One-and-a-half syndrome, type II: A case with rostral brain stem infarction

Celebisoy N. , AKYUREKLI O.

NEURO-OPHTHALMOLOGY, vol.16, no.6, pp.373-377, 1996 (Journal Indexed in SCI) identifier identifier

  • Publication Type: Article / Article
  • Volume: 16 Issue: 6
  • Publication Date: 1996
  • Title of Journal : NEURO-OPHTHALMOLOGY
  • Page Numbers: pp.373-377


This article is about a patient who suddenly developed a right hemiparesis and stupor. Her neuro-ophthalmological examination revealed a left-sided ptosis and a combined vertical gaze palsy in addition to right esotropia, right conjugate gaze palsy, and abduction paralysis of the left eye on attempted gaze to the left with adduction nystagmus of the right eye. The horizontal eye movement disorder was similar to that in one-and-a-half syndrome, except for an abduction paralysis and an adduction nystagmus. MRI showed a rostral brain stem infarction on the left side. Left-sided ptosis and adduction paralysis were attributed to a left oculomotor fascicular involvement in the presence of a right hemiparesis. Right-sided esotropia and abduction paresis were consistent with a 'pseudo-abducens palsy', which has been reported in thalamo-mesencephalic lesions. Combined vertical gaze palsy is a classical finding of rostral brain stem infarction. Left-sided abduction paralysis with adduction nystagmus on the right side on attempted gaze to the left is thought to be due to involvement of the para-MLF on the left side and is called internuclear ophthalmoplegia of abduction (INO-abd). To our knowledge, this type of horizontal eye movement disorder has never been reported before with rostral brain stem infarction.