Diffuse Patterns of Nonaneurysmal Subarachnoid Hemorrhage Originating from the Basal Cisterns Have Predictable Vasospasm Rates Similar to Aneurysmal Subarachnoid Hemorrhage

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.

Current status of perimesencephalic non-aneurysmal subarachnoid hemorrhage

Perimesencephalic nonaneurysmal subarachnoid hemorrhage (PNSAH) is a distinctive disease, representing SAH centered in perimesencephalic cisterns, with negative angiography findings. In recent years, the number of patients with PNSAH has increased significantly; however, the knowledge of PNSAH is insufficient. Therefore, we performed a review of the literature from a PubMed search and recounted our understanding of PNSAH. In this review, we summarized that current high-resolution computed tomography angiography is an acceptable replacement for digital subtraction angiography to rule out aneurysms in PNSAH with strict criteria. The current hypothesis about the etiology of PNSAH is that there is deep vein rupture from aberrant venous anatomy and increased intracranial venous pressure. PNSAH is associated with mild symptoms and lower rates of hydrocephalus and symptomatic vasospasm. For PNSAH, conservative treatment has been the mainstream treatment. PNSAH has a benign clinical course and an excellent prognosis; in long-term follow-up, re-bleeding and death were uncommon.

Diffuse Angiogram-Negative Subarachnoid Hemorrhage is Associated with an Intermediate Clinical Course

BACKGROUND

The cerebral angiography result is negative for an underlying vascular lesion in 15-20% of patients with nontraumatic subarachnoid hemorrhage (SAH). Patients with angiogram-negative SAH include those with perimesencephalic SAH and diffuse SAH. Consensus suggests that perimesencephalic SAH confers a more favorable prognosis than diffuse SAH. Limited data exist to contextualize the clinical course and prognosis of diffuse SAH in relation to aneurysmal SAH in terms of critical care complications, neurologic complications, and functional outcomes. Here we compare the clinical course and functional outcomes of patients with perimesencephalic SAH, diffuse SAH, and aneurysmal SAH to better characterize the prognostic implications of each SAH subtype.

METHODS

We conducted a retrospective cohort study that included all patients with nontraumatic SAH admitted to a tertiary care referral center between January 1, 2012, and December 31, 2017. Bleed patterns were radiographically adjudicated, and patients were assigned to three groups: perimesencephalic SAH, diffuse SAH, and aneurysmal SAH. Patient demographics, complications, and clinical outcomes were reported and compared.

RESULTS

Eighty-six patients with perimesencephalic SAH, 174 with diffuse SAH, and 998 with aneurysmal SAH presented during the study period. Patients with aneurysmal SAH were significantly more likely to be female, White, and active smokers. There were no significant differences between patients with diffuse SAH and perimesencephalic SAH patterns. Critical care complications were compared across all three groups, with significant between-group differences in hypotension and shock (3.5% vs. 16.1% vs. 38.4% for perimesencephalic SAH vs. diffuse SAH vs. aneurysmal SAH, respectively; p < 0.01) and endotracheal intubation (0% vs. 26.4% vs. 48.8% for perimesencephalic SAH vs. diffuse SAH vs. aneurysmal SAH, respectively; p < 0.01). Similar trends were noted with long-term supportive care with tracheostomy and gastrostomy tubes and length of stay. Cerebrospinal fluid diversion was increasingly required across bleed types (9.3% vs. 54.6% vs. 76.3% for perimesencephalic SAH vs. diffuse SAH vs. aneurysmal SAH, respectively, p < 0.001). Vasospasm and delayed cerebral ischemia were comparable between perimesencephalic SAH and diffuse SAH but significantly lower than aneurysmal SAH. Patients with diffuse SAH had intermediate functional outcomes, with significant rates of nonhome discharge (23.0%) and poor functional status on discharge (26.4%), significantly higher than patients with perimesencephalic SAH and lower than patients with aneurysmal SAH. Diffuse SAH similarly conferred an intermediate rate of good functional outcomes at 1-6 months post discharge (92.3% vs. 78.6% vs. 47.3% for perimesencephalic SAH vs. diffuse SAH vs. aneurysmal SAH, respectively; p < 0.016).

CONCLUSIONS

We confirm the consensus data that perimesencephalic SAH is associated with a more benign clinical course but demonstrate that diffuse SAH confers an intermediate prognosis, more malignant than perimesencephalic SAH but not as morbid as aneurysmal SAH. These results highlight the significant morbidity associated with diffuse SAH and emphasize need for vigilance in the acute care of these patients. These patients will likely benefit from continued high-acuity observation and potential support to avert significant risk of morbidity and neurologic compromise.

Contrast extravasation from basilar artery without aneurysm formation on digital subtraction angiography in computed tomography angiogram-negative subarachnoid hemorrhage: A case report

Background:

The causes of angiogram-negative subarachnoid hemorrhage (SAH) on initial angiography, which accounts for 10–30% of spontaneous SAH, are heterogeneous and still unclear. We report a case of nonaneurysmal SAH, in which initial computed tomographic angiography (CTA) showed no source of bleeding, but the subsequent digital subtraction angiography (DSA) revealed contrast extravasation from the basilar artery without aneurysms.

Case Description:

A 67-year-old woman with a medical history of hypertension presented as SAH of World Federation of Neurological Surgeons Grade II. CTA on admission did not show any cause of bleeding and DSA was subsequently performed to show contrast extravasation from a perforator of the middle third of the basilar artery without aneurysms during the subsequent DSA, resulting in profound deterioration SAH and neurological status. The patient was conservatively treated. Follow-up DSAs on days 2 and 16 showed no source of bleeding as well.

Conclusion:

Although the precise cause of bleeding in this case is uncertain, SAH might be caused by local dissection of the basilar artery perforator, and the bleeding site might heal spontaneously without forming of a pseudoaneurysm.

Subarachnoid Hemorrhage Pattern Predicts Acute Cerebral Blood Flow Response in the Rat

There is considerable variability in the presentation of patients with acute subarachnoid hemorrhage (aSAH). Evidence suggests that a thick, diffuse clot better predicts the development of delayed cerebral ischemia and poor outcomes. In a rodent model of acute SAH, we directly measured the effects of the volume of blood injected versus the pattern of distribution of hemorrhage in the subarachnoid space on markers of early brain injury, namely, cerebral blood flow (CBF), cerebrospinal fluid (CSF) concentrations of P450 eicosanoids and catecholamines, and cortical spreading depolarizations (CSDs). There is a significant decrease in CBF, an increase in CSF biomarkers, and a trend toward increasing frequency and severity of CSDs when grouped by severity of hemorrhage but not by volume of blood injected. In severe hemorrhage grade animals, there was a progressive decrease in CBF after successive CSD events. These results suggest that the pattern of SAH (thick diffuse clots) correlates with the "clinical" severity of SAH.

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.

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.

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.

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).

Subarachnoid Hemorrhage Following Angioplasty and Stenting in a Patient with Primitive Drainage Pattern of the Basal Vein of Rosenthal

Severe visual loss may occur in patients with pseudotumor cerebri (PTC), also known as idiopathic intracranial hypertension. Transverse sinus stenosis is 1 cause of PTC syndrome. Although the role of transverse sinus stenosis in the pathogenesis of the disease remains controversial, recent case series of transverse sinus stenting have reported very high rates of symptom response and resolution of papilledema with improvement or at least stabilization of the visual fields and visual acuity (Ahmed et al., 2011).¹ We report a previously unpublished complication of diffuse, nonaneurysmal subarachnoid hemorrhage following angioplasty and stenting in a patient with refractory PTC.