ABSTRACT
PURPOSE: The one-and-a-half syndrome is an eye movement disorder characterized by a unilateral gaze palsy and an ipsilateral internuclear ophthalmoplegia. The authors describe a previously unrecognized association between the one-and-a-half syndrome and oculopalatal myoclonus (OPM). METHODS: Five clinical cases are presented, with pertinent physical findings and radiologic studies. RESULTS: A previously unrecognized association of the one-and-a-half syndrome with subsequent development of OPM appears to exist. Involvement of the facial nerve in patients with the one-and-a-half syndrome may be a predictor of the subsequent development of OPM. CONCLUSION: Patients with the one-and-a-half syndrome and facial nerve palsy should be followed closely for possible future development of OPM.