Unusual symptoms of ocular MG in young girl ease after treatment
In children, the disease’s incidence ranges from 3 to 9 cases per million people
A young girl who showed unusual symptoms of ocular myasthenia gravis — persistent upper eyelid droopiness and outward deviation of the right eye — saw her symptoms ease after she received standard treatment, a case report shows.
“This case emphasizes the diverse presentation of MG in ophthalmology, with ocular signs serving as indicators in approximately half of the cases,” the researchers wrote in “Ocular Myasthenia Gravis As Unilateral Ptosis and External Ophthalmoplegia: A Case Report,” which was published in Cureus. They said “emergency physicians should consider MG as a potential cause for unilateral ocular symptoms after excluding [other] causes.”
Myasthenia gravis (MG) is an autoimmune condition caused by autoantibodies that target and attack proteins involved in nerve-muscle communication, most commonly acetylcholine receptors (AChRs), which leads to symptoms of muscle weakness and fatigue.
Ocular MG primarily affects the muscles that control eye and eyelid movements, and symptoms include paralysis of eye muscles, upper eyelid droopiness, or ptosis, and double vision. In children, the disease’s incidence ranges from 3-9.1 cases per million people and occurs mainly in those of Asian ethnicity.
Reaching a diagnosis of ocular MG
Here, researchers described the case of a girl, 4, with a two-year history of right eye ptosis and outward deviation, who was seen at a specialized hospital in Peshawar, Pakistan. The girl had been healthy, but developed the symptoms suddenly after waking up from sleep, according to her father.
She occasionally had fatigue during playtime and reported intermittent body aches and tiredness, but didn’t have shortness of breath or sleep apnea.
At the hospital, she appeared pale and apathetic, with evident unilateral ptosis that was accompanied by outward deviation of her right eye. Her upper limb reflexes were normal, but her lower limb reflexes were weak.
Blood tests showed signs of anemia. Anti-AChR antibodies were also detected in the bloodstream, warranting further tests.
The girl was evaluated for MG and positive findings in the ice pack test, the Cogan’s lid twitch test, and the neostigmine test were indicative of ocular MG. Applying ice or administering neostigmine, a compound that enhances muscle strength, eases ptosis in ocular MG, while the upper lid appears to twitch when suddenly moving upward in the Cogan’s test.
An electromyography revealed a decreased response of individual muscle fibers to stimulation. Brain imaging scans showed no abnormalities.
The girl was diagnosed with ocular MG and started treatment with the muscle strengthener pyridostigmine (sold as Mestinon) and oral steroids. She also received treatment for anemia. After a month, her ptosis was significantly reduced and after three months her eyes were completely straight. The steroids were discontinued, but she remained on pyridostigmine.
The case underscores the need to maintain a high degree of suspicion for diagnosing MG in children to prevent missing cases and minimize morbidity and mortality, the researchers said. “Accurate diagnosis and comprehensive management of MG are complex yet essential for ensuring optimal patient health.”