Olney's lesions

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Olney's Lesions, also known as NMDA Antagonist Neurotoxicity (NAN), are a form of brain damage caused by high doses of dissociative anaesthetics.

Animal testing conducted by J.W. Olney evidences the post-dissociative development of tiny holes, or lesions, primarily in the posterior cingulate cortex and retrosplenial cortex regions of the brain. The dissociatives were also antecedents of other forms of brain damage in the test subjects.

In 1998, researcher William E. White published an article, ["This Is Your Brain On Dissociatives], warning of a possible correlation between high doses of dissociatives and brain damage in humans. His statements were refuted in 2003 by researcher Cliff Anderson and [retracted] in 2004.

Anderson's article, ["The Bad News Isn't In"], quotes J.W. Olney and colleague Nuri B. Farber on the subject:

"The evidence is that ketamine and many other NMDA antagonists that have been tested in humans, cause an acute disturbance in neural circuitry that leads to psychotic manifestations. These same drugs cause the same disturbance in neural circuitry in rats and when we look at their brains we see evidence for physical neuronal injury. Since no one has looked at the brains of humans immediately after administering these drugs, we do not know whether the physical neuronal injury occurs." --J.W. Olney, 28 January 2002

"The quick and easy answer is that we do not know. The reason is that one cannot study the brain of a human in an adequate fashion after exposure to a NMDA antagonist. Since there are no data on humans, I do not see how anybody can be "certain" one way or another. Based on the totality of the evidence I have concerns that NAN can occur in the human brain." --Nuri B. Farber, 15 April 2002

Olney's Lesions have not yet been proven to manifest in humans.

Dissociatives

External links

[Erowid.org: DXM Vault]
[Erowid.org: This Is Your Brain On Dissociatives]
[Erowid.org: The Bad News Isn't In]

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