Diabetic neuropathy: a question and an answer

One of the readers of my blog emailed me this query. A very good question and I wanted to reproduce it here, my answer follows.

Bree Johnson on November 28, 2008 said: Edit Link

I am very confused about whether I have diabetic neuropathy or not. I have been a diabetic for 21 years. A podiatrist confiremd recently that I have VERY good sensation in the feet & there is no evidence of neuropathy. I do not experience any numbness, pins & needles as such but I do have signficant pain at times in the my feet. The pain is largely due to a heightenend sensitivity at skin level. For example having things brush against my skin is unbearable, or putting on my shoes is also uncomfortable or walking on rough surfaces. But applying direct pressure on my feet – as in reflexology – is not painful. The podiatrist could not explain what this heightened sensitivity is due to.

I am however prone to occasional bouts of deep aching pain the feet & legs – which seems to always be the case now when I am a bit rundown & tired.

I also do have electrical type of stabbing pains that come & go – they can be quite painful stabs. Again they seem to be apparent only when rundown & tired.

Can you please offer any comments on the above? It would be greatly appreciated.

Bree

Dear Bree,

Thank you for writing in. You ask a very good question and that is what I shall attempt to answer. First at the onset let me tell you that most diabetics (especially those who have had long standing diabetes, in your case for over 21 years) shall have clinical evidence of diabetic neuropathy if one subjects them to a thorough clinical examination and electrodiagnostic testing (we use tests like nerve conduction velocities (NCV) and electromyogram (EMG) to unearth evidence of nerve damage/ neuropathy).  

Diabetes can cause different kinds of neuropathies depending upon what kind of nerves are preferentially involved:

(large nerves that carry sensations like joint sense and vibration versus smaller nerves that carry sensations of crude touch, pain and temperature)

(motor nerves that help in moving muscles and joints versus sensory nerves which carry sensation)

THE MOST COMMON NEUROPATHY THOUGH IN DIABETES IS A MIXED MOTOR SENSORY POLYNEUROPATHY WHICH USUALLY INVOLVES THE SMALL NERVES WHICH CARRY SENSATIONS LIKE PAIN, CRUDE TOUCH AND TEMPERATURE. MEANING THAT AT LEAST INITIALLY IN THE DISEASE COURSE THE MOTOR NERVES AND THE LARGE SENSORY NERVES (CARRY SENSATIONS OF VIBATION, JOINT SENSE AND POSITION SENSE) MAY BE SPARED OR AT LEAST WE DO NOT SEE EVIDENCE OF THEIR DEGENERATION ON NERVE CONDUCTION TESTING.

Patients who have small nerve fiber involvement commonly have what we refer to as allodynia and hyperpathia. What is allodynia you may ask?

Well allodynia is when a normally non-painful stimulus becomes painful. Let me explain with the aid of an example. You are lying in the bed, settling down to sleep. You pull the sheets over your bare legs. The sheets touch your legs, now they are silk sheets that is not a painful stimulus. But a patient with diabetic neuropathy may find it excruciatingly painful. THERE THAT IS ALLODYNIA.

They also have hyperpathia. What is hyperpathia? Well lets take another example. I take a pin and stab you with it. Now that is a painful stimulus and everyone shall find it so.  A normal person may say “ouch”, a patient with diabetic neuropathy though may jump out of his seat. SO HYPERPATHIA IS WHEN YOU FEEL A GREATLY EXAGGERATED PAIN SENSATION TO A PAINFUL STIMULI.

So in conclusion, it is more that likely that you have diabetic neuropathy. My advise to you would be to see a neurologist. If you do indeed have diabetic neuropathy, there are many good medicines out there that can treat the pain and more over prevent the progression of this painful and disabling condition.

Personal Regards,

Nitin Sethi, MD

Diabetic neuropathy: how to deal with it

In this post lets discuss about diabetic neuropathy. Diabetes is one of the most common causes of neuropathy. Neuropathy is a general term which refers to any condition which involves the nerves of the body. Diabetes involves the peripheral nerves of the body and can also involve the cranial nerves. The damage to the peripheral nerves is thought to be mediated by the increased levels of glucose and other metabolic factors in diabetic patients.

As I have stated in my earlier posts (see by my website http://braindiseases.info) neuropathies can be of different types. One may have a motor neuropathy in which only the motor nerves of the body are involved (hence patients present with weakness), one may have a predominantly sensory neuropathy in which the sensory nerves of the body are involved ( patients present with sensory complaints of numbness, tingling, pins and needles sensation) or one have a mixed sensory motor neuropathy (patients have a combination of motor and sensory findings in varying proportion).

Diabetes usually causes a mixed sensory motor neuropathy.

Clinical presentation: So how do patients with diabetic neuropathy present clinically? Well most patients seek medical help when they are bothered by dysesthesias (dysesthesias refers to uncomfortable sensations like feeling a part of the body usually the feet and hands are numb or “dead”, patients may also complain of feeling pins and needles sensation, tingling, burning etc). Patients with diabetic neuropathy have allodynia ( a condition in which a non-painful stimulus feels painful. Let me explain with an example. Suppose I touch your feet with a feather, you are not going to feel that as a painful stimulus. Now if I do the same to a patient with diabetic neuropathy, he may perceive that as a painful stimulus). They also have hyperpathia ( a condition in which the patient experiences a greatly exaggerated pain sensation to painful stimuli. Let me explain this with an  example. I touch the same diabetic patient’s leg with a sharp pin. Now any healthy person shall perceive this as a painful stimuli but to a patient with diabetic neuropathy, the pain may be so intense that it might be unbearable).

We sometimes divide these sensations experienced by patients with neuropathy into positive and negative symptoms.

Postitive symptoms include sensations of burning, pins and needles, pain etc while negative symptoms include sensations of feeling a part is numb or “dead”. It is easier to treat and control the positive symptoms while negative symptoms are more hard to treat.

The neuropathy in diabetes is length dependent (by that I mean, the longest nerves are the first to get involved). Hence symptoms first start in the feet (numbness in the toes etc and then proceed upwards. As the neuropathy progresses patients complain of numbness in the feet, then ankles, then shin, finger tips and so on).

Diagnosis of diabetic neuropathy: so now we come to the question of how do we diagnose diabetic neuropathy. The diagnosis of neuropathy is mostly clinical. If you are a diabetic patient presenting to a neurologist with compliants of numbness and tingling in the hands and feet, the diagnosis is readily apparent. Your doctor may test with with a tuning fork (to dtermine how well you perceive vibration), a disposable pin (pain sensation) and shall be able to determine if you clinically have an evidence of neuropathy or not. If the diagnosis is not apparent, he may order other tests like a Nerve Conduction Velocity test (we call this a NCV). During a NCV study, we check for the conduction of a nerve and whether it is delayed or not (this is done by giving a short electrical stimulus and then recording the response as it travels down the length of the nerve. As we are applying a short electrical current as stimulus, patients at times are not very comfortable during the test. The NCV study also helps in grading the severity of the neuropathy and helps in following the response to treatment.

Management of diabetic neuropathy: the management of diabetic neuropathy is twofold. One is the treatment of the underlying disease process (in this case the diabetes which is the cause of the neuropathy in the first case) and the other is the treatment of the neuropathy itself (how to control its symptoms so patients are not bothered by the sensations of numbness, tingling etc).

First and foremost in the managment of diabetic neuropathy, one should ensure good control of the blood sugar. Studies have shown that neuropathy develops in those diabetics who have uncontrolled or poorly controlled blood sugars. Hence aiming for euglycemia is essential (euglycemia means normal or near normal blood sugars). There are oral medications as well as insulin which can be used to achieve euglycemia and your doctor shall guide you in this. It is also essential to follow the blood sugars on a periodic basis so that one is sure that the blood sugar is well controlled.

There are many medications available to treat neuropathic symptoms. Some anti-depressants and anti-convulsants group of drugs are used for this purpose. The role of complimentary therapies like acupuncture, acupressure is not clearly determined as there are not many scientific studies to determine whether these are truly beneficial.

Patients should be advised about the importance of skin and foot care. Patients with diabetic neuropathy are prone to ulcers and infections in the foot, hence the feet should be kept clean and dry, avoid wearing ill fitting shoes and always always do wear clean pair of socks.

I hope this is useful to some of you.

Personal Regards,

Nitin Sethi, MD

Neuropathy presenting features

Neuropathy presenting features

So what are the signs and symptoms of someone with a neuropathic condition:

Sensory neuropathies present with the following signs and symptoms:

1) Numbness in the arms or legs ( a clue to neuropathy is that the signs and symptoms are usually symmetrical and start distally. For example the patient may complain of numbness in both legs or hands initially in the toes and the fingertips. As the disease progresses this numbness also moves more proximally reaching to the ankles, shin and the arms).

The patient may not complain of numbess rather may use words like ” my legs feel dead” or “my hands burn” to describe his symtoms.

2) Pins and needles sensation in the arms and legs: people with neuropathy have what doctors call paresthesias or abnormal sensations.  They may complain of feeling pins and needles , electric shocks or at times as if their skin is been touched with a feather.

They have allodynia (a non-noxious stimuli feels noxious meaning that if I touch you with a feather you may feel as if I am boring a sharp pin into your skin) and hyperalgesia (meaning that they have an increased sensitivity to pain).

3) Patients with neuropathy may present with skin changes. This is most commonly noted on the skin overlying the shin and feet. The skin is shiny and atrophic, the overlying hair are sparse or completely lost. At times people may develop non-healing ulcers of the feet which may get infected and even gangrenous. This condition is commonly seen in diabetic patients with severe neuropathy (diabetic foot).

4) If a patient has a large fiber neuropathy, he may complain of difficulty with balance especially at night or when his eyes are closed. They feel as if they are walking on cotton wool.

5) Patients may present with ulcers or burns in their hands: this is because as they are not able to detect the sensations of heat etc they may touch something hot like a gas stove and get burnt.

 

 

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