Tensilon test
The tensilon test is used for the pharmacological diagnosis of certain muscle diseases, in particular myasthenia gravis .
Mode of action
Tensilon ( edrophonium chloride ) is an active ingredient that is one of the short-acting cholinesterase inhibitors . If the cholinesterase is inhibited, this leads to an increase in the acetylcholine concentration , e.g. B. in the synaptic gap of the neuromuscular endplate . This allows nerve signals to be transmitted more clearly to the muscle .
Myasthenia gravis
In myasthenia gravis , the transmission of nerve signals to the muscle is disturbed and quickly becomes weaker with repeated movement stimuli. If, for example, a patient with myasthenia gravis is allowed to open and close the eyes approx. 20-30 times, the eyelid lifter becomes weaker and weaker and the upper eyelids droop ( ptosis ). If Tensilon is administered intravenously to the patient , the transmission of nerve signals from the nerve endings to the muscle is strengthened. If you open and close your eyes again 20-30 times you can see a clear improvement in ptosis; the tensilon test is positive. Another way of doing this is to let the patient look up for a long time without lifting his head ( Simpson test ). In the positive case, fatigue-related, slow lowering of the upper eyelid results, which can no longer be detected after the administration of Tensilon.
If the tensilon test is used on a patient with suspected myasthenia gravis and the result is positive, the presence of myasthenia is likely. However, other muscle diseases can be excluded from the differential diagnosis. For example, a tensilon test B. also be positive in Lambert-Eaton syndrome .
Tensilon is not suitable for treating myasthenia due to its undesirable effects in numerous other parts of the body ( asthma attack , bradycardia ). Caution should also be exercised in patients with certain pre-existing conditions, e.g. B. in cardiovascular diseases .
literature
- Th. Axenfeld (conception), H. Pau (ed.): Textbook and atlas of ophthalmology. With the collaboration of R. Sachsenweger et al., Stuttgart: Gustav Fischer Verlag, 1980, ISBN 3-437-00255-4
