Objective: Although gait ataxia is usually associated with cerebellar lesions, we review a less familiar cause. We present three patients with dorsal midbrain lesions and correlate these presentations with recent findings in the functional anatomy of the midbrain.
Conclusion: We suggest that these lesions involve a well-studied but generally unfamiliar area of the dorsal midbrain known as the mesencephalic locomotor region. More specifically, we hypothesize that involvement of the pedunculopontine nucleus, a major component of the mesencephalic locomotor region, may be at least partially responsible for producing midbrain ataxia.