Early sign of Myasthenia Gravis is?

NIMHANS Nursing Officer - 2019

Edition 3

Easy

Appeared in: NIMHANS Nursing Officer - 2019

Explanation

Myasthenia Gravis (MG) is an autoimmune disease where antibodies attack acetylcholine receptors at the neuromuscular junction, causing muscle weakness.
The extraocular muscles, which control eye and eyelid movement, are highly active and particularly susceptible, making them the most common site for initial symptoms.
This initial ocular muscle weakness leads to the characteristic early signs of diplopia (double vision) and ptosis (drooping of the eyelids).
Symptoms are often intermittent and worsen with activity and towards the end of the day, which is a key feature of the disease.

Option B: Dystocia is an obstetric term for difficult or obstructed labor during childbirth. It has no connection to the neuromuscular pathology of Myasthenia Gravis.
Option C: Dyspnoea (shortness of breath) is a sign of respiratory muscle weakness. In Myasthenia Gravis, this is a feature of advanced disease or a life-threatening myasthenic crisis, not an early sign.
Option D: Dystonia is a distinct neurological movement disorder characterized by involuntary, sustained muscle contractions causing twisting and repetitive movements. Myasthenia Gravis causes fatigable weakness, not sustained contractions.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Early clinical manifestations of Myasthenia Gravis as background academic context rather than a clinical decision trigger.
Nurses must perform a focused neurological assessment, including checking for ptosis and diplopia, in any patient presenting with unexplained, fluctuating weakness.
A critical nursing responsibility is the timely administration of anticholinesterase medications (e.g., pyridostigmine) to maintain muscle strength and prevent exacerbations.
Patient education should focus on energy conservation techniques, medication adherence, and recognizing signs of a myasthenic crisis.

How to Approach the Question

First, identify the key concepts in the question: "Early sign" and "Myasthenia Gravis".
Recall the basic pathophysiology of Myasthenia Gravis: it is an autoimmune disorder causing fatigable weakness of skeletal muscles.
Remember the typical pattern of disease onset. MG most commonly presents with weakness in the small, highly active muscles of the eyes and eyelids.
Evaluate the options based on this knowledge. Diplopia (double vision) is a direct result of eye muscle weakness.
Eliminate the other options. Dyspnoea (breathing difficulty) involves respiratory muscles and occurs later. Dystocia (difficult labor) and Dystonia (a movement disorder) are unrelated conditions.
Conclude that diplopia is the most fitting early sign among the choices.

Concept Tested & Keywords

Quiq8ODYRG5kaGv9h1w-03

E6 Medicine Davidson Principles Practice 24e p. 1161-1163

E6 Nelson Textbook of Pediatrics(2024) — Volume 2 p. 1665-1667

E6 Ghai Essential Pediatrics(pp 26-904 of 913) p. 613-615