A Subarachnoid Hemorrhage (SAH) is a type of bleeding in the brain that can cause major strokes; it usually occurs when an aneurysm ruptures. An aneurysm is when the wall of an artery balloons out like a bubble, weakening. It develops gradually over years, nobody knows how & why this happens. There are almost never any symptoms during this time period.
When the aneurysm finally bursts, half the time the SAH is major, and the patient dies or suffers permanent brain damage. But the other half, there’s only small bleeding, called a “warning leak,” and the aneurysm seals itself temporarily. Major rupture will occur within the next few weeks, but now there’s time to make a diagnosis & perform life-saving surgery.
The headache from this is always the “worst headache ever” that a person has experienced. It may be severe or not so bad (depending on how much blood leaks), but it’s always worse than any other headache they may have ever had. And it almost always occurs abruptly, reaching its full strength with 60 seconds, sometimes immediately like a “thunderclap.” If the pain begins while straining (lifting, coughing, sex, etc.), it’s more suggestive.
If two close relatives (parents, siblings) had aneurysms, we’re much more concerned. This would include relatives who had a “stroke” at an early age, since that would most likely have been from an aneurysm. People with Polycystic Kidney Disease & some other rare diseases are also at increased risk.
In the first few days, it’s easy to make the diagnosis by a CT scan.ย Within the first week or two, a lumbar puncture (LP) (spinal tap) is accurate.ย But these tests become false-negative as time goes by and blood gets reabsorbed.ย Some clinicians don’t realize that the physical exam may be completely normal after a small warning leak, but if they don’t act promptly and obtain the tests (most easily in an ER), catastrophe will occur.ย If they wait too long (like going on 2 weeks), the basic tests above are much less accurate.
If either CT or LP is positive, or if a Neurologist or Neurosurgeon is suspicious, they’ll order the necessary angiogram (aka arteriogram), squirting dye directly into the brain’s arteries to locate the aneurysm. Surgery, if done in time, is usually successful.