Abstract
The one-and-a-half syndrome is characterised by a lateral gaze palsy in one direction and internuclear ophthalmoplegia in the other. It is due to a unilateral lesion of the dorsal pontine tegmentum, involving the ipsilateral paramedian pontine reticular formation, internuclear fibres of the ipsilateral medical longitudinal fasciculus and, usually, the abducens nucleus. The main causes of this rare syndrome are stroke and multiple sclerosis. Few cases have been reported since the introduction of MRI. Our aim was to examine clinicoradiological correlations in six patients with a one-and-a-half syndrome due to a stroke. Ophthalmological symptoms were diplopia, oscillopsia or blurred vision. Four patients had an associated facial nerve palsy, three a hemiparesis and one a unilateral hemihypoaesthesia. MRI revealed an infarct in the pons in all patients. The cause of the infarct was a basilar artery dissection in one patient, bilateral vertebral artery dissection in a second and unknown in the other four. All patients recovered within 2 days to 8 weeks. This study showed a good correlation between the site of the lesion (superior, inferior or extensive pontine ischaemia) and clinical deficits.
Similar content being viewed by others
Author information
Authors and Affiliations
Additional information
Received: 26 May 1998 Accepted: 5 January 1999
Rights and permissions
About this article
Cite this article
de Seze, J., Lucas, C., Leclerc, X. et al. One-and-a-half syndrome in pontine infarcts: MRI correlates. Neuroradiology 41, 666–669 (1999). https://doi.org/10.1007/s002340050821
Issue Date:
DOI: https://doi.org/10.1007/s002340050821