CT angiography and perfusion CT in cerebral vasospasm after subarachnoid hemorrhage

BACKGROUND AND PURPOSE: We investigated the association of multisection CT angiography (MSCTA) and perfusion CT (PCT) for the characterization of vasospasm secondary to aneurysmal subarachnoid hemorrhage. Materials and METHODS: Among 27 patients with symptomatic cerebrovascular vasospasm investigated by digital subtraction angiography (DSA), 18 underwent both cerebral PCT and MSCTA. For the remaining 9, only PCT or MSCTA could be performed. MSCTA was compared with DSA for the detection and characterization of vasospasm on 286 intracranial arterial segments. PCT maps were visually reviewed for mean transit time, relative cerebral blood flow, and relative cerebral blood volume abnormalities and were qualitatively compared with the corresponding regional vasospasm detected by DSA. RESULTS: Vasospasm was grouped into 2 categories: mild-moderate and severe. The depiction of vasospasm by MSCTA showed the best sensitivity, specificity, and accuracy at the level of the A2 and M2 arterial segments (100% for each), in contrast to the carotid siphon (45%, 100%, and 85% respectively). The characterization of vasospasm severity by MSCTA showed a sensitivity, specificity, and accuracy of 86.8%, 96.8%, and 95.2%, respectively, for mild-moderate vasospasm, and 76.5%, 99.5%, and 97.5%, respectively, for severe vasospasm. The PCT abnormalities were related to severe vasospasm in 9 patients and to mild-to-moderate vasospasm in 2. The sensitivity, specificity, and accuracy of PCT in detecting vasospasm were 90%, 100%, and 92.3%, respectively, for severe vasospasm, and 20%, 100%, and 38.5%, respectively, for mild-moderate vasospasm. CONCLUSION: MSCTA/PCT can assess the location and severity of cerebrovascular vasospasm and its related perfusion abnormalities. It can identify severe vasospasm with risk of delayed ischemia and can thus guide the invasive treatment.     

Comparison of cerebral perfusion in perimesencephalic subarachnoid hemorrhage and aneurysmal subarachnoid hemorrhage

Purpose

Perimesencephalic hemorrhage (PMH) is a benign subtype of nonaneurysmal subarachnoid hemorrhage (SAH). We aimed to investigate if cerebral perfusion in PMH is less affected than in aneurysmal SAH (aSAH).

Methods

From a prospective cohort of 80 patients with spontaneous SAH, we included PMH patients (n?=?15) and selected aSAH patients (n?=?39) with similar clinical grade at admission (World Federation of Neurosurgeons Scale-WFNS I/II). Computed tomography (CT) perfusion was performed at <?72 h and/or at 8–10 days. Cerebral perfusion parameter values were compared between groups with nonparametric tests. Subgroup analyses compared PMH and aSAH patients stratified according to aneurysmal location (anterior or posterior circulation) and blood burden (Fisher grade).

Results

At <?72 h, no significant differences in perfusion parameters were found between PMH and aSAH patients. At 8–10 days, PMH patients had lower MTT than aSAH patients, and a trend for higher CBF. PMH patients had higher CBF and CBV at <?72 h when compared to posterior circulation aSAH patients. When compared to aSAH patients with similar blood burden, PMH patients had higher CBF and lower MTT at <?72 h, and lower MTT at 8–10 days.

Conclusion

PMH patients had better cerebral perfusion compared to patients with aSAH, particularly during the vasospasm time window. After stratifying for the amount of blood, PMH patients also had better cerebral perfusion in the first 72 h after SAH. These results are in line with the better clinical presentation and prognosis of PMH, and possibly with a different etiology.

     

CT angiography and perfusion imaging in patients with subarachnoid hemorrhage: correlation of vasospasm to perfusion abnormality

INTRODUCTION: We retrospectively evaluated computed tomography angiography (CTA) and perfusion imaging (CTP) of patients with aneurysmal subarachnoid hemorrhage (SAH) for any correlation between degree of vasospasm and perfusion deficit. MATERIALS AND METHODS: Sequentially performed CTP and CTA of 41 patients at least at the third day of postbleeding were reviewed for vasospasm and perfusion deficit throughout the anterior and middle cerebral arteries and corresponding territories. Vasospasm was noted comparing the contralateral normal ones or extradural components of the vessel itself and graded to negative, mild, moderate, and severe as luminal narrowing none, <25%, between 25% and 50%, and >/=50%, respectively. CTP abnormality was noted using cerebral blood flow and volume and mean transit time maps. RESULTS: Of 41 patients, 20 had no vasospasm; 15 had mild to moderate and six had severe vasospasm. Three of 20 patients with no vasospasm (15%), four of 15 patients with mild to moderate vasospasm (26%), and five of six patients with severe vasospasm (83%) had perfusion abnormality. Perfusion abnormalities noted were ischemia, infarction, and hyperperfusion. Perfusion abnormality without vasospasm was observed in the watershed areas and adjacent to sulcal clots. CONCLUSION: In SAH patients, if there is a macrovascular vasospasm with luminal narrowing >/=50%, there is a high likelihood (83%) of perfusion abnormality in the territory of the vasospastic vessel. There may also be perfusion abnormality without macrovascular vasospasm in the watershed areas or in the vicinity of sulcal clots.     

Relationship between vasospasm,cerebral perfusion,and delayed cerebral ischemia after aneurysmal subarachnoid hemorrhage

Introduction  

Vasospasm after aneurysmal subarachnoid hemorrhage (SAH) is thought to cause ischemia. To evaluate the contribution of vasospasm to delayed cerebral ischemia (DCI), we investigated the effect of vasospasm on cerebral perfusion and the relationship of vasospasm with DCI.     

Dynamic CT perfusion imaging in subarachnoid hemorrhage-related vasospasm

BACKGROUND AND PURPOSE: Nimodipine is a therapy that reduces morbidity and mortality in patients with subarachnoid hemorrhage (SAH), though the mechanisms by which it does so are not well understood. In a rabbit model of SAH, we studied the effects of nimodipine by using functional CT imaging. We hypothesized that the nimodipine treatment group would have (1) increased mean basilar artery diameter, (2) less diminished cerebral blood flow (CBF) following vasospasm, and (3) better neurologic outcomes. METHODS: SAH was induced in 26 New Zealand White rabbits randomized to 2 groups: treated (nimodipine) or control (no treatment). CT perfusion and CT angiography were used to measure CBF and basilar artery diameter at baseline, 10, 30, and 60 minutes after SAH, and on days 3, 5, 7, 9, and 16. Neurologic assessments were performed on each day of scanning. RESULTS: Basilar artery diameter in the treated group was greater than in the control group post-SAH (P < .05). When vasospasm was >15%, CBF in the nimodipine group was significantly greater than in the control group in the brain stem, cerebellum, parieto-occipital cerebrum, and deep gray matter (P < .05). Neurologic scores in the nimodipine group were significantly better than in the control group on days 5 and 9 (P < .05). CONCLUSION: Animals treated with nimodipine showed (1) increased mean basilar artery diameter, (2) improved neurologic outcome, and (3) increased mean CBF despite no significant difference in the incidence and severity of delayed vasospasm. These data provide a basis for future studies comparing the efficacy of new treatments for SAH to that of nimodipine.     

Intra-arterial colforsin daropate for the treatment of cerebral vasospasm after aneurysmal subarachnoid hemorrhage

Introduction

Cerebral vasospasm (CV) remains a major cause of mortality and morbidity in patients with subarachnoid hemorrhage (SAH). Here, we examined the effectiveness and safety of intra-arterial injection of colforsin daropate hydrochloride (CDH).

Methods

A consecutive series of 29 patients with angiographically confirmed CV received intra-arterial CDH (IAC) therapy. Angiographic changes in spastic vessels and the cerebral circulation time (CCT) were assessed before and after IAC treatment, together with the change in clinical status.

Results

IAC treatment was performed in 53 procedures in 29 patients. Angiographic improvement was observed following all procedures (100%), and clinical improvement was observed following 36 of 42 procedures (86%) in symptomatic cases. CCT improved significantly. At the 3-month follow-up, 19 patients (66%) showed good recovery or moderate disability on the Glasgow Outcome Scale. Major adverse effects were headache and increased heart rate.

Conclusions

IAC treatment was effective and safe for the treatment of CV after SAH     

Intra-arterial nimodipine for severe cerebral vasospasm after aneurysmal subarachnoid hemorrhage: influence on clinical course and cerebral perfusion

BACKGROUND AND PURPOSE: The efficacy of intra-arterial administration of nimodipine (IAN) in patients with severe vasospasm after aneurysmal subarachnoid hemorrhage (SAH) remains unproved. The goal of the present study was to investigate the clinical effect and cerebral perfusion after IAN in patients with severe vasospasm refractory to hemodynamic treatment.MATERIALS AND METHODS: Twenty-six of 214 patients with aneurysmal SAH were included in the prospective study, approved by the local ethics committee. All patients met the criteria of medically refractory cerebral vasospasm. Effectiveness was monitored angiographically by digital subtraction angiography and by transcranial Doppler (TCD), perfusion CT (PCT), and neurologic examination during treatment course and follow-up.RESULTS: No angiographic effect was observed in 8 patients. The pooled PCT values revealed a reduction of time to peak (P = .03) and mean transit time (P = .17) 1 day after intervention. This effect did not persist during the following days. The pooled TCD analysis demonstrated a transient increase in flow 1 day after intervention (P = .03). No trend was evident during the next 7 days after intervention. Additional infarction was experienced by 61.1% of patients.CONCLUSIONS: IAN in a selective patient group resulted in a positive response with reduction of angiographic vasospasm and increase in cerebral perfusion as detected by PCT after 24 hours. Therefore, IAN appears more effective than intra-arterial papaverine. Nevertheless the efficacy of IAN is temporary. Therefore, the search for more effective treatment strategies to reduce critical vasospasm and to improve cerebral perfusion must be continued.

Severe cerebral vasospasm constitutes the dominant factor of secondary morbidity and mortality after aneurysmal subarachnoid hemorrhage (SAH).^1-4 The current strategies for preventing vasospasm comprise the systemic administration of the calcium channel blocker nimodipine.^5-7 Moreover, the use of intracisternal thrombolysis⁸ and the intracisternal application of nicardipine-prolonged implants^9,10 demonstrated effectiveness in preventing cerebral vasospasm. Despite these treatment methods,^6,11 the rate of vasospasm-related permanent disability is estimated as totaling 10%–20%.^12,13 Meta-analyses on the efficacy of hemodynamic therapy are partially contradictory but usually recommend hemodynamic optimization for symptomatic vasospasm.^6,13-15For symptomatic vasospasm refractory to hemodynamic therapy, endovascular strategies such as balloon angioplasty¹⁶ and intra-arterial spasmolysis with papaverine¹⁷ or nimodipine¹⁸ have been recommended. Balloon angioplasty was found effective, but the procedure is limited to proximal vessel segments. In addition, it demands an experienced endovascular surgeon and is associated with significant risk.^19,20 Intra-arterial papaverine has been shown to reverse angiographic vasospasm and to reduce the velocities as detected by transcranial Doppler (TCD).^17,21 However, clinical trials have failed to demonstrate the effectiveness of intra-arterial papaverine on outcome.²² The most likely reason for this failure is the short duration of effect that has been documented: it is limited to a mere few hours.²³ Intra-arterial nimodipine (IAN) in patients with severe vasospasm has been reported by several authors.^24-26 Data from a larger series by Biondi et al¹⁸ suggested that IAN is effective and safe for the treatment of vasospasm after SAH. However, no information regarding the influence of IAN on cerebral perfusion is available. Moreover, there is a lack of information about the duration of effect.The objective of the present study was to investigate the effect and duration of the action of IAN by repeated assessment of the clinical condition with TCD, digital subtraction angiography (DSA), and perfusion measurements by means of perfusion CT (PCT).     

Early quantitative CT perfusion parameters variation for prediction of delayed cerebral ischemia following aneurysmal subarachnoid hemorrhage

Objectives

To prospectively evaluate the predictive value of cerebral perfusion–computerized tomography (CTP) parameters variation between day0 and day4 after aneurysmal subarachnoid haemorrhage (aSAH).

Methods

Mean transit time (MTT) and cerebral blood flow (CBF) values were compared between patients with delayed cerebral ischemia (DCI+ group) and patients without DCI (DCI- group) for previously published optimal cutoff values and for variations of MTT (ΔMTT) and of CBF (ΔCBF) values between day0 and day4. DCI+ was defined as a cerebral infarction on 3-months follow-up MRI.

Results

Among 47 included patients, 10 suffered DCI+. Published optimal cutoff values did not predict DCI, either at day0 or at day4. Conversely, ΔMTT and ΔCBF significantly differed between the DCI+ and DCI- groups, with optimal ΔMTT and ΔCBF values of 0.91 seconds (83.9 % sensitivity, 79.5 % specificity, AUC 0.84) and -7.6 mL/100 g/min (100 % sensitivity, 71.4 % specificity, AUC 0.86), respectively. In multivariate analysis, ΔCBF (OR?=?1.91, IC95% 1.13–3.23 per each 20 % decrease of ΔCBF) and ΔMTT values (OR?=?14.70, IC95% 4.85–44.52 per each 20 % increase of ΔMTT) were independent predictors of DCI.

Conclusions

Assessment of MTT and CBF value variations between day0 and day4 may serve as an early imaging surrogate for prediction of DCI in aSAH.

Key points

? CT perfusion values are an imaging surrogate for prediction of DCI.? Early variations (day0–day4) after aneurysmal subarachnoid haemorrhage predicted DCI.? A CBF decrease of 7.6 mL/min/100 g predicted DCI with 100?% sensitivity.? An MTT increase of 0.91 seconds predicted DCI with 83.9?% sensitivity.? DCI risk multiplied by 2 per 20?% ΔCBF decrease and by 15 per 20?% ΔMTT increase.

     

Intra-arterial nimodipine for the treatment of symptomatic cerebral vasospasm after aneurysmal subarachnoid hemorrhage: preliminary results

BACKGROUND AND PURPOSE: Cerebral vasospasm remains a major problem in patients recovering from aneurysmal subarachnoid hemorrhage despite advances in medical, surgical, and endovascular care. Our purpose was to assess the efficacy of intra-arterial nimodipine, a calcium-channel blocker acting mainly on cerebral vessels, in preventing delayed neurologic deficits in patients with symptomatic vasospasm. METHODS: Clinical charts of 25 consecutively treated patients were retrospectively reviewed. A multifactorial decision tree was used to determine the indication for angiography and subsequent endovascular treatment. Nimodipine was infused intra-arterially via a diagnostic catheter in the internal carotid artery or vertebral artery at a rate of 0.1 mg/min. Angiographic vasospasm before endovascular treatment, immediate vessel caliber modifications, and short- and long-term clinical efficacy of the procedure were assessed. RESULTS: Thirty procedures were performed in 25 patients. Clinical improvement was observed in 19 (76%), 16 of whom improved after the first endovascular procedure, two after the second intra-arterial treatment, and one after the third. Of these 19 patients, only 12 (63%) had notable vascular dilatation at postprocedural angiography. Dilatation of infused vessels occurred in only 13 (43%) of 30 procedures. After follow-up of 3-6 months, 18 (72%) of 25 patients had a favorable outcome (Glasgow outcome scale score of 1-2 and modified Rankin scale score of 0-2). No complications were observed. CONCLUSION: Intra-arterial nimodipine is effective and safe for the treatment of symptomatic vasospasm after subarachnoid hemorrhage. Further prospective randomized studies of cerebral blood flow are needed to confirm these results.     

Computed tomography angiography findings predictive of post-intervention vasospasm in patients with aneurysmal subarachnoid hemorrhage

Objective:To evaluate the association of CT/CT angiography (CTA) findings and clinical characteristics with subsequent vasospasm in patients with aneurysmal subarachnoid hemorrhage (aSAH).Methods-:Consecutive presentation CTA head exams in patients with aSAH between January 2005 and June 2015 were retrospectively evaluated for intracranial arterial calcification, undulation and non-calcified stenosis. Additional variables including modified Fisher Scale (mFS), Glasgow Coma Scale (GCS) and neurological exam status were reviewed. Associations of CTA findings with the incidence of angiographic vasospasm were assessed with multivariate logistic regression models using the least absolute shrinkage and selection operator machine-learning algorithm. Model performance was summarized using c-index with bootstrap optimism-adjustment.ResultsIntracranial arterial calcification, seen in 51.7% of 195 total patients, was protective against vasospasm (OR-0.6; 95% CI-0.52–0.67; p = 0.009), while arterial undulation (24%) was associated with subsequent vasospasm (OR-2.6; 95% CI-1.3–5.1; p = 0.007). Non-calcified intracranial arterial stenosis (5%) was associated with subsequent vasospasm, (OR-4.7; 95% CI-1.0–22.8; p = 0.054). Least absolute shrinkage and selection operator selected all three CTA findings as predictors in a multivariate model for vasospasm in addition to clinical factors, which demonstrated superior predictive performance (c-index-0.74; 95% CI-0.69–0.82) compared to a model based on mFS and clinical factors only (c-index-0.66; 95% CI-0.57–0.75; p = 0.010 for the difference).Conclusion:Presentation CTA findings combined with clinical factors may better predict the development of vasospasm in patients with aSAH compared to current prognostic models alone.Advances in knowledge:The combination of initial CT/CTA and clinical findings better predict development of vasospasm after aSAH. This can lead to better markers for use in future clinical trials to develop vasospasm preventative treatments and potentially provide better targets for early aggressive treatment.     

CT angiography for the detection of cerebral vasospasm in patients with acute subarachnoid hemorrhage

BACKGROUND AND PURPOSE: Digital subtraction angiography (DSA) is the standard of reference for detecting cerebral vasospasm after subarachnoid hemorrhage (SAH). CT angiography (CTA) is a relatively recent method for depicting the intracranial arterial vasculature. The purpose of this study was to compare CTA and DSA in the detection and quantification of cerebral vasospasm. METHODS: Seventeen patients with SAH underwent initial CTA with or without DSA and follow-up CTA and DSA. The follow-up CTA and DSA studies were performed within 24 hours of each other and 5 to 10 days after SAH. Maximum intensity projection images were produced for each CTA. Six arterial locations were examined for spasm: the suprasellar internal carotid artery (ICA), the M1 and M2 segments of the middle cerebral artery, the A1 and A2 segments of the anterior cerebral artery, and the basilar artery. Vasospasm was categorized as none, mild (<30% luminal reduction), moderate (30% to 50% reduction), or severe (>50% reduction). RESULTS: The overall correlation between CTA and DSA was 0.757, but was better for proximal than distal locations (0.88-1.00 versus 0.152-0.446). Agreement between CTA and DSA was greater for no spasm (92%) and severe spasm (100%) than for mild (57%) or moderate (64%) spasm. CTA was highly accurate for no spasm or severe spasm in proximal locations (96%, and 100%, respectively); it was less accurate (90% and 95%, respectively) for mild or moderate spasm in these locations. For distal locations, the accuracy for absent, mild, moderate, or severe spasm was 78%, 81%, 94%, and 100%, respectively. CONCLUSION: CTA is highly sensitive, specific, and accurate in detecting no spasm or severe cerebral vasospasm in proximal arterial locations; it is less accurate for detecting mild and moderate spasm in distal locations.     

Multidetector-row CT angiography of cerebral vasospasm after aneurysmal subarachnoid hemorrhage: comparison of volume-rendered images and digital subtraction angiography

BACKGROUND AND PURPOSE: Cerebral vasospasm remains a major problem in patients recovering after surgical treatment of cerebral aneurysms. The purpose of this study was to evaluate cerebral vasospasm at multidetector-row spiral CT angiography (MDCTA) compared with digital subtraction angiography (DSA) in patients with aneurysmal subarachnoid hemorrhages (SAHs). METHODS: Seventeen patients suspected of having vasospasm on clinical findings underwent both postoperative MDCTA and DSA. MDCTA was analyzed by using volume-rendered images as well as axial images. A total of 251 arterial segments were analyzed for vasospasm by using a 5-point grading system. The MDCTA results were then compared with findings on the corresponding DSA images. Sensitivity, specificity, and accuracy of MDCTA for detection of hemodynamically significant spasms were also calculated, with findings at DSA used as the reference standard. RESULTS: On DSA, 74 spasmatic segments were found among the 251 segments evaluated, and 40 segments with hemodynamically significant vasospasms were present. The overall agreement between MDCTA and DSA was 95.2%. We had 12 (4.8%) cases of disagreement between MDCTA and DSA. In 11 segments, the degree of stenosis was overestimated at MDCTA. Overall accuracy, sensitivity and specificity of MDCTA in the detection of hemodynamically significant vasospasm were 97.5%, 98.1%, and 98.0%, respectively, with positive and negative predictive values of 90.7% and 99.5%. CONCLUSION: MDCTA appears to be a reliable alternative imaging technique to DSA in the assessment of patients with cerebral vasospasm after aneurysmal SAH.     

CT perfusion-derived mean transit time predicts early mortality and delayed vasospasm after experimental subarachnoid hemorrhage

BACKGROUND AND PURPOSE: There are limited indicators available to predict cerebral vasospasm in patients with subarachnoid hemorrhage (SAH). The purpose of this study was to determine if CT perfusion–derived hemodynamic parameters are predictors of vasospasm severity and outcome after experimental SAH.MATERIALS AND METHODS: SAH was induced in 25 New Zealand white rabbits. Cerebral blood flow (CBF), cerebral blood volume (CBV), and mean transit time (MTT) were measured with CT perfusion before SAH, within 1 hour after SAH, and on days 2, 4, 7, 9, and 16 after SAH. Basilar artery diameter, measured with CT angiography and neurologic scoring, was also obtained on the same days. Differences between animals with moderate-severe delayed vasospasm (≥24% basilar artery narrowing) and mild delayed vasospasm (<24% basilar artery narrowing) were investigated with repeated measures analysis of variance. Multiple linear regression analysis was used to investigate the relationship between CT perfusion parameters (CBF, CBV, MTT), basilar artery diameter, and neurologic score.RESULTS: MTT increase <1 hour after SAH independently predicted mortality within 48 hours of SAH (P < .05). MTT and neurologic deficits were significantly greater with moderate-severe than with mild vasospasm (P < .05). MTT on day 2, but not CBF or CBV, was a significant predictor of subsequent moderate-severe delayed vasospasm (P < .05).CONCLUSION: In the rabbit model of experimental SAH, the CT-derived hemodynamic parameter MTT on day 0 predicted early mortality, and MTT on day 2 predicted development of moderate-severe delayed vasospasm. MTT was also significantly correlated with arterial diameter and neurologic score.

Delayed ischemia is the most significant risk factor contributing to death and disability in patients who initially survive subarachnoid hemorrhage (SAH).¹ Repeat hemorrhage can also lead to poor outcomes after SAH; however, early aneurysm repair by surgical clipping or endovascular coiling has significantly reduced the incidence of rebleeding in patients with aneurysm.^2,3 Unfortunately, even for patients who undergo early aneurysm repair, the risk of morbidity and mortality due to vasospasm-related ischemia remains high.^3–5Effective therapeutic intervention for vasospasm depends on timely identification.⁶ Commonly used methods of screening patients suspected of having vasospasm include transcranial Doppler and CT angiography (CTA). Both of these methods can be used successfully for diagnosing patients with vasospasm; however, both may be limited for technical reasons. Narrowing in small distal vessels cannot be detected with transcranial Doppler due to its limited spatial resolution and low sensitivity, so examinations of the microcirculation are limited.⁷ In addition, a proper acoustic window for insonating patients is lacking in approximately 20% of patients.⁸ CTA can be limited for evaluation of vessels near to a treated aneurysm because of streak artifacts from the surgical clip or coil pack.⁹Recently, there has been interest in using CT perfusion imaging for assessment of patients with vasospasm.¹⁰ A number of different hemodynamic parameters are available using CT perfusion imaging. One such parameter, mean transit time (MTT), is a measure of the mean time for blood to perfuse a region of tissue. MTT is related to cerebral blood flow (CBF) and cerebral blood volume (CBV) by the central volume principle: MTT = CBV / CBF.¹¹ Thus, MTT is highly sensitive to hemodynamic disturbances involving changes in both CBV and CBF.CT perfusion imaging is a rapid and relatively inexpensive imaging technique that has the ability to identify hemodynamic disturbances associated with vasospasm.^6,12,13 In a recent clinical investigation, MTT was identified as the most sensitive perfusion parameter for the detection of SAH-related vasospasm.¹⁰ These results, however, rely on a single measurement made between 6 and 9 days after SAH. To our knowledge, the temporal relationship between MTT and vasospasm has yet to be studied throughout the course of delayed vasospasm after SAH. This lack of information is, in part, due to the difficulty of performing serial CT perfusion measurements in a patient population in the weeks following SAH, when delayed vasospasm is likely to occur.The diagnostic potential of CT perfusion imaging in patients with vasospasm has been demonstrated and is thus a realistic clinical goal; however, less is known about its ability to predict vasospasm onset or patient outcomes. The possibility of predicting an individual patient''s risk for bad outcome or symptomatic vasospasm is an attractive clinical goal. The ability to predict outcomes such as death, neurologic injury, or onset of symptomatic vasospasm after SAH could lead to early interventions resulting in improved patient care and patient outcomes.The purpose of our study was to determine the temporal relationship between hemodynamic parameters, arterial diameter, and neurologic score in a rabbit model of SAH-induced vasospasm. We investigated CT perfusion–derived measurements of MTT, CBF, and CBV as predictors and correlates of delayed vasospasm severity and outcome after experimental SAH. We hypothesized that increased MTT and decreased CBF are predictors for delayed arterial narrowing and neurologic deficits subsequent to SAH.     

Long-term impact of perfusion CT data after subarachnoid hemorrhage

Introduction

Dynamic perfusion computed tomography (PCT) has been established as a diagnostic instrument for the detection of vasospasm after subarachnoid hemorrhage (SAH). The purpose of this study was to assess the prognostic impact of PCT parameters after SAH on the long-term outcome of patients.

Methods

Three hundred twelve patients were retrospectively interrogated with a questionnaire 23.06?±?14.33 months after spontaneous subarachnoid hemorrhage. The modified Rankin scale (mRS) was determined, respectively. Scheduled PCT data sets from the first days after ictus were available for all patients.

Results

The maximum mean transit time over several examinations per hemisphere (MTT_PEAK) values were significantly correlated (p?≤?0.001, r?=?0.422) with the clinical long-term outcome (mRS). Corresponding to our linear regression analysis, MTT_PEAK is the second most important regressor (behind clinical severity of the initial hemorrhage) for the prediction of long-term mRS. An MTT_PEAK threshold of 3.98 s (identified by receiver operating characteristic analysis, area under the curve?=?0.75) predicted an unfavorable long-term outcome (mRS?≥?2) with a sensitivity, specificity, positive predictive value, negative predictive value, and diagnostic accuracy of 67.3, 74.3, 84.5, 52.1, and 69.6 %, respectively.

Conclusion

The presented data corroborate the relevance of PCT data for the clinical long-term outcome of SAH patients. By identification of patients who are at risk for a bad outcome and may need escalation of therapy, risk-benefit analysis is supported.     

Angiographic evaluation of the effect of intra-arterial milrinone therapy in patients with vasospasm from aneurysmal subarachnoid hemorrhage

Introduction  

Several methods have been used to treat cerebral vasospasm, which is a major cause of morbidity and mortality in patients with aneurysmal subarachnoid hemorrhage (SAH). Here, we examined the effectiveness and safety of intra-arterial injection of milrinone for the treatment of vasospasm.     

Cortical blood flow during cerebral vasospasm after aneurysmal subarachnoid hemorrhage: three-dimensional N-isopropyl-p-[(123)I]iodoamphetamine single photon emission CT findings

BACKGROUND AND PURPOSE: The relationship between regional cerebral blood flow (rCBF) during cerebral vasospasm after subarachnoid hemorrhage (SAH) and angiographic vasospasm and the value of rCBF in predicting vasospasm and the prognosis are not fully delineated. Our aim was to investigate the changes in extent of vasospasm-induced decreased cortical rCBF on three-dimensional (3D) displays of single photon emission CT (SPECT) findings. The clinical usefulness of these assessments was analyzed. METHODS: In 58 cases of SAH, SPECT and digital subtraction angiography were performed on the same day, 5-9 days after SAH or within 24 hours after the onset of delayed ischemic neurologic deficit (DIND). Cerebral blood flow data were assessed by measuring the area of decreased cortical rCBF on 3D SPECT images. RESULTS: The area of decreased cortical rCBF on the 3D images was significantly increased in cases with DIND (P <.001), in cases with a large infarction due to vasospasm (P =.006), and in cases with a poor prognosis after vasospasm (P =.045). These increases were also related to the type of angiographic vasospasm; the greatest decrease in cortical rCBF occurred in the combined type (combination of the peripheral and proximal types) of vasospasm, followed by cases with the peripheral type, proximal type, and no angiographic vasospasm. In cases with DIND, patchy decreased cortical rCBF areas were seen before the onset of DIND. CONCLUSION: Combined-type vasospasm leads to reductions in CBF greater than those due to isolated peripheral or proximal vasospasm. Two-dimensional and mean-hemispheric CBF analyses are less sensitive for this change than is 3D SPECT.     

Pre-operative micro-angioplasty of refractory vasospasm secondary to subarachnoid hemorrhage

Summary A patient with subarachnoid hermorrhage secondary to a basilar artery aneurysm developed severe bilateral middle and anterior cerebral artery vasospasm with extensive neurologic deficits. Microangioplasty of the middle cerebral artery segments bilaterally led to reversal of the neurologic deficits, allowing early operative treatment of the aneurysm in a previously inoperable patient.