This transcript has been edited for clarity.
Hi. I'm Dr Nick Silvestri. I'm a professor of neurology at the University at Buffalo Jacobs School of Medicine and Biomedical Sciences, where I'm also a neuromuscular specialist.
Today, I'd like to talk to you about the diagnosis of myasthenia gravis.
Myasthenia gravis is a prototypical autoimmune disorder. It is generally caused by antibodies against the acetylcholine receptor, which then leads to impairment of neuromuscular transmission and weakness in patients.
It turns out that most patients who develop myasthenia gravis initially present to their primary care doctor. In myasthenia gravis, the presentation can be quite variable, which is why patients call it the "snowflake disease" — everyone's a little bit different. The majority of patients with myasthenia gravis will present with ocular symptoms, specifically droopy eyelids or double vision.
The key feature of myasthenia gravis, which is true for all symptoms, is that the symptoms tend to worsen throughout the course of the day or as an activity progresses. So, for example, a patient that experiences ocular symptoms like double vision or droopy eyelids might say that in the morning they're symptom-free, but as the day progresses, they start experiencing more of the symptoms.
They may also say that as they're reading a book or watching television, initially they're OK. But as they progress throughout the reading or watching television, the double vision worsens or the ptosis worsens, and if they take a brief rest, things get better. Patients will typically say their best time is their morning.
Other symptoms that can occur in myasthenia gravis, because the disease can affect any skeletal muscle of the body, include problems speaking, such as dysarthria or dysphonia — slurring of words or hoarseness. They can experience swallowing trouble, chewing trouble, breathing trouble. They can experience weakness of their limbs. When patients experience weakness of their limbs, it tends to be proximally predominant.
People will say that they have trouble combing their hair, brushing their teeth, climbing stairs, and getting out of a low chair. The key feature of all of these symptoms, whether they are ocular or bulbar or limb-related, is that they tend to be worse throughout the course of the day or as a patient is doing the activity.
So you can see a patient in the morning, for example, in clinic and they can look perfectly fine. But as that day goes on, they can look worse and worse, which is why I typically like to see patients with myasthenia sometimes in the morning, and then other times in the afternoon to really appreciate the symptoms they experience and that variability.
So if you see a patient with fatigable weakness involving the ocular muscles, the bulbar muscles, or the limb muscles, you need to suspect myasthenia gravis and make an urgent neurology referral. Now, much like you, neurologists are obviously quite busy as well. But if we hear a patient has a disorder like myasthenia gravis, where time is often of the essence to get the patient properly diagnosed and treated, we'll do everything we can to get those patients in expeditiously.
What you can do in the meantime is get the workup going. That workup would include sending blood or serum for acetylcholine receptor antibody measurement, or you can order thyroid function studies. You should probably order both. And the reason for ordering thyroid function studies is that oftentimes, myasthenia gravis and thyroid disease co-occur. But there is a bit of an overlap, especially when it comes to ocular symptoms, between what thyroid disease can cause and what myasthenia gravis can cause.
It's really important that we get the ball rolling when you suspect myasthenia gravis because sometimes patients with myasthenia gravis can experience severe symptoms, such as dysphagia, dyspnea, or orthopnea, which can be a sign of impending respiratory failure — what we call myasthenic crisis, which is a true neurologic emergency. And we really want to get patients treated to prevent that.
Myasthenia gravis is an example of a very treatable neurologic condition in most cases. We've had many therapies for many decades. And thankfully, we've been blessed to have many new therapies available to us, which are quite efficacious, work very quickly, and are generally safer than those therapies that we've traditionally used.
So again, if you have a patient who presents to you with weakness that involves the eye muscles, the bulbar muscles, or the limb muscles that has an element of fluctuation, consider myasthenia gravis. Send off for those tests — the acetylcholine receptor antibodies, the thyroid function studies — while you're waiting to get that patient in to see a neurologist so that we can take the reins and get that patient completely diagnosed, properly treated, and hopefully back to a happy, healthy, and normal life.
COMMENTARY
"Get the Workup Going": Early Detection of Myasthenia Gravis May Lessen Symptom Severity and Improve Outcomes
Nicholas J. Silvestri, MD
DISCLOSURES
| July 12, 2024This transcript has been edited for clarity.
Hi. I'm Dr Nick Silvestri. I'm a professor of neurology at the University at Buffalo Jacobs School of Medicine and Biomedical Sciences, where I'm also a neuromuscular specialist.
Today, I'd like to talk to you about the diagnosis of myasthenia gravis.
Myasthenia gravis is a prototypical autoimmune disorder. It is generally caused by antibodies against the acetylcholine receptor, which then leads to impairment of neuromuscular transmission and weakness in patients.
It turns out that most patients who develop myasthenia gravis initially present to their primary care doctor. In myasthenia gravis, the presentation can be quite variable, which is why patients call it the "snowflake disease" — everyone's a little bit different. The majority of patients with myasthenia gravis will present with ocular symptoms, specifically droopy eyelids or double vision.
The key feature of myasthenia gravis, which is true for all symptoms, is that the symptoms tend to worsen throughout the course of the day or as an activity progresses. So, for example, a patient that experiences ocular symptoms like double vision or droopy eyelids might say that in the morning they're symptom-free, but as the day progresses, they start experiencing more of the symptoms.
They may also say that as they're reading a book or watching television, initially they're OK. But as they progress throughout the reading or watching television, the double vision worsens or the ptosis worsens, and if they take a brief rest, things get better. Patients will typically say their best time is their morning.
Other symptoms that can occur in myasthenia gravis, because the disease can affect any skeletal muscle of the body, include problems speaking, such as dysarthria or dysphonia — slurring of words or hoarseness. They can experience swallowing trouble, chewing trouble, breathing trouble. They can experience weakness of their limbs. When patients experience weakness of their limbs, it tends to be proximally predominant.
People will say that they have trouble combing their hair, brushing their teeth, climbing stairs, and getting out of a low chair. The key feature of all of these symptoms, whether they are ocular or bulbar or limb-related, is that they tend to be worse throughout the course of the day or as a patient is doing the activity.
So you can see a patient in the morning, for example, in clinic and they can look perfectly fine. But as that day goes on, they can look worse and worse, which is why I typically like to see patients with myasthenia sometimes in the morning, and then other times in the afternoon to really appreciate the symptoms they experience and that variability.
So if you see a patient with fatigable weakness involving the ocular muscles, the bulbar muscles, or the limb muscles, you need to suspect myasthenia gravis and make an urgent neurology referral. Now, much like you, neurologists are obviously quite busy as well. But if we hear a patient has a disorder like myasthenia gravis, where time is often of the essence to get the patient properly diagnosed and treated, we'll do everything we can to get those patients in expeditiously.
What you can do in the meantime is get the workup going. That workup would include sending blood or serum for acetylcholine receptor antibody measurement, or you can order thyroid function studies. You should probably order both. And the reason for ordering thyroid function studies is that oftentimes, myasthenia gravis and thyroid disease co-occur. But there is a bit of an overlap, especially when it comes to ocular symptoms, between what thyroid disease can cause and what myasthenia gravis can cause.
It's really important that we get the ball rolling when you suspect myasthenia gravis because sometimes patients with myasthenia gravis can experience severe symptoms, such as dysphagia, dyspnea, or orthopnea, which can be a sign of impending respiratory failure — what we call myasthenic crisis, which is a true neurologic emergency. And we really want to get patients treated to prevent that.
Myasthenia gravis is an example of a very treatable neurologic condition in most cases. We've had many therapies for many decades. And thankfully, we've been blessed to have many new therapies available to us, which are quite efficacious, work very quickly, and are generally safer than those therapies that we've traditionally used.
So again, if you have a patient who presents to you with weakness that involves the eye muscles, the bulbar muscles, or the limb muscles that has an element of fluctuation, consider myasthenia gravis. Send off for those tests — the acetylcholine receptor antibodies, the thyroid function studies — while you're waiting to get that patient in to see a neurologist so that we can take the reins and get that patient completely diagnosed, properly treated, and hopefully back to a happy, healthy, and normal life.
Any views expressed above are the author's own and do not necessarily reflect the views of WebMD or Medscape.
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