Perverted head-shaking and positional downbeat nystagmus in pregabalin intoxication.

Dizziness and ataxia are known adverse effects of pregabalin, but characteristic oculomotor signs in pregabalin intoxication have not been reported. Here we describe a patient who displayed perverted head-shaking and positional downbeat nystagmus after prescription of a high dosage of pregabalin. Since pregabalin reduces excitatory neurotransmitter secretion in the central nervous system, decreased excitatory inputs from the brainstem may lead to cerebellar dysfunction, causing perverted head-shaking and positional downbeat nystagmus.