Medical Interventions for Bell’s Palsy
Steroids, such as prednisone, prednisolone, and methylprednisolone, work by reducing the inflammatory reaction of the body, since it is felt that the inflammatory reaction can be more harmful than the disease process itself.
Antiviral medications, such as valacyclovir, have been shown to provide a benefit in Bell’s palsy. They work by inhibiting viral replication, and the fact that they show a small improvement in recovery from Bell’s palsy gives strength to the argument that viral infection plays a role in the disease.
In cases where selected muscles of the face are overactive, clenched, or “hypertonic”, one way to achieve more facial balance is to intentionally weaken the selected muscles. Botulinum, a substance produced by the bacterium Clostridium Botulinum, has the ability to temporarily paralyze muscles into which it is injected. It works by blocking the release of neurotransmitters from the nerve fibers to the muscle cells, which are responsible for triggering muscle action. The botulinum is selectively injected only into the areas that are overactive, and begins working within several days. It is an extremely effective therapy for facial synkinesis, spasm, and contracture. It is also used to weaken the normal side of the face in facial paralysis, providing more symmetry to the two sides.
The effects of botulinum administration last for a period of three to six months. This can be advantageous for patients that do not like the achieved results because it is not permanent. The drawback is that if the effect achieved is desirable, the therapy needs to be repeated on a semi-annual basis. The development of antibodies to botulinum toxin can occur, though it is rare. This results in a loss of effectiveness in this subgroup of patients.
Sometimes, botulinum therapy is utilized to see what the effect of selective myectomy would be. If the effect is acceptable, myectomy (excision or weakening of a muscle) can be performed in selected situations to achieve the permanent result.