Physicians should consider a myasthenia gravis diagnosis in patients who exhibit symptoms such as dysphagia (difficulty swallowing), dysphonia (difficulty speaking), palatal weakness, or a feeling that the tongue is swollen, according to a case report.
The case study, “Misdiagnosis of myasthenia gravis presenting with tongue and palatal weakness,” was published in Oxford Medical Case Reports.
Patients with myasthenia gravis (MG) typically present with symptoms that affect the ocular (eye) and respiratory muscles. Sometimes symptoms can be amplified by the presence of stress on the body — such as an infection.
Every so often, MG patients can present with bulbar symptoms, which refer to those that impair speech and swallowing. However, these symptoms only occur in up to 6% of MG patients.
In this case report, physicians present the case of an elderly man who went to the hospital for dysphagia he’d had for six weeks.
The patient also had a feeling that his tongue was swollen for the previous four days. Suspecting an allergic reaction, the general practitioner prescribed epinephrine, which did not improve his symptoms.
The physicians at the hospital noted he had dysphonia with a significant nasal quality to his voice during longer periods of speech.
Additionally, he suffered from tongue weakness and fatigue, which caused him to be unable to elevate his tongue. He also reported a decreased ability to physically move his tongue by the end of his meals.
Physicians initially suspected either amyotrophic lateral sclerosis, cerebrovascular accident, a central nervous system tumor, or cranial polyneuropathy. However, computed tomography (CT) scans and tests did not show evidence of any of these diseases.
After a consultation with a neurologist, bulbar MG (MG that affects the lower cranial nerves) was suspected, and the patient did an anti-acetylcholine receptor antibody test, with a positive result.
He was started on prostigmin (neostigmine) with an initial dose of 60 mg twice a day, with a steady increase to 60 mg three times daily. He was also prescribed 30 mg of oral prednisolone once daily.
Subsequently, the patient reported gradual symptom relief of both dysphonia and dysphagia and was almost symptom-free on discharge one week after diagnosis.
This case is an example of the difficulties physicians sometimes experience in diagnosing MG.
“Although bulbar symptoms such as dysphonia and dysphagia are a well-recognized component of the disease, in isolation they may direct the physician down various routes of neurological investigation,” the authors wrote.
“The sensation of tongue swelling without objective evidence of any anatomical abnormality, combined with palatal weakness and dysphonia should warrant investigation of a local neurological cause such as MG,” they added.