-- a lot of this, for Alan, may depend on several factors.

I imagine the cryosurgery has a much better chance of success in cases where it can be demonstrably proven that a particular large nerve is the symptom culprit, such as it would be in Morton's neuroma, in which the neuroma is obviously growing from a particular nerve.

It would have to be one of the larger, myelinated nerves for it to work even in this case, though. And that's where the caveat comes in. If Alan could be proven to have neuropathy due to a specific compression of one fairly large nerve somehwere in the foot leading to the toe area, then cryosurgery would have the chance of zapping that nerve and getting rid of the symptoms.

But, I suspect that more is involved with him than that; that he does have some systemic autoimmune issues (and, of course, he has psoraisis) that are contributing to his condition.

Moreover, it's likely that at least some of his really small unmyelinated fibers are affected, and those would be too small to find and zap accurately with the currently available instruments.

Now, it is true that he may get good symptom relief from things that release compression from the area--Dr. T's manipulations, your toe spreaders and sponge creations--because of the double crush phenomenon. This is the idea that people with damage to nerves from other, systemic causes are more likely to get increased or new symptoms from compressive forces on the nerves than "neuronormals"; increased compression has a much greater affect on already "damaged" nerves, and even if these nerves were not very symptomatic before, the additional compressive forces may trip them over.
This phenomenon in well documented in diabetics, who suffer far more from compressive carpal and tarsal tunnel than "neuronormal" groups. Many of us here, of course, myself among them, have reported being more prone to pressure palsies and other compessive nerve effects after our neuropathies began than we ever were before. I even wonder, for instance, if your own situation may be exacerbating your sciatica more than it otherwise would be--you could have some sciatic damage traceable to your diabetes, and feel symptoms more often from the pressure there than you would if you didn't have the condition.

This, of course, is another strong argument for controlling blood sugar and taking B12 and other neuroprotective and neurobuilding supplements.

It wold be interesting, if Alan is seen by this doctor, and you give said doc all of Alan's medical history, how he would interpret the chances of the surgery. My supposition is that if Alan had a mono- or multiple mononeuropathy down there directly traceable to compression and no other cause, he'd be a better candidate--given the autoimmune history and the probability of systemic invovlement, it'd be much harder to assume success from the procedure.