What is the most appropriate confirmatory test for a postpartum woman presenting with fever, severe headache, and subarachnoid hemorrhage, after a non-contrast Computed Tomography (CT) scan, considering options such as CT angiography, magnetic resonance imaging (MRI) of the brain, or right venography for suspected thrombosis?

From the Guidelines

For a postpartum woman presenting with fever, severe headache, and subarachnoid hemorrhage, the most appropriate confirmatory test is CT angiography, as it is a crucial step in detecting and characterizing aneurysms in acute subarachnoid hemorrhage, according to the guidelines for the management of aneurysmal subarachnoid hemorrhage 1.

When considering the options for a confirmatory test, it is essential to weigh the benefits and limitations of each modality. CT angiography is widely used in the investigation of subarachnoid hemorrhage and is considered sufficient on its own when an aneurysm will be treated with surgical clipping 1. However, in cases where the hemorrhage pattern is diffuse or when the initial CT angiography findings are negative, digital subtraction angiography (DSA) or 3-dimensional cerebral angiography may be necessary to detect small aneurysms or to confirm the diagnosis 1.

The American College of Radiology Appropriateness Criteria for cerebrovascular diseases, including aneurysm, vascular malformation, and subarachnoid hemorrhage, recommend CT angiography as the next imaging study after initial detection of subarachnoid hemorrhage on CT 1. This recommendation is based on the high incidence of aneurysmal subarachnoid hemorrhage and the importance of early diagnosis and repair to prevent rebleeding and reduce morbidity and mortality.

Some key points to consider when choosing a confirmatory test include:

• The ability of CT angiography to detect and characterize aneurysms in acute subarachnoid hemorrhage 1
• The limitations of CT angiography in detecting small aneurysms, particularly those less than 3 mm in size 1
• The importance of digital subtraction angiography or 3-dimensional cerebral angiography in cases where the initial CT angiography findings are negative or when the hemorrhage pattern is diffuse 1
• The recommendation of the American College of Radiology Appropriateness Criteria for cerebrovascular diseases, including aneurysm, vascular malformation, and subarachnoid hemorrhage, to use CT angiography as the next imaging study after initial detection of subarachnoid hemorrhage on CT 1

In terms of radiation exposure, it is essential to consider the risks and benefits of each imaging modality. While CT angiography involves radiation, it is a crucial step in detecting and characterizing aneurysms in acute subarachnoid hemorrhage. However, efforts should be made to reduce radiation exposure whenever possible, particularly in patients who require multiple imaging studies 1.

Overall, CT angiography is the most appropriate confirmatory test for a postpartum woman presenting with fever, severe headache, and subarachnoid hemorrhage, due to its ability to detect and characterize aneurysms in acute subarachnoid hemorrhage, as recommended by the guidelines for the management of aneurysmal subarachnoid hemorrhage 1 and the American College of Radiology Appropriateness Criteria for cerebrovascular diseases 1.

From the Research

Diagnostic Approach for Postpartum Woman with Fever, Severe Headache, and Subarachnoid Hemorrhage

• The patient's presentation of fever, severe headache, and subarachnoid hemorrhage after a non-contrast Computed Tomography (CT) scan requires further evaluation to determine the underlying cause of the subarachnoid hemorrhage.
• Considering the options for confirmatory tests, CT angiography, magnetic resonance imaging (MRI) of the brain, or right venography for suspected thrombosis can be useful in different scenarios.

CT Angiography

• CT angiography is a valuable tool for evaluating cerebral vasospasm following acute subarachnoid hemorrhage, as shown in a study published in 2012 2.
• This study found that CT angiography was accurate for diagnosing central vasospasm, with high sensitivity and specificity, and was helpful in treatment decision-making, particularly regarding the need for balloon angioplasty.

Magnetic Resonance Imaging (MRI)

• MRI can be useful in detecting subarachnoid hemorrhage, especially in the subacute phase, as reported in a study published in 2004 3.
• MRI using FLAIR sequences can show comparable sensitivity to CT in acute subarachnoid hemorrhage and can be superior to CT in some cases.

Cerebral Venous Thrombosis

• Cerebral venous thrombosis (CVT) can present with subarachnoid hemorrhage, as described in case reports and reviews published in 2009 4 and 2016 5.
• These studies highlight the importance of considering CVT in the differential diagnosis of patients presenting with subarachnoid hemorrhage, particularly in the presence of risk factors such as hypercoagulable states or oral contraceptive use.

Reversible Cerebral Vasoconstriction Syndrome

• Reversible cerebral vasoconstriction syndrome (RCVS) is a rare condition that can occur in the postpartum period, as reported in a case study published in 2020 6.
• RCVS can present with severe headache, confusion, and neurological deficits, and can be associated with subarachnoid hemorrhage and intracranial hemorrhage.

Diagnostic Recommendations

• Based on the patient's presentation and the available evidence, a combination of CT angiography and MRI may be the most appropriate confirmatory tests to evaluate the underlying cause of the subarachnoid hemorrhage.
• CT angiography can help diagnose cerebral vasospasm and guide treatment decisions, while MRI can provide additional information on the presence of subarachnoid hemorrhage, cerebral venous thrombosis, or reversible cerebral vasoconstriction syndrome.
• Right venography for suspected thrombosis may also be considered if cerebral venous thrombosis is suspected based on the patient's risk factors and clinical presentation.