings of 3 were used in the data analysis as an indicator of a probable pathologic process. Three regions were separately rated: the cerebral white matter, insular subcortex white matter, and subcortical gray matter (basal ganglia and thalamus region).

RESULTS

Significantly increased risk of severe lesions was observed in the two white matter regions of the cocaine-dependent group (odds ratio of 16.7 and 20.3) but not in the subcortial gray matter region (odds ratio of 1.4). In the insula subcortex white matter, the risk of lesions increased with age in the cocaine-dependant sample, but remained essentially absent among normal controls through the age of 80 years. In the cerebral white matter, the relationship of age and risk of lesion among normal participants was similar in shape to that in cocaine-dependent participants, but equivalent risk was seen 20 years earlier among cocaine-dependent participants.

CONCLUSIONS

Cocaine-dependent participants had a significantly increased age-related risk of white matter damage. The possible clinical implications of this damage are discussed.