Suspected Subarachnoid Hemorrhage Research Articles

Beyond the AJR: Intracranial CTA Versus Lumbar Puncture for Suspected Subarachnoid Hemorrhage With Negative Head CT.

Beyond the AJR: Intracranial CTA Versus Lumbar Puncture for Suspected Subarachnoid Hemorrhage With Negative Head CT.

The added value of cerebrospinal fluid analysis in patients with subarachnoid hemorrhage after negative noncontrast CT.

In patients presenting within 6 hours after signs and symptoms of suspected subarachnoid hemorrhage (SAH), CSF examination is judged to be no longer necessary if a noncontrast CT (NCCT) scan rules out SAH. In this study, the authors evaluated the performance of NCCT to rule out SAH in patients with positive CSF findings. Between January 2006 and April 2018, 1657 patients were admitted with a nontraumatic SAH. Of these patients, 1546 had positive SAH findings on the initial NCCT and 111 patients had an NCCT scan that was reported as negative in the acute setting, but with positive CSF examination for subarachnoid blood. Demographic data, World Federation of Neurosurgical Societies grade, and SAH time points (ictus, time of NCCT, and time of lumbar puncture) were collected. All 111 NCCT scans were reevaluated by an experienced neuroradiologist. Of the 111 patients with positive CSF findings, SAH was initially missed on NCCT in 25 patients (23%). Reevaluation of 21 patients presenting within 6 hours of symptom onset confirmed NCCT negative findings in 12 (5 aneurysms), an aneurysmal SAH (aSAH) pattern in 8 (7 aneurysms), and a perimesencephalic pattern in 1 patient. Reevaluation of 90 patients presenting after 6 hours confirmed negative NCCT findings in 74 patients (37 aneurysms), aSAH pattern in 10 (4 aneurysms), and a perimesencephalic pattern in 6 (2 aneurysms). CSF examination is still mandatory to rule out SAH as NCCT can fail to show blood, even within 6 hours after symptom onset. In addition, the diagnosis SAH was frequently missed during initial reporting.

In Reply to the Letter to the Editor Regarding “Determining the Diagnostic Utility of Lumbar Punctures in CT Negative Suspected Subarachnoid Hemorrhage: A Systematic Review and Meta-Analysis”

In Reply to the Letter to the Editor Regarding “Determining the Diagnostic Utility of Lumbar Punctures in CT Negative Suspected Subarachnoid Hemorrhage: A Systematic Review and Meta-Analysis”

Letter to the Editor Regarding “Determining the Diagnostic Utility of Lumbar Punctures in CT Negative Suspected Subarachnoid Hemorrhage: A Systematic Review and Meta-Analysis”

Letter to the Editor Regarding “Determining the Diagnostic Utility of Lumbar Punctures in CT Negative Suspected Subarachnoid Hemorrhage: A Systematic Review and Meta-Analysis”

Determining the Diagnostic Utility of Lumbar Punctures in Computed Tomography Negative Suspected Subarachnoid Hemorrhage: A Systematic Review and Meta-analysis

While headache is a common neurologic symptom, subarachnoid hemorrhage (SAH) is a rare and potentially catastrophic cause of sudden-onset severe headache. The utility of the imaging modalities and interventional procedures are central to the investigation of the causes of headache; however, they are not without their limitations, risks, and complications. A meta-analysis in accordance with the Preferred Reporting for Systematic Reviews and Meta-analysis guidelines was conducted searching PubMed, EMBASE, and Google Scholar. Patients investigated for suspected subarachnoid hemorrhage (SAH) with a negative computed tomography (CT) and positive lumbar puncture (LP) and final diagnosis of SAH were included. The sensitivity of LP in the context of a negative CT and vsubsequent imaging confirming the cause of SAH (computed tomography angiography, magnetic resonance angiography, digital subtraction angiography [DSA]) was quantified. The pooled data were analyzed using the DerSimonian-Laid random effects model. Four studies with 2782 patients who presented with headache suspicious for SAH were included with an initial negative CT report and a subsequent LP to rule out SAH. All included studies had an observational prospective cohort design. A combined pooled proportion of 0.383 (0.077, 0.756); 0.086 (0.007, 0.238); and 0.22 (0.04, 0.49) forLP+, DSA+, and DSA/computed tomography angiography+ investigations were estimated with a 95% confidence interval. The current clinical workflow of an LP after a negative CT head for a patient presenting with a sudden-onset severe headache is observed to have a high enough proportion to warrant its continued use despite the sensitivity of modern CT scanners of ≥97%.

Erythrophages do not develop when lumbar CSF and blood samples are mixed in vitro

BackgroundCerebrospinal fluid (CSF) analysis is a crucial method in the diagnostic process for suspected subarachnoid hemorrhage (SAH), especially when cerebral imaging is negative or inconclusive. CSF cytology (detection of erythrophages or siderophages) is used to determine whether a bloodstained CSF resembles a genuine SAH. Whether erythrophages may develop in vitro after a traumatic puncture in case of delayed CSF analysis is unclear. An in vitro development of erythrophages after traumatic puncture would diminish the diagnostic properties of CSF analysis. We assessed whether erythrophagocytosis is detectable in CSF after an imitated traumatic lumbar puncture.MethodsWe mimicked a traumatic lumbar puncture by mixing surplus CSF with whole blood from the same patient. From this mixture, cytological specimens were obtained immediately and repeatedly at time intervals of 1 h, until 7 h after mixing, or until the mixture was exhausted. Each cytological specimen was microscopically examined independently by four experienced CSF cytologists for the presence of erythrophages.ResultsWe studied 401 CSF cytological specimens of 96 punctures in 90 patients. We could not identify any erythrophages in all cytological specimens. Fleiss’ Kappa for interrater-reliability was 1.0.ConclusionsWe did not find evidence for an in vitro erythrophagocytosis after a mimicked traumatic lumbar puncture. Therefore, the occurrence of erythrophages in CSF cytology can be regarded as a reliable sign of an autochthonous bleeding in the subarachnoid space. Our results support the crucial role of CSF analysis in clinical practice in case of a suspected SAH but negative cerebral imaging.

To Head CT Scan or Not: The Clinical Quandary in Suspected Subarachnoid Hemorrhage; a Validation Study on Ottawa Subarachnoid Hemorrhage Rule.

Introduction:The Ottawa Subarachnoid Hemorrhage rule (OSR) is a clinical decision tool identified for ruling out subarachnoid hemorrhage (SAH) in those patient above 15 years of age who present to the emergency department (ED) with acute onset atraumatic headache. Objective:The primary objective of this study was to externally validate the OSR in a single national health service (NHS) setting in the UK and secondly, to compare it with our current practice without using a decision rule.Method: A retrospective review of computerized medical records was done for all patients registered with headaches from January to December 2016. The data were manually charted on a data sheet from individual patient records. Patients fulfilling the preset inclusion and exclusion criteria as per the OSR were enrolled in the analysis. According to the OSR, if patient had any of the 6 criteria enlisted (age > 40 years, neck stiffness/pain, witnessed loss of consciousness, onset during exertion, thunderclap headache, limited neck flexion on examination), further diagnostic decision was required. All patients were followed up for 6 months on the computer system as it gets highlighted if the patient is represented again to the ED or is deceased.Results:A total of 737 ED visits with acute headache were reviewed for potential eligibility. Out of these, 649 were estimated to be eligible. On excluding 485 patients that could not meet the predetermined inclusion criteria and 19 patients as per the exclusion criteria, 145 (19.7%) patients were included in the analysis. There were 5 cases of SAH, yielding an incidence of 3.4 % (95% CI 1.3 % – 8.3 %). The sensitivity for SAH was 100% (95% CI, 46.3 % - 100 %); specificity of 44.2 % (95% CI, 36 % - 53 %); positive predictive value of 6.02 % (95% CI 2.2 % - 14.1 %); and negative predictive value of 100% (95% CI, 92.7 % - 100%).Conclusion:Although being poorly specific, the OSR is a highly sensitive, simple tool for ruling out SAH in alert patients with a headache in ED settings.

38 Validation of a Multi-Wavelength Spectrophotometric Assay for Detection of Xanthochromia in Suspected Subarachnoid Hemorrhage

38 Validation of a Multi-Wavelength Spectrophotometric Assay for Detection of Xanthochromia in Suspected Subarachnoid Hemorrhage

Factors Influencing Time to CT in ER for Patients with Suspected Subarachnoid Hemorrhage

Background: IN our present review, the main goal was to determine the factors that influence the time of CT in diagnosis of SAH in emergency department, since the ED physicians are the first who are approaches to the patients, awareness and attitude of those physicians are very important for the benefit of SAH patients. Methods: We conducted a comprehensive search using following databases; PUBMED, EMBASE, SCOPUS of studies that involving data on the roles and time of CT in diagnosis of subarachnoid hemorrhage (SAH) in ED patients with acute headache, published in English language up to 2017. Conclusion: CT within 6 hours might be considered enough to rule out SAH in the following circumstances: a neurologically regular patient, a thunderclap headache presentation, a clear time of beginning, and a modern-day CT scan carried out within 6 hours of beginning read by a going to radiologist. Time from headache beginning to imaging is reasonably associated with favorable imaging for SAH. Postpone to health center presentation represent the biggest portion of time to imaging, especially those without SAH. These findings recommend restricted opportunity to minimize lumbar puncture rates merely by accelerating in-hospital processes when imaging hold-ups are under 2 hours, as diagnostic yield of imaging decreases beyond the 6-hour imaging window from headache beginning.

Outcomes of CSF spectrophotometry in cases of suspected subarachnoid haemorrhage with negative CT: two years retrospective review in a Birmingham hospital

Aim: The aim of this study was to evaluate the adherence to current guidelines for the investigation of suspected subarachnoid haemorrhage and the prevalence and outcome of computed tomography (CT)-negative aneurysmal subarachnoid haemorrhage.Design: A retrospective review in a single large tertiary referral centre.Subjects: A total of 796 patients, aged 16–90 years, who underwent lumbar puncture (LP) for suspected subarachnoid haemorrhage (SAH) following a negative or equivocal CT scan between January 2012 and November 2013 (23 months).Methods: Xanthochromia reports were obtained using the hospital’s department of biochemistry database and clinical data for these patients were reviewed using patient notes.Results: Of 796 CSF reports reviewed, 728 (91%) were negative for xanthochromia, 31 (4%) were positive and 37 (5%) were equivocal. Only 2 out of the 31 patients with positive spectrophotometry results were subsequently found to have an underlying aneurysm on CT angiography. A further 9 out of these 31 patients underwent digital subtraction angiography, with no cerebral aneurysms being detected. Amongst the 37 patients with equivocal xanthochromia reports, 13 underwent CT angiography and only 1 cerebral aneurysm was detected.Conclusions: In patients with clinically suspected SAH but who have negative or questionable CT findings, CSF analysis is likely to be negative in the vast majority of cases, which was 91% in our series. In patients yielding positive or equivocal CSF results the likelihood of an aneurysm being detected is low, amounting to three out of 68 or approximately one in 23 (approximately 4%). Overall in suspected SAH cases where CT scan has been negative, the rate for the detection of cerebral aneurysm is three out of 796 cases (0.4%).

Diagnosis of subarachnoid haemorrhage: a survey of Australasian emergency physicians and trainees.

This study aims to establish current practice among Australasian emergency physicians and trainees on several aspects of the investigation of suspected subarachnoid haemorrhage (SAH). An electronic questionnaire (SurveyMonkey™) was distributed to emergency physicians and trainees by email through the ACEM. Survey recipients were asked about demographics, followed by a series of questions relating to the investigation of SAH. There were 878 survey respondents (response rate 24%). Our data showed that 47.3% of respondents agreed or strongly agreed that a CT brain within 6 h of headache onset is sufficient to exclude a diagnosis of SAH. For a CT performed within 12 h of ictus, 14.4% were satisfied that SAH could be excluded. After a negative CT scan, for further investigation of SAH, 88% of respondents preferred lumbar puncture to CT angiography. For detection of xanthochromia in the cerebrospinal fluid, 57.7% of respondents felt that spectrophotometry (vs visual inspection) is necessary to accurately diagnose SAH. A range of information was collected regarding the investigation of suspected SAH. We report significant differences in the diagnostic approach of Australasian emergency physicians and trainees to this condition, in particular the utility of CT within 6 h for exclusion of SAH.

Lumbar puncture and the diagnosis of CT negative subarachnoid haemorrhage: time for a new approach?

Objective. Because of potential risks of poor outcome, lumbar puncture (LP) is recommended to exclude the presence of blood breakdown products in patients with suspected subarachnoid haemorrhage (SAH) and a normal CT scan. The aim of this study was to document how often this test proved useful. Method. A retrospective analysis of prospectively recorded data was conducted. Patients with suspected SAH and a normal CT scan in whom LP was recommended between May 2008 and May 2010 were identified using the neurosurgical referral database. CT scan results, LP results, inpatient stay, investigations and interventions were recorded. Results. One hundred and sixty-three patients were identified in whom LP was recommended after a reported negative CT scan. Thirty-six of these 163 patients had a positive LP of which seven had evidence of SAH on the initial CT scan. In 66 patients, the LP was not diagnostic and 59/66 (90%) patients underwent secondary imaging in whom five with aneurysms were identified and treated. Conclusion. LP-driven decision making in patients with a normal scan and suspected SAH is suboptimal in over a third of cases. Patients with a non-diagnostic LP harboured five aneurysms that merited treatment. These results support the need for secondary investigations following suspected SAH, but suggest that these could take the form of secondary imaging rather than a lumbar puncture.

Differential diagnostic yield of lumbar puncture in investigation of suspected subarachnoid haemorrhage: a retrospective study

The diagnostic algorithm of computerized tomography (CT) and lumbar puncture (LP) for suspected subarachnoid haemorrhage (SAH) has lately been challenged by the advancement of radiological techniques, such as higher resolution offered by newer generation CT-scanners and increased availability of CT-angiography. A purely radiological workup of suspected SAH offers great advantages for both patients and the health care system, but the risks of abandoning LP in this setting are not well investigated. We have characterized the differential diagnostic yield of LP in the investigation of suspected SAH by a retrospective study. From the hospital laboratory database, we analyzed the medical records of all patients who had undergone CSF-analysis in search of subarachnoid bleeding during 2009-2011. A total of 453 patients were included. In 14 patients (3%) the LP resulted in an alternative diagnosis, the most common being aseptic meningitis. Two patients (0.5%) received treatment for herpes meningitis. Five patients (1%) with subarachnoid haemorrhages were identified. Among these, the four patients presenting with thunderclap headache had non-aneurysmal bleedings and did not require surgical intervention. We conclude that the differential diagnostic yield of LP in investigation of suspected SAH is low, which indicates that alternative diagnoses is not a reason to keep LP in the workup when a purely radiological strategy has been validated. However, algorithms should be developed to increase the recognition of aseptic meningitis. One hundred and fifty-three patients (34%) were admitted to undergo LP, which estimates the number of hospital beds that might be made available by a radiological diagnostic algorithm.

Cost‐effectiveness of Diagnostic Strategies for Evaluation of Suspected Subarachnoid Hemorrhage in the Emergency Department

Diagnosing subarachnoid hemorrhage (SAH) in emergency department (ED) patients is challenging. Potential diagnostic strategies include computed tomography (CT) only, CT followed by lumbar puncture (CT/LP), CT followed by magnetic resonance imaging and angiography (CT/MRA), and CT followed by CT angiography (CT/CTA). The objective was to determine the relative cost-effectiveness of diagnostic strategies for SAH. The authors created a decision model to evaluate the cost-effectiveness of SAH diagnostic strategies in ED patients with suspected SAH. Clinical probabilities were obtained from published data; sensitivity analyses were conducted across plausible ranges. In the base-case scenario, CT-only had a cost of $10,339 and effectiveness of 20.25 quality-adjusted life-years (QALYs), and CT/LP had a cost of $15,120 and effectiveness of 20.366 QALYs. Among the alternative strategies, CT/CTA had a cost of $12,840 and effectiveness of 20.24 QALYs, and CT/MRA had a cost of $16,207 and effectiveness of 20.27 QALYs. In sensitivity analyses, probability of severe disability from SAH, sensitivity of noncontrast CT, and specificity of LP and MRA were key drivers of the model, and CT-only and CT/LP were preferable. In the base-case scenario, CT-only was preferable to the CT/CTA and CT/MRA strategies. When considering sensitivity analyses and the current medicolegal environment, there are no overwhelming differences between the cost-effectiveness of CT/LP and the alternative strategies to suggest that clinicians should abandon the standard CT/LP approach.

When LP Is Not Necessary to Detect Subarachnoid Bleed

Standard teaching is that lumbar puncture (LP) is essential in patients with suspected subarachnoid hemorrhage (SAH) despite normal head computed

Cerebrospinal Fluid Ferritin Level, a Sensitive Diagnostic Test in Late-Presenting Subarachnoid Hemorrhage

The workup of patients with suspected subarachnoid hemorrhage (SAH) presenting late is complicated by a loss of diagnostic sensitivity of computed tomography (CT) brain imaging and cerebrospinal fluid (CSF) bilirubin levels. In this prospective longitudinal study of CSF ferritin levels in SAH, serial CSF samples from 14 patients with aneurysmal SAH requiring extraventricular drainage (EVD) were collected. The control group comprised 44 patients presenting with headache suspicious of SAH. Nine patients underwent a traumatic spinal tap. CSF ferritin levels were significantly higher in the patients with SAH compared with controls (P < .0001). The upper reference range of CSF ferritin is 12 ng/mL, and there was no significant difference between the traumatic and normal spinal taps (mean, 9.0 ng/mL vs 3.9 ng/mL; P = .59). CSF ferritin levels increased after SAH, from an average of 65 ng/mL on day 1 to 1750 ng/mL on day 11 (P < .01). Both the Fisher and Columbia CT scores were significantly correlated with CSF ferritin level. The increase in CSF ferritin level after SAH and possibly may provide additional diagnostic information in patients with suspected SAH who present late to the clinic.

Comparison of original (2003) and revised (2008) national guidelines for reporting of cerebrospinal fluid spectrophotometric scanning for suspected subarachnoid haemorrhage against patient outcome

National guidelines for cerebrospinal fluid (CSF) analysis and its reporting in suspected subarachnoid haemorrhage (SAH) were published in 2003, but revised in 2008 to give greater clarity in interpretation. It is not known whether the less ambiguous reporting of 2008 guidelines may lead to a false assurance and adversely affect patient outcome. We, therefore, re-interpreted scans reported under the 2003 guidelines, using the 2008 guidelines and compared these reports against final diagnosis and patient outcome obtained from a retrospective case-note review audit. We identified requests for CSF xanthochromia studies from the laboratory system between September 2006 and August 2007. Spectroscopy scans were then retrieved and re-interpreted using the 2008 guidelines. The original reports and re-interpreted scans were compared against diagnosis and patient outcome using case-note review. We received 93 requests for CSF spectroscopy on 90 patients. Fourteen requests were not processed due to insufficient sample, but of these three patients had a repeat lumbar puncture (LP). Two further requests were not processed at the request of the clinician as they were no longer clinically indicated. Therefore, 77 spectroscopic scans were re-interpreted. The revised guidelines re-classified 11 previously equivocal scans into the not supportive of SAH category. On case-note review, one patient had a subsequent fatal SAH. The remaining 10 were given non-SAH final diagnoses and none had similar further inpatient episodes for at least 12 months and up to 18 months following LP. The revised (2008) national guidelines for the analysis of CSF in suspected SAH offer greater clarity in reporting without adversely affecting patient outcome.

Emergency physician interpretation of head CT in trauma and suspected subarachnoid haemorrhage—is it viable? An audit of current practice

Background and objectivesThe number of emergency CT head examinations has increased since the introduction of the National Institute for Health and Clinical Excellence (NICE) head injury guidelines. In addition, government...

The Longitudinal Profile of Bilirubin and Ferritin in the Cerebrospinal Fluid Following a Subarachnoid Hemorrhage: Diagnostic Implications

Cerebrospinal fluid (CSF) spectrophotometry for bilirubin is a highly sensitive test in the diagnostic work up of a suspected subarachnoid hemorrhage (SAH). We report two cases suffering from an aneurysmal SAH in which extraventricular drainage for acute hydrocephalus was required. Longitudinal analyses of the CSF samples demonstrated that CSF bilirubin was detectable in all cases during the first week, becoming undetectable in one case in the second week. Importantly, CSF ferritin levels rose substantially (>1,000 ng/ml) after 6 days, peaking around 3,000 ng/ml after 2 weeks (normal upper reference range 12 ng/ml). In both cases blood was visible on the initial CT brain scan, disappearing on a later scan. CSF ferritin levels may be an important additional laboratory test in the diagnostic work-up of patients with a suspected SAH. CSF ferritin levels may prove particularly helpful in cases with late presentation if the CT brain scan is normal and CSF bilirubin level is undetectable.

CT evaluation of subarachnoid hemorrhage: a practical review for the radiologist interpreting emergency room studies

Radiologists working in an emergency radiology setting frequently interpret computed tomography (CT) studies of patients with suspected subarachnoid hemorrhage (SAH). This article reviews the sensitivity of CT for detection of SAH, some major patterns of SAH related to a ruptured aneurysm, and the differential diagnosis of SAH not due to aneurysmal rupture.