How Important Is It To Know The Cause Of Your Neuropathy?

Today's post from neuropathyjournal.org (see link below) is written by LtCol Eugene B Richardson who has quite rightly been a long-term critic of general diagnoses such as 'idiopathic neuropathy' (where they can't find the cause) and 'peripheral neuropathy' which can refer to any number of branches of nerve damage. In this article, he encourages patients to push for more accurate diagnoses and for better testing to pinpoint the probable reasons for a patient's symptoms. That said, there are often cases where no matter how stringent the testing; isolating the cause can be pretty much like thrusting the needle in the proverbial haystack and a diagnosis of idiopathic neuropathy is unavoidable. It's also true that addressing the symptoms (which are pretty much common to most neuropathy forms) is the main aim and depending on a patient's history, the cause may stem from several other conditions and treatments from the past. Nevertheless this is an excellent article and well worth a read.

Neuropathy Types: How Important?
By LtCol Eugene B Richardson, USA (Retired) BA, MDiv, EdM, MS Aug 2015

Patients must work with their doctor to obtain a diagnosis of their type of neuropathy and never settle for a diagnosis that is limited to Idiopathic and/or just Peripheral Neuropathy.

Why?

By identifying the type of neuropathy, there is a very high probability that the type of neuropathy will point to a possible cause, especially the immune mediated neuropathies and even a possible treatment.

A diagnosis of Idiopathic Neuropathy is not helpful to the patient or to the clinical practitioner and is overused for a number of reasons. Too many doctors are not trained or skilled in neuromuscular neurology and worse do not taking neuropathy seriously. (Note: From patient experience Idiopathic means of unknown cause to doctors and no objective proof to lawyers).

With the testing available in 2015 the type of neuropathy, outside the single focus on a cause, will often point to a possible cause. This would include understanding of the EMG, Nerve Conduct Test, Skin Biopsy, Spinal Tap for immune mediated, Radiological examinations, (limited use of the Nerve/Muscle Biopsy), Evoked Potentials, Blood Tests, and Genetic Testing in addition to the careful reading of the patients health history/symptoms and a skilled neurological examination in the hands of a trained Neuromuscular Neurologist.

The type neuropathy will help the patient grasp a concept of what is wrong and provide some hope for finding a cause by the doctor, while helping the patient with coping and seeking support for their condition. (See reference 2 in the Textbook by Dr. Donofrio showing differential diagnosis between types).

Affirmation is no small matter as to what the doctor calls a disease. Without a name for a disease or condition, the diagnosis feels to the patient like they are swinging fists against an unknown wind. Without a name hope wilts and spirits sag. Support systems disappear or grow tired of the endless symptoms in chronic illness that has no meaningful name. The patient may even feel like they are losing their mind and others will imply they are ‘crazy’. Without a name a neuropathy patient is left out on the limb with no place to go except treating symptoms, grasping at ‘snake oil’, endless searching for answers while hoping that it will just go away.

In too many cases, an inappropriate diagnosis of idiopathic neuropathy has delayed treatments which were available or at a minimum the consideration of a possible treatment, while a progressive neuropathy eats away at the nerves increasing the possibility of more serious disabilities. This is exactly what happen to Col Richardson a 27 year military veteran who served in Vietnam and who came to Jacksonville in 2009 to give his lecture on “Coping with Chronic Neuropathy“. This well known DVD on the subject has reached thousands around the world and is endorsed by several nationally known Neurologists. (See his story of struggle and courage with undiagnosed or treated symptoms of neuropathy for over four decades in the article One Man’s Journey).

What are the types of neuropathy to name just a few?

Patients who have read the book by Norman Latov MD PhD, (Reference 1) one of the things that they note stands out is the manifestations within the different types of neuropathy. It became obvious to patients in looking at this information with deductive reasoning in the diagnostic process, is to provide a clue as to what may be happening to the patient! The facts of what is affecting some part of the peripheral nervous system, often points to a type and thus to a cause or even a clue for treatment!

In the book by Drs. Herskovitz, Scelsa, and Schaumburg, (Reference 3) the use of the word idiopathic is used only in reference to the recent research focus on axonal polyneuropathy and small fiber neuropathy and its use is limited and the focus is clearly on the “careful, intensive evaluation of undiagnosed neuropathies” as “this will uncover an etiology in many cases”.

The authors go on to note that about one-third to one-half of these neuropathies will remain ‘idiopathic or cryptogenic”, but these are almost exclusively axonal, either sensory or sensory motor or small fiber types. So why not call them axonal sensory/motor or small fiber neuropathy? The doctors go on to discuss the components of both the known and unknown, while seeking to provide some direction in the diagnosis and treatment for these patients.

The point here is that current books have no chapter dedicated to Idiopathic Neuropathies as in the past. Yet significant coverage is given to the different types of neuropathy and the keys to diagnosis or clues for the clinician to consider for each type.

Dr. Donofrio (Reference 2) who wrote with contributions from other experts does an outstanding job in noting the differences between types, the symptoms, the nerves involved, patients’ symptoms and complaints, the neurological examination, and so on.

Types of Neuropathy: While not exhaustive, this list will provide you with the point being made:
Axonal Neuropathy / Polyneuropathy
Sensory Neuropathy / Polyneuropathy
Multifocal Motor Neuropathy (MMN)
Multifocal Demyelinating Sensorimotor Neuropathy (Lewis Summer Syndromes)
Neuropathy with IgM Monoclonal Gammopathy
Anti-Mag or Gangliosides Antibodies
Sensory/Motor Neuropathy / Polyneuropathy
Immune Mediated Neuropathy / Polyneuropathy
Large Fiber Neuropathy / Polyneuropathy
Small Fiber Neuropathy (SFN)
Autonomic Neuropathy
Autoimmune Sensory Neuronitis
Guillian Barré Syndrome (GBS)
Distal Symmetric Polyneuropathy
Chronic Inflammatory Demyelinating Polyneuropathy (CIDP)
Sjogren’s Syndrome


Types when there is a suspected cause:
Diabetic Neuropathy or Glucose Intolerance
Diabetic Amyotrophy
Vitamin E, B1, B6, B12 Deficiency
Vitamin B6 toxicity
Bariatric Surgery and Malabsorbtion with nutritional deficiency
Celiac Neuropathy
Chemotherapy/Radiation induced neuropathy
Neuropathy in alcoholic abuse
Neuropathy in Nutritional Deficiencies
Hereditary or genetic neuropathy
Neuropathy in Agent Orange/Blue/White with Arsenic exposure***
Entrapment Neuropathy (Carpel Tunnel Syndrome)
Toxic neuropathy
Drug induced neuropathy
Neuropathy with IgA, IgM Monoclonal Gammopathy
Hepatitis C Infection
Vasculitic neuropathy
Neuropathy in AIDS
Neuropathy in Lyme disease
Diphtheric (bacterial infections) neuropathy
Sarcoid or Parasitic Infection (Chagas’ Disease) neuropathy
Leprosy
Neuropathy in cancer or Lymphoproliferative disorders
Paraneoplastic neuropathy
Neuropathy in myeloma or POEMS
Neuropathy in amyloidosis
Ulcerative Colitis
Crohn’s Disease
Shingles or Cytomegalovirus infections

(***Supported by the findings of the Institute of Medicine in 2010 and confirmed by the Veterans Affairs Administration law in 2012 as presumptive to Agent Orange/Blue/White (arsenic and other toxins) exposure. For guidance in submitting a claim to the VA go to this link on Guidelines for Veterans or send an E Mail to gene@neuropathysupportnetwork.org for more guidance.)

References:
Peripheral Neuropathy: When the Numbness, Weakness and Pain Won’t Stop by Norman Latov, MD PhD Demos Medical Press, New York 2007
Textbook of Peripheral Neuropathy by Peter D Donofrio Professor of Neurology, Chief of the Neuromuscular Section, Vanderbilt University Medical Center, Nashville, TN, Demos Medical Press, New York, 2012 with contributions by other experts.
Peripheral Neuropathies in Clinical Practice by Drs. Steven Herskovitz, Stephen Scelsa and Herbert Schaumberg, Contemporary Neurology Series, Oxford University Press, 2010.
“The Problem with a Diagnosis of Idiopathic Neuropathy” on the Neuropathy Journal website. https://neuropathyjournal.org/the-problem-with-a-diagnosis-of-idiopathic-neuropathy/

https://neuropathyjournal.org/neuropathy-types-how-important/