Quiz Form

Question Date: 22/09/2023

Question: Which of these statements is true regarding MuSK myasthenia gravis?

Options:

• Musk myasthenia responds to cholinesterase inhibitors
• Wasting of tongue muscles may be seen
• Eculizumab is the most effective therapy for MuSK myasthenia
• It is more often associated with thymoma

Correct Answer: Wasting of tongue muscles may be seen

Explaination: MuSK myasthenia comprises 50 % of generalized seronegative myasthenia gravis and shows a female predilection. Severe weakness and wasting of facial and bulbar muscles, including tongue may be seen. Patients with neck, shoulder and respiratory weakness may mimic a myopathy. Electrophysiology may show myopathic changes in weak muscles. Many patients do not respond to cholinesterase inhibitors, some worsen and show fasciculations. There are no thymic changes and thymectomy is not considered beneficial. MuSK antibody belongs to Ig G4 class and do not bind complement. Hence Eculizumab may not be useful.

Reference: Rodolico C et al. MuSK-associated Myasthenia Gravis Clinical features and management. Front. Neurol. 2020