Strokes and Old Strokes

Most people have some vague idea of what a stroke is. There has been a significant education campaign by the American Heart Association so that people can recognize a stroke quickly, call 911, and get to the ER for appropriate care. Common symptoms include inability to speak, slurred speech, facial droop, and weakness on one side of the body.

Strokes generally come in two varieties. The most common type is referred to as an ischemic stroke, which is caused by clotting of a blood vessel in the brain. This leads to damage downstream from the blockage because that area is deprived of blood flow—and specifically oxygen. The other type of stroke, which is much rarer, results from the rupture of a blood vessel in the brain. These are referred to as hemorrhagic strokes.

Most people have also heard of what is often called “clot-busting medication.” There are multiple generic and trade names for these medications, but for simplicity, I will refer to them by their class: tPA, or tissue plasminogen activator.

Strokes also come in various sizes. Very small strokes do not cause significant symptoms, and as you would guess, large strokes cause significant symptoms. Put another way, the smaller the blood vessel that gets blocked, the less brain tissue that gets damaged and the smaller the area of the body affected. If a very large vessel in the brain is blocked, there will usually be unmistakable symptoms of stroke that anyone would recognize.

Not all strokes are treated the same. Some are treated with tPA, while others are amenable to mechanical removal of the clot. For mechanical removal to be possible, the clot needs to be in a large vessel, as the technology does not currently exist to remove very tiny clots from very tiny vessels.

But as you might guess, giving a medication that breaks up a clot can lead to the opposite problem—increased bleeding. It is probably quite obvious that you would not treat a hemorrhagic stroke with tPA. In fact, one of the major concerns when giving tPA is that an ischemic stroke may turn into a hemorrhagic one. No medication is without risk, and tPA certainly comes with risks.

If you personally had a very small ischemic stroke with limited symptoms, would you want a medication that carries a risk of making that stroke worse? And if you have a very large ischemic stroke, your risk of conversion to a hemorrhagic stroke is much higher with tPA—so the medication is not used in those cases either.

With that limited background, I want to point out a problem that the ER does not have a great solution for. Patients who have had a prior stroke—sometimes within the last weeks or months—will occasionally experience waxing and waning symptoms. Let’s assume that because of a prior stroke, they have left leg weakness and left arm weakness, but the arm generally works better than the leg. For any number of reasons, patients sometimes feel worse on any given day. There are a myriad of explanations for this, very few of which I would have a specific test for in the ER. But let’s say that on this particular day, the patient’s left leg is now weaker than usual. They normally can walk with a walker but now need extra assistance because that leg feels weaker. The patient or family will often call 911 and rush to the ER, worried that they are having another stroke. And it’s true—it’s possible. But most of the time, nothing is done about symptoms like this.

Depending on the degree of change from the patient’s baseline, more imaging tests may be performed. This may include CT scans and MRIs—essentially the same tests the patient likely received when they first had their stroke. However, most of the time, nothing significant is found. Furthermore, even if there is some small change or evidence of a worsening stroke, having recently had a stroke puts that patient at higher risk for bleeding. So if I were to give tPA hoping to improve their slightly worse symptoms, there is a much greater risk that I would cause a hemorrhagic stroke, which can be far more debilitating.

Sometimes stroke symptoms wax and wane because the patient is ill with some other problem. Infections are probably the most common cause of this. They can drain any metabolic reserve from a chronically ill patient, which makes the rest of their functioning worse. This commonly includes neurologic symptoms such as worsening of prior stroke deficits, increased weakness, and confusion. The neurologic symptoms don’t need any specific treatment. The correct treatment is to address the underlying infection, and the neurologic symptoms will usually resolve on their own.

Almost without exception, the highest risk factor for having a condition is having previously had that condition. So you can imagine it’s pretty hard for any medical authority to tell stroke patients to stay home when they appear to have worsening stroke symptoms. But now you can see my point of view: there is rarely, if ever, any intervention that needs to be made acutely for slightly worsening stroke symptoms in the setting of a prior stroke. If the patient is otherwise ill or has symptoms suggesting something else is going on, those issues are certainly worth looking for and treating as appropriate.

So if a patient has only a slight worsening of prior stroke symptoms, with no other concerning complaints or symptoms, the chance of me finding anything significant—and more specifically, anything treatable—is very low.

Which begs the question: Does the patient need to call 911? Does EMS need to rush them to the ER? Do we need to perform all kinds of imaging tests, only to arrive at the same end state with no options for intervention?