Acorn November 2000

The other day I was trying to explain to a culinary oriented patient something I had learned at a seminar. It was a new method of treating a variety of conditions using a concoction consisting of local anesthesia and pure alcohol. I told her we might consider sclerosing her corn and I spelled the technique, "s-c-l-e-r-o-s-i-n-g". "Thank goodness you spelled it", she replied. "I thought you said slow roasting."

Sclerosing has had a varied usage in medicine, most notably as a method of treating varicose veins. Injecting a sclerosing solution into such a vein can result in its eventual collapse.

A second use of sclerosing is the treatment of nerve pain. A sclerosing can actually cause the death of nerves, a process called neurolysis (neuro-lie-sis). The destruction of a nerve is appropriate in a number of conditions. Nerves trapped in a scar or an injury can cause extreme pain that can be relieved with sclerosing. Neuromas are swollen nerves often found in the foot. Removing a neuroma at surgery is frequently done when cortisone injections, foot inserts and anti-inflammatory medication fail. Sclerosing (sometimes called alcohol surgery) can be a wonderful alternative to an open hospital surgery. Sclerosing a neuroma can be done in the office with a series of weekly injections that avoids the need to take any time off of work or school.

A final use of sclerosing is the treatment of tiny little seed corns (see picture). Seed corns get their name from the central core that, when picked at and removed, looks like a little seed. Removing the seed, unfortunately, does not remove the corn. They always seem to come back. These tiny corns put pressure on underlying nerves resulting in a tiny local nerve pain. This nerve pain can be blunted with a series of sclerosing injections. Serendipitously the corns frequently flatten, thin and sometimes seem to go away entirely.

Sclerosing corns or nerves requires up to eight weekly injections. Because injections have been given a "surgery code" by insurance companies, it will appear on your bill as a surgery even though you never approached an operating room.

Now you know when your hear me telling you about sclerosing corns, I am not referring to a summer barbecue.

By: Michael Zapf, DPM, MPH, FACFAS, FACFAOM

"Doc, I heard that you can do something about neuromas that will not require me to be off of work. That’s what I want." These were Maria’s initial words to me. Maria was a hair stylist with a neuroma and needed to be on her feet to work.

A neuroma is a thick pinched nerve. In the feet it commonly occurs just behind the third and fourth toes. It is thought to be caused by trauma. In shoes, especially tight shoes, the third and fourth metatarsals rub a foot nerve and caused it to thicken, much like a callous. The thicker the nerve gets the easier it is to pinch it when walking or standing.

Maria’s nerve was initially diagnosed by her internist who treated it with a course of anti-inflammatory medications. When this did little for the pain Maria was sent to a podiatrist. The podiatrist did the standard forms of treatment, including a series of cortisone injections. Cortisone has a bad reputation in some circles. It is, however, a naturally occurring body chemical that can shrink swollen tissues and stop inflammation. For a number of aches and pains of the feet cortisone can be a great treatment. I have seen many people with heel pain, joint arthritis and even neuromas receive long lasting relief with a cortisone injection or two. Maria’s podiatrist gave her three injections of cortisone, but the relief never lasted more than a month. Maria was frustrated with her pain and her doctor recommended that the neuroma be surgically removed.

Neuroma surgery is also common and also very effective. In the surgery about one inch of the nerve is removed. This quickly cures the problem at the expense of creating a little area of numbness between the third and fourth toes. Fortunately this nerve does not control any muscles so there is no loss of function. Like all foot surgeries, however, there will be some time off of work. Maria could not afford to take any time off of work. She wanted another alternative. From one of her clients, Maria heard that I was doing an injection method to treat neuromas.

I told Maria about my sclerosing injections. The word sclerosing is usually applied to injections of varicose leg veins. In vein sclerosing a small amount of an irritating substance in injected into a leg vein and compression is applied to permanently close the veins. One of the chemicals that can cause sclerosing is alcohol. For sclerosing, alcohol is mixed with an anesthetic. Alcohol not only closes veins, but it is toxic to nerves. I take advantage of this fact when I place a tiny quantity of alcohol next to a neuroma. Once a week for 8 weeks I placed a quick injection of 4% alcohol next to Maria’s neuroma. She came between clients and never missed an appointment.

Like 60-70% of my neuroma patients, Maria had complete resolution of her neuroma symptoms. It has been more than two years since the last injection so she seems to have passed the test of time. She successfully avoided neuroma surgery.

Some days are weirder than others and I thought last Wednesday was going to be one for the books. On my daily schedule was a new patient. Her name was Miriam and she said she was coming to see me about a painful aroma. For a podiatrist such feet are sort of an occupational hazard. Fortunately bad cases are few and far between and are easily treated. But Miriam said she had a painful aroma. How bad could it be, I wondered. And what would make it painful? She was scheduled for the afternoon so I just had to wait and see.

When I returned from lunch Miriam was already in a treatment room. As I walked toward the room I did not sense any strange scents. The smoke alarm was quiet. I approached the room and gently opened the door. I was surprised. Sitting in the chair was a demure, pretty young woman. The only thing I could smell was a delightful perfume. She introduced herself and pointed to her toes. "I have a painful naroma", said Miriam with a decided southern drawl. From where she was pointing I surmised that she had, not a naroma, but a neuroma. The afternoon was saved.

I explained that neuromas are as painful as they are common. A nerve that supplies sensation to one of the spaces between the toes gets trapped and hurts. Nerves are similar to an electric cord. In an electric cord, a wire is surrounded by a rubber insulation that protects the wire. Similarly, a nerve is surrounded by an insulating cover called a sheath. The sheath similarly protects the nerve.

This is where the analogy ends. If the wire was caught under the leg of a chair, multiple movements of the chair might cut the wire. If a neuroma is caught between two metatarsal heads, the sheath gets thicker. This whole process is designed to protect the nerve. If the swollen nerve sheath gets too large, the pressure of any part of the foot causes pain. The pain is often described as a sharp needle-like pain at the base of the toes with occasional shooting pains that travel to the tip of the toe.

In short, Miriam has a trapped nerve that is causing pain. It is made worse by shoes that are tight at the ball of the foot, especially elevated heels. This is just the kind of shoe that Miriam needs to wear at work.

A neuroma will either get larger or stay the same size. Without outside help it rarely gets smaller. One possible way to shrink a neuroma is with cortisone. An injection of cortisone can sometimes eliminate the pain by shrinking the thick neuroma sheath.

Should the injections not work, Miriam will be looking at a surgical solution. Neuromas can be removed from the foot in an out-patient surgery performed under local anesthesia. The recovery is rapid with patients returning to tennis shoes within two weeks and leather shoes shortly thereafter. Neuroma removal results in numbness between the toes where once there was pain. The numb sensation seems to decrease after several months.

I explained all this to Miriam and administered her first cortisone injection. I believe she will do well with just an injection or two. I smelled success.