Subarachnoid hemorrhage without evident cause on initial angiography studies: diagnostic yield of subsequent angiography and other neuroimaging tests

Outcome correlates with blood distribution in subarachnoid hemorrhage of unknown origin

PURPOSE

Between 15 and 30 % of patients with subarachnoid hemorrhage (SAH) have no bleeding source and usually have a benign clinical course and outcome. The objectives of this study were to classify the pattern of blood distribution on initial computed tomography (CT) and to correlate it with clinical outcome in aneurysmal (ASAH) and SAH of unknown origin (SAHuO).

METHODS

We reviewed 112 CTs of SAHuO and 104 CTs of ASAH patients. Blood distribution was classified according to a new grading system (type 0-4) and correlated to Hunt and Hess (H&H) grade and modified Rankin scores (MRS) at short- and long-term follow-up.

RESULTS

Fifty percent of 112 SAHuO patients were classified as type 0 (no visible blood on CT) or 1 (blood restricted to prepontine cisterns). Most ASAH patients presented with bleeding into the lateral Sylvian fissure (66%; type 3) or with intracerebral hemorrhage (27%; type 4) whereas types 0 and 1 were not observed. SAHuO patients were in better clinical condition on admission than ASAH patients (p < 0.0001). H&H grades of SAHuO patients correlated with the amount of subarachnoid blood according to the new classification (p = 0.004). Short-term outcome was obtained from 100% and long-term outcome from 95% patients (follow-up 29 +/- 31 months). Short- and long-term MRS correlated with blood distribution in SAHuO patients (p = 0.012) and was significantly better than in ASAH patients (p < 0.0001). No correlation was observed between blood distribution, H&H grade, and short- and long-term outcome in aneurysmal patients.

CONCLUSIONS

In SAH of unknown origin, a new classification allows to predict outcome based on the extent of blood on CT.

Long-term outcome and quality of life after nonaneurysmal subarachnoid hemorrhage

PURPOSE

Nonaneurysmal subarachnoid hemorrhage (SAH) is an uncommon form of SAH. As nonaneurysmal SAH is often concentrated around the pons and midbrain, the term perimesencephalic SAH (pmSAH) is widely accepted to describe this entity, though there are patients with a more widespread distribution of subarachnoid blood (non-pmSAH). The outcome of pmSAH is commonly regarded as good, although often outcome is not analyzed using standardized tools of outcome measurement. In this study we focused on the patient's quality of life after nonaneurysmal SAH.

METHODS

We included 26 patients in this study who experienced a nonaneurysmal SAH between 2003 and 2007. Neurological status upon admission as well as on discharge was recorded. All patients received a detailed postal questionnaire on their current neurological situation, dependence on care (Barthel Index), quality of life regarding their physical and psycho-social well-being (Short-form 36) and current employment situation and ability to work, respectively.

RESULTS

After 32.68 +/- 19.81 months, almost all patients achieved a Glasgow Outcome Score of 4 or 5 and a Barthel Index of more than 90, although there was a difference between patients suffering from pmSAH and patients with non-pmSAH. Physical and social functioning recovered to almost normal levels but vitality and individual health were often perceived as reduced in self-evaluation.

CONCLUSION

Nonaneurysmal SAH is a begnin entity, though there is a difference between pmSAH and non-pmSAH in outcome. Self-evaluations of vitality and individual health in both groups are often experienced as reduced, thus imposing the question of whether neurological rehabilitation should be recommended despite good neurological outcome.

Negative CT angiography findings in patients with spontaneous subarachnoid hemorrhage: When is digital subtraction angiography still needed?

BACKGROUND AND PURPOSE

CTA is becoming the frontline modality to reveal aneurysms in patients with SAH. However, in about 20% of SAH patients no aneurysm is found. In these cases, intra-arterial DSA is still performed. Our aim was to evaluate whether negative findings on CTA can reliably exclude aneurysms in patients with acute SAH.

MATERIALS AND METHODS

We conducted a retrospective analysis of all negative findings on CTAs performed from 2005 to 2009 in patients with spontaneous SAH. Findings were compared with DSA. CTAs were performed with a 64-section multidetector row CT scanner.

RESULTS

One hundred ninety-three patients with SAH and negative findings on CTA who underwent subsequent DSA were identified. The distribution of blood on unenhanced CT was the following: PMH in 93 patients, diffuse aneurysmal pattern in 50, no blood on CT (xanthochromic LP) in 32, and peripheral sulcal distribution in 18. All patients with PMH had negative findings on DSA. One patient with no blood on CT had vasculitis on DSA. Six of 18 (33%) patients with peripheral blood had vasculitis on DSA. Three of these were also diagnosed by CTA. All except 1 patient with diffuse aneurysmal blood had negative findings on DSA. One patient was diagnosed with an aneurysm on DSA (1/50, 0.5%). Repeat delayed DSA performed in 28 of these patients revealed a small aneurysm in 4 (14%). Five patients had a complication of DSA (2.6%); 1 was a clinical stroke (0.5%).

CONCLUSIONS

In patients with SAH, negative CTA findings are reliable in ruling out aneurysms in the PMH pattern or no blood on CT. DSA is indicated in the diffuse aneurysmal pattern of SAH, and repeat delayed DSA is required if the initial DSA findings are negative. When the blood is peripheral, CTA should be scrutinized for vasculitis and DSA is recommended for confirmation.

Nonaneurysmal nonperimesencephalic subarachnoid hemorrhage: is it a benign entity?

BACKGROUND

Although the clinical profile of patients with PMN SAH is well documented, there are scarce data available for patients with nonaneurysmal n-PMN SAH. In the present study, the clinical characteristics of patients with n-PMN SAH were analyzed and compared with those of PMN SAH and aneurysmal SAH.

METHODS

Patients with spontaneous SAH, in whom the initial DSA or 3-dimensional CTA result was normal, underwent another investigation (CTA/DSA). If the results of both of these were negative, a second DSA was done after 4 to 6 weeks. Patients in whom even the second DSA failed to reveal an aneurysm or any other vascular abnormality were labeled as nonaneurysmal SAH. Within this group, 2 different types were identified: PMN SAH and n-PMN SAH.

RESULTS

There were 61 patients in whom the results of the first DSA and CTA were both negative. In 2 of these patients, an aneurysm was demonstrated at a second DSA. Seven patients died before a second DSA could be done. After excluding these, there were 18 patients with PMN SAH and 34 with n-PMN SAH. There was no mortality in these patients; and at a mean follow-up of 1.8 years, all patients with PMN SAH and 94.1% of patients with n-PMN SAH had a good outcome. Associated comorbid illnesses were more frequent in patients with PMN SAH and n-PMN SAH as compared with the aneurysmal SAH patients.

CONCLUSIONS

Once an aneurysm is definitely excluded, patients with n-PMN SAH have a good outcome, and like PMN SAH, have a benign clinical course. However, a second DSA is mandatory to avoid missing an aneurysm or any other vascular lesion.

Ruptured “Occult” Aneurysm Disclosed by Three-Dimensional Angiographic Reconstructions

Rotational angiographic sequences and their three-dimensional reconstructions have led to major improvements in angiographic diagnostics, especially in the study of brain aneurysms. Reconstructions accurately depict the morphology of the aneurysm, namely any wall irregularities and the possible origin of arterial branches from the aneurysmal sac, and display the aneurysm on multiple spatial planes, measuring its different diameters and ratios (particularly the dome to neck ratio). Lastly, three-dimensional angiographic reconstructions will sometimes disclose ruptured or intact aneurysms not depicted by digital subtraction angiography. A 43-year-old woman was admitted to the emergency room of Maggiore Hospital, Bologna Local Health Trust, presenting severe headache, confusion and nuchal rigidity. Emergency CT scan disclosed cisternal subarachnoid haemorrhage. Subsequent 3D sequences revealed an aneurysm of the left carotid artery siphon. This occult aneurysm found in our patient had been masked by the overlying infundibular origin of the posterior communicating artery. This prevented detection of the lesion not only in standard oblique anteroposterior, craniocaudal and lateral sequences but also in the rotational sequence. Identification of the aneurysm in our patient was the result of the diagnostic strategy adopted. When cisternal subarachnoid haemorrhage is detected, our protocol routinely includes a rotational angiographic sequence centred on the anterior circulation and on the posterior circulation when the standard examination fails to depict the course of all the vessels or when the features of subarachnoid haemorrhage strongly suggest aneurysm rupture in that anatomical location. Three-dimensional angiographic reconstructions are extremely useful not only to characterize brain aneurysms, but also to disclose ruptured occult aneurysms and additional zero grade lesions.

Onyx embolization of a thoracolumbar perimedullary spinal arteriovenous fistula in an infant presenting with subarachnoid and intraventricular hemorrhage

Identifying a source of spontaneous subarachnoid hemorrhage (SAH) or intraventricular hemorrhage (IVH) in patients with negative results on cranial angiographic imaging can be a diagnostic challenge. The authors present the case of a 14-month-old girl who presented with lethargy and spontaneous SAH and IVH, and later became acutely paraplegic. Except for the SAH and IVH, findings on neuroimages of the brain were normal. Magnetic resonance imaging revealed an intramedullary thoracolumbar spinal cord hemorrhage that was found to be associated with arterialized veins intraoperatively. Catheter-based diagnostic angiography identified a spinal perimedullary macroarteriovenous fistula (macro-AVF) that was completely embolized with Onyx, negating the need for further surgical intervention. The authors believe this to be the first reported case of a thoracolumbar perimedullary macro-AVF presenting with SAH and IVH. In addition, descriptions of Onyx embolization of a spinal AVF in the literature are rare, especially in pediatric patients.

Psychosocial and neurocognitive performance after spontaneous nonaneurysmal subarachnoid hemorrhage related to the APOE-ε4 genotype: a prospective 5-year follow-up study

Object

In this study, the authors prospectively evaluated long-term psychosocial and neurocognitive performance in patients suffering from nonaneurysmal, nontraumatic subarachnoid hemorrhage (SAH) and investigated the association between the APOE-ε4 genotype and outcome in these patients.

Methods

All patients admitted to the authors' institution between January 2001 and January 2003 with spontaneous nonaneurysmal SAH were prospectively examined (mean follow-up 59.8 months). The APOE genotype was determined in all patients by polymerase chain reaction from a blood sample. Of the 30 patients included in this study, 11 were carriers of the ε4 allele.

Results

All patients showed a good recovery and regained full independence with no persisting neurological deficits. The patients with the ε4 allele, however, scored significantly higher on the Beck Depression Inventory (22.1 ± 6.3 vs 14.1 ± 5.1). At follow-up, depression was more persistent in the group with the ε4 allele compared with the group that lacked the allele. This finding reached statistical significance (p < 0.05). Selective attention was impaired in all patients during the first year of follow-up, with an earlier recovery noted in the patients without the ε4 allele. Moreover, there was a tendency toward a linear relationship between the Beck Depression Inventory and the d2 Test of Attention. Two patients who carried the ε4 allele did not return to their employment even after 5 years.

Conclusions

The findings in this study suggest that the APOE genotypes may be associated with the psychosocial and neurocognitive performance after spontaneous nonaneurysmal SAH, even in the absence of neurological impairment. Physicians should consider patient genotype in assessing the long-term consequences of nonaneurysmal SAH.

BLISTER-LIKE ANEURYSMS OF THE ANTERIOR COMMUNICATING ARTERY

OBJECTIVE

Blood blister-like aneurysms are small hemispherical bulges from the dorsomedial wall of the internal carotid artery that resemble berry aneurysms but differ in their clinical and surgical features. On the basis of our literature review, blister-like aneurysms have been reported to occur only at nonbranching sites of the dorsomedial internal carotid artery. In this report on our series of five patients, we describe blister-like aneurysms of the anterior communicating artery (AComA) and discuss important diagnostic and therapeutic aspects unique to them.

METHODS

In our retrospective review of 719 patients with nontraumatic subarachnoid hemorrhage admitted to our service from 1998 to 2003, 181 (25.17%) patients harbored AComA aneurysms. Five (2.76%) patients (four women, one man) had blister-like aneurysms that were recognized at the time of surgery.

RESULTS

Initial digital subtraction angiography was diagnostic in only one patient. A second digital subtraction angiogram was diagnostic in one patient but failed to reveal an aneurysm in the remaining three patients; these were eventually diagnosed by computed tomographic angiography. All aneurysms were clipped. At the time of surgery, the aneurysms arose from the horizontal portion of the AComA without any involvement of the branches of the anterior cerebral artery. All presented as blister-like aneurysms that were thin-walled and lacking a surgical neck. On dissection, two of the lesions ruptured. All lesions were treated with straight fenestrated clips through the A1–AComA junction, thus remodeling the AComA. No delayed rupture was noted at the time of the last follow-up evaluation. At the time of discharge, outcomes were good in two patients, fair in two, and poor in the remaining patient.

CONCLUSION

Blister-like aneurysms constitute technically challenging lesions that may occur at the AComA. Computed tomographic angiography is valuable in diagnosis. Blister-like aneurysms should be suspected when digital subtraction angiography findings are negative for subarachnoid hemorrhage.

Additional value of 3D rotational angiography in angiographically negative aneurysmal subarachnoid hemorrhage: how negative is negative?

BACKGROUND AND PURPOSE

In some patients with nonperimesencephalic nontraumatic subarachnoid hemorrhage (aneurysmal SAH), no aneurysm can be found on digital subtraction angiography (DSA), and repeat DSA is advocated. 3D rotational angiography (3DRA) is considered superior to DSA in the detection of small intracranial aneurysms. In this study, we assessed the additional diagnostic value of 3DRA in detecting DSA-occult aneurysms in 23 patients with aneurysmal SAH.

MATERIALS AND METHODS

Between January 2006 and September 2007, 298 patients with suggested ruptured intracranial aneurysm were referred for DSA, and in 98 patients, DSA was negative. Of these 98 patients, 28 had aneurysmal SAH, and in 23 of these additional 3DRA was performed in the same or in a repeat angiographic procedure.

RESULTS

In 18 of 23 patients (78%), a ruptured small aneurysm was diagnosed on additional 3DRA. The location of 18 aneurysms was the anterior communicating artery (n = 11), the middle cerebral artery (n = 3), the posterior communicating artery (n = 2), the ophthalmic artery (n = 1), and the posterior inferior cerebellar artery (n = 1). Aneurysm size was 3 mm in 4, 2 mm in 9, and 1 mm in 5. Of 18 aneurysms, 9 were treated with coil placement; 7 with surgical clipping; and 2 were not treated.

CONCLUSION

In this study, 18 of 23 (78%) patients with negative findings on DSA had a small ruptured aneurysm when studied with 3DRA. These were most commonly located on the anterior communicating artery.

Giant, partially thrombosed aneurysm develops after remote angiographically negative subarachnoid hemorrhage: case report

OBJECTIVE

This is the first report of the rupture of a giant aneurysm in a patient who sustained a remote angiographically negative subarachnoid hemorrhage (SAH).

CLINICAL PRESENTATION

A 62-year old woman initially presented with a Fisher Grade III SAH 9 years ago. Her evaluation, which included cerebral angiography, magnetic resonance imaging scans, and magnetic resonance angiography of the head and neck, failed to reveal the cause of the hemorrhage. Nine years after her initial hemorrhage, the patient presented with a Fisher Grade IV SAH and a giant right supraclinoid internal carotid artery aneurysm.

INTERVENTION

Computed tomographic and catheter angiography showed a partially thrombosed giant aneurysm of the right supraclinoid internal carotid artery. She underwent clip reconstruction and obliteration of the aneurysm. Review of her previous angiograms and magnetic resonance imaging scans did not show an aneurysm in its nascency.

CONCLUSION

Initial catheter angiography and magnetic resonance imaging scans may fail to disclose a subtle dissection or blister aneurysm as a cause for SAH. As in our case, the dissection or blister may progress to a giant aneurysm with time.

Disappearance and reappearance of a cerebral aneurysm: a case report

BACKGROUND

The false-negative rate of DSA in the setting of a ruptured cerebral aneurysm is approximately 15% (Topcuoglu M, Ogilvy C, Carter B, et al. Subarachnoid hemorrhage without evident cause on initial angiography studies: diagnostic yield of subsequent angiography and other neuroimaging tests. J Neurosurg 2003;98:1235-1240). Detecting these aneurysms is imperative to avoid repeat hemorrhage. Rarely, one is able to document the phenomenon of the disappearance and subsequent reappearance of the ruptured aneurysm.

CASE DESCRIPTION

This is a case report of subarachnoid hemorrhage (SAH) in which a cerebral aneurysm of the M1 segment of the left proximal middle cerebral artery was initially detected by CTA at an outside hospital only to evade detection with both CTA and DSA at our institution. Repeat DSA 1 week later revealed the culprit aneurysm, which was then treated endovascularly.

CONCLUSIONS

Patients with significant SAH and negative DSA findings should be considered for further diagnostic testing including CTA or repeat DSA. The current literature supports the strategy used at our institution of initial CTA and DSA in the setting of SAH, and then subsequent repeat DSA as warranted if the initial studies are nondiagnostic. Timing of repeat examination, as demonstrated in this case, should favor a shorter time course.

Ruptured internal carotid artery anterior wall aneurysm identified during vasospasm: case report

OBJECTIVE AND IMPORTANCE

Aneurysms of the paraclinoid segment arising from the anterolateral wall of the proximal internal carotid artery (ICA) are usually located in the intradural space, and the proximal neck of the aneurysm is closely adjacent to the dural ring. Although most of these aneurysms can be identified by cerebral angiography, the top of the aneurysm can be flattened because of its relationship to the undersurface of the clinoid process. We report a rare case of a ruptured ICA anterolateral wall aneurysm that was not identified by initial angiography but was clearly observed at the time of vasospasm.

CLINICAL PRESENTATION

A 59-year-old female patient was transferred to our hospital because of sudden loss of consciousness. Initial angiography failed to disclose any aneurysm except for one projecting to the right at the C3-C4 portion of the left ICA. A left frontotemporal craniotomy with drilling of the anterior clinoid process was performed 1 day after the onset of subarachnoid hemorrhage. Within the operative field, however, no hemorrhage was detected near the C3-C4 portion of the left ICA. Subsequent angiography performed during vasospasm clearly demonstrated a ruptured aneurysm in the anterior paraclinoid segment of the right ICA.

INTERVENTION

After drilling the anterior clinoid process and cutting the dural ring, we successfully clipped the aneurysm. The aneurysm was saccular, with a broad neck that extended below the dural ring. Intraoperative inspection demonstrated that the dome of the aneurysm was in a subclinoid location, suggesting that most of the aneurysm might have been flattened by the dural ring at the time of initial angiography but before the onset of vasospasm.

CONCLUSION

The presented case suggests that this type of aneurysm may be missed by routine angiography performed before and after vasospasm. If initial angiography fails to reveal the origin of the subarachnoid hemorrhage but computed tomography still discloses hemorrhage from an ICA aneurysm, repeated angiography should be considered within 14 days after the onset of subarachnoid hemorrhage to confirm whether the aneurysm has arisen from the anterior clinoid segment of the ICA.

Spontaneous subarachnoid haemorrhage with negative initial angiography: A review of 143 cases

The need for repeat angiography in patients with subarachnoid haemorrhage (SAH) who initially present with a negative angiogram is still debated. The aim of this study was to provide a management protocol for 'angiogram-negative SAH'. From January 1986 to June 2004, 143 patients with SAH were admitted to our institution with negative initial angiograms. We classified the 143 patients into three groups: group I, with no SAH on CT scan, but confirmed by cerebrospinal fluid analysis; group II, with a perimesencephalic pattern of SAH; and group III, with a non-perimesencephalic pattern of SAH. Out of the 143 patients, 103 underwent repeat angiography, and 18 were found to have ruptured aneurysms that were not detected on the initial angiogram (false negative rate: 17.5% overall, 0% in group I, 1.5% in group II, and 45.9% in group III). Repeat angiography should be performed, particularly in patients who have a non-perimesencephalic SAH pattern, for detection of initially unrecognised ruptured aneurysms.

Acute subarachnoid hemorrhage: using 64-slice multidetector CT angiography to “triage” patients’ treatment

INTRODUCTION

To evaluate the clinical role of CT angiography (CTA) in patients with acute subarachnoid hemorrhage (SAH) for treatment decision-making.

METHODS

Consecutive patients with acute SAH had CTA using a 64-slice scanner for initial clinical decision-making. Image processing included multiplanar volume reformatted (MPVR) maximum intensity projections (MIP) and 3D volume-rendered reconstructions. CTAs were used for (1) evaluating the cause of SAH, and (2) triaging aneurysm-bearing patients to the more appropriate management, either surgical clipping or endovascular coiling. CTA findings were confirmed by neurosurgical exploration or catheter angiography (digital subtraction angiography, DSA). Successful coiling provided evidence that triaging to endovascular treatment was correct.

RESULTS

Included in the study were 73 patients. CTA findings were confirmed by DSA or neurosurgical operation in 65 patients, and of these 65, 47 had aneurysmal SAH, 3 had vasculitis, 1 had arterial dissection and 14 had no underlying arterial abnormality. The cause of SAH was detected with CTA in 62 out of the 65 patients (95.4%, sensitivity 94%, specificity 100%). CTA revealed the aneurysm in 46 of 47 patients (98%, sensitivity 98%, specificity 100%, positive predictive value 100%, negative predictive value 82.3%), 1 of 3 vasculitides and 1 of 1 dissection. Of the 46 patients with aneurysm, 44 (95.7%) were referred for treatment based on CTA. In 2 patients (2 of 46, 4.4%) CTA was not informative enough to choose treatment requiring DSA. Of the 44 patients, 27 (61.4%) were referred to endovascular treatment and successful coiling was achieved in 25 (25 of 27, 92.6%).

CONCLUSION

CTA using a 64-slice scanner is an accurate tool for detecting and characterizing aneurysms in acute SAH. CTA is useful in the decision process whether to coil or clip an aneurysm.

Repeated digital substraction angiography after perimesencephalic subarachnoid hemorrhage?

BACKGROUND AND PURPOSE

In patients with perimesencephalic subarachnoid hemorrhage (pSAH) DSA is recommended to exclude aneurysms to due false negative findings in CT-angiography. However, whether a second DSA is indicated during the clinical course to exclude--in addition to aneurysms--fistulas, too, is still under debate. We aimed to evaluate the benefit of repeated DSA in patients with pSAH.

METHODS

The source of data was a prospective database set up at the neurological, neurosurgical and neuroradiological departments in our institution. A total of 69 patients with pSAH were enrolled and analyzed by reviewing the medical records and neuroradiological findings.

RESULTS

68 patients presented with Hunt & Hess Grade I-II and one patient with Hunt & Hess Grade III. Median in-hospital stay was 8 days (3-22). In 2 patients mild vasospasm were diagnosed. DSA was performed in all patients at least once. DSA was repeated in 38 patients (55%) after a median of 7 (3-21) days. None of the repeated DSA did show any additional distinctive features with respect to the first DSA.

CONCLUSIONS

In our opinion the procedure of repeating DSA in patients with pSAH is likely to become obsolete. One DSA should be performed prior to discharge--and subsequent to possible vasospasm--to exclude hemorrhage caused by aneurysms of the posterior circulation mimicking a perimesencephalic SAH pattern.