Neurology diagnoses and treats disorders of the nervous system, including the brain, spinal cord, and nerves, as well as thought and memory.

We're Here to Help.
Get in Touch.

Send us all your questions or requests, and our expert team will assist you.

Doctors

Peripheral Neuropathy: Diagnosis and Imaging

Peripheral Neuropathy: Diagnosis and Imaging

Diagnosing peripheral neuropathy involves more than just confirming nerve damage; it requires a detective like approach to uncover the underlying cause. A specific diagnosis is essential because treating the root cause is the only way to stop the progression. The process begins with a meticulous clinical history and physical examination.

  • Comprehensive medical history review
  • Detailed neurological physical examination
  • Electrophysiological testing (NCS/EMG)
  • Laboratory and genetic screening
  • Tissue biopsy and imaging
Icon LIV Hospital

Clinical Evaluation and Examination

The neurologist will perform a detailed sensory exam using tools to test different nerve fibers. A tuning fork is used to test vibration (large fibers), while a cold metal object or pin is used to test temperature and pain (small fibers). Reflexes are checked, as the ankle jerk reflex is often lost early in neuropathy.

Muscle strength is graded to identify patterns of weakness. The doctor will also look for visible signs of neuropathy, such as high arches (pes cavus), hammer toes, or thinning of the muscles between the thumb and index finger. Observation of the patient’s gait can reveal balance issues or foot drop.

  • Vibration testing with 128Hz tuning fork
  • Monofilament testing for pressure sensation
  • Deep tendon reflex assessment
  • Manual muscle strength testing
  • Gait and balance observation (Romberg test)
Icon 1 LIV Hospital

Electrophysiology: NCS and EMG

Electrophysiology: NCS and EMG

Nerve Conduction Studies (NCS) and Electromyography (EMG) are the gold standard for evaluating large fiber neuropathy. NCS involves stimulating the nerve with small electrical shocks and recording the speed and size of the response. This helps distinguish between axonal damage (small response) and demyelinating damage (slow response).

EMG involves inserting a fine needle into the muscle to record electrical activity. This helps determine if weakness is due to nerve damage or muscle disease. It can also detect active denervation, indicating that the nerve damage is ongoing and acute. These tests, however, cannot detect small fiber neuropathy.

  • Measurement of nerve conduction velocity
  • Assessment of compound muscle action potential amplitude
  • Evaluation of sensory nerve action potentials
  • Detection of active denervation (fibrillations)
  • Differentiation of axonal vs demyelinating types

Skin Biopsy for Small Fiber Neuropathy

Skin Biopsy for Small Fiber Neuropathy

Since standard electrical tests (NCS/EMG) only assess large nerves, patients with burning pain but normal EMG results often need a skin biopsy. This is a simple procedure where a tiny punch of skin is taken from the leg. The sample is stained to count the intraepidermal nerve fiber density.

A reduced density of these tiny nerve endings confirms the diagnosis of small fiber neuropathy. This validates the patient’s pain symptoms and allows the physician to move forward with a treatment plan. It is considered the definitive test for small fiber pathologies.

  • Punch biopsy from distal leg and thigh
  • Quantification of intraepidermal nerve fiber density
  • Staining for PGP 9.5 protein marker
  • Comparison to age matched normative data
  • Validation of “invisible” pain syndromes

Laboratory Screening Protocols

A broad panel of blood tests is ordered to look for treatable causes. This includes screening for diabetes (HbA1c), kidney and liver function, and thyroid levels. Vitamin levels, specifically B12 and its metabolites (methylmalonic acid), are crucial.

Further testing may include looking for autoimmune markers, such as ANA or specific antibodies like anti MAG. Protein electrophoresis is checked to rule out paraproteinemias or myeloma. In select cases, genetic testing is performed to look for Charcot Marie Tooth disease.

  • Fasting glucose and HbA1c
  • Vitamin B12, folate, and thiamine levels
  • Serum protein electrophoresis (SPEP)
  • Autoimmune antibody panels (Sjogren’s, Lupus)
  • Heavy metal toxicology screens

Advanced Neuroimaging

While not routine for all neuropathies, MRI is invaluable for specific structural causes. MRI of the spine can rule out nerve root compression (radiculopathy) that mimics neuropathy. Magnetic Resonance Neurography (MRN) is a specialized technique that can visualize the peripheral nerves themselves, showing swelling or inflammation.

Ultrasound of the nerves is an emerging tool. It allows for bedside visualization of nerve enlargement or compression. It is particularly useful for entrapment neuropathies like carpal tunnel or for identifying thickened nerves in genetic or inflammatory conditions.

  • MRI of the spine to rule out stenosis
  • Magnetic Resonance Neurography for plexus imaging
  • High resolution nerve ultrasound
  • Identification of nerve hypertrophy
  • Detection of nerve tumors or cysts

30 Years of
Excellence

Trusted Worldwide

With patients from across the globe, we bring over three decades of medical

Book a Free Certified Online
Doctor Consultation

Clinics/branches

Was this article helpful?

Was this article helpful?

We're Here to Help.
Get in Touch.

Send us all your questions or requests, and our expert team will assist you.

Doctors

FREQUENTLY ASKED QUESTIONS

Do the electrical tests hurt?

The Nerve Conduction Study involves small electrical shocks that feel like a static snap, and the EMG involves a thin needle; most patients find it uncomfortable but tolerable.

The EMG only tests large nerves; if you have small fiber neuropathy (which causes pain and temperature issues), the EMG will be normal, requiring a skin biopsy instead.

It is a minor procedure where a tiny piece of skin, about the size of a pencil tip, is removed to count the number of nerve endings under a microscope.

Standard MRIs usually don’t show the tiny nerves in the feet, but they are used to check the spine to make sure the problem isn’t coming from a pinched nerve back there.

For some patients, the cause is found immediately (like diabetes), but for about 25 to 30 percent of cases, no clear cause is found despite extensive testing, which is called idiopathic neuropathy.

Spine Hospital of Louisiana

Let's Talk About Your Health

BUT WAIT, THERE'S MORE...

Leave your phone number and our medical team will call you back to discuss your healthcare needs and answer all your questions.

Let's Talk About Your Health

Let's Talk About Your Health

Leave your phone number and our medical team will call you back to discuss your healthcare needs and answer all your questions.

Let's Talk About Your Health

How helpful was it?

helpful
helpful
helpful
Your Comparison List (you must select at least 2 packages)