II. Indications
- Ptosis evaluation in suspected Myasthenia Gravis
III. Contraindications
- Elderly
- Coronary Artery Disease
- Asthma
IV. Adverse Effects
- Increased Salivation
- Abdominal cramping
- Bradycardia
- Syncope
- Bronchospasm
V. Mechanism
- Edrophonium (Tensilon) is a rapid onset, short acting Acetylcholinesterase Inhibitor
VI. Preparation
- Perform with telemetry monitoring
- Atropine 0.5 mg IV prn Symptomatic Bradycardia
VII. Technique
- Edrophonium (10 mg/ml) 1 ml is drawn into a 1 cc syringe (tuberculin syringe)
- Inject edrophonium 2 mg (0.2 cc) IV every minute up to cummulative dose of 10 mg
- Stop when improvement in Ptosis is observed or 10 mg is reached (typically at 4-6 mg or 0.4 to 0.6 cc)
VIII. Interpretation
- Ptosis improvement with edrophonium is suggestive of Myasthenia Gravis
IX. Efficacy
- Test Sensitivity: 80-90%
-
False Positives
- Motor Neuron disorders
- Brainstem tumor
- Compressive cranial Neuropathy