Peripheral neuropathy - can normal sensory function resume?


This page is for health-care professionals who see patients who experience a loss of sensation or pain from peripheral neuropathy.

More than 100 types of peripheral neuropathy have been identified, each with its own characteristic set of symptoms and prognosis. Impaired function and symptoms depend on the type of nerves that are damaged.

Current pain-masking medications and interventions provide significant pain relief for many people.

However, these methods seldom restore normal sensory functions impaired or lost to diabetes, chemotherapy or, in some cases, surgery.


What does a return of normal function look like?

PhotoMed’s team sponsored studies to learn which disorders might respond to its new algorithm. Inventing the therapy was the easy part.

Thanks to pain specialist anesthesiologists and neurologists, the studies welcomed patients who experienced treatment-resistant pain and impairments. The outcomes challenged notions across specialties and neuroscience.

We wondered, what’s the problem with impaired functions that unexpectedly become normal?

As skeptical nerdy engineers, we could see the physiological responses in real-time recordings taken by the Instant Feedback System™. Unsurprising, our cold and numb hands innately warm and regain normal sensory abilities after coming indoors.

The warming trends in thermal image recordings appeared to us as “special” only because we knew about the years of malfunction. The response timing and profile suggested to us that a thermostat had been reset. (Lighter gray is warmer.)

WarmingHandsWithChart - Labeled-2400.jpg

The anesthesiologists and neurologists were delighted by their patient’s unexpected improvement. Our neurosurgeon advisor wondered where to look for a thermostat in the brain. One clue, he said, was the bilateral nature of the responses and outcomes.

However, there still was no medical model or hypothesis to explain what might be going on. The studies yielded real-time recordings that were even more puzzling.

Can sensation return while you watch?

You’’ll just have to watch for yourself. We’ll give you the background later.

Clip 1 shows von Frey monofilament testing at 5.1 grams about 6 and 28 minutes after therapy to his right foot began. (0:47)

Clip 1 uncovered something physiologists previously predicted: cortical-map misalignment. They do experiments, such as with mosaic glasses, that scramble the visual contents. Then they remove the mosaic and watch normal vision resume.

George (not his real name) was different. He reported that his feet were numb for the past 8-10 years. Would his cortical representations of touch be scrambled upon its reawakening?

You may be wondering: how can this crazy realignment happen? We don’t know.

+ Read the backstory

George experienced diabetes for 40 years with many complications. He reported that his feet had been numb for 8+ years. He looked at his feet while walking when he arrived at his first visit. Unilateral therapy to his left foot appeared to awaken slight sensation of heavy pressure.

George arrived at his second visit, one week later, looking at the technician. George greeted him with a smile and handshake. George reported that “not much happened” during the week. His wife suggested otherwise. Von Frey monofilament testing found bilaterally improved sensation. But not to a protective level.

The technician requested George to keep his feet still and to NOT look at them until requested. George complied. (Otherwise would have ruined this experiment.) The aim was to avoid cross-sensory feedback.

The camera rolled while George received two 2-minute treatments to his left foot. The time code, added for the advisory team, starts when George began the first treatment to his right foot. Then his right foot received a second 2-minute treatment. Monofilament testing began at about 6 minutes. Therapy and intermittent testing continued until the long-anticipated event arrived at about minute 28.

It’s your turn to speculate: how can the misalignment last so long? PhotoMed’s team would appreciate your sharing your thoughts or questions. Please use the form below.


Clip 2 provides an end-of-the-visit interview, additional testing, and what George thought about what had just happened.

Clip 2 - Interview and testing of George's (not his real name) reawakened sensation in his feet. (1:05)

What might you say to your next patients who experience a profound loss of sensation?

George is only one example of unexpected resumption of normal functions. Link to the disorder list.

Got questions or ideas to share?