Vertical and horizontal one and a half syndrome with ipsiversive ocular tilt reaction in unilateral rostral mesencephalic infarct: A rare entity

ABSTRACT

Supranuclear ocular movements comprise mainly vertical and horizontal movements. Vertical movements are controlled by the centres located mainly at the rostral midbrain and horizontal movements at the level of the pons.1 Pontine tegmental lesions usually present with gaze palsies, internuclear ophthalmoplegia (INO), abducens palsy and one and a half syndrome. Usually, one and a half syndrome is produced by a unilateral caudal pontine tegmental lesion that includes the paramedian pontine reticular formation (PPRF) and medial longitudinal fasciculus (MLF) on the same side causing horizontal gaze palsy in one eye and INO in the other eye.2 Similarly, vertical one and a half syndrome has also been described. The literature on co-existence of horizontal and vertical one and a half syndrome is few. The co-existence of horizontal and vertical one and a half syndrome with ocular tilt reaction (OTR) has not been reported so far. Here, we report a patient who presented with left horizontal one and a half syndrome along with bilateral conjugate upgaze palsy and right downward palsy suggestive of vertical one and a half syndrome and left ocular tilt reaction. Magnetic resonance imaging (MRI) brain revealed infarct in left rostral midbrain with sparing of pons