Eight-and-a-half syndrome: a rare presentation of pontine infarction.

"Eight-and-a-half" syndrome is "one-and-a-half" syndrome (conjugated horizontal gaze palsy and internuclear ophthalmoplegia) plus ipsilateral fascicular cranial nerve seventh palsy. This rare condition, particularly when isolated, is caused by circumscribed lesions of the pontine tegmentum involving the abducens nucleus, the ipsilateral medial longitudinal fasciculus, and the adjacent facial colliculus. Its recognition is therefore of considerable diagnostic value. We report a case of a 65-year-old man who presented with eight-and-a-half syndrome in which brain magnetic resonance imaging scan revealed a lacunar pontine infarction.