This often misdiagnosed condition ‘should be on the radar’ of every physician
MDlinx Jun 04, 2025
Industry Buzz
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“Diagnostic accuracy can be improved through greater awareness across disciplines, and it has been increasingly recognised by emergency medicine, PCPs, optometrists, and ophthalmologists.” — Min Kang, MD, director of the myasthenia gravis clinic at UCSF
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“Fatigue is usually the main concern of the main symptom. So you can imagine how many different medical conditions present with fatigue, and that is the reason why often people are not super sensitive to looking for this diagnosis.” — Rodrigo Rodriguez, MD, neurologist with Keck Medicine of USC
A patient presents to you with fatigue and symptoms like drooping eyelids or double vision.
The diagnosis could be myasthenia gravis, but experts say the condition is too often overlooked due to diagnostic challenges.
“Diagnosis of myasthenia gravis can be challenging, due to the fluctuating nature of weakness, which often leads to normal examination in the clinic. Additionally, patients’ vague complaints of fatigue can be often misleading,” Min Kang, MD, director of the myasthenia gravis clinic at UCSF, tells MDLinx.
“Often, it can mimic more common conditions like thyroid disorders, strabismus, aponeurotic ptosis, multiple sclerosis, or even functional neurological disorders," Dr. Kang continues. "Early on, symptoms may be subtle or intermittent, leading to underrecognition. Without clinical suspicion, important diagnostic studies for [myasthenia gravis], including antibody panels and electrophysiologic studies, are not pursued.”
The problem with fatigue
Many patients with myasthenia first present with fatigue, causing difficulties and delays in diagnosis.
“Fatigue is usually the main concern of the main symptoms,” Rodrigo Rodriguez, MD, neurologist with Keck Medicine of USC, tells MDLinx. “So you can imagine how many different medical conditions present with fatigue, and that is the reason why often people are not super sensitive to looking for the diagnosis of myasthenia. So patients will linger in that state with fatigue for a long time without anybody suspecting that neuromuscular junction dysfunction could be an explanation.”
“Before those more obvious symptoms start, the physicians whom these patients go to initially are going to be bewildered a little bit and say, ‘Okay, well, you have this fatigue.’ But that is such a nonspecific symptom, so patients will linger in that state for months without somebody looking closer,” Dr. Rodriguez says.
How is it diagnosed?
A diagnosis of myasthenia gravis may be reached through a physical and neurological examination, testing muscle strength, coordination, and eye movements, and also with electrodiagnostics like EMG or blood work.
National Institute of Neurological Disorders and Stroke. Myasthenia gravis. July 19, 2024.
Some people with myasthenia will have abnormally elevated anti-MuSK antibodies or acetylcholine receptor antibodies. But part of the diagnostic challenge is that not everyone with myasthenia will have abnormal blood work.
“Even though we have blood tests for the condition, only about 75% to 80% of people who have myasthenia gravis will actually have abnormal blood studies. So you're left with about a good 20% to 25% of patients who have normal blood studies but who actually have the condition,” Dr. Rodriguez says.
“Their physician, who initially sees them, might say, ‘Well, all your blood tests were normal. I don't know what else to tell you. I don't know what else we can do to figure this out.’ So that's the biggest problem.”
Why do all specialities need to know it?
As a patient moves toward a diagnosis of myasthenia gravis, they may engage with a primary care physician, emergency medicine physician, optometrist, and ophthalmologist before eventually seeing a specialist neurologist.
For this reason, Dr. Kang argues, it is essential for awareness of the condition to be improved across all fields of medicine, not just neurology.
“Diagnostic accuracy can be improved through greater awareness across disciplines, and it has been increasingly recognised by emergency medicine, PCPs, optometrists, and ophthalmologists. They are often the first point of contact, particularly with isolated ocular symptoms,” she says.
“Early recognition and urgent consultation with neurology, particularly those with neuromuscular medicine training, would help improve prompt diagnosis. As serology testing takes some time, I advise PCPs to send a screening serology test (AchR binding antibody) at the time of referral and even consider a trial of pyridostigmine. Ultimately, cross-disciplinary education and streamlined referral pathways are key.”
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