Angiogram-Negative Subarachnoid Hemorrhage: Outcomes Data and Review of the Literature

Comparison of Risk Factors for Early Seizures Between Angiogram-Negative and Aneurysmal Subarachnoid Hemorrhage

BACKGROUND

Early-onset seizures are common in aneurysmal subarachnoid hemorrhage (aSAH), with risk factors that have been explored. However, early-onset seizures in patients with angiogram-negative nonperimesencephalic SAH (an-SAH) are less understood. We sought to compare the incidence and risk factors of early-onset seizures between these groups.

METHODS

We conducted a retrospective study of a cohort of consecutive patients admitted to an academic center between July 2016 and July 2023. Patients were categorized into aSAH or an-SAH based on imaging findings. Clinical data and electroencephalogram findings were retrieved and analyzed. Multivariable logistic regression analysis was used to determine risk factors for clinical or electrographic seizures, as well as other epileptic features.

RESULTS

We included 473 patients (63% female) in the final analysis, of whom 79 had an-SAH and 394 had aSAH. Patients with an-SAH were older (mean age 61.9 years [standard deviation 15.9] vs. 56.7 [standard deviation 13.4]; p = 0.02). The rate of clinical or electrographic seizures was similar between the two groups (13% in aSAH vs. 11% in an-SAH; p = 0.62). Highly epileptic features (electrographic seizures, ictal-interictal continuum, and periodic epileptic discharges) occurred more frequently in the aSAH group compared with the an-SAH group, although this difference was not significant (15% vs. 8%; p = 0.09). Risk factors for seizures in aSAH were Hunt and Hess grade (odds ratio [OR] 1.25 per grade increase, 95% confidence interval [CI] 1.05-1.49; p = 0.011), modified Fisher score (OR 1.64 per point increase, 95% CI 1.25-2.15; p < 0.001), cerebral infarct (OR 3.64, 95% CI 2.13-6.23; p < 0.001), and intracerebral hemorrhage (OR 10, 95% CI 1.35-76.9; p = 0.017). However, none of these factors were associated with seizures in an-SAH.

CONCLUSIONS

Early-onset seizures occur at similar rates in patients with an-SAH and aSAH. However, seizure risk factors appear to differ between these groups. Larger prospective studies are needed to identify predictors of seizures in patients with an-SAH.

Re-evaluating patient communication and care in angiographically negative subarachnoid hemorrhage: Balancing realism and optimism

Angiographically negative subarachnoid hemorrhage (anSAH) has traditionally been considered a benign condition, mainly because of favorable outcomes in the acute stage in comparison to the often negative acute outcomes of aneurysmal subarachnoid hemorrhage. However, a growing body of research in recent years shows that anSAH often leads to cognitive impairments, emotional distress, and difficulties in resuming work or other daily life activities. Therefore, in this position paper, we call for a change in neurological care and a shift in patient communication, emphasizing the importance of addressing patient needs and fostering realistic expectations rather than solely focusing on the benign nature of the condition.

Stroke Unit as an alternative to Intensive Care Unit for initial hospital admission of low-grade non-aneurysmal subarachnoid haemorrhage: A safety and cost-minimisation analysis

INTRODUCTION

Stroke Units (SU) have been suggested as an alternative to Intensive Care units (ICU) for initial admission of low-grade non-aneurysmal spontaneous subarachnoid haemorrhage (naSAH). We hypothesised that the incidence of in-hospital complications and long-term clinical outcomes in low-grade naSAH patients would be comparable in both settings, and that a cost-minimisation analysis would favour the use of SU.

PATIENTS AND METHODS

Retrospective, single-centre study at a third-level stroke-referral hospital, including low-grade spontaneous naSAH patients with WFNS 1-2. Primary outcomes were death and functional status at 3 months. Secondary outcomes were incidence of in-hospital major neurological and systemic complications. Additionally, a cost-minimisation analysis was conducted to estimate the average cost savings that could be achieved with the most efficient approach.

RESULTS

Out of 96 naSAH patients, 30 (31%) were initially admitted to ICU and 66 (69%) to SU. Both groups had similar demographic and radiological features except for a higher proportion of WFNS 2 in ICU subgroup. There were no statistically significant differences between ICU and SU-managed subgroups in death rate (2 (7%) and 1 (2%), respectively), functional outcome at 90 days (28 (93%) and 61 (92%) modified Rankin Scale 0-2) or neurological and systemic in-hospital complications. Cost-minimisation analysis demonstrated significant monetary savings favouring the SU strategy.

DISCUSSION AND CONCLUSION

Initial admission to the SU appears to be a safe and cost-effective alternative to the ICU for low-grade naSAH patients, with comparable clinical outcomes and a reduction of hospitalisation-related costs. Prospective multicenter randomised studies are encouraged to further evaluate this approach.

Contribution of Deep Cerebral Venous Anomaly to the Emergence of Nonaneurysmal Subarachnoid Hemorrhage as Opposed to Aneurysmal Subarachnoid Hemorrhage

BACKGROUND

The exact reason of nonaneurysmal subarachnoid hemorrhage (SAH) is an enigma. The aim of this study is to identify if type III deep cerebral venous drainage is exclusively prevalent in patients with nonaneurysmal SAH and to enumerate the predictors of poorer outcome in these patients.

METHODS

All patients of age >18 years, presented at our centre with spontaneous SAH on noncontrast computed tomography head and were divided into 2 groups, aneurysmal and nonaneurysmal SAH after 4-vessel DSA. Based on the deep venous drainage pattern on both sides, basal venous drainage was found and classified into 3 types: type I, type II, and type III. The 3 groups were pitted against one another. Regression analysis were performed to predict the occurrence of nonaneurysmal-SAH with different types of basal vein.

RESULTS

There were 100 nonaneurysmal SAH cases and 103 aneurysmal SAH cases. The mean age of presentation was 47.8 ± 13.55 years with slight male predominance (52%). The patients with type III venous drainage have 2 times more risk of developing nonaneurysmal SAH (95% confidence interval = 1.21-4.31) as compared to those with aneurysmal SAH. On multivariate analysis, type III basal venous drainage, worse Hunt and Hess grade at presentation, extensive bleeding were predictors of an adverse outcome.

CONCLUSIONS

The presence of type III venous distribution is associated with a 2-fold increase in the probability of having nonaneurysmal SAH, as well as a 3-fold increase in the risk of developing poorer neurological sequelae.

Automated magnetic resonance imaging quantification of cerebral parenchymal and ventricular volume following subarachnoid hemorrhage: associations with cognition

This study aims to investigate cerebral parenchymal and ventricular volume changes after subarachnoid hemorrhage (SAH) and their potential association with cognitive impairment. 17 patients with aneurysmal SAH (aSAH) and 21 patients with angiographically negative SAH (anSAH) without visually apparent parenchymal loss on conventional magnetic resonance imaging (MRI) were included, along with 76 healthy controls. Volumetric analyses were performed using an automated clinical segmentation and quantification tool. Measurements were compared to on-board normative reference database (n = 1923) adjusted for age, sex, and intracranial volume. Cognition was assessed with tests for psychomotor speed, attentional control, (working) memory, executive functioning, and social cognition. All measurements took place 5 months after SAH. Lower cerebral parenchymal volumes were most pronounced in the frontal lobe (aSAH: n = 6 [35%], anSAH n = 7 [33%]), while higher volumes were most substantial in the lateral ventricle (aSAH: n = 5 [29%], anSAH n = 9 [43%]). No significant differences in regional brain volumes were observed between both SAH groups. Patients with lower frontal lobe volume exhibited significantly lower scores in psychomotor speed (U = 81, p = 0.02) and attentional control (t = 2.86, p = 0.004). Additionally, higher lateral ventricle volume was associated with poorer memory (t = 3.06, p = 0.002). Regional brain volume changes in patients with SAH without visible parenchymal abnormalities on MRI can still be quantified using a fully automatic clinical-grade tool, exposing changes which may contribute to cognitive impairment. Therefore, it is important to provide neuropsychological assessment for both SAH groups, also including those with clinically mild symptoms.

Clinical Outcomes of Diffuse Angiogram-Negative Subarachnoid Hemorrhage Versus Aneurysmal Subarachnoid Hemorrhage: A Propensity Score-Matched Analysis

BACKGROUND

The outcome of diffuse angiogram-negative subarachnoid hemorrhage (dan-SAH) compared with aneurysmal SAH (aSAH) remains unclear. This study aimed to compare outcomes using propensity score matching.

METHODS AND RESULTS

Sixty-five patients with dan-SAH and 857 patients with aSAH admitted between January 2018 and December 2022 were retrospectively reviewed. Propensity score matching resulted in matching 65 patients with dan-SAH to 260 patients with aSAH, and clinical outcomes were compared between the groups. Compared with patients with dan-SAH, patients with aSAH were more likely to experience rehemorrhage (8.8% versus 0%, P=0.027), death (11.2% versus 1.5%; odds ratios [OR] 8.04 [95% CI, 1.07-60.12]; P=0.042), or delayed cerebral ischemia (12.3% versus 3.1%; OR, 4.42 [95% CI, 1.03-18.95]; P=0.045). Multivariate analysis revealed that Hunt-Hess grade 4 to 5 (OR, 3.13 [95% CI, 2.11-4.64]; P<0.001), presence of intraventricular hemorrhage (OR, 3.58 [95% CI, 1.72-7.46]; P=0.001), and smoking (OR, 2.44 [95% CI, 1.12-5.28]; P=0.024) were independently associated with the incidence of unfavorable outcomes (modified Rankin scale score >2 at 3 months), whereas dan-SAH was not (OR, 0.66 [95% CI, 0.25-1.73]; P=0.40).

CONCLUSIONS

Compared with patients with dan-SAH, patients with aSAH had higher rehemorrhage rates and in-hospital mortality, as well as a higher incidence of delayed cerebral ischemia. Unfavorable outcomes were associated with admission Hunt-Hess grade, the presence of intravenetricular hemorrhage, and smoking history, but there was no relation with the  pathogenesis of the hemorrhage (dan-SAH versus aSAH).

Delayed appearance of basilar trunk small atypical aneurysms in nontraumatic, initially angiogram-negative subarachnoid hemorrhage: A report of three patients

BACKGROUND

Repeat angiography will identify vascular pathology in approximately 10% of cases following angiogram-negative subarachnoid hemorrhage (anSAH), but small atypical aneurysms of the basilar artery are very uncommon.

OBJECTIVE

To report a case series of delayed appearance of nontraumatic basilar artery small atypical aneurysms.

METHODS

IRB approval was obtained for this retrospective case series and patient consent was waived.

RESULTS

Herein we report three cases of spontaneous anSAH, all of whom had a negative digital subtraction angiogram (DSA) on admission and all of whom had appearance of a small atypical aneurysms of the upper basilar trunk/apex on follow-up imaging (two during the initial admission and one in a delayed fashion). All three patients were ultimately treated with flow diversion (although one patient underwent attempted coiling that was abandoned due to inability to catheterize the aneurysm).

CONCLUSION

This report highlights the importance of a repeat DSA in cases of anSAH as well as the importance of scrutinizing the basilar trunk for these very small atypical aneurysms that may go unnoticed.

Systemic Inflammatory Response in Spontaneous Subarachnoid Hemorrhage from Aneurysmal Rupture versus Subarachnoid Hemorrhage of Unknown Origin

OBJECTIVE

It is well known that spontaneous non-aneurysmal subarachnoid hemorrhage (SAH), also known as sine materia SAH (smSAH), has usually a better course and prognosis than its aneurysmal counterpart (aSAH). This might depend on different inflammatory mechanisms initiated by bleeding events of different origins. The aim of the present study was to explore the systemic inflammatory response in spontaneous SAH, comparing aSAH and smSAH.

METHODS

We performed a prospective observational study over a consecutive series of patients with SAH. For these patients, we collected all clinical data and, furthermore, performed venous blood sampling over six time points to analyze blood cells. We further performed the analysis of lymphocytes and monocytes by means of flow cytometry to quantify common subtypes. Statistical analysis included a t-student test, Chi-square test, multivariate logistic regression, and ROC analysis.

RESULTS

48 patients were included: six (12.5%) with a diagnosis of spontaneous smSAH, and forty-two patients (87.5%) with aSAH. Significant differences on Day 0 were found for neutrophils and a systemic neuro-inflammatory index, namely, systemic inflammatory response index (SIRI). At the ROC analysis, neutrophil-to-lymphocyte ratio (NLR), lymphocyte-to-monocyte ratio (LMR), and SIRI exhibited satisfactory predictive power on day 0. At the multivariable logistic regression analysis, the combined index (NLR, LMR, SIRI at day 0) yielded an OR of 0.59 (95% CI 0.29-1.21]). LMR at day 0 yielded an OR of 1.25 ([95% CI 0.94-1.68]), NLR at day 0 exhibited an OR of 0.68 ([95% CI 0.42-1.09]), and SIRI at day 0 displayed an OR of 0.31 ([95% CI 0.06-1.49]).

CONCLUSION

This preliminary study indicated a possible role of some inflammatory indices that point out the importance of innate and adaptive immunity in the etiopathogenetic mechanisms. Drugs modulating these responses could eventually counteract or, at least, reduce secondary damage associated with SAH.

Stress-Induced Subarachnoid Hemorrhage: A Case Report

While there are many forms of intracranial hemorrhage (ICH), the most common form affecting young to middle-aged patients is subarachnoid hemorrhage (SAH). SAHs are primarily traumatic, while a minority of cases are spontaneous. The majority of spontaneous SAHs occur due to the rupture of a cerebrovascular aneurysm. A small number of spontaneous SAHs occur without any objective findings of an aneurysm. Most of these cases are in older patients with certain risk factors such as smoking, hypertension, and alcohol use. This article reports a young female patient without any known significant risk factors who developed an acute spontaneous SAH while experiencing a significant psychological stressor. Recent literature has focused on certain somatic manifestations of psychological stressors, such as stress-induced (Takotsubo) cardiomyopathy. We postulate that our patient’s SAH was a sequela of psychological stress and that the pathophysiology may be similar to Takotsubo cardiomyopathy.

Effect of stress-induced hyperglycemia after non-traumatic non-aneurysmal subarachnoid hemorrhage on clinical complications and functional outcomes

Background

Despite having an overall benign course, non‐traumatic non‐aneurysmal subarachnoid hemorrhage (naSAH) is still accompanied by a risk of clinical complications and poor outcomes. Risk factors and mechanisms of complications and poor outcomes after naSAH remain unknown. Our aim was to explore the effect of stress‐induced hyperglycemia (SIH) on complication rates and functional outcomes in naSAH patients.

Methods

We retrospectively reviewed patients with naSAH admitted to our institution between 2013 and 2018. SIH was identified according to previous criterion. Symptomatic vasospasm, delayed cerebral infarction, and hydrocephalus were identified as main complications. Outcomes were reviewed using a modified Rankin Scale (mRS) at discharge, 3 months, and 12 months. A statistical analysis was conducted to reveal the associations of SIH with complications and outcomes.

Results

A total of 244 naSAH patients were included in the cohort with 74 (30.3%) SIH. After adjusting for age, gender, hypertension, Hunt and Hess (HH) grade, modified Fisher Scale (mFS), intraventricular hemorrhage (IVH), and subarachnoid blood distribution, SIH was significantly associated with symptomatic vasospasm (p < 0.001, 12.176 [4.904–30.231]), delayed cerebral infarction (p < 0.001, 12.434 [3.850–40.161]), hydrocephalus (p = 0.008, 5.771 [1.570–21.222]), and poor outcome at 12 months (p = 0.006, 5.506 [1.632–18.581]), whereas the correlation between SIH and poor outcome at discharge (p = 0.064, 2.409 [0.951–6.100]) or 3 months (p = 0.110, 2.029 [0.852–4.833]) was not significant. Incorporation of SIH increased the area under curve (AUC) of ROC in the combined model for predicting symptomatic vasospasm (p = 0.002), delayed cerebral infarction (p = 0.024), hydrocephalus (p = 0.037), and 12‐month poor outcome (p = 0.087).

Conclusions

SIH is a significant and independent risk factor for symptomatic vasospasm, delayed cerebral infarction, hydrocephalus, and long‐term poor outcome in naSAH patients. Identifying SIH early after naSAH is important for decision‐making and treatment planning.

Non-aneurysmal subarachnoid hemorrhage: Is the deep venous system the hidden culprit?

AIM

The exact cause of bleeding in non-aneurysmal sub-arachnoid hemorrhage (SAH) is yet to be established. The present study intends to evaluate the morphological variants of deep cerebral venous drainage, especially basal veins of Rosenthal (BVR), and to correlate if such a venous anomaly is associated with increased incidence of non-aneurysmal SAH.

METHODS

A prospective analysis of all the patients of age more than 12 years with spontaneous non-aneurysmal SAH and undergone 4-vessel DSA for the diagnosis of the source of bleeding was included in the study (n = 59). The anatomy of the basal venous distribution was evaluated and was divided into 3 different types, namely normal (Type A), normal variant (Type B), and primitive (Type C), based on DSA findings. The follow-up of these cases was noted. The three groups were compared with one another.

RESULTS

The median age of presentation was 51 years with slight male predominance (52%). Primitive venous drainage was associated with a poorer grade at presentation (p = 0.002), more severe bleed (p = 0.001), vasospasm (p = 0.045), and a poorer outcome at 6 months (p = 0.019). Hydrocephalous and vasospasm were seen in patients with primitive venous drainage. On multivariate regression analysis for poorer outcome, it was observed that a worse grade at presentation, extensive bleed, primitive venous drainage are independent predictors of an adverse outcome.

CONCLUSION

The presence of primitive venous drainage has a linear relationship with the development of non-aneurysmal SAH with multi-cisternal hemorrhage, worse grade at presentation, and unfavorable outcome.

Spontaneous angiogram-negative subarachnoid hemorrhage: a retrospective single center cohort study

Background

Spontaneous angiogram-negative subarachnoid hemorrhage (SAH) is considered a benign illness with little of the aneurysmal SAH-related complications. We describe the clinical course, SAH-related complications, and outcome of patients with angiogram-negative SAH.

Methods

We retrospectively reviewed all adult patients admitted to a neurosurgical intensive care unit during 2004–2018 due to spontaneous angiogram-negative SAH. Our primary outcome was a dichotomized Glasgow Outcome Scale (GOS) at 3 months. We assessed factors that associated with outcome using multivariable logistic regression analysis.

Results

Of the 108 patients included, 84% had a favorable outcome (GOS 4–5), and mortality was 5% within 1 year. The median age was 58 years, 51% were female, and 93% had a low-grade SAH (World Federation of Neurosurgical Societies grading I–III). The median number of angiograms performed per patient was two. Thirty percent of patients showed radiological signs of acute hydrocephalus, 28% were acutely treated with an external ventricular drain, 13% received active vasospasm treatment and 17% received a permanent shunt. In the multivariable logistic regression model, only acute hydrocephalus associated with unfavorable outcome (odds ratio = 4.05, 95% confidence interval = 1.05–15.73). Two patients had a new bleeding episode.

Conclusion

SAH-related complications such as hydrocephalus and vasospasm are common after angiogram-negative SAH. Still, most patients had a favorable outcome. Only acute hydrocephalus was associated with unfavorable outcome. The high rate of SAH-related complications highlights the need for neurosurgical care in these patients.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00701-021-05069-7.

Retrospective 6 month-outcomes and prognostic factors following spontaneous angiogram-negative non-perimesencephalic subarachnoid hemorrhage

Our objective was to analyze functional outcomes and prognostic factors in patients suffering from angiogram-negative non-perimesencephalic subarachnoid hemorrhage (non-PMH). In total, 1601 patients presenting with spontaneous SAH between January 2009 to December 2019 admitted to our institution were reviewed. Among them, 51 patients with angiogram negative non-perimesencephalic subarachnoid hemorrhage were analyzed. We divided patients into groups according to hemorrhage pattern and duration. Prognostic factors were assessed according to initial neurologic grade, early hydrocephalus, fisher grade, and duration of hemorrhage. Outcomes were assessed according to the modified Rankin Scale after 6 months. Overall, 41 patients (80.3%) with angiogram-negative non-PMH achieved a favorable outcome. In univariate analysis, good initial neurologic grade, absence of early hydrocephalus, non-Fisher-type 3 bleeding pattern, and short term hemorrhage (blood wash out <7 days after onset) duration were significantly associated with a favorable outcome. In multivariate analysis, a non-Fisher-type 3 hemorrhagic pattern (p < 0.05) and good initial neurologic state (p < 0.01) were independent predictors of favorable outcomes in angiogram-negative non-PMH patients. Patients with angiogram-negative non-PMH generally had favorable outcomes. A non-Fisher-type 3 hemorrhagic pattern and good initial neurologic state were prognostic factors of a favorable outcome in non-PMH. Furthermore, patients with long-term SAH were more likely to develop hydrocephalus. Evaluating the pattern and duration of subarachnoid hemorrhage may allow better prediction of outcomes in patients with angiogram negative and non-PMH.

Arterial Wall Imaging in Angiographically Occult Spontaneous Subarachnoid Hemorrhage : New Insight into the Usual Suspect

Objective

The etiology of angiographically occult spontaneous subarachnoid hemorrhage (AOsSAH) is unclear. Threedimensional (3D) high-resolution vessel wall magnetic resonance imaging (HVM) might be useful in detecting the hidden arterial wall angiopathy in patients with AOsSAH. We aimed to demonstrate the feasibility of HVM for detecting the arterial cause of AOsSAH.

Methods

Patients, who were diagnosed with AOsSAH in the first evaluations and underwent HVM, were enrolled. Their clinical and radiologic data were retrospectively reviewed. Especially, focal enhancement of arterial wall on HVM and repetitive catheterized angiograms were precisely compared.

Results

Among 251 patients with spontaneous SAH, 22 patients were diagnosed with AOsSAH in the first evaluations (8.76%). After excluding three patients who did not undergo 3D-HVM, 19 patients were enrolled and classified as convexal (n=2) or perimesencephalic (n=4), and diffuse (n=13) groups. In convexal and perimesencephalic groups, no focal enhancement on HVM and no positive findings on repetitive angiography were noted. In diffuse group, 10 patients showed focal enhancement of arterial wall on HVM (10/13, 76.9%). Repeated angiography with 3D reconstruction revealed four patients of angiographically positive causative arteriopathy and possible lesion in one case in the concordant location of intramural enhancement on 3D-HVM (5/10, 50%). Three of them were treated with endovascular stent insertion. All patients, except one, recovered with good clinical outcome (3-month modified Rankin score, 0 and 1).

Conclusion

3D-HVM was useful in detecting hidden true arteriopathy in AOsSAH. It may provide new insights into the etiologic investigation of AOsSAH by proving information about the arterial wall status.

Factors determining outcome of post-angiogram-negative subarachnoid hemorrhage

Aim:

To determine the risk factors affecting outcome at the end of 90 days of post-angiogram-negative subarachnoid hemorrhage (SAH).

Methods:

Non-traumatic SAH cases were reviewed from the case records of patients who had reported to the Department of Neurology of a tertiary care hospital and 50 angio-negative SAH cases were included after excluding all the cases with known cause of hemorrhage after doing computed tomography angiography (CTA)/digital subtraction angiography (DSA). The presence of hypertension, diabetes mellitus, coronary artery disease (CAD), history of alcohol and smoking, and various scales like Hunt and Hess Scale (HHS), World Federation of Neurological Surgeons (WFNS), and Fisher scale had been recorded at admission. The outcome was assessed at 90 days post-SAH using the Modified Rankin Scale (mRS).

Statistical analyses:

The association between the outcome and the factors was assessed using the Pearson Chi-Square test and the risk factors/predictors of outcome were assessed using logistic regression.

Results:

The following variables were important risk factors for predicting poor outcome of angio-negative SAH (mRS 3 to 6): hypertension (P = 0.011), diabetes mellitus (P = 0.032), being an alcoholic (P = 0.019), HHS grade 4 to 5 (P < 0.01), and WFNS grade 4 to 5 (P < 0.01). On multivariate regression analysis, hypertension (P = 0.032) was an independent predictor of unfavorable outcome.

Conclusions:

At time of admission, presence of hypertension, diabetes mellitus, history of alcohol consumption, and poor grades of HHS and WFNS scale are predictors of poor outcome of angio-negative SAH.

Dural Venous Sinus Variations in Idiopathic Subarachnoid Hemorrhage: A New Indicator of the Venous Origin with Diagnostic Usefulness?

OBJECTIVE

Venous hypertension associated with a primitive basal vein of Rosenthal (BVR) has been noted as the most likely cause of idiopathic subarachnoid hemorrhage (iSAH). Other types of venous drainage variations have been scarcely studied but may further explain the cases not associated with a BVR anomaly. Our aim was to investigate if dural venous sinus (DVS) anomalies are related with iSAH.

METHODS

A total of 76 patients diagnosed with iSAH were identified from a prospectively maintained database and their angiographic findings compared with 76 patients diagnosed with aneurysmal subarachnoid hemorrhage.

RESULTS

On top of the BVR variations, our data showed a higher prevalence of transverse sinus hypoplasia (47.4% vs. 28.9%; P = 0.019), superior petrosal sinus hypoplasia (32.9% vs. 13.2%; P = 0.003), and clival plexus hyperplasia (65.8% vs. 43.4%; P = 0.005) in patients with iSAH. Analyzing by total number of angiograms, the iSAH group showed also a higher prevalence of inferior petrosal sinus hyperplasia (36.2% vs. 25%; P = 0.003). Of the patients with iSAH without a primitive BVR, 84% harbored ≥1 perimesencephalic DVS variation and the overall number of venous drainage variations was significantly higher in patients with iSAH.

CONCLUSIONS

In addition to the well-documented BVR anomalies, there seems to be a significant relationship of other DVS variations in patients with iSAH. Transverse sinus hypoplasia, superior petrosal sinus hypoplasia, inferior petrosal sinus hyperplasia, and clival plexus hyperplasia were significantly more frequent in patients with iSAH. The presence of ≥3 of those variations would increase the suspicion of a nonaneurysmatic subarachnoid hemorrhage and could help avoid a second angiogram.

Low-Pressure Hydrocephalus in Spontaneous Angiogram-Negative Subarachnoid Hemorrhage Following COVID-19 Infection

A preliminary report warned that severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) could have neuro-invasive potential as it was observed that some patients showed neurologic symptoms such as headache, nausea, and vomiting. Following early speculation there have been reports of neurologic manifestations involving both the central nervous system and peripheral nervous system including reports that coronavirus disease 2019 (COVID-19) may increase the risk of acute ischemic stroke. Here we present a patient with recent COVID-19 infection who experienced low-pressure hydrocephalus requiring high-output cerebrospinal fluid (CSF) diversion following spontaneous angiogram-negative subarachnoid hemorrhage. We hypothesize that patients who are either currently or who have recently been infected with SARS-CoV-2 may have altered ventricular compliance and/or altered CSF hydrodynamics from mechanisms that are not yet understood but potentially related to previously described pathophysiologic mechanisms of the virus and associated inflammatory reaction.

Hyperactive delirium in patients after non-traumatic subarachnoid hemorrhage

PURPOSE

Hyperactive delirium is common after subarachnoid hemorrhage (SAH). We aimed to identify risk factors for delirium and to evaluate its impact on outcome.

METHODS

We collected daily Richmond Agitation Sedation Scale (RASS) and Intensive Care Delirium Screening Checklist (ICDSC) scores in 276 SAH patients. Hyperactive delirium was defined as ICDSC ≥4 when RASS was >0. We investigated risk factors for delirium and its association with 3-month functional outcome using generalized linear models.

RESULTS

Patients were 56 (IQR 47-67) years old and had a Hunt&Hess (H&H) grade of 3 (IQR 1-5). Sixty-five patients (24%) developed hyperactive delirium 6 (IQR 3-16) days after SAH. In multivariable analysis, mechanical ventilation>48 h (adjOR = 4.46; 95%-CI = 1.89-10.56; p = 0.001), the detection of an aneurysm (adjOR = 4.38; 95%-CI = 1.48-12.97; p = 0.008), a lower H&H grade (adjOR = 0.63; 95%-CI = 0.48-0.83; p = 0.001) and a pre-treated psychiatric disorder (adjOR = 3.17; 95%-CI = 1.14-8.83; p = 0.027) were associated with the development of delirium. Overall, delirium was not associated with worse outcome (p = 0.119). Interestingly, patients with delirium more often had a modified Rankin Scale Score (mRS) of 1-3 (77%) compared to an mRS of 0 (14%) or 4-6 (9%).

CONCLUSION

Our data indicate that hyperactive delirium is common after SAH patients and requires a certain degree of brain connectivity based ono the highest prevalence found in SAH patients with intermediate outcomes.

Nontraumatic Nonaneurysmal Subarachnoid Hemorrhage: Risk Factors, Complications, and Clinical Outcomes

Background The present study aimed to investigate the risk factors, complications, and clinical outcomes of patients with nontraumatic, nonaneurysmal subarachnoid hemorrhage (NNSAH).

Methods We retrospectively evaluated 78 consecutive patients with NNSAH admitted to our center between April 2009 and April 2019. Patients were divided into two groups based on the distribution of blood in the CT scan, perimesencephalic subarachnoid hemorrhage ( PM-SAH) and nonperimesencephalic subarachnoid hemorrhage (nPM-SAH) groups. The outcome was assessed according to the Glasgow outcome scale (GOS). The demographic data and clinical records including age, sex, smoking history, hypertension, diabetes, history of anticoagulant medication, Glasgow coma score (GCS), Hunt–Hess (HH) grades, and in-hospital complications and clinical outcomes were retrospectively reviewed and compared between the two groups.

Results There were 45 patients (57.69%) in the PM-SAH group and 33 cases (42.30%) in the nPM-SAH group with the mean age of 53.98 ± 7.7 years. There were no significant differences between the two groups based on age, sex, smoking history, diabetes, hypertension, anticoagulation medication history, and HH grade at admission. The nPM-SAH group was significantly associated with a higher incidence of radiological and clinical vasospasm (p < 0.05). Moreover, the need for external ventricular drainage (EVD) placement because of the development of hydrocephalus was significantly higher in the nPM group (p < 0.05). Patients with PM-SAH had better clinical outcomes than those with nPM-SAH (p = 0.037).

Conclusions Our results showed that patients with nonaneurysmal subarachnoid hemorrhage (NSAH) had favorable clinical outcomes. The PM group had better clinical outcomes and lower complication rates in comparison with the nPM group. Repeated digital subtraction angiography (DSA) examinations are strongly recommended for patients with nPM-SAH.

Deep venous drainage variant rate and degree may be higher in patients with perimesencephalic than in non-perimesencephalic angiogram-negative subarachnoid hemorrhage

OBJECTIVES

The basal vein of Rosenthal (BVR) variant is a potential origin of bleeding in angiogram-negative subarachnoid hemorrhage (AN-SAH). We compared the rate and degree of BVR variants in patients with perimesencephalic AN-SAH (PAN-SAH) and non-perimesencephalic AN-SAH (NPAN-SAH).

METHODS

We retrospectively reviewed the records of AN-SAH patients admitted to our hospital between 2013 and 2018. The associations between variables (baseline characteristics, clinical and radiological data, and outcome) with bleeding patterns and degree of BVR variants were analyzed. Additionally, potential predictors of positive findings on repeated digital-subtracted angiogram (DSA), rebleeding, delayed cerebral infarction (DCI), and poor outcome were further studied.

RESULTS

A total of 273 patients with AN-SAH were included. The incidence rate and degree of BVR variants were significantly higher in PAN-SAH patients compared with those in NPAN-SAH patients (p < 0.001). Patients with normal bilateral BVRs are more likely to have a severe prognosis and diffused blood distribution (p < 0.05). We found an increased rate of positive findings on repeated DSA, DCI, rebleeding, and poor outcome at 3 months and 1 year after discharge (all p < 0.05) in patients with bilateral normal BVRs. Bilateral normal BVRs were considered a risk factor (predictor) of positive findings on repeated DSA, rebleeding, and poor outcome (all p < 0.05).

CONCLUSIONS

PAN-SAH patients have a higher rate and degree of BVR variants compared with patients with NPAN-SAH. Those AN-SAH patients with bilateral normal BVRs are more likely to be of arterial origin and are at risk of suffering from rebleeding and a poor outcome.

KEY POINTS

• Patients with PAN-SAH have a higher rate and degree of BVR variants compared with patients with NPAN-SAH, which suggested that AN-SAH patients with normal BVRs are more likely to originate from arterial bleeding. • AN-SAH patients with normal BVRs are more likely to have positive findings on repeated DSA examinations, as well as an increased incidence of rebleeding and poor outcome, which may assist and guide neurologists in selecting treatment.

Impact of temperature decline from the previous day as a trigger of spontaneous subarachnoid hemorrhage: case-crossover study of prefectural stroke database

OBJECTIVE

Several environmental factors have been reported to correlate with incidence of spontaneous subarachnoid hemorrhage (SAH). However, because of different patient selection and study designs among these studies, meteorological factors that trigger the incidence of SAH in a short hazard period remain unknown. Among meteorological factors, daily temperature changes may disrupt and violate homeostasis and predispose to cerebrovascular circulatory disturbances and strokes. The authors aimed to investigate whether a decline in the temperature from the highest of the previous day to the lowest of the event day (temperature decline from the previous day [TDP]) triggers SAH in the prefecture-wide stroke database.

METHODS

All 28 participating institutions with primary or comprehensive stroke centers located throughout Kochi Prefecture, Japan, were included in the study. Data collected between January 2012 and December 2016 were analyzed, and 715 consecutive SAH patients with a defined date of onset were enrolled. Meteorological data in this period were obtained from the Kochi Local Meteorological Observatory. A case-crossover study was performed to investigate association of TDP and other environmental factors with onset of SAH.

RESULTS

The increasing TDP in 1°C on the day of the SAH event was associated with an increased incidence of SAH (OR 1.041, 95% CI 1.007-1.077) after adjustment for other environmental factors. According to the stratified analysis, a significant association between TDP and SAH was observed in women, patients < 65 years old, and patients with weekday onset. Among these factors, increasing TDP had a great impact on SAH onset in patients < 65 years old (p = 0.028, Mann-Whitney U-test).

CONCLUSIONS

TDP, temperature decline from the highest of the previous day to the lowest of the day, was correlated with the incidence of spontaneous SAH, particularly in younger patients < 65 years old.

A comparison of frailty indices in predicting length of inpatient stay and discharge destination following angiogram-negative subarachnoid hemorrhage

BACKGROUND AND PURPOSE

While patients with angiogram-negative subarachnoid hemorrhages (ANSAH) have better prognoses than those with aneurysmal SAH, frailty's impact on outcomes in ANSAH is unclear. We previously showed that the modified frailty index (mFI-11) is associated with poor outcomes following ANSAH. Here, we compared the mFI-5, mFI-11, Charlson Comorbidity Index (CCI), and temporalis thickness (TMT) to determine which index was the best predictor of ANSAH outcomes and mortality rates.

METHODS

In this retrospective cohort analysis between 2014 and 2018, patients with non-traumatic, angiogram negative SAH (ANSAH) were identified. The admission mFI-5, mFI-11, CCI, and TMT were calculated for each patient. Primary outcomes were mortality rate, discharge location, and prolonged length of stay (PLOS; LOS >85^th percentile). Multivariate logistic regression and receiver operating characteristic (ROC) curves were used to evaluate frailty as predictors of primary endpoints.

RESULTS

We included 75 patients with a mean age of 55.4 ± 1.5 years. There were 4 patient deaths (5.3%), 53 patients (70.7%) discharged home, and 11 patients (14.7%) with PLOS. On ROC analysis, the mFI-5 had the highest discriminatory value for mortality (AUC = 0.97) while the mFI-11 was most discriminatory for discharge home (AUC = 0.85) and PLOS (AUC = 0.78). On multivariate analysis, the only independent predictor of mortality was the mFI-11 (OR = 0.46; 95%CI: 1.45-14.23; p = 0.009) while the mFI-5 was the best predictor of discharge home (OR = 0.21; 95% CI: 0.08-0.61; p = 0.004). On multivariate analysis, the only independent predictor of PLOS was the Hunt and Hess score (OR = 2.63; 95%CI: 1.38-5.00; p = 0.003). The CCI and TMT were inferior to either mFI for predicting primary endpoints.

CONCLUSIONS

Increasing frailty is associated with poorer outcomes and higher mortality following ANSAH. The mFI-5 and mFI-11 were found to be superior predictors of discharge home and mortality rate. While larger prospective study is needed, frailty, as measured by mFI-11 and -5, should be considered when evaluating ANSAH prognosis.

Seizure incidence of angiogram-negative subarachnoid hemorrhage: An updated meta-analysis

BACKGROUND

To provide updated information on seizure events and patterns in patients with angiogram-negative subarachnoid hemorrhage based on the initial hemorrhage patterns: perimesencephalic subarachnoid hemorrhage (PMH) vs non-PMH.

METHODS

A review of online database literature from January 1990 to November 2017 was systematically performed. In case of heterogeneity <50%, a fixed effect model was used. Publication bias was determined using Begg funnel plot and the trim-and-fill method.

RESULTS

A total of 9 studies with 645 patients were included for final analysis after excluding one study without any seizure within either cohort. PMH patients had lower seizure rates (odds ratio, 0.393; 95% CI, 0.158-0.978) compared with non-PMH patients. The funnel plot showed a relatively asymmetric pattern, suggesting possible publication bias. After correction of the forest plot, the adjusted odds ratio was 0.362 (95% CI, 0.148-0.886), indicating significant relationships between PMH and lower incidence of seizure.

CONCLUSION

PMH is associated with lower seizure risk than non-PMH. However, possible publication bias could be a concern to the interpretation. Additional meta-analyses based on individual patient data from prospective large-scale studies are necessary.

Ten Years' Experiences in the Treatment of Nonaneurysmal Subarachnoid Hemorrhage: A Retrospective Analysis of Outcome Parameters in a Single-Center Study

Objectives:

Subarachnoid hemorrhage (SAH) with negative angiographic findings has a heterogeneous nature with variations in clinical course and outcome as compared to the aneurysmal SAH. It makes up to 15% of the spontaneous SAH and is characterized by milder clinical presentation. The purpose of this study was the analyses of risk factors, clinical observations, radiologic characteristics, and outcome in patients with nonaneurysmal SAH (NA-SAH).

Patients and Methods:

In a retrospective design, 77 consecutive patients with NA-SAH were recruited from May 2008, to October 2018. All patients underwent conventional cerebral angiography. We stratified patients into two groups based on the distribution of blood on their CT scan into perimesencephalic (PM) and non-PM (NPM) SAH. We performed the Outcome using Glasgow Coma Scale (GCS) and modified Rankin scale (favorable mRS 0–2 vs. unfavorable mRS 3–6). Data were analyzed using IBM^® SPSS^® Statistics V22.0.

Results:

The mean age at presentation was 48.5 ± 8.4 years with male predominance (71.4%). About 76.7% of the patients had headache and vomiting, most of the patients (75.3%) presented with GCS 15 at initial clinical presentation (61.03%) had NPM versus (38.96%) with PM characters in computed tomography scans. Fourteen (17.9%) patients developed hydrocephalus and 12 (15.3%) needed external ventricular drain placement, while none of the patients needed permanent shunt placement. However, all patients had a favorable clinical and functional outcome at discharge and at late follow-up (up to 3 months).

Conclusions:

NA-SAH does not affect the short- and long-term prognosis. In our results, the pattern of bleeding affects the initial presentation, clinical course, and complications. The clinical and functional outcomes in the majority of our patients were comparable in both groups with good prognosis. Hypertension, smoking, and elevated venous pressure, such as a history of deep venous thrombosis and asthma might be considered as a risk factor.

Clinical Policy: Critical Issues in the Evaluation and Management of Adult Patients Presenting to the Emergency Department With Acute Headache

This clinical policy from the American College of Emergency Physicians addressed key issues in the evaluation and management of adult patients presenting to the emergency department with acute headache. A writing subcommittee conducted a systematic review of the literature to derive evidence-based recommendations to answer the following clinical questions: (1) In the adult emergency department patient presenting with acute headache, are there risk-stratification strategies that reliably identify the need for emergent neuroimaging? (2) In the adult emergency department patient treated for acute primary headache, are nonopioids preferred to opioid medications? (3) In the adult emergency department patient presenting with acute headache, does a normal noncontrast head computed tomography scan performed within 6 hours of headache onset preclude the need for further diagnostic workup for subarachnoid hemorrhage? (4) In the adult emergency department patient who is still considered to be at risk for subarachnoid hemorrhage after a negative noncontrast head computed tomography, is computed tomography angiography of the head as effective as lumbar puncture to safely rule out subarachnoid hemorrhage? Evidence was graded and recommendations were made based on the strength of the available data.

Increasing Frailty Predicts Worse Outcomes and Increased Complications After Angiogram-Negative Subarachnoid Hemorrhages

BACKGROUND

The effect of frailty on outcomes after angiogram-negative subarachnoid hemorrhages (ANSAH) is currently unknown. We investigated frailty's effects on ANSAH outcomes, including mortality and in-hospital complications.

METHODS

Patients from 2014 to 2018 with non-traumatic subarachnoid hemorrhage and cerebral angiograms with an unidentifiable hemorrhage source were retrospectively reviewed. The cohort was divided into non-frail (modified frailty index [mFI] = 0) and frail (mFI ≥1) groups based on pre-hemorrhage characteristics. Primary outcomes were mortality rate and discharge location. Multivariate logistic regression analyses determined predictors of ANSAH severity and primary endpoints. Receiver operating characteristic curves were used to discriminate risks for primary endpoints comparing mFI, Hunt and Hess and Fisher scores, and age.

RESULTS

We included 75 patients with a mean age of 55.4 ± 1.5 years, comprising 42 (56%) women, and 41 (54.7%) with perimesencephalic bleeds. A total of 32 of 75 (42.7%) patients were classified as frail. Frail individuals were 6.2 times less likely to be discharged home (odds ratio [OR] = 0.16; 95% confidence interval [CI]: 0.05-0.5; P = 0.001) and all mortalities occurred in frail patients (12.5% [n = 4 of 32]; P = 0.030). The only independent predictor of mortality was higher mFI (OR = 5.4; 95% CI: 1.5-19.1; P = 0.009), and lower mFI best predicted discharge home (OR = 0.39; 95% CI: 0.17-0.88; P = 0.023). Receiver operating characteristic analysis showed that mFI best predicted both mortality (area under the curve = 0.9718; P = 0.002) and discharge home (area under the curve = 0.7998; P < 0.001).

CONCLUSIONS

Frail ANSAH patients have poorer outcomes and increased mortality compared with non-frail patients. Although prospective study is needed, this information significantly impacts our understanding of ANSAH outcomes and frailty should be used for prognostication as it was a better predictor than Hunt and Hess or Fisher scores.

Subarachnoid haemorrhage with negative initial neurovascular imaging: a systematic review and meta-analysis

Background

In patients with spontaneous subarachnoid haemorrhage (SAH), a vascular cause for the bleed is not always found on initial investigations. This study aimed to systematically evaluate the delayed investigation strategies and clinical outcomes in these cases, often described as “non-aneurysmal” SAH (naSAH).

Methods

A systematic review was performed in concordance with the PRISMA checklist. Pooled proportions of primary outcome measures were estimated using a random-effects model.

Results

Fifty-eight studies were included (4473 patients). The cohort was split into perimesencephalic naSAH (PnaSAH) (49.9%), non-PnaSAH (44.7%) and radiologically negative SAH identified on lumbar puncture (5.4%). The commonest initial vascular imaging modality was digital subtraction angiography. A vascular abnormality was identified during delayed investigation in 3.9% [95% CI 1.9–6.6]. There was no uniform strategy for the timing or modality of delayed investigations. The pooled proportion of a favourable modified Rankin scale outcome (0–2) at 3–6 months following diagnosis was 92.0% [95% CI 86.0–96.5]. Complications included re-bleeding (3.1% [95% CI 1.5–5.2]), hydrocephalus (16.0% [95% CI 11.2–21.4]), vasospasm (9.6% [95% CI 6.5–13.3]) and seizure (3.5% [95% CI 1.7–5.8]). Stratified by bleeding pattern, we demonstrate a higher rate of delayed diagnoses (13.6% [95% CI 7.4–21.3]), lower proportion of favourable functional outcome (87.2% [95% CI 80.1–92.9]) and higher risk of complications for non-PnaSAH patients.

Conclusion

This study highlights the heterogeneity in delayed investigations and outcomes for patients with naSAH, which may be influenced by the initial pattern of bleeding. Further multi-centre prospective studies are required to clarify optimal tailored management strategies for this heterogeneous group of patients.

Electronic supplementary material

The online version of this article (10.1007/s00701-019-04025-w) contains supplementary material, which is available to authorized users.

Surgical timing in infective endocarditis complicated by intracranial hemorrhage

Given the growing incidence of infective endocarditis (IE), understanding the risks and benefits of valvular surgery is critical. This decision is particularly complex for the 1 in 10 cases complicated by intracranial hemorrhage (ICH). While guideline recommendations currently favor early surgery in general, delayed intervention of at least 4 weeks is still recommended for patients with ICH. To date, there are no randomized controlled trials that inform management of patients with an indication for surgery but concomitant ICH, and even reported observational data are rare. This paper reviews the current literature on timing of surgery with a specific focus on cases of ICH. It emphasizes a growing body of literature challenging the current paradigm that surgery within 4 weeks is associated with neurologic deterioration and high mortality rates by demonstrating favorable outcomes for patients with pre-operative ICH who undergo early valvular surgery. Based on these data, we propose a practical management algorithm to facilitate decisions on surgical timing in these complicated cases. Since more rigorous evidence may never be available, clinicians should make patient-specific surgical timing decisions that attempt to balance the competing risks of neurologic versus cardiac complications.

Acute Hydrocephalus Requiring External Ventricular Drainage Following Perimesencephalic Nonaneurysmal Subarachnoid Hemorrhage in a Pediatric Patient: Case Report and Review of the Literature

BACKGROUND

Perimesencephalic nonaneurysmal subarachnoid hemorrhage (PNSAH) is a well-described subset of subarachnoid hemorrhage with an excellent prognosis in adults. However, its characteristics in the pediatric population have not yet been fully understood. We present a case of acute hydrocephalus requiring external ventricular drainage following pediatric PNSAH.

CASE DESCRIPTION

A previously healthy 10-year-old girl was admitted to our neurosurgical department after sudden onset of severe headache with vomiting during exercise. Cerebral non-contrast computed tomography detected subarachnoid hemorrhage filling all perimesencephalic cisterns. However, digital subtraction angiography could not locate the hemorrhage source. Her consciousness deteriorated within 7 hours of onset, and a computed tomography scan revealed acute hydrocephalus. We subjected the patient to external ventricular drainage for 10 days. She was discharged after 38 days of hospitalization, when she was physically and neuropsychologically healthy. Repeated digital subtraction angiography performed at the 6-month follow-up did not show any obvious source of hemorrhage except for a variant drainage pattern of the basal vein of Rosenthal. Based on the observations, we diagnosed the patient with PNSAH of a venous origin.

CONCLUSIONS

We propose that acute hydrocephalus be suspected in pediatric patients with nonaneurysmal subarachnoid hemorrhage filling all perimesencephalic cisterns, as in adults. We also propose that one of the possible causes of pediatric PNSAH as of venous origin and related to the abnormal drainage pattern of basal vein of Rosenthal and elevation of venous pressure with exercise. Immediate surgical drainage could obtain a good outcome in a symptomatic case.

Clinical complications and outcomes of angiographically negative subarachnoid hemorrhage

OBJECTIVE

To define the in-hospital course, complications, short- and long-term functional outcomes of patients with angiographically negative subarachnoid hemorrhage (anSAH), particularly those with aneurysmal-pattern anSAH (aanSAH).

METHODS

Retrospective cohort study of patients with aneurysmal subarachnoid hemorrhage (aSAH), aanSAH, and perimesencephalic-pattern anSAH (panSAH) treated at a single tertiary referral center between January 2006 and April 2018. Ninety-nine patients with anSAH (33 aanSAH and 66 panSAH) and 464 patients with aSAH were included in this study. Outcomes included symptomatic hydrocephalus requiring CSF drainage, need for ventriculoperitoneal shunt, radiographic vasospasm, delayed cerebral ischemia (DCI), radiographic infarction, disability level within 1 year of ictus, and at last clinical follow-up as defined by the modified Rankin Scale.

RESULTS

Patients with aanSAH and panSAH had similar rates of DCI and radiologic infarction, and patients with aanSAH had significantly lower rates compared to aSAH (p ≤ 0.018). Patients with aanSAH were more likely than those with panSAH to require temporary CSF diversion and ventriculoperitoneal shunt (p ≤ 0.03), with similar rates to those seen in aSAH. Only one patient with anSAH died in the hospital. Compared to those with aSAH, patients with aanSAH were significantly less likely to have a poor functional outcome within 1 year of ictus (odds ratio 0.26, 95% confidence interval 0.090-0.75) and at last follow-up (hazard ratio 0.30, 95% confidence interval 0.19-0.49, p = 0.002).

CONCLUSIONS

DCI is very uncommon in anSAH, but patients with aanSAH have a similar need for short- and long-term CSF diversion to patients with aSAH. Nevertheless, patients with aanSAH have significantly better short- and long-term outcomes.

Analysis of biochemical laboratory values to determine etiology and prognosis in patients with subarachnoid hemorrhage: a clinical study

OBJECTIVES

The aim of this study was to establish prognostic and predictive markers in patients with subarachnoid hemorrhage (SAH) using simple laboratory methods.

METHODS

A retrospective examination was made of patients with SAH diagnosed secondary to isolated head trauma, isolated anterior communicating artery aneurysm rupture, and angiography-negative SAH. Age, gender, Glasgow Coma Scale (GCS) scores, and Fisher's grade scores, Glasgow Outcome Scale (GOS) scores, leukocyte count, neutrophil count, lymphocyte count, platelet count, neutrophil-lymphocyte ratio (NLR) and platelet-lymphocyte ratio results (PLR) were evaluated.

RESULTS

NLR and PLR values, which were similar in patients with spontaneous SAH, were significantly high in patients with traumatic SAH. NLR and PLR values could be 80% sensitive and 75% specific for distinguishing traumatic SAH from spontaneous SAH. Eosinophil count was lower in patients with angiography-negative SAH and patients with aneurysmal SAH than in patients with traumatic SAH. Initially measured GCS score, Fisher's grade score, eosinophil, neutrophil and lymphocyte counts could be prognostic in all patients with SAH. Moreover, it was concluded that the initially measured number of eosinophils might be directly related to patient prognosis. The eosinophil count was generally found to be high in traumatic SAH patients and it was observed that this parameter could be predictive for these patients. Lymphocyte count and NLR values could be prognostic markers in patients with angiography-negative SAH.

CONCLUSION

NLR, PLR and eosinophil count values could be predictive for etiological factors (traumatic SAH or spontaneous SAH) of patients who were admitted unconscious to the emergency room with SAH detected on radiological imaging.

Elevated C-reactive protein and white blood cell count at admission predict functional outcome after non-aneurysmal subarachnoid hemorrhage

INTRODUCTION

Patients with non-aneurysmal subarachnoid hemorrhage (SAH) are considered to have an overall benign course of disease compared to patients suffering from aneurysmal SAH. Nevertheless, a small but significant number of such patients might only achieve unfavorable outcome. Therefore, the purpose of the present study was to determine if routine laboratory markers of acute phase response are associated with unfavorable outcome in patients with non-aneurysmal SAH.

METHODS

From 2006 to 2017, 154 patients suffering from non-aneurysmal SAH were admitted to our institution. Patients were stratified according to the distribution of cisternal blood into patients with perimesencephalic SAH (pSAH) versus non-perimesencephalic SAH (npSAH). C-reactive protein (CRP) and white blood cells (WBC) assessments were performed within 24 h of admission as part of routine laboratory workup. Outcome was assessed according to the modified Rankin Scale (mRS) after 6 months and stratified into favorable (mRS 0-2) vs. unfavorable (mRS 3-6).

RESULTS

The multivariate regression analysis revealed "CRP > 5 mg/l" (p = 0.004, OR 143.7), "WBC count > 12.1 G/l" (p = 0.006, OR 47.8), "presence of IVH" (p = 0.02, OR 13.5), "poor-grade SAH" (p = 0.01, OR 45.2) and "presence of CVS" (p = 0.003, OR 149.9) as independently associated with unfavorable outcome in patients with non-aneurysmal SAH.

CONCLUSION

Elevated C-reactive protein and WBC count at admission were associated with unfavorable outcome after non-aneurysmal SAH.

The Incidence of Hydrocephalus and Shunting in Patients with Angiogram-Negative Subarachnoid Hemorrhage: An Updated Meta-Analysis

OBJECTIVE

To evaluate the incidence of hydrocephalus and implanted shunts in angiogram-negative subarachnoid hemorrhage (SAH) according to hemorrhage patterns: perimesencephalic SAH (PMH) versus non-PMH.

METHODS

The online database literature from January 1990 to November 2017 was systematically reviewed. A fixed-effect model was used when heterogeneity was <50%. A Begg funnel plot was used to assess publication bias. An additional trim and fill method was used to estimate the number of missing studies. A subgroup analysis with studies, which defined angiogram-negative SAH using repeated angiography or computed tomography angiography, was further performed.

RESULTS

A total of 28 articles including 2577 patients were enrolled. Patients with PMH showed a significantly decreased incidence of hydrocephalus (odds ratio [OR], 0.269; 95% confidence interval [CI], 0.208-0.348) and shunts (OR, 0.263; 95% CI, 0.169-0.411) than did patients without PMH. A subgroup analysis of 7 studies with 675 patients showed less hydrocephalus in patients with PMH than in patients without PMH (OR, 0.358; 95% CI, 0.161-0.793), with possible publication bias. Shunt procedures were marginally less common in patients with PMH compared with those patients without PMH (OR, 0.490; 95% CI, 0.236-1.018) with possible publication bias. After correction of the forest plot, the adjusted OR was 0.617 (95% CI, 0.251-1.513) for hydrocephalus and 0.618 (95% CI, 0.310-1.232) for shunts, suggesting no significant relationships between PMH and the risk of hydrocephalus or shunting.

CONCLUSIONS

Hydrocephalus and shunts were more evident in non-PMH than PMH. However, subgroup analyses did not show significant associations between PMH and lower risks of these events after correction for possible publication bias. Further meta-analyses based on individual patient data are necessary.

Delayed Cerebral Ischemia and Vasospasm After Spontaneous Angiogram-Negative Subarachnoid Hemorrhage: An Updated Meta-Analysis

OBJECTIVE

To report clinical outcomes of delayed cerebral ischemia (DCI) and vasospasm in angiogram-negative subarachnoid hemorrhage (SAH) according to hemorrhage patterns, perimesencephalic hemorrhage (PMH) and non-PMH.

METHODS

Online databases from January 1990 to December 2017 were systematically reviewed. A fixed-effects model was used to control heterogeneity. To resolve publication bias, the trim and fill method was used to estimate number of missing studies and adjusted odds ratio (OR). Subgroup analysis of data from studies that defined angiogram-negative subarachnoid hemorrhage by angiography repeated at least twice or computed tomography angiography was performed.

RESULTS

Among 24 studies including 2083 patients, 23/985 patients (2.3%) with PMH and 144/1098 patients (13.1%) with non-PMH had DCI, indicating that patients with PMH experienced significantly lower DCI than patients with non-PMH (OR = 0.219; 95% confidence interval [CI], 0.144-0.334). Regarding vasospasm, 99/773 patients (12.8%) with PMH and 231/922 patients (25.1%) with non-PMH exhibited vasospasm, indicating that patients with PMH experienced significantly lower vasospasm than patients with non-PMH (OR = 0.445; 95% CI, 0.337-0.589). Funnel plots show asymmetry indicating possible publication bias. After trimming 10 studies for DCI and 7 for vasospasm, the adjusted ORs remained significant between PMH and lower risks of DCI and vasospasm. Subgroup analysis of 789 patients in 8 studies showed a lower risk of DCI (OR = 0.268; 95% CI, 0.151-0.473) and vasospasm (OR = 0.346; 95% CI, 0.221-0.538) in patients with PMH.

CONCLUSIONS

PMH showed a significantly lower risk of DCI and vasospasm than non-PMH. Clinical outcomes of angiogram-negative subarachnoid hemorrhage, based on meta-analysis of individual patient data, need to be investigated.

Risk factors for shunt dependency in patients suffering from spontaneous, non-aneurysmal subarachnoid hemorrhage

Patients presenting with spontaneous, non-aneurysmal subarachnoid hemorrhage (SAH) achieve better outcomes compared to patients with aneurysmal SAH. Nevertheless, some patients develop shunt-dependent hydrocephalus during treatment course. We therefore analyzed our neurovascular database to identify factors determining shunt dependency after non-aneurysmal SAH. From 2006 to 2016, 131 patients suffering from spontaneous, non-aneurysmal SAH were admitted to our department. Patients were stratified according to the distribution of cisternal blood into patients with perimesencephalic SAH (pSAH) versus non-perimesencephalic SAH (npSAH). Outcome was assessed according to the modified Rankin Scale (mRS) at 6 months and stratified into favorable (mRS 0-2) versus unfavorable (mRS 3-6). A multivariate analysis was performed to identify predictors of shunt dependency in patients suffering from non-aneurysmal SAH. Overall, 18 of 131 patients suffering from non-aneurysmal SAH developed shunt dependency (14%). In detail, patients with npSAH developed significantly more often shunt dependency during treatment course, when compared to patients with pSAH (p = 0.02). Furthermore, patients with acute hydrocephalus, presence of intraventricular hemorrhage, presence of clinical vasospasm, and anticoagulation medication prior SAH developed significantly more often shunt dependency, when compared to patients without (p < 0.0001). However, "acute hydrocephalus" was the only significant and independent predictor for shunt dependency in all patients with non-aneurysmal SAH in the multivariate analysis (p < 0.0001). The present study identified acute hydrocephalus with the necessity of CSF diversion as significant and independent risk factor for the development of shunt dependency during treatment course in patients suffering from non-aneurysmal SAH.

A Comparison of Pathophysiology in Humans and Rodent Models of Subarachnoid Hemorrhage

Non-traumatic subarachnoid hemorrhage (SAH) affects an estimated 30,000 people each year in the United States, with an overall mortality of ~30%. Most cases of SAH result from a ruptured intracranial aneurysm, require long hospital stays, and result in significant disability and high fatality. Early brain injury (EBI) and delayed cerebral vasospasm (CV) have been implicated as leading causes of morbidity and mortality in these patients, necessitating intense focus on developing preclinical animal models that replicate clinical SAH complete with delayed CV. Despite the variety of animal models currently available, translation of findings from rodent models to clinical trials has proven especially difficult. While the explanation for this lack of translation is unclear, possibilities include the lack of standardized practices and poor replication of human pathophysiology, such as delayed cerebral vasospasm and ischemia, in rodent models of SAH. In this review, we summarize the different approaches to simulating SAH in rodents, in particular elucidating the key pathophysiology of the various methods and models. Ultimately, we suggest the development of standardized model of rodent SAH that better replicates human pathophysiology for moving forward with translational research.

Cerebral Vasospasm-Dependent and Cerebral Vasospasm-Independent Cerebral Infarctions Predict Outcome After Nonaneurysmal Subarachnoid Hemorrhage: A Single-Center Series with 250 Patients

OBJECTIVE

The number of patients with nonaneurysmal subarachnoid hemorrhage (naSAH) has increased during the last decade. Data regarding infarctions in naSAH are still limited. The aim of this study was to identify the rate of cerebral vasospasm (CVS)-dependent and CVS-independent infarctions and their influence on clinical outcomes.

METHODS

Between 1999 and 2015, 250 patients suffering from naSAH were analyzed retrospectively. A delayed infarction was analyzed whether it was associated with CVS (CVS-dependent infarction) or not (CVS-independent).

RESULTS

A total of 36 patients (14%) had cerebral infarctions. CVS was detected in 54 patients (22%), and 15 (6%) of them developed infarctions (CVS-dependent). Infarctions without signs of CVS (CVS-independent) occurred in 21 patients (8%). Overall, 86% of the patients had favorable outcome. Patients without cerebral infarctions had the best outcome (91% favorable outcome, 5% mortality rate). Patients with CVS-independent infarctions (57%) as well as patients with CVS-dependent infarctions (53%) had a favorable outcome less often. The mortality rate was also significantly greater in patients with CVS-independent (19%) and CVS-dependent infarctions (33%). A further independent predictor was anticoagulative therapy, which increased during study period and was associated with nonperimesencephalic blood distribution.

CONCLUSIONS

CVS-dependent and independent infarctions occur in naSAH and contribute to unfavorable outcomes. Whereas CVS-independent infarctions occur in any subgroup, CVS-dependent infarctions seem to be associated with blood pattern (Fisher 3). Anticoagulative therapy seems to be not only a predictor for worse outcome but also for nonperimesencephalic SAH. Accordingly, the proportion of perimesencephalic and nonperimesencephalic SAH changed during the study period (from 2.2:1 to 1:1.7).

Perimesencephalic Nonaneurysmal Subarachnoid Hemorrhage After Clipping of an Unruptured Aneurysm

BACKGROUND

Perimesencephalic nonaneurysmal subarachnoid hemorrhage (PNSAH) is a benign form of subarachnoid hemorrhage with an excellent clinical outcome. The cause of PNSAH remains unknown. We report a case of PNSAH in a patient with a history of clipping of an unruptured aneurysm. PNSAH after clipping of an unruptured aneurysm is extremely rare.

CASE DESCRIPTION

A 56-year-old man with a history of clipping surgery for an unruptured aneurysm 10 months previously presented with severe headache. No precipitating causes were shown; however, the patient had been engaged in an exertional activity before the event. After conservative treatment, he was discharged home without any complication from the hemorrhage.

CONCLUSIONS

On the basis of this case report, clinicians should consider the possibility of PNSAH in a patient who had an unruptured aneurysm previously treated with clipping. Nevertheless, diagnostic workup can be more important than keeping in mind that a subarachnoid hemorrhage might be a PNSAH.

Nonaneurysmal Perimesencephalic Hemorrhage Is Associated with Deep Cerebral Venous Drainage Anomalies: A Systematic Literature Review and Meta-Analysis

BACKGROUND AND PURPOSE

Mechanisms underlying bleeding in nonaneurysmal perimesencephalic SAH remain unclear. Previous investigators have suggested a relationship between nonaneurysmal perimesencephalic SAH and primitive venous drainage of the basal vein of Rosenthal. We performed a meta-analysis to evaluate the relation between primitive basal vein of Rosenthal drainage and nonaneurysmal perimesencephalic SAH.

MATERIALS AND METHODS

We performed a comprehensive literature search of all studies examining the prevalence of primitive basal vein of Rosenthal drainage in patients with aneurysmal SAH and nonaneurysmal perimesencephalic SAH. Data collected were primitive basal vein of Rosenthal drainage (direct connection of perimesencephalic veins into the dural sinuses instead of the Galenic system) in at least 1 cerebral hemisphere, normal bilateral basal vein of Rosenthal drainage systems, and the number of overall primitive venous systems in the nonaneurysmal perimesencephalic SAH and aneurysmal SAH groups. Statistical analysis was performed by using a random-effects meta-analysis.

RESULTS

Eight studies with 888 patients (334 with nonaneurysmal perimesencephalic SAH and 554 with aneurysmal SAH) and 1657 individual venous systems were included. Patients with nonaneurysmal perimesencephalic SAH were more likely to have a primitive basal vein of Rosenthal drainage in at least 1 hemisphere (47.7% versus 22.1%; OR, 3.31; 95% CI, 2.15-5.08; P < .01) and were less likely to have bilateral normal basal vein of Rosenthal drainage systems than patients with aneurysmal SAH (18.3% versus 37.4%; OR, 0.27; 95% CI, 0.14-0.52; P < .01). When we considered individual venous systems, there were higher rates of primitive venous systems in patients with nonaneurysmal perimesencephalic SAH than in patients with aneurysmal SAH (34.9% versus 15.3%; OR, 3.90; 95% CI, 2.37-6.43; P < .01).

CONCLUSIONS

Patients with nonaneurysmal perimesencephalic SAH have a higher prevalence of primitive basal vein of Rosenthal drainage in at least 1 hemisphere than patients with aneurysmal SAH. This finding suggests a venous origin of some nonaneurysmal perimesencephalic SAHs. A primitive basal vein of Rosenthal pattern is an imaging finding that has the potential to facilitate the diagnosis of nonaneurysmal perimesencephalic SAH.

Perimesencephalic subarachnoid hemorrhage with a positive angiographic finding: case report and review of the literature

The vast majority of perimesencephalic subarachnoid hemorrhage cases are reported as negative-finding etiologies. Recently, high-resolution images allowed us to overcome the previous difficulty of finding the source of bleeding, which underlies the concept of a "negative finding". We discovered a venous etiology, hidden behind the tip of the basilar artery; namely, the lateral pontine vein. Here, we review the literature on perimesencephalic subarachnoid hemorrhage and on venous aneurysm. We highlight this type of aneurysm as a candidate source of perimesencephalic hemorrhage. This case may change our way of dealing with what we have termed a negative finding of subarachnoid hemorrhage.

Increasing numbers of nonaneurysmal subarachnoid hemorrhage in the last 15 years: antithrombotic medication as reason and prognostic factor?

OBJECT

Subarachnoid hemorrhage (SAH) is usually caused by a ruptured intracranial aneurysm, but in some patients no source of hemorrhage can be detected. More recent data showed increasing numbers of cases of spontaneous nonaneurysmal SAH (NASAH). The aim of this study was to analyze factors, especially the use of antithrombotic medications such as systemic anticoagulation or antiplatelet agents (aCPs), influencing the increasing numbers of cases of NASAH and the clinical outcome.

METHODS

Between 1999 and 2013, 214 patients who were admitted to the authors’ institution suffered from NASAH, 14% of all patients with SAH. Outcome was assessed according to the modified Rankin Scale (mRS) at 6 months. Risk factors were identified based on the outcome.

RESULTS

The number of patients with NASAH increased significantly in the last 15 years of the study period. There was a statistically significant increase in the rate of nonperimesencephalic (NPM)-SAH occurrence and aCP use, while the proportion of elderly patients remained stable. Favorable outcome (mRS 0–2) was achieved in 85% of cases, but patients treated with aCPs had a significantly higher risk for an unfavorable outcome. Further analysis showed that elderly patients, and especially the subgroup with a Fisher Grade 3 bleeding pattern, had a high risk for an unfavorable outcome, whereas the subgroup of NPM-SAH without a Fisher Grade 3 bleeding pattern had a favorable outcome, similar to perimesencephalic (PM)-SAH.

CONCLUSIONS

Over the years, a significant increase in the number of patients with NASAH has been observed. Also, the rate of aCP use has increased significantly. Risk factors for an unfavorable outcome were age > 65 years, Fisher Grade 3 bleeding pattern, and aCP use. Both “PM-SAH” and “NPM-SAH without a Fisher Grade 3 bleeding pattern” had excellent outcomes. Patients with NASAH and a Fisher Grade 3 bleeding pattern had a significantly higher risk for an unfavorable outcome and death. Therefore, for further investigations, NPM-SAH should be stratified into patients with or without a Fisher Grade 3 bleeding pattern. Also, cases of spontaneous SAH should be stratified into NASAH and aneurysmal SAH.

Spontaneous retroclival hematoma: a case series

OBJECT

Retroclival hematomas are rare, appearing mostly as posttraumatic phenomena in children. Spontaneous retroclival hematoma (SRH) in the absence of trauma also has few descriptions in the literature. None of the reported clinical cases features the combination of an SRH and intraventricular hemorrhage (IVH). Nevertheless, despite extensive cases of idiopathic or angiographically negative subarachnoid hemorrhage (SAH) of the posterior fossa, only a single case report of a patient with a unique spontaneous retroclival hematoma has been identified. In this study, the authors reviewed the presentation, management, and clinical outcome of this rare entity.

METHODS

The authors performed a retrospective analysis of all patients with diagnosed SRH at their institution over a 3-year period. Collected data included clinical history, laboratory results, treatment, and review of all imaging studies performed.

RESULTS

Four patients had SRH. All were appropriately evaluated for coagulopathic and/or traumatic etiologies of hemorrhage, though no etiology could be found. Moreover, all of the patients demonstrated SRH that both clearly crossed the basioccipital synchondrosis and was contained within a nondependent configuration along the retroclival dura mater.

CONCLUSIONS

Spontaneous retroclival hematoma, often associated with IVH, is a rare subtype of intracranial hemorrhage frequently recognized only when MRI demonstrates compartmentalization of the posterior fossa hemorrhage. When angiography fails to reveal an underlying lesion, SRH patients, like patients with traditional angiographically negative SAH, enjoy a remarkably good prognosis.

Cerebral vasospasm and delayed cerebral infarctions in 225 patients with non-aneurysmal subarachnoid hemorrhage: the underestimated risk of Fisher 3 blood distribution

OBJECTIVE

Recent data have shown increasing numbers of non-aneurysmal subarachnoid hemorrhage (NASAH). However, data are limited and often only small series have been published. Our objective was to analyze the rate of cerebral vasospasm (CVS), delayed cerebral infarction (DCI), and their influence on the clinical outcome, especially in patients with diffuse Fisher 3 bleeding pattern NASAH (Fi3).

METHODS

Between 1999 and 2014, 225 patients had NASAH. CVS, DCI, and outcome (according to the modified Rankin Scale at 6 months) were analyzed retrospectively. Patients were stratified according to the bleeding type. After univariate analysis a multivariate analysis was performed and NASAH Fi3 was also compared with aneurysmal SAH Fi3.

RESULTS

Patient characteristics and the outcome of perimesencephalic (PM) and non-PM (NPM) SAH were similar. Excluding Fi3, PM and NPM without Fi3 had similar patient characteristics, clinical course, and outcome. In particular, the Fi3 subgroup had a significantly increased risk of CVS, DCI, unfavorable outcome, hydrocephalus, and death. Early hydrocephalus was associated with Fi3 and intraventricular hemorrhage. The multivariate regression model showed the variables elderly patients, Fi3, and early hydrocephalus as independent and significant predictors for an unfavorable outcome. A further comparison of NASAH Fi3 with aneurysmal SAH Fi3 showed similar characteristics, CVS rate, and mortality.

CONCLUSIONS

Patients with NASAH without a Fi3 bleeding pattern had a similar excellent outcome to patients with PM-SAH. Patients with Fi3 had a high risk for early hydrocephalus, CVS, DCI, and an unfavorable outcome, similar to patients with aneurysmal SAH. After multivariate analysis, early hydrocephalus, elderly patients, and Fi3 were identified as negative prognostic factors. Therefore, patients with Fi3 are at risk and need careful clinical observation.

High-Resolution Vessel Wall Magnetic Resonance Imaging in Angiogram-Negative Non-Perimesencephalic Subarachnoid Hemorrhage

PURPOSE

Standard magnetic resonance imaging (MRI) rarely identifies the cause of hemorrhage in patients with an angiogram-negative, non-perimesencephalic subarachnoid hemorrhage (SAH). Yet up to 10 % of these patients have recurrent hemorrhage. The aim of the study was to explore the potential role of high-resolution contrast-enhanced 3-Tesla vessel wall-MRI in patients with angiogram-negative SAH.

METHODS

We performed intracranial vessel wall-MRI of the circle of Willis using a 3-Tesla scanner in consecutive patients presenting with a spontaneous, angiogram-negative, non-perimesencephalic SAH. Vessel wall-MRI included T1-, T2-, and gadolinium-enhanced T1-weighted two-dimensional black-blood sequences in multiple planes (voxel size 0.4 × 0.4 × 2.0 mm). Two neuroradiologists independently scored abnormalities of the arterial wall.

RESULTS

In all, 11 patients (mean age 59 years) underwent vessel wall-MRI. A total of seven patients had vessel wall abnormalities despite normal catheter angiography. Two patients had focal abnormalities contiguous with the outer margin of the basilar artery wall for which we considered a differential of ruptured blood blister aneurysm, thrombosed aneurysm, and loculated extramural blood from elsewhere. Two patients had arterial wall enhancement involving multiple arteries, possibly secondary to SAH. Three patients had arterial wall enhancement at sites of dural penetration, remote from the SAH, likely related to age and atherosclerotic risk factors. Vessel wall-MRI did not alter patient management in this cohort.

CONCLUSION

Vessel wall-MRI showed abnormalities in seven patients with angiogram-negative SAH. These findings did not alter patient management, but the findings may be useful for other physicians who choose to perform vessel wall-MRI in this patient population.

Recurrent Perimesencephalic Subarachnoid Hemorrhage After 12 Years: Missed Diagnosis, Vulnerable Anatomy, or Random Events?

BACKGROUND

Perimesencephalic subarachnoid hemorrhage (PMSAH) is a well-defined subtype of angiogram-negative SAH, characterized by a benign natural history and a virtually nonexistent risk of recurrence. Few case reports of recurrent PMSAH exist in the literature, all occurring after relatively short time intervals ranging from 5 days to 31 months, mostly in patients on antithrombotic therapy. We present a unique case of ultra-late PMSAH recurrence after 12 years, in a patient not receiving antithrombotic medications.

CASE DESCRIPTION

A woman presented with 2 similar episodes of sudden-onset severe headache and neck pain, without associated neurologic deficits: a first episode at the age of 48 years and a second at 60 years. In each instance, the pattern of hemorrhage was consistent with PMSAH, platelet count and coagulation tests were normal, and a full etiologic work-up, including CTA, catheter angiography, and magnetic resonance imaging, failed to reveal an underlying vascular or tumoral etiology. The patient had a favorable clinical course each time.

CONCLUSIONS

Although exceptional, recurrence of PMSAH is not impossible. If the 2 events are assumed to be random and independent of each other, binomial statistics yield approximately a 79 per billion chance of 2 or more episodes occurring over an 80-year lifetime. However, other possibilities should be kept in mind, including tiny and radiographically occult vascular lesions or particular venous anatomy predisposing patients to recurrent bouts of PMSAH. Patients should not be told that the risk of recurrence is zero, but that it is close to zero.