Yes, been tested and research available.
Yes, heavy metals “should” be tested at the very beginning of any search for the cause(s) of neuropathy. But, then, a complete history “should” also be taken. This might point to when and where such an exposure occurred.
As for research, I like to use the medical websites and libraries associated with the National Institutes of Health. Here is one example:
“Toxins can also cause peripheral nerve damage. People who are exposed to heavy metals (arsenic, lead, mercury, thallium), industrial drugs, or environmental toxins frequently develop neuropathy. Certain anticancer drugs, anticonvulsants, antiviral agents, and antibiotics have side effects that can include peripheral nerve damage, thus limiting their long-term use.”
The entire article is here: