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subarachnoid_hemorrhage_diagnosis

Subarachnoid hemorrhage diagnosis

For Aneurysmal subarachnoid hemorrhage diagnosis in the early phase, during the first 24 hours, cerebral CT, combined with intracranial CT angiography is recommended to make a positive diagnosis of SAH, to identify the cause and to investigate for an intracranial aneurysm.

Cerebral MRI may be proposed if the patient's clinical condition allows it. FLAIR imaging is more sensitive than CT to demonstrate a subarachnoid hemorrhage and offers greater degrees of sensitivity for the diagnosis of restricted subarachnoid hemorrhage in cortical sulcus. A lumbar puncture should be performed if these investigations are normal while clinical suspicion is high 1).

CT angiography is an appropriate initial investigation to detect macrovascular causes of non-traumatic intracerebral haemorrhage, but accuracy is modest. Additional MRI/MRA may find cavernomas or alternative diagnoses, but DSA is needed to diagnose macrovascular causes undetected by CT angiography or MRI/MRA 2).

CT

In the early phase, during the first 24hours, cerebral CT, combined with intracranial CT angiography is recommended to make a positive diagnosis of SAH, to identify the cause and to investigate for an intracranial aneurysm. Cerebral MRI may be proposed if the patient's clinical condition allows it. FLAIR imaging is more sensitive than CT to demonstrate a subarachnoid hemorrhage and offers greater degrees of sensitivity for the diagnosis of restricted subarachnoid hemorrhage in cortical sulcus. A lumbar puncture should be performed if these investigations are normal while clinical suspicion is high 3).

Noncontrast computed tomography is highly sensitive in detecting subarachnoid blood, especially within 6 hours of haemorrhage.

The distribution of the subarachnoid blood as shown on the first CT scan after aneurysm rupture barely allows to predict the symptomatic aneurysm site. Thus, neurosurgical decision making (identification of the ruptured aneurysm in patients with multiple aneurysms; surgical exploration in patients with non-perimesencephal SAH, but negative angiography) should not rely on the first CT scan after SAH 4).

Rogers et al. 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 5).

Cerebral MRI

The T2* sequence can detect and localize a previous SAH a few months after aneurysmal bleeding 6). 7).

By combining Susceptibility weighted imaging (SWI) and FLAIR, MRI yields a distinctly higher detection rate for SAH than CT alone, particularly due to their complementary detection characteristics in different anatomical regions. Detection strength of SWI is high in central areas, whereas FLAIR shows a better detection rate in peripheral areas 8).

Lumbar Puncture

MRI of the spinal axis

The yield and clinical relevance of MRI of the spinal axis in patients who present with nonperimesencephalic subarachnoid hemorrhage (NPSAH) is low. Germans et al. do not recommend routine MRI of the spinal axis in this patient population, but it might be justified in a subgroup of patients 9).

The yield and clinical relevance of MRI of the spinal axis in patients who present with NPSAH is low. Germans et al. do not recommend routine MRI of the spinal axis in this patient population, but it might be justified in a subgroup of patients 10) 11).

Computed tomography angiography

Digital subtraction angiography

The knowledge from digital subtraction angiography (DSA) guides both definitive therapy and perioperative management based on the number, size and location of aneurysm and status of collateral circulation and vasospasm.

Hemogram, renal and hepatic function, electrolytes, coagulation status, electrocardiogram (ECG), echocardiogram and chest radiograph provides information about systemic effects of aSAH.

Certain patterns of SAH are associated with a low yield of abnormalities on repeat imaging if the initial angiography is normal. 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 12).

Transcranial Doppler (TCD) and ICP monitoring also help evaluation and management.

see Angiogram negative subarachnoid hemorrhage

Screening

The low 1.14% per-person year risk of DNIA detection and small DNIA size at detection cannot justify routine screening for DNIAs in all patients with a personal history of IAs. If imaging follow-up is considered for selected patients, early screening will likely yield the most benefit in patients who continue to smoke cigarettes 13).


Since its introduction, digital subtraction angiography has been considered the gold standard in diagnostic imaging for neurovascular disease. Modern post-processing techniques have made angiography even more informative to the cerebrovascular neurosurgeon or neurointerventionalist.

In patients with a head computed tomography scan performed less than 6 h after headache onset and reported negative by a staff radiologist, lumbar puncture can be withheld. 14). Intracranial vascular lesions, such as a vascular loop, infundibulum, and stump of an occluded vessel, are sometimes misdiagnosed as aneurysms during imaging examinations 15).

It is difficult to differentiate such lesions from aneurysms on the basis of imaging findings 16) 17).

1) , 3)
Edjlali M, Rodriguez-Régent C, Hodel J, Aboukais R, Trystram D, Pruvo JP, Meder JF, Oppenheim C, Lejeune JP, Leclerc X, Naggara O. Subarachnoid hemorrhage in ten questions. Diagn Interv Imaging. 2015 Jul-Aug;96(7-8):657-66. doi: 10.1016/j.diii.2015.06.003. Epub 2015 Jul 2. PubMed PMID: 26141485.
2)
van Asch CJ, Velthuis BK, Rinkel GJ, Algra A, de Kort GA, Witkamp TD, de Ridder JC, van Nieuwenhuizen KM, de Leeuw FE, Schonewille WJ, de Kort PL, Dippel DW, Raaymakers TW, Hofmeijer J, Wermer MJ, Kerkhoff H, Jellema K, Bronner IM, Remmers MJ, Bienfait HP, Witjes RJ, Greving JP, Klijn CJ; DIAGRAM Investigators. Diagnostic yield and accuracy of CT angiography, MR angiography, and digital subtraction angiography for detection of macrovascular causes of intracerebral haemorrhage: prospective, multicentre cohort study. BMJ. 2015 Nov 9;351:h5762. doi: 10.1136/bmj.h5762. PubMed PMID: 26553142; PubMed Central PMCID: PMC4637845.
4)
Rohde V, Mayfrank L, Bertalanffy H, Mull M, Gilsbach JM. [Aneurysmal subarachnoid hemorrhage: role of computerized tomography for correct prediction of the ruptured aneurysm site]. Zentralbl Neurochir. 2003;64(3):116-22. German. PubMed PMID: 12975746.
5)
Rogers A, Furyk J, Banks C, Chu K. Diagnosis of subarachnoid haemorrhage: a survey of Australasian emergency physicians and trainees. Emerg Med Australas. 2014 Oct;26(5):468-73. doi: 10.1111/1742-6723.12284. Epub 2014 Sep 3. PubMed PMID: 25186282.
6)
Mulé S, Soize S, Benaissa A, Portefaix C, Pierot L. Detection of aneurysmal subarachnoid hemorrhage 3 months after initial bleeding: evaluation of T2* and FLAIR MR sequences at 3 T in comparison with initial non-enhanced CT as a gold standard. J Neurointerv Surg. 2015 Jul 24. pii: neurintsurg-2015-011819. doi: 10.1136/neurintsurg-2015-011819. [Epub ahead of print] PubMed PMID: 26208516.
7)
Falter B, Wiesmann M, Freiherr J, Nikoubashman O, Mull M. Frequency and appearance of hemosiderin depositions after aneurysmal subarachnoid hemorrhage treated by endovascular therapy. Neuroradiology. 2015 Jul 19. [Epub ahead of print] PubMed PMID: 26188767.
8)
Verma RK, Kottke R, Andereggen L, Weisstanner C, Zubler C, Gralla J, Kiefer C, Slotboom J, Wiest R, Schroth G, Ozdoba C, El-Koussy M. Detecting subarachnoid hemorrhage: comparison of combined FLAIR/SWI versus CT. Eur J Radiol. 2013 Sep;82(9):1539-45. doi: 10.1016/j.ejrad.2013.03.021. Epub 2013 Apr 28. PubMed PMID: 23632159.
9) , 10)
Germans MR, Coert BA, Majoie CB, van den Berg R, Lycklama À Nijeholt G, Rinkel GJ, Verbaan D, Vandertop WP. Yield of spinal imaging in nonaneurysmal, nonperimesencephalic subarachnoid hemorrhage. Neurology. 2015 Mar 31;84(13):1337-40. doi: 10.1212/WNL.0000000000001423. Epub 2015 Feb 27. PubMed PMID: 25724231.
11)
Germans MR, Coert BA, Majoie CB, van den Berg R, Verbaan D, Vandertop WP. Spinal axis imaging in non-aneurysmal subarachnoid hemorrhage: a prospective cohort study. J Neurol. 2014 Nov;261(11):2199-203. doi: 10.1007/s00415-014-7480-y. Epub 2014 Sep 3. PubMed PMID: 25182702.
12)
Yap L, Dyde RA, Hodgson TJ, Patel UJ, Coley SC. Spontaneous subarachnoid hemorrhage and negative initial vascular imaging-should further investigation depend upon the pattern of hemorrhage on the presenting CT? Acta Neurochir (Wien). 2015 Jul 16. [Epub ahead of print] PubMed PMID: 26174752.
13)
Wang JY, Smith R, Ye X, Yang W, Caplan JM, Radvany MG, Colby GP, Coon AL, Tamargo RJ, Huang J. Serial Imaging Surveillance for Patients With a History of Intracranial Aneurysm: Risk of De Novo Aneurysm Formation. Neurosurgery. 2015 Jul;77(1):32-43. doi: 10.1227/NEU.0000000000000730. PubMed PMID: 25790068.
14)
Rinkel GJ. Management of patients with aneurysmal subarachnoid haemorrhage. Curr Opin Neurol. 2016 Feb;29(1):37-41. doi: 10.1097/WCO.0000000000000282. PubMed PMID: 26641816.
15)
Park J, Baik SK, Kim Y, Hamm IS. Occluded vascular stump mimicking middle cerebral artery bifurcation aneurysm: report of 2 cases. Surg Neurol. 2008;70(6):664–667.
16)
Komiyama M, Ishiguro T, Morikawa T, Nishikawa M, Yasui T. Distal stump of an occluded intracranial vertebral artery at the vertebrobasilar junction mimicking a basilar artery aneurysm. Acta Neurochir (Wien) 2001;143(10):1013–1017.
17)
Nakano S, Yokogami K, Ohta H, Wakisaka S. A Stump of Occluded Posterior Cerebral Artery Mimicking a Ruptured Aneurysm: Case Report. Int J Angiol. 2000;9(1):51–52.
subarachnoid_hemorrhage_diagnosis.txt · Last modified: 2016/01/06 20:59 (external edit)