をよそに　vs　顧みず（かえりみず）

Hi everyone,

In an online article, I ran into 顧みず（かえりみず）which I have never seen before previously. So I decided to look up what this particular grammar pattern meant. To my surprise, I found it that it had a very similar meaning to をよそに. I was wondering if anyone knows the difference between the two, whether that may be what context it is used in or how it should be used.

Thanks.

The original meaning of よそ is "other place", so ～をよそに has a nuance of unconcern, and the main clause is always negative/bad things.
顧みる means "to take notice of/pay attention to/think of", and ～を/も顧みず（に） is the adverbial usage of a negative form. The meaning is close to ～をよそに, but positive/good things can follow this expression. That's the main difference.
e.g.
医者の忠告をよそに/顧みず、彼は酒を飲み続けた。
Disregarding the doctor's advice, he kept drinking.

彼は危険も顧みず、海に飛び込んで彼女を救った。(をよそに can't be used here)
Reckless of danger, he jumped into the sea and saved her.

Thank you for the reply, Totoribe. I have understood most of the differences.
However, not being familiar with linguistic terms, I'm not quite sure what the ' adverbial usage of a negative form' means. Could you perhaps explain that point a bit more?

Thanks.

As you might know, ず is a classical negative auxiliary verb, and 顧みず（に） corresponds to 顧みないで "without taking notice of/paying attention to/thinking of" in modern Japanese.