In a study, a single low dose of EPO improved symptoms in 1 patient out of 2. The improvement was of 80% and lasted for 6 months and more.

You can find it here :
http://www.doctorellis.com/Lecture.html

But epo is a little dangerous for those who have vein/arterial compression.

So i have found this, but i don't know what to think about it yet :

Docosahexaenoic acid and arachidonic acid are fundamental supplements for the induction of neuronal differentiation
http://www.jlr.org/content/48/3/513

Basically they say :

When you eat DHA, the level of AA decrease. But when you add AA to DHA supplementation, it induce neuronale differentiation.

"However, supplementation with both DHA and AA yielded a fatty acid profile resembling that of neural tissue. It also resulted in enhanced outgrowth of neurite-like processes, hallmarks of neuronal differentiation. "

AA : http://en.wikipedia.org/wiki/Arachidonic_acid
DHA : http://en.wikipedia.org/wiki/Docosahexaenoic_acid

So the article suggest that AA+DHA may be as good as EPO for toser.



Other links about dha/aa and neuronal differentiation :

Docosahexaenoic acid promotes neuronal differentiation by regulating basic helix-loop-helix transcription factors and cell cycle in neural stem cells.
http://www.ncbi.nlm.nih.gov/pubmed/19272428

Distinctive effects of arachidonic acid and docosahexaenoic acid on neural stem /progenitor cells
http://onlinelibrary.wiley.com/doi/1...1.01527.x/full