Are all Blepharospasms the same?
BSP can vary from one patient to another and also change overtime after few sessions of Botulinum toxin injections.In daily life, we can close our eyes in different ways; for instance when we are in the shower and we get shampoo into our eyes (by the way I am not sure that shampoo are still stinging), we spontaneously frown, screw and close our eyes very tight. On the other hand when we go to sleep, we pulled down very gently our eyelids, which feel heavy. In case of a patient with BSP, there is the same diversity; the eyes can closed very tight with a forceful spasm of or closed with only the eyelids pulling down, despite sometimes one finger trying to hold it up.
The orbicularis oculi muscle which is the muscle responsible of closing the eyes are organized in 3 circular parts: an inner circle (the pretarsal part responsible of the eyelid going down), a middle circle (the preseptal part) and an external circle (the orbital part); these 3 parts can contract independently.In the situation of the shampoo in the eyes, it’s the orbital part, which is contracting. When sleeping, it‘s only the pretarsal portion of the orbicularis oculi, which is involved, pulling down the eyelid.
When treating the patient with injection of Botulinum toxin, the sites of the injections have to be placed in the right portion of the orbicularis oculi muscle depending of the type of BSP. The treatment needs to be customized for each individual, not very far from the world of the haute couture!