Overview of Peripheral Neuropathy

What is this?

And what can I do about it?

Sara Austin, MD, FAAN

Specialty: Neuromuscular disease Board Certified in Neurology and EMG

711 F West 38th Street

Austin, TX 78705

512-637-5854

Peripheral Neuropathy

Peripheral vs. Central

Neuro=nerve

‘pathy’=sickness

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Types of peripheral nerves

Motor nerves –from spinal cord to muscle

Sensory nerves – from sensory organelle to spinal cord

Small fiber (pain, temperature)

Large fiber (vibration, position, balance)

Autonomic nerves – control blood pressure, sweating, bladder function, heart rate, gut, etc. All the things you don’t have to think about

Symptoms (how can I be numb and hurt at the same time?)

Weakness

Pain

Burning

Thick soles

Walking on stones

Tingling

Imbalance

Distribution of numbness or weakness in peripheral neuropathy

Causes of Neuropathy

Inflammatory (blood vessels or myelin)

Hereditary (Charcot Marie Tooth)

Metabolic (diabetes, liver, kidney)

Toxic (alcohol, chemical exposure)

Vitamin deficiency (B12, D, Thiamine…)

Drug related (chemo drugs)

Related to tumor (paraneoplastic)

Most common neuropathies

Diabetic

Distal sensory motor, painful

Autonomic

Proximal amyotrophy (usually legs)

Vasculitic

Cranial nerve

Most common neuropathies

Hereditary – CMT type 1, CMT type 2

B12 deficiency

Hypothyroid

Chronic inflammatory demyelinating polyneuropathy (CIDP)

Acute inflammatory demyelinating neuropathy (Guillian Barre syndrome)

Related to rheumatological diseases

Toxic – EtOH abuse

Diagnosis

History and physical exam

Weakness? Proximal or distal?

Sensory loss? Small fiber or large fiber

Autonomic symptoms? Sweat? BP? bladder?

EMG/NCS

Lab tests: CBC, liver, kidney, electrolytes, ESR, thyroid, inflammatory markers, protein study, Vit D, B12, 2 hour diabetes test

Chronic Inflammatory Demyelinating Neuropathy (CIDP)

Proximal and distal weakness and numbness

Usually responds to steroids or IVIG

Diagnosed by EMG/NCS

ICE study

Advice: calendar with dates, dose and drug maker

Peripheral Nerve Myelinated vs. demyelinated

Chemo Neuropathies

Most common with cisplatin, taxanes, ara-C, ifosfamide

Initial symptoms are numbness, paresthesias and pain in feet

Drug withdrawal, if possible, usually reverses symptoms- hard decision

Symptoms may continue to progress for weeks to months (coasting), then plateau and fade (hopefully)

Neuropathy mimics

Restless Leg Syndrome (RLS)

Erthyromelalgia

Entrapment neuropathies (carpal tunnel, ulnar neuropathy, tarsal tunnel syndrome)

Treatment

Try to find cause of neuropathy and reverse it

Treat symptoms

Treatment of symptoms

Tricyclic antidepressants and SNRI’s Nortriptyline, Amitriptyline, Cymbalta, Effexor

Anti-seizure medications Gabapentin, Lyrica, Topamax, …..

Topical agents-lidocaine patch, creams, capsacin

Narcotics

NSAID’s

Treatment of Symptoms

Alpha lipoic acid (?)

Stuff:

Good shoes

Practice balance

Rub feet

Watch weight

Vitamins

If you are B12 deficient taking B12 helps

No proof that vitamins in general help/or hurt neuropathy except

B6 (pyridoxime) can cause neuropathy, don’t take more than 200mg per day

Vitamin D is getting some press recently, doesn’t hurt to take more

Questions?