Joe,

I was motivated to check my L-serine levels by a study that I read about Hereditary Sensory and Autonomic Neuropathy (HSAN). This neuropathy presents like a small fiber neuropathy so it got me interested. I ran across a term that i had never seen before: Deoxysphingolipid. I googled the term and it was pretty illuminating.

Researchers have found that these neurotoxic lipids induce mitochondrial dysfunction which has been strongly associated with small fiber neuropathy
(Localization of 1-deoxysphingolipids to mitochondria induces mitochondrial dysfunction. - PubMed - NCBI)

Researchers have found highly elevated levels of these lipids in diabetic neuropathy, HSAN, paclitaxel neuropathy, neuropathy associated with mitochondrial disease and neuropathy associated with metabolic syndrome.

HSAN and paclitaxel neuropathy
(Neurotoxic 1-deoxysphingolipids and paclitaxel-induced peripheral neuropathy)

diabetic neuropathy (Lowering Plasma 1-Deoxysphingolipids Improves Neuropathy in Diabetic Rats | Diabetes)

All of these neuropathies had similar symptoms to mine (small fiber dysfunction) so I went to an online blood test site Order Any Lab Test or Blood Tests Online | Walk-In Lab and ordered an Amino Acid Blood Test. I took the test and found that my L-serine levels were lower than normal. After doing some checking, I realized that the ratio that I had was similar to a person who had Diabetes.

Neurotoxic Deoxysphingolipids are produced by an imbalance in the L-serine to L-alanine ratio.
(L-Serine Deficiency Elicits Intracellular Accumulation of Cytotoxic Deoxysphingolipids and Lipid Body Formation. - PubMed - NCBI)

L-Serine supplementation has been shown to help neuropathy
https://www.thieme-connect.com/produ...s-0034-1375013


I started to supplement to correct the ratio and I started tingling like crazy everywhere that I had neuropathy. Tingling can be a sign of nerve regeneration ( Tinel's sign ). I also noticed an increasing level of sensation in my feet, hands, and legs (touch and thermal). My finger tips also wrinkle more when exposed to water ( autonomic nerve fiber function). I also noticed less allodynia at my wrists. It took about week for the tingling to happen and a couple of months to notice some sensation differences.

In addition, I am using oxybutynin which is a M1R antagonist that has been shown to improve small nerve function: https://diabetes.diabetesjournals.or...lement_1/58-OR

FYI, I tried to talk about this to a neurologist and he had no idea what the hell I was talking about. I showed him the studies but he never followed up and read them. Unfortunately, the idiopathic neuropathy patient is pretty much orphaned by the Neurology field. There is little money for research, big pharma is just interested in pain management drugs (gabapentin, Lyrica, VX-150) so they can make profits, and the technology to identify things like new autoantibodies and metabolic waste like deoxysphingolipids is just coming into it's own. The research by Winsantor for nerve regeneration though gives me hope as does the new generation of sodium channel drugs that will come onto the market.

Wow thanks for all the links and info MH - there's definitely a lot to digest there and I plan to read all of it and prob order the genetic test also. I just can't accept that there's no explanation/ no diagnosis/ no real treatment. Keep me posted on your treatment/ progress. I am definitely interested!