Ophthalmoplegia plus, an electro-oculographic study.

To find out whether the central structures governing conjugate eye movements are affected in ophthalmoplegia plus (OP), we conducted an electro-oculographic study in 6 patients suffering from OP with varying degrees of extraocular involvement and with mitochondrial changes in the skeletal musculature. All the patients presented alterations of the smooth pursuit and saccadic movements, of optokinetic nystagmus as well as of the vestibular reflexes and of visuovestibular interaction, thus confirming impairment of the central oculomotor structures and particularly of those of the archicerebellum and brainstem. These data suggest a supranuclear component in the pathogenesis of ophthalmoplegia and are in accord with the findings of brainstem spongiosis in OP, which in turn seem to express a multisystem pathological state of the mitochondria.