Spontaneous subarachnoid hemorrhage and negative initial vascular imaging--should further investigation depend upon the pattern of hemorrhage on the presenting CT?

BACKGROUND: Multiple investigations are usually performed in patients with spontaneous SAH who have negative initial angiography. This study aimed to evaluate the most appropriate use of additional imaging studies and how this may be influenced by the findings of the initial CT. METHODS: A retrospective analysis was performed on a prospectively collected cohort of patients referred with spontaneous SAH and negative initial angiography. The patients were divided into four categories based upon the distribution of blood on the initial CT: perimesencephalic (pSAH), diffuse (dSAH), sulcal (sSAH) and CT negative (CSF positive for xanthochromia) (nCT-pLP). The number and nature of the subsequent imaging investigations were reviewed, and the results were correlated with the findings of the presenting CT. RESULTS: One hundred fourteen patients were included in the study. Repeat imaging found five relevant abnormalities. Three cases of vasculitis were diagnosed on the first DSA following a negative CTA. A case of dissecting aneurysm was revealed on the third neurovascular study. A hemorrhagic spinal tumor presented with xanthochromia. No subsequent abnormality was found on the third DSA or MRI head. No case of pSAH had a subsequent positive finding if the initial CTA was negative. CONCLUSIONS: Certain patterns of SAH are associated with a low yield of abnormalities on repeat imaging if the initial angiography is normal. The authors believe that the pattern of hemorrhage on the presenting CT should be used to guide the most appropriate use of further imaging modalities and present a diagnostic algorithm for this purpose.

Embolization of residual fistula following stereotactic radiosurgery in cerebral arteriovenous malformations.

Treatment of brain arteriovenous malformations (BAVMs) often requires a multitechnique approach. We present 2 cases of BAVM, in which initial stereotactic radiosurgery (SRS) was successful in obliterating a significant volume of the nidus. At follow-up angiography, residual fistulas were identified and selectively embolized; this procedure cured the lesions. Many series describe initial embolization to reduce the nidal volume followed by SRS to the remnant. The described cases highlight the value of primary radiosurgery followed by selective fistula embolization.

Extruded aneurysm coils found at craniotomy: report of two cases.

The operative findings are presented in two patients following inadequate coil embolization. At craniotomy, part of the coil mass had extruded through the fundus of both aneurysms. It is unclear if this phenomenon is confined to aneurysms that demonstrate significant regrowth and if there is an increased risk of rebleeding.

Complications of cerebral angiography: a prospective analysis of 2,924 consecutive procedures.

INTRODUCTION: Cerebral angiography is an invasive procedure associated with a small, but definite risk of neurological morbidity. In this study we sought to establish the nature and rate of complications at our institution among a large prospective cohort of consecutive patients. Also, the data were analysed in an attempt to identify risk factors for complications associated with catheter angiography. METHODS: Data were prospectively collected for a consecutive cohort of patients undergoing diagnostic cerebral angiography between January 2001 and May 2006. A total of 2,924 diagnostic cerebral angiography procedures were performed during this period. The following data were recorded for each procedure: date of procedure, patient age and sex, clinical indication, referring specialty, referral status (routine/emergency), operator, angiographic findings, and the nature of any clinical complication or asymptomatic adverse event (arterial dissection). RESULTS: Clinical complications occurred in 23 (0.79%) of the angiographic procedures: 12 (0.41%) significant puncture-site haematomas, 10 (0.34%) transient neurological events, and 1 nonfatal reaction to contrast agent. There were no permanent neurological complications. Asymptomatic technical complications occurred in 13 (0.44%) of the angiographic procedures: 3 groin dissections and 10 dissections of the cervical vessels. No patient with a neck dissection suffered an immediate or delayed stroke. Emergency procedures (P = 0.0004) and angiography procedures performed for intracerebral haemorrhage (P = 0.02) and subarachnoid haemorrhage (P = 0.04) were associated with an increased risk of complications. CONCLUSION: Neurological complications following cerebral angiography are rare (0.34%), but must be minimized by careful case selection and the prudent use of alternative noninvasive angiographic techniques, particularly in the acute setting. The low complication rate in this series was largely due to the favourable case mix.

Imaging findings and referral outcomes of rapid assessment stroke clinics.

AIM: A rapid assessment stroke clinic (RASC) was established to provide a rapid diagnostic service to individuals with suspected transient cerebral or ocular ischaemia or recovered non-hospitalized strokes. In this report we review imaging findings and clinical outcomes of patients proceeding to the carotid surgery programme. METHODS: Between October 2000 and December 2002, 1339 people attended the RASC. The findings of head CT and carotid Doppler ultrasound of the 1320 patients who underwent brain and carotid imaging were reviewed, and the number subsequently proceeding to carotid angiography and intervention was reported. RESULTS: CT head scans were normal in 57% of cases; 38% demonstrated ischaemia or infarction; and 3% yielded incidental or other significant findings not related to ischaemia. On screening with carotid Doppler ultrasound, 7.5% showed greater than 50% stenosis on the symptomatic side. A total of 83 patients (6.2%) proceeded to cerebral angiography and 65 (4.8%) underwent carotid endarterectomy or endovascular repair. CONCLUSION: Rapid-access neurovascular clinics are efficient in selecting patients for carotid intervention, but this is at a cost and the number of potential strokes prevented is small. Alternative management pathways based on immediate medical treatment need to be evaluated.

How well do we investigate patients with suspected subarachnoid haemorrhage? The continuing need for cerebrospinal fluid investigations.

OBJECTIVE: To demonstrate the extent of compliance with established guidelines for the investigation of suspected subarachnoid haemorrhage (SAH) and the implications of non-compliance. DESIGN: Prospective observational study of practice in three hospitals in the Trent region. SETTING: One teaching hospital with a tertiary neuroscience referral centre and two large district general hospitals. PARTICIPANTS: 50 consecutive patients from each centre referred for suspected SAH with negative computed tomography. MAIN OUTCOME MEASURES: Diagnosis of SAH confirmed or excluded according to guidelines. RESULTS: When the data from the three centres were combined (n = 150 computed tomography negative cases) cerebrospinal fluid (CSF) investigation was not performed in 60/150 (40%). In the 90 cases where CSF studies were performed SAH was confirmed in 11 (12%). CONCLUSION: There is significant non-compliance in following the established guidelines for the investigation of SAH at the centres studied. As the primary cause of non-traumatic SAH is ruptured aneurysm, which is associated with high morbidity and mortality from second haemorrhage, this highlights a major source of concern for clinical governance.

Coil embolization of giant serpentine aneurysms: report of two cases arising from the posterior cerebral artery.

The authors describe the presentation, investigation and successful treatment of two giant serpentine aneurysms with Guglielmi detachable coils. Both aneurysms selectively involved the P2 segment of the posterior cerebral artery. The authors describe an endovascular approach to these challenging lesions as an alternative/adjunct to conventional surgery.

Multimodality MR imaging depiction of hemodynamic changes and cerebral ischemia in subarachnoid hemorrhage.

BACKGROUND AND PURPOSE: Subarachnoid hemorrhage (SAH) is a common and serious neurologic emergent condition. We tested the hypothesis that multimodality MR imaging depicts changes in cerebral blood flow SAH, before any surgical or endovascular intervention, and that the frequency of these changes increases with time after ictus. METHODS: We prospectively examined 37 patients with suspected SAH and three with symptoms of acute stroke but who subsequently had SAH. Routine CT and multimodality MR imaging were performed within 18 h of presentation. Standard MR imaging, diffusion-weighted MR imaging, time-of-flight MR angiography, and dynamic first-pass gadolinium-enhanced MR perfusion imaging were performed. Images were reviewed for abnormalities in cerebral blood flow, ischemia, and infarction. Nine patients did not have SAH at CT and CSF investigations. Of 31 patients with proved SAH, 13 were examined during the acute stage (within 4 d of ictus) and 18, during the subacute stage (4-14 d after ictus). RESULTS: MR imaging showed alteration in cerebral blood flow parameters in 16 of 31 patients before surgery or endovascular treatment. The frequency of blood flow changes and associated complications increased with worsening clinical grade and increasing time after ictus. CONCLUSION: Multimodality MR imaging provides information not available from CT in patients with SAH. MR imaging shows oligemic and ischemic areas in SAH before surgery or endovascular treatment. MR imaging is a simple noninvasive method of assessing cerebral blood flow and its complications in SAH. It can be performed in a clinical environment.

Spontaneous obliteration of pial arteriovenous malformations: a review of 27 cases.

BACKGROUND AND PURPOSE: Brain arteriovenous malformations (AVMs) occur in approximately 0.14% of the population. The most common presentations are hemorrhage (50%) and seizures (25%). Although they are congenital abnormalities, their angioarchitecture may vary over time. A rare but well-recognized phenomenon of AVMs is that of spontaneous obliteration. It is not known what factors predispose to spontaneous obliteration. The purpose of our study was to determine whether spontaneous thrombosis of AVMs can be predicted by their angioarchitecture and whether there is any risk of recurrence once obliteration has occurred. METHODS: We retrospectively reviewed the angiographic and cross-sectional imaging data amassed over an 18-year period, including follow-up imaging studies and mail surveys of referring and family physicians. A control group was obtained from contemporaneous AVMs of a similar size. RESULTS: We identified 28 cases of spontaneous obliteration in a series of 2162 patients. The mean time between initial diagnostic angiography and angiographic obliteration was 10 months, during which time there was no intervention and no history of repeat hemorrhage; nor had hemorrhage recurred during the follow-up period (mean, 53 months). Most of the AVMs were deep (22/27) with only one draining vein (21/27) and few feeding arteries. In more than half the cases (15/27) drainage was exclusively into the superficial venous system. CONCLUSION: Spontaneous obliteration is rare (1.3%). Common features include hemorrhagic presentation and few arterial feeding vessels. Although we found no instance of repeat hemorrhage during the follow-up period, AVMs can recanalize, and follow-up is therefore recommended.

Acute neuromedical and neurosurgical admissions. Standard and ultrafast MR imaging of the brain compared with cranial CT.

PURPOSE: To evaluate the role of standard and ultrafast MR brain imaging and compare the information with CT. MATERIAL AND METHODS: This was a prospective study of 114 patients with acute neurological symptoms and signs. CT brain examinations consisted of axial non-enhanced images. MR imaging consisted of standard spin-echo/fast spin-echo sequences and a series of rapid techniques including echoplanar and single shot fast spin-echo sequences. RESULTS: Using standard MR methods, 41% of the patients had all five sequences of good technical quality, while using ultrafast methods 81% of the patients had good technical quality examinations in all five sequences. In 3% of the cases, ischaemic stroke was incorrectly reported on CT. In 24% of the cases, MR gave extra diagnostic information not reported on CT and in a further 8%, one neuroradiologist reported the abnormality in agreement with the MR, whilst the other neuroradiologist reported the CT as normal. In 2 cases, subarachnoid haemorrhage was missed on MR. Subarachnoid haemorrhage was not shown on the ultrafast sequences. CONCLUSION: MR can be used to image acute neurological admissions with a high success rate, particularly using ultrafast methods. In many cases, MR provided extra information of direct clinical relevance not shown on CT.

Stereotactic radiosurgery and the risk of haemorrhage from cavernous malformations.

Eighteen patients with cerebral cavernous malformations were treated with single dose of cobalt 60 source stereotactic radiosurgery. All had suffered at least one haemorrhage prior to treatment with six suffering 2, four suffering 3 and one suffering 4. Mean follow-up was 4.5 years. A total of 36 pretreatment haemorrhages occurred in 139 patient years. The first haemorrhage each patient suffered was taken as the start of observation and not included in the rehaemorrhage rate calculation. Three posttreatment haemorrhages occurred in 81 patient years of observation. The annual haemorrhage rate thus fell from 13% before to 3.7% after treatment. The odds ratio was thus 0.29 with a 95% confidence interval of (0.08-0.97), but this must be interpreted with caution because of the prereferral selection of this group of patients. Three patients developed complications of radiosurgery, two of them recovered fully.

Proximal aneurysms in association with arteriovenous malformations: do they resolve following obliteration of the malformation with stereotactic radiosurgery?

One-hundred consecutive patients were identified who had arteriovenous malformations (AVMs) treated by stereotactic radiosurgery (STRS) which were totally obliterated as shown by follow-up angiography. Of these cases, seven had intracerebral aneurysms at initial angiography, two of which were multiple. Five patients had saccular aneurysms at commonly recognized sites on the circle of Willis or main proximal cerebral arteries, while two patients had aneurysms on distal AVM feeder arteries in atypical sites (one saccular, one fusiform). Saccular aneurysms at typical sites were found to be unchanged in size following AVM obliteration. The significance of this finding in the management of patients who present with subarachnoid haemorrhage and who have both aneurysms and AVMs is discussed.

Subarachnoid hemorrhage due to late recurrence of a previously unruptured aneurysm after complete endovascular occlusion.

We present a case of subarachnoid hemorrhage attributed to rupture of an aneurysm 18 months after endovascular occlusion. The aneurysm was diagnosed after the patient had a seizure; however, there was no evidence of subarachnoid hemorrhage. Angiography at 6 months revealed a totally occluded aneurysm. This case illustrates that the long-term results of endovascular occlusion remain uncertain.

The role of imaging in the follow up of meningiomas.

A retrospective study of 60 patients with meningiomas was conducted to evaluate the role of imaging in postoperative follow up. Using case notes and imaging studies, requests were assessed with reference to the indications for imaging radiological findings and effect on patient management. Patients were divided into three groups: 34 who had undergone a macroscopically complete resection, 18 with known residual tumour, and eight in whom surgery was not performed. These 60 patients underwent a total of 165 CT and 11 MRI studies. In the complete resection group only two patients developed a recurrence, both having highly suggestive symptoms or signs. It is concluded that routine imaging is not indicated in asymptomatic patients after complete tumour clearance. Both CT and MRI contribute to patient management in those with residual disease, MRI probably being the imaging method of choice.

Thrombolysis and angioplasty for acute lower limb ischemia in Buerger's disease.

Acute lower limb ischemia secondary to Buerger's disease in a young patient responded to thrombolysis and subsequent popliteal and anterior artery angioplasty. The value of angioplasty in non-limb-threatening ischemia in Buerger's disease has not been established but this case illustrates a role for thrombolysis and angioplasty in acute ischemia.

Case report: metastatic renal cell carcinoma presenting as intracerebral haemorrhage.

Cerebral haemorrhage is a well-established, albeit rare, complication of intracranial tumours. An autopsy series of 461 cerebral tumours revealed haemorrhage into only 2%. A case is described of intracerebral haemorrhage which complicated a metastatic renal cell carcinoma. There are four previous cases reported in the literature with this presentation, but this case differs in that the diagnosis was by cerebral angiography and at a site distant to the original haemorrhage.

Anterior abdominal wall hernias: diagnosis by ultrasound and tangential radiographs.

Spigelian and epigastric hernias can cause diagnostic problems as they often present in elderly, obese patients with few specific symptoms or signs. Early diagnosis is important as both groups of hernia have a high rate of bowel strangulation. The combined value of ultrasound and tangential radiographs in the diagnosis of these hernias is presented along with a review of the literature.

Case report: the ultrasound and Doppler appearances of pelvic varices.

Dilatation of the veins of the broad ligament and ovarian plexi cause a very specific clinical entity called the pelvic congestion or pelvic pain syndrome. The ultrasound and Doppler appearances of this condition are unique and should be easily recognized. We describe these appearances in one patient and review the literature.