| Multiple sclerosis (commonly bilateral) |
| Brainstem infarction (commonly unilateral) |
| Brainstem and fourth ventricle tumors |
| Arnold-Chiari malformation |
| Infection: bacterial, viral, and other forms of meningoencephalitis |
| Hydrocephalus, subdural hematoma, supratentorial arteriovenous malformation |
| Nutritional disorders: Wernicke encephalopathy and pernicious anemia |
| Metabolic disorders: hepatic encephalopathy, maple syrup urine disease, abetalipoproteinemia, Fabry disease |
| Drug intoxications: tricyclic antidepressants, phenothiazines, narcotics, lithium, barbiturates, propranolol |
| Cancer |
| Head trauma |
| Degenerative conditions: progressive supranuclear palsy |
| Syphilis |
| Pseudointernuclear ophthalmoplegia of myasthenia gravis and Miller Fisher syndrome |
