When comparing BEB to Myokymia, which statement is NOT true?

When comparing BEB to Myokymia, which statement is NOT true?

• A. Myokymia is typically caused by caffeine and stress
• B. BEB affects the Orbicularis oculi, Procerus, and Corrugator
• C. BEB is typically bilateral in nature
• D. Myokymia usually only affects the Corrugator muscles

Answer: (D)

Understanding these conditions hinges on how eyelid muscles are affected and the pattern of involvement. Myokymia is a benign, usually transient quivering of the eyelid caused by spontaneous activity in the eyelid muscles, most often the orbicularis oculi. It is commonly linked to caffeine, stress, or fatigue and is typically unilateral rather than spreading to multiple muscles. In contrast, benign essential blepharospasm is a dystonia of the eyelid muscles that commonly involves several muscles around the eye — the orbicularis oculi, procerus, and corrugator — and is typically bilateral, often more sustained and functionally limiting. Therefore, saying that myokymia usually only affects the Corrugator is not true, since the primary muscle affected is usually the orbicularis oculi and the condition is not restricted to the corrugator.

Understanding these conditions hinges on how eyelid muscles are affected and the pattern of involvement. Myokymia is a benign, usually transient quivering of the eyelid caused by spontaneous activity in the eyelid muscles, most often the orbicularis oculi. It is commonly linked to caffeine, stress, or fatigue and is typically unilateral rather than spreading to multiple muscles. In contrast, benign essential blepharospasm is a dystonia of the eyelid muscles that commonly involves several muscles around the eye — the orbicularis oculi, procerus, and corrugator — and is typically bilateral, often more sustained and functionally limiting. Therefore, saying that myokymia usually only affects the Corrugator is not true, since the primary muscle affected is usually the orbicularis oculi and the condition is not restricted to the corrugator.