If you have diabetes, chances are you’ve developed a tolerance for the prick of a needle to test your blood sugar. But if you’re among the roughly 5 million Americans who suffer from painful diabetic neuropathy, you’re not likely to get used to the agony.
“People describe it like walking on a bed of nails or feeling like their feet are on fire,’’ said Shai Gozani, chief executive of NeuroMetrix Inc. of Waltham.
Gozani’s company is doing its best to dull the nails and extinguish the flames with a wearable electrical nerve stimulator that just received FDA approval for overnight use this summer. NeuroMetrix’s SENSUS pain management device is a lightweight plastic band that PDN patients can wrap around their calves.
At the push of a single button, the device monitors nerve activity and relieves pain by transmitting electrical impulses through the skin. It has been on the market since the beginning of the year, but the recent green light for nighttime use represents a major breakthrough because a patient’s pain tends to escalate over the course of a day, often peaking around bed time.
The FDA had previously warned against wearing any electrical nerve stimulator to bed because of the risk of burning. A device like NeuroMetrix’s SENSUS transmits electrical impulses through an electrode pad that adheres to a patient’s skin. Spread out across the entire surface of the pad, the impulses bring relief. But if part of the pad becomes dislodged during sleep, leaving only a small portion in contact with skin, the impulses become highly concentrated and can cause damage.
The SENSUS device won FDA approval for overnight use thanks to a feature that detects when an electrode pad is peeling and shuts off stimulation automatically.
So far, NeuroMetrix has sold about 750 stimulators, which require a prescription and are generally covered by insurance. They retail for $300, and the cost of the disposable electrode pads works out to about $1 per day.
Gozani said the device is best used in conjunction with pain medications like Lyrica and Cymbalta, which are often prescribed to treat PDN. For most patients, he explained, a day of diabetic nerve pain could be charted in a jagged sawtooth shape. Medication helps lower every point on the graph, he said, “and what we can do is take the edges off — smooth it out so that you’re not getting spikes during the course of a day.’’