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:

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

Ginkgo biloba for memory-a dream that did not materalize

Just a quick post about Ginkgo biloba. Some of my patients use Ginkgo biloba extract as a supplement to enhance memory and prevent neurodegenerative conditions like Alzhemier’s dementia. The data that it is indeed effective has always been inconclusive. I always feel that if  a drug is truly effective for a condition then we seldom need studies to prove it. It is only when the evidence is insufficient to suport a recommendation that studies are needed. Many of these are funded by the drug manufacturer (large pharmaceutical companies).

Recently results were made available from a big study looking at whether Ginkgo biloba extract actually aided in preventing Alzheimer’s dementia. The study found that Ginkgo biloba did not prevent or delay dementia or Alzhemier’s disease. In simple words, the study showed that it does not work. Further there is some data to show that it may actually be dangerous to take this extract as it increases the risk of hemorrhagic strokes (bleeding in the brain).

My advise to my readers would be to avoid taking this supplement till we have more conclusive data on its effectiveness. Especially avoid taking supratherapeutic doses (large doses).

 

Nitin Sethi, MD

Non epileptic seizures or pseudoseizures

Non epileptic seizures or pseudoseizures-what are they and what is to be done about them?

Nitin K Sethi, MD

Assistant Professor of Neurology

New York-Presbyterian Hospital

Weill Cornell Medical Center

New York, NY

I thought in this post of mine, I shall discuss pseudoseizures. As the name suggests pseudoseizures means “not true seizures”. We nowdays prefer to refer to them as non-epileptic events (NEE).

So what do we mean when we say someone has pseudoseizures? Let me illustrate with the aid of an example. A patient lets say Ms.XYZ comes to me for initial consultation for her seizure disorder. History is as follows. She has had 2 episodes where-in she was witnessed to have violent jerking movements of her arms and legs. First episode occurred in school after she got into a heated verbal argument with her best friend while the second occurred after a similar confrontation at home with her mother. None of these events were preceded by any aura. As per history she did not bite her tongue or have loss of bladder control though she says she felt tired after the events.

Hmm sounds suspicious for seizures you might rightly say. I tell her I would like to bring her into the hospital to do a video-EEG study to better characterize her seizure type (see my posts on seizure types at
http://braindiseases.info
). She agrees to the study.

EEG recording is initiated and is read as normal after 24 hours. The next day in the hospital, I tell her and her mother about the results of the normal EEG. A few hours after my discussion with the family, she is noted by the nursing staff to have a violent “seizure”. I review her EEG. On the camera I notice her to suddenly stiffen and then have violent out of phase (uncoordinated) flinging movements of the arms and legs. Her head moves from side to side and I overhear her  yelling “too much, too much, let me go!!! let me go!!!). The event occurs while her mother and her best friend are by her bedside.

I look at the time locked EEG (EEG synchronized with the video in real time). While she is clinically having a “seizure”, her brain waves are normal (the brain is not having a seizure). A correct diagnosis of pseudoseizures (non-epileptic event) is made and she is discharged home with advise to follow up with a psychiatrist.

So what is a pseudoseizure?

1. It is not a true seizure but rather an episode or episodes which clinically look like seizures but are not accompanied by any EEG changes.

2. It usually has a psychological basis. In my experience I commonly see them in people who are passing through tremendous stress be it interpersonal relationships or at the job.

3. A person may have pseudoseizures to achieve a secondary gain (in the case of our patient, attention and love from her mother and best friend).

4. Pseudoseizures are not treated like seizures. These patients do not need anti-seizure medications. They rather at times need a psychiatrist to explore the underlying reasons for the NEE (conflicts in family etc).

5. Some patients who have true seizures (epilepsy) may also have pseudoseizures.

 

Forget so that you can remember

Read another fascinating article by Melinda Beck in the Wall Street Journal titled ” You must remember this: forgetting has its benefits”. Her articles in the Wall Street Journal always tweak the neurologist in me. Ms. Beck in her piece talks about the importance of forgetting and how it is important in formulation and consolidation of memories.

Let us take a simple example, how many of us remember what we were doing at noon last Monday or what we ate for dinner a week ago (now some of you may very well remember what you ate for dinner a week ago if you eat the same thing every night or lead a very regimented life). The rest of us do not remember this information. Why you may ask does out brain not remember all these details? Well the answer is simple. This information is trivial and the brain does not consolidate these memories and hence these memoried are easily erased.

To continue with the above example, you may very well remember what you ate or did the night Senator Obama became President Elect Obama and you might be able to recall that information even many years from now. Why?  Well the brain has linked the “trivial information” of what you were eating or wearing that night to more important information “the night when history was made with the election of Senator Obama as President elect”. This linking of information leads to long term potentiation and hence consolidation of memories. Memories like these are not easily erased or lost.

The brain is always purging trivial memories, this keeps the hippocampi and other memory pathways always available and free to make new memories. Put in a different way, it prevents memory overload. If we remembered each and everything we did in our lives we shall be inundated with memories and not know what is important and what is not.

So is there anything practical which you can take away from what I said above? Well for one thing if you want to remember something and never forget, associate that memory to something important to you (eg associate something  to your birthday). Memory becomes more and more resilient when you associate it with other memories (eg a scent to a pretty lady, you smell the perfume, her picture comes up in your mind!!!).  Secondly forgetting is not always bad, it “frees up” space in the brain so that when something important comes along your brain has space to store that memory trace.

Nitin Sethi, MD

A neurologist reflects…..

Nitin Sethi, MD

Assistant Professor of Neurology

New York Presbyterian Hospital

Weill Cornell Medical Center

New York, NY 10065

 

Saturday morning finds me in my favorite  coffee shop in the West Village reflecting on the week that went by.  It was a long week, even by my standards and I am happy to have the time to sit down and reflect on it. The week also saw me confronted with a moral and ethical delimma. Electroencephalogram (EEG) (this is a test to look at the brain waves) monitoring was requested for prognostication purposes on a patient in the intensive care unit. Patient had suffered multiple strokes and was on a mechanical ventilator. The purpose of getting the EEG was to get an idea of the extent of his cerebral dysfunction. His EEG showed some slowing of brain waves but otherwise surprisingly looked “good” given the extent of pathology in the brain and the fact that he was comatosed.

His wife tearfully was considering termination of care. Patient had a living will, in which he had clearly made his wishes apparent that he did not wish to live in a state where he was dependent on others, bed-bound and unable to participate in activities of daily living. Objectively as a doctor I knew he was not brain dead, my neurological examination told me that. I did know that his chances of a meaningful neurological recovery were very poor and likely he was heading to a persistent vegetative state (read more about PVS on my website
http://braindiseases.info
).

His wife had justifiably struggled to come to the decision of termination of care of her beloved husband. Next day when she finally made her decision to terminate care, the patient was noted to wince to pain as she walked into his room…..

There started the moral and ethical delimma for everyone, his wife as well as us doctors. Can we ever prognosticate sufficiently about the extent of someone’s neurological recovery? Can we ever be 100% sure about the extent of someone’s neurological recovery especially if we are attempting to make that decision soon after the neurological insult. Various neurological papers have attempted to answer this vexing question. We do have some leads. We know that a patient who loses brainstem reflexes such as pupillary light reflex (shine a light into the pupils and the pupils constrict) shall have a universally poor outcome. Tests like MRI brain, EEG and evoked potentials further help us in prognostication.

But what does meaningful neurological recovery  mean to the patient, his family and to us doctors? To us doctors it means being independent in activities of daily living, a patient conscious and alert and productive member of society. We have scales to help us grade this recovery. But meaningful neurological recovery might have a completely different meaning for the patient and his family. For his wife, the very fact that her husband is alive, someone she can reach out and touch may mean the world. True along with that shall come the burdens of caregiving.

Now what about the patient? True our patient made a living will, a will made when he was fully alert and in control of his senses. He made his choices known. But did he plan for a situation like this?  He is critically ill and the doctors are not certain what his chances for a meaningful neurological recovery are. Would he have liked to have his life sustanied if the answer was not black or white but a shade of grey?

The more I reflect on this, the more I realise that life is never simple and there are seldom easy answers. The struggle continues…..

Pinched nerve-a question and an answer

One of the readers of my blog raised a great question. Her question and my answer follows.

Merely me

Thanks for this information. I have never experienced that before fortunately. I have heard that some folks who have MS may think that they have a pinched nerve at first.

Dear Merely me,

                               thank you for writing in. You raise an important point. Multiple sclerosis rarely may present with signs and symptoms of radiculopathy. This usually occurs when a MS plaque (MS demyelinating lesion) occurs at the root entry zone of a nerve. Let me explain that in more common language. If a plaque of MS happens to be where a nerve is starting off, it shall cause demyelination and present with signs and symptoms mimicking radiculopathy.

This though is not a common way with which MS presents and hence MS is not the first diagnosis which comes to a doctor’s mind when a patient presents with radiculopathy.

 

Personal Regards,

Nitin Sethi, MD