Most LOST electromyographic (EMG) studies of paradoxical synkineses between the eye or jaw movement and upper eyelid movement have concerned primarily the synkinetic excitation of levator neurons and the resulting lid retraction. A neglected, but equally important, physiologic aspect of these congenital anomalies of levator innervation is the mechanism underlying the ptosis which is usually associated with them. Commonly dismissed as partial paresis, this ptosis represents a congenital disorder of brain stem cells and inhibitory mechanisms affecting levator neurons.
This report presents clinical and electromyographic evidence of anomalous inhibition in a 74-year-old man whose right lid would fall during ipsilateral ocular adduction or elevation (synkinetic levator inhibition), and whose upper lids would retract, together or alternately, during various jaw movements (synkinetic levator excitation, the Marcus Gunn synkinesis).
Report of a Case
A 74-year-old white man examined at the University of California Medical Center (San Francisco) for mild symptoms of
Hepler RS, Hoyt WF, Loeffler JD. Paradoxical Synkinetic Levator Inhibition and ExcitationAn Electromyographic Study of Unilate Oculopalpebral and Bilateral Mandibulopalpebral (Marcus Gunn) Synkineses in a 74-Year-Old Man. Arch Neurol. 1968;18(4):416–424. doi:10.1001/archneur.1968.00470340102009