What is the Difference Between Axonal and Demyelinating Neuropathy

The key difference between axonal and demyelinating neuropathy is that axonal neuropathy is a type of polyneuropathy that is due to axon loss while demyelinating neuropathy is a type of polyneuropathy that is due to impaired interaction between Schwann cells and the axons.

Polyneuropathy is a neurological condition due to the dysfunction of many or all nerves. Based on pathophysiology, polyneuropathy can be classified into two categories: axonal and demyelinating neuropathy. Systemic illnesses normally cause axonal neuropathy, while demyelinating neuropathy is caused by immune-mediated, toxic, and hereditary aetiologies.

CONTENTS

1. Overview and Key Difference
2. What is Axonal Neuropathy
3. What is Demyelinating Neuropathy
4. Similarities – Axonal and Demyelinating Neuropathy
5. Axonal vs. Demyelinating Neuropathy in Tabular Form
6. Summary – Axonal vs. Demyelinating Neuropathy

What is Axonal Neuropathy?

Axons are specialized extensions of nerve cells that involve in transmitting nerve impulses. Axonal neuropathy is related to axon loss. It may be caused by a broad spectrum of systemic illnesses and inherited genetic mutations. Moreover, the signs and symptoms of axonal neuropathy may include problems with walking, loss of sensation, strength, and reflexes in their limbs, difficulty in coordinating movements, requiring wheelchair assistance, an abnormal curvature of the spine (scoliosis), visual and hearing problems, having extremely kinky hair, experiencing problems with constipation, heat intolerance, the release of urine (neurogenic bladder), and a reduction in or loss of the ability to sweat. The complications resulting from this condition include paralysis, seizures, difficulty breathing or swallowing, and a gradual decline in mental function (dementia).

Axonal neuropathy can be diagnosed through nerve conduction velocity, brain MRI, peripheral nerve biopsy, and molecular genetic testing. Furthermore, treatment options for axonal neuropathy may include symptomatic and supportive therapies, which often involve physiotherapy, psychological therapy, and speech and language therapy.

What is Demyelinating Neuropathy?

Demyelinating neuropathy is related to the impaired interaction between Schwann cells and the axons. Demyelinating neuropathy is a result of different aetiologies such as diphtheria, immune-mediated (autoimmune diseases such as Guillain-Barré syndrome), toxic, hereditary, diabetic, cancer of lymphatic system, systematic lupus erythematosus, overactive thyroid, and side effect of medicines to cancer or HIV. Signs and symptoms of demyelinating neuropathy may include numbness and pain in specific body regions, tingling or reduced sensation in fingers and toes, diminished reflexes leading to weakness in limbs, loss of deep tendon reflexes, general fatigue, and unusual bodily sensations. The complications resulting from demyelinating neuropathy include muscle weakness and paralysis.

Demyelinating neuropathy can be diagnosed through nerve conduction velocity, lumbar puncture, MRI imaging of nerve roots, and genetic testing. Furthermore, demyelinating neuropathy is treated through glucocorticoids (steroids), intravenous immunoglobulin (IVIg), plasma exchange (PLEx), and physical therapy.

What are the Similarities Between Axonal and Demyelinating Neuropathy?

• Axonal and demyelinating neuropathy are two different types of polyneuropathies.
• Both neuropathies can cause similar symptoms, such as loss of sensation, strength, reflexes, etc.
• They can cause complications such as paralysis.
• Both neuropathies can be diagnosed through nerve conduction velocity, MRI, and genetic testing.
• They can be treated through supportive therapy.

What is the Difference Between Axonal and Demyelinating Neuropathy?

Axonal neuropathy is a type of polyneuropathy that is due to axon loss while demyelinating neuropathy is a type of polyneuropathy that is due to impaired interaction between Schwann cells and the axons. Thus, this is the key difference between axonal and demyelinating neuropathy. Furthermore, the complications resulting from axonal neuropathy include paralysis, seizures, difficulty breathing or swallowing, and a gradual decline in mental function (dementia). On the other hand, the complications resulting from demyelinating neuropathy include muscle weakness and paralysis.

The infographic below presents the differences between axonal and demyelinating neuropathy in tabular form for side-by-side comparison.

Summary – Axonal vs. Demyelinating Neuropathy

Polyneuropathy involves damage to many or all nerves. It can have a wide range of aetiologies and presentations. Based on the pathophysiology, polyneuropathy can be classified into two general categories: axonal and demyelinating neuropathy. Axonal neuropathy is related to axon loss, whereas demyelinating neuropathy is related to the impaired interaction between Schwann cells and the axons. Furthermore, axonal neuropathy is caused by systemic illnesses and genetic mutations, while demyelinating neuropathy is caused by immune-mediated, toxic, and hereditary aetiologies. So, this summarizes the difference between axonal and demyelinating neuropathy.

Reference:

1. DC, Raynor., EM, Ross., MH, Shefner., JM, Preston. “Differentiation between Axonal and Demyelinating Neuropathies: Identical Segments Recorded from Proximal and Distal Muscles.” Muscle & Nerve.
2. “Demyelinating Neuropathy.” ScienceDirect Topics.

Image Courtesy:

1. “MMNScheme” By BiologyAndTıbbiye4Science – Own work (CC BY-SA 4.0) via Commons Wikimedia
2. “Blausen 0311 Diabetic Neuropathy” By BruceBlaus. “Medical Gallery of Blausen Medical 2014”. WikiJournal of Medicine 1 (2). DOI:10.15347/wjm/2014.010. ISSN 2002-4436. – Own work (CC BY 3.0) via Commons Wikimedia