Synkinesia

Q: What is Synkinesia?

Answer: Synkinesia means an involuntary contraction or twitching of part of the musculature upon voluntary movement of the related muscles. It can occur after stroke to any group of muscles but now the term is almost always applied to facial muscles, particularly after Bell's Palsy. This represents a complication of disorganized and misdirected nerve regeneration. Not all patients develop this complication.

Some examples are: 

• twitching of the angle of the mouth when the patient blinks forcefully
• contracture of the orbicular oculi and narrowing of the palpebral fissure with smiling
• a salivary stimulus resulting in excess lacrimation - called syndrome of gustatory tearing or "crocodile tears."
• salivation causes facial sweating

In severe cases, botulinum toxin injections can be applied.

#neurology

References:

1. Guntinas-Lichius O, Prengel J, Cohen O, Mäkitie AA, Vander Poorten V, Ronen O, Shaha A, Ferlito A. Pathogenesis, diagnosis and therapy of facial synkinesis: A systematic review and clinical practice recommendations by the international head and neck scientific group. Front Neurol. 2022 Nov 9;13:1019554. doi: 10.3389/fneur.2022.1019554. PMID: 36438936; PMCID: PMC9682287.

2. Husseman J, Mehta RP. Management of synkinesis. Facial Plast Surg. 2008 May;24(2):242-9. doi: 10.1055/s-2008-1075840. PMID: 18470836.