UMEM Educational Pearls

Category: Toxicology

Title: Toxin-induced nystagmus

Keywords: nystagmus, toxic (PubMed Search)

Posted: 2/22/2018 by Hong Kim, MD, MPH
Click here to contact Hong Kim, MD, MPH

Abnormal ocular movement (e.g. nystagmus) can often be observed in select CNS pathology.

Certain drugs/toxin overdose can also induce nystagmus.

  • Anti-epileptics: carbamazepine, lamotrigine, topiramate, phenytoin
  • Ethanol
  • Ketamine, phencyclidine (PCP), dextromethorphan – vertical or rotary nystagmus
  • Serotonergic syndrome/5-HT agonists – opsoclonus
  • Monoamine oxidase inhibitors – ping-pong nystagmus
  • Lithium
  • Scorpion envenomation 

In an "unknown" intoxication, physical exam findings such as nystagmus may help narrow the identity of the suspected ingestion/overdose.