Lateral gaze disturbance due to cerebral microbleed in the medial lemniscus in the mid-pontine region: a case report.

A 72-year-old man who was attending the outpatients clinic in our hospital because of multiple lacunar cerebral infarctions and mild mental disturbance developed an inability to gaze to the left side voluntarily. MR imaging revealed a new cerebral microbleed in the medial lemniscus of the right side in the mid-pontine region. The finding in this case suggests that the pathways from the frontal eye field descend at least to the level of the mid-pontine region ipsilaterally, and that the pathways then contralaterally decussate and terminate in the paramedian pontine reticular formation. Cerebral microbleeds can be symptomatic depending on the neuro-anatomical structures involved.