visual system the physician identifies the cribriform plate 23 this is a relatively small region roughly the size of a dime or less than 2 cm in diameter through which all olfactory nerves pass a needle is then inserted through the olfactory mucous membrane and into the tissue in this region 24 the needle may be passed through a port in the endoscope a needle may be passed into the nasal cavity in another way a neurotoxin such as phenol or zinc sulfate is injected 25 through the needle into the tissue phenol and zinc sulfate are known neurotoxins with known dosages for their efficacious use when properly used they will desiccate or effectively destroy the targeted nerves but they do not have unintended physiological side effects multiple injections can be quickly made throughout the region if necessary to confidently ablate or interrupt the path of all of the olfactory nerves with the olfactory ablation the patient experiences a cessation in his or her sense of smell a lack of smell has been found to result in a reduced desire to eat combined with a motivation to eat less a patient may be more successful in dieting the physician should regularly monitor the patient over the subsequent months 26 as the patient establishes new eating habits without a sense of smell the patient may experience a.