A neurologist is a medical doctor who specializes in diagnosing and treating diseases and disorders of the nervous system. This includes the brain, spinal cord, peripheral nerves, muscles, and nerves controlling organs. Neurologists are trained to evaluate nerve damage and determine the cause and best course of treatment.
How neurologists evaluate nerve damage
There are several ways a neurologist can detect and evaluate nerve damage:
- Medical history – The neurologist will ask about symptoms, onset, progression, pain levels, weakness, numbness, tingling, etc. This helps identify affected areas.
- Physical exam – Reflexes, muscle strength, sensation, coordination, and balance will be tested. Abnormalities indicate nerve problems.
- Nerve conduction studies – Small electrodes placed on the skin measure how fast electricity travels through a nerve. This can locate damage.
- Electromyography – A needle electrode put into muscles records their electrical activity at rest and during contraction. This finds nerve-muscle abnormalities.
- Blood tests – Levels of muscle enzymes or proteins related to nerve function can point to nerve disorders.
- Genetic testing – Detects mutated genes linked to hereditary neuropathies.
- Imaging – MRI and CT scans reveal structural issues like disc herniations, tumors, inflammation, or injury compressing nerves.
- Biopsy – Removing and examining nerve tissue under a microscope can help diagnose some conditions.
Combining a person’s symptoms and medical history with multiple tests allows neurologists to confirm nerve damage, determine the type and location, and pinpoint a cause.
Types of nerve damage a neurologist can detect
There are various types and causes of nerve damage a trained neurologist can diagnose:
Peripheral neuropathy
Damage to the peripheral nerves that connect the brain and spinal cord to the rest of the body. Causes include:
- Diabetes – High blood sugar injures nerve fibers
- Autoimmune diseases – Immune system attacks nerves
- Infections – Viruses, shingles, HIV can inflame nerves
- Toxins – Alcoholism, environmental toxins like lead or mercury
- Nutritional deficiencies – Lack of vitamins B1, B6, B12, E
- Inherited disorders – Charcot-Marie-Tooth disease
- Injuries/trauma – Broken bones, laceration, compression
Symptoms depend on type of nerves affected – sensory, motor, or autonomic. These include numbness, tingling, burning, loss of sensation, muscle weakness, dizziness, digestive issues, etc.
Carpal tunnel syndrome
Compression of the median nerve as it passes through the wrist. Causes swelling and damage to nerve fibers. Symptoms in the hand include numbness, tingling, weakness, and pain.
Bell’s palsy
A dysfunction of the facial nerve causes weakness or paralysis of the muscles on one side of the face. Caused by inflammation, infection, injury, tumor, or unknown reasons.
In addition to facial drooping, symptoms include pain, twitching, drooling, impaired taste.
Guillain-Barré syndrome
The immune system mistakenly attacks the peripheral nerves. Leads to tingling, muscle weakness, and paralysis. Usually starts in legs and spreads upward. Most people recover fully.
Multiple sclerosis
Autoimmune disease that eats away at myelin coating around nerve fibers in brain and spinal cord. Causes communication problems between nerves leading to numbness, vision loss, pain, weakness, tremors, and mobility problems.
Motor neuron diseases
Diseases like amyotrophic lateral sclerosis (ALS) destroy the nerve cells that control voluntary muscle movement. This leads to twitching, cramps, stiffness, and progressively worsening weakness.
Nerve root compression
Herniated discs or bone spurs in the spine can pinch nerves as they exit the spinal cord causing back pain, numbness, tingling, and muscle weakness in the area the nerve travels.
Neuropathies from chemotherapy
Certain chemotherapy drugs are toxic to nerves. This can cause pain, sensitivity to cold and heat, muscle wasting, and foot or hand numbness and tingling.
Diagnostic tests neurologists use to evaluate nerve damage
Neurologists have a variety of tests to precisely locate nerve damage, determine severity, and guide treatment:
Nerve conduction study (NCS)
Measures how fast electrical signals move through a nerve. Small electrodes placed on the skin stimulate nerves with small electric shocks. Abnormal speed, strength, or responses indicate damaged nerves.
Electromyography (EMG)
A needle electrode is inserted into muscles to measure electrical activity at rest and during contraction. Irregular and abnormal patterns reflect problems with nerves supplying the muscles.
Quantitative sensory testing (QST)
Uses calibrated stimuli like vibration, heat, cold, or touch to map response across skin areas. Compares sensations on damaged and healthy areas to pinpoint abnormal spots.
Skin biopsy
Removes a small sample of skin containing nerve fibers to count density and look for damage under a microscope. Helps diagnose small fiber neuropathies.
Neuropsychological testing
A psychologist assesses cognitive skills like attention, memory, language, problem-solving, and information processing affected by brain or nervous system disorders.
Spinal tap
A needle extracts a sample of cerebrospinal fluid from the spine to look for blood, infections, immune cells, or proteins suggesting nerve disorders like multiple sclerosis, meningitis, or Guillain-Barre.
Imaging
MRI and CT scans provide images that help identify compressed nerves, nerve inflammation, tumors, stroke, or damage to nerve pathways in the brain and spinal cord.
How neurologists determine the cause and location of nerve damage
Neurologists use a patient’s symptoms, medical history, physical exam findings, diagnostic tests, and the pattern of nerve damage to determine the cause and location. Some examples:
- Diabetic neuropathy typically causes symmetric burning, numbness, and tingling in a “stocking-glove” distribution starting in the feet.
- A lumbar herniated disc compresses the sciatic nerve root causing radiating pain down the back of the leg.
- Multiple sclerosis damages nerves in the brain and spinal cord leading to vision problems, limb weakness, numbness, and cognitive changes.
- Brachial plexus injuries affect shoulder and arm nerves causing weakness and numbness.
- Bell’s palsy affects the facial nerve causing one-sided facial paralysis.
Once the area of nerve damage is located, neurologists determine the underlying cause based on clinical evaluation, diagnostic tests, and potential risk factors the patient has like diabetes, trauma, toxin exposure, or family history.
How neurologists monitor nerve damage progression
To monitor ongoing or worsening nerve damage, neurologists may periodically re-check:
- Symptoms like pain, weakness, numbness through exams
- Nerve conduction velocities and EMG readings
- Reactions to sensory stimuli during QST
- Disability and impairment through scales and questionnaires
- Medication effectiveness and side effects
- Neurological exam results – reflexes, coordination, balance, cognitive function
- New symptoms or complaints
For conditions like multiple sclerosis and spinal cord injuries, MRIs help track nerve damage progression over time. Nerve and muscle biopsies may also be repeated. This monitoring helps guide treatment adjustments and determines prognosis.
Treatments a neurologist may recommend for nerve damage
Treatment depends on the cause, but commonly includes:
- Medications – Pain relievers, anti-seizure drugs, antidepressants, immunotherapy drugs, vitamin supplements.
- Therapy – Physical, occupational therapy helps maintain strength and function.
- Orthotics – Braces, splints provide external support.
- Surgery – For severe carpal tunnel, spine impingement of nerves.
- Lifestyle changes – Diet, exercise, reducing toxins and alcohol intake.
While most neuropathies have no cure, treatment can relieve symptoms and prevent further damage in many cases.
Prognosis for different types of nerve damage
The prognosis depends on the specific nerve disorder:
- Bell’s palsy – Most achieve full facial muscle recovery in weeks.
- Carpal tunnel – Relief after wrist splinting or surgery but may recur.
- Diabetic neuropathy – Lifelong condition but blood sugar control helps.
- Guillain-Barré – Most fully recover over 1-2 years.
- MS – Inevitably worsens over time but hard to predict rate.
- Post-chemotherapy neuropathy – Often improves significantly over months.
- ALS – Steadily worsens leading to disability and death within 2-5 years.
A neurologist can give prognoses for specific cases based on the cause, symptoms, test results, progression rate, age, and general health of the patient.
When to see a neurologist for nerve damage evaluation
See a neurologist promptly if you have symptoms such as:
- Progressive numbness, tingling, burning, or pain in arms, legs, hands, or feet
- Sharp shooting pains down the legs or arms
- Muscle weakness making it difficult to walk, grip objects, or hold the head up
- Clumsiness, falling, or inability to feel where your limbs are in space
- Double vision, loss of vision, or blurred vision
- Facial drooping
- Dizziness, lightheadedness, or loss of balance
- Difficulty speaking, swallowing, or breathing
Seeking early diagnosis allows prompt treatment to manage symptoms, slow further damage, and in some cases restore nerve function.
Conclusion
Neurologists have specialized expertise in diagnosing the many potential causes of nerve damage throughout the body. A combination of a medical history, physical examination, diagnostic tests like NCS/EMG, imaging, and biopsies allow neurologists to pinpoint areas of nerve damage, determine the underlying cause, and monitor progression over time. While not all nerve damage can be reversed, prompt diagnosis and appropriate treatment can often significantly improve the prognosis and quality of life for affected patients.