[Pseudo abducens palsy]

In this study, we present two cases of different eye movement disorders with variable case histories but with the same end stage; abduction paresis of one of the eyes, which ceased when the other eye was covered. Our differential diagnosis is that either the ocular form of myasthenia gravis, convergence spasm or ocular myotonia could explain the symptoms. However, we hypothesize that the clinical picture corresponds to pseudo abducens palsy or focal dystonia of the extraocular muscle, which in turn could be the result of impaired inhibition of the tonic resting activity of the antagonistic medial rectus muscle. We offer an explanation for the patomechanism of pseudoabducens palsy and the variants of internuclear ophthalmoplegia.