The Roadmap to Diagnosis: Tests and Scoring Systems
At a Glance
Doctors diagnose an aneurysmal subarachnoid hemorrhage using CT scans, angiograms, and sometimes lumbar punctures. They use the Hunt and Hess scale to assess symptom severity and the modified Fisher scale to predict the risk of delayed complications like vasospasm.
When a “brain bleed” is suspected, doctors move quickly to confirm the diagnosis and find the exact source of the bleeding. This involves a series of highly specialized tests and the use of grading systems that act as a “roadmap” for your care team.
The Diagnostic Pathway
The process usually follows a specific order to ensure accuracy and speed.
1. Confirming the Bleed (NCCT and LP)
- Non-Contrast CT (NCCT): This is the first step. It is a fast, painless scan that uses X-rays to look for blood in the space around the brain [1]. It is very accurate if done shortly after the headache begins [2].
- Lumbar Puncture (LP): If the CT scan looks normal but your symptoms strongly suggest a bleed, doctors may perform a lumbar puncture (often called a “spinal tap”) [3]. They collect a small amount of cerebrospinal fluid from your lower back to check for the presence of blood that the CT might have missed [1]. During this test, doctors specifically look for a yellow tint to the spinal fluid called xanthochromia, which is evidence of old blood in the system [3].
2. Finding the Aneurysm (CTA and DSA)
Once a bleed is confirmed, the team must find the aneurysm.
- CT Angiography (CTA): This is a CT scan that uses a special dye injected into your veins to create detailed maps of your blood vessels [1]. It is often the first tool used to find an aneurysm [4].
- Digital Subtraction Angiography (DSA): Considered the gold standard, this is a more invasive but highly detailed procedure [5]. A specialist (neuro-interventionalist) threads a thin tube (catheter) through an artery in your leg or wrist up toward the brain to take precise pictures of the blood vessels [1].
Understanding the Grading Systems
Your medical reports will likely mention two important scores. These are not just numbers; they help doctors predict risks and plan your treatment.
The Hunt and Hess Scale (Severity of Symptoms)
This scale (Grades I to V) measures your clinical condition based on your symptoms at the time you arrived at the hospital [6].
- Grade I or II: Usually involves a headache and perhaps a stiff neck, but you are alert and oriented [7].
- Grade III to V: Indicates more severe symptoms, such as significant confusion, drowsiness, or weakness [7].
A higher grade helps the team prepare for more intensive monitoring and support [8].
The Modified Fisher Scale (Risk of Vasospasm)
While the Hunt and Hess scale looks at your symptoms, the modified Fisher Scale (Grades 1 to 4) looks at the amount of blood seen on the CT scan [9].
- Why it matters: Blood in the subarachnoid space can irritate the arteries, causing them to narrow (a complication called vasospasm) [10].
- Tracking Risk: A higher score (specifically grades 3 and 4) indicates a larger volume of blood, which means a higher risk for delayed cerebral ischemia (DCI), a condition where parts of the brain don’t get enough oxygen in the weeks following the bleed [10][9].
| Scale | What it Measures | What it Predicts |
|---|---|---|
| Hunt and Hess | Your symptoms and neurological state | Overall severity and survival [11] |
| Modified Fisher | Amount of blood on the CT scan | Risk of vasospasm and DCI [10] |
By understanding these tests and scores, you can better follow the “why” behind the frequent neurological checks and the medications being used in your care. Find out how doctors use these scores to plan your treatment in Securing the Aneurysm.
Common questions in this guide
How is a brain bleed diagnosed?
What is the difference between a CTA and a DSA?
What does my Hunt and Hess score mean?
Why is the modified Fisher scale important?
What is delayed cerebral ischemia (DCI)?
Questions to Ask Your Doctor
Curated prompts to bring to your next appointment.
- 1.What was my score on the Hunt and Hess scale, and what does it tell you about my current neurological state?
- 2.What was my modified Fisher scale grade, and how does that influence the plan for monitoring for vasospasm or DCI?
- 3.If the CT scan was negative, was a lumbar puncture performed to be absolutely sure?
- 4.Was the aneurysm identified via CTA, or do we need a DSA (the gold standard) to get a better look?
- 5.Based on these scores, what specific complications are you most concerned about in the next 10 to 14 days?
Questions For You
Tap a prompt to share your answer — we'll use it plus this page's context to start a tailored conversation.
References
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PMID: 29685416
This page provides educational information on the diagnostic tests and scoring systems for subarachnoid hemorrhage. It is for informational purposes only and does not replace professional medical advice. Always discuss your specific test results and care plan with your neurologist or neurosurgeon.
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