NeuropathyMorning Report January 5th, 2010

Summary

Recognizing neuropathy Classifying neuropathy Myriad neuropathies CIDP

Diagnosis Spectrum of disease Treatment

Clues a neuropathy is present: History:

Distal motor neuropathy: ▪ tripping over toes, dropping coffee cups.

Proximal motor neuropathy:▪ trouble climbing stairs, getting up from sitting,

raising arms to brush teeth and hair. Sensory neuropathy: ▪ burning, lancinating pain, paresthesias, dysesthesias,

a tight band-like sensation around wrists or ankles, hypesthesia, restless legs, numbness.

Acute vs. chronic

Clues a neuropathy is present: Physical Exam:

Motor Strength: ▪ 5= full strength, 4= falls to moderate resistance, 3= falls

to minimal resistance, 2= falls to gravity, 1= muscle contraction, 0= no movement.

Sensation: ▪ vibration/proprioception (large myelinated axons) vs.

pain/temperature (small myelinated axons)▪ Light touch shared by both fiber types.

Trophic Changes: ▪ pes cavus, kyphoscoliosis, loss of hair, ulceration,

thinning of phalanges, charcot joints (neurogenic arthropathy).

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What type of neuropathy? Neuronopathy

Cell body damage of the motor neuron or dorsal root ganglion.

SMA, ALS, CMT (sometimes). Axonopathy

Traumatic, toxic, metabolic Often length dependent- “die back”: symmetric,

distal. Myelinopathy

Hereditary or inflammatory Non-length dependent. ▪ Patchy or segmental (inflammatory)▪ Diffuse (hereditary)

Electromyelogram (EMG) andNerve Conduction Studies (NCS)

Axonopathy Loss of amplitude of

AP Evidence of

denervation- fasciculation

Myelopathy Slowed conduction Prolonged distal

latency Conduction block Temporal dispersion Prolonged minimum

f-wave latency.

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Ddx: Neuropathy

•Diabetes•Hypothyroidism

Metabolic

•Alcohol•Lead•Platinum chemo, tacrolimus

amiodarone, chloroquine.Toxic

•Sarcoidosis•Vasculitis: RA, SLE•Non-systemic vasculitis

Inflammatory

Infectious

•B12 (cyanocobalamine), B6 (pyridoxine), B1 (thiamine)

•E (alpha-tocopherol)

Nutritional Deficiency

•Carcinoma-associated•Lymphoma-associated•Monoclonal gammopathy

Paraneoplastic

•SMA•CMT•ALS

Hereditary

Compressive• Leprosy• Borreliosis (Lyme)• HIV

• Carpal tunnel, ulnar, …• Myxedema, • RA, Acromegaly

•Guillain-Barré•CIDP

Demyelinating

Chronic Inflammatory Demyelinating Polyneuropathy

C = progresses over >1 month. I = presumed to have an autoimmune

origin D= demyelinating P = neuropathy that is poly-

Motor and sensory Symmetrical (or more than one limb) Non-length-dependent

CIDP Diagnosis

American Academy of Neurology Criteria Clinical: 2 more more months,

hypo/areflexia, motor/sensory involvement, >1 limb.

EMG/NCS: 1. Conduction block, 2. decr conduction velocity, 3. incr distal latency, 4. incr F-wave latency. (Must have 3 of 4)

Pathologic: unequivocal evidence of demyelination, remyelination.

CSF: WBC < 10, VDRL neg, elevated protein.

The Larger World of Demyelinating Polyneuropathies Distal Acquired Demyelinating Symmetric (DADS) Neuropathy

Men over 50 Mostly distal sensory loss, mild distal weakness, unsteady gait. 2/3rds

have a IgM paraproteinemia. Multifocal Motor Neuropathy (MMN)

Asymmetric, all weakness, no sensory loss Some have antiganglioside antibodies

Multifocal Acquired Demyelinating Sensory and Motor (MADSAM) Neuropathy (Lewis-Sumner Syndrome) Motor and sensory, elevated CSF protein, asymmetric, some with

antiganglioside antiboties. Axonal chronic inflammatory demyelinating polyneuropathy,

pure sensory chronic inflammatory demyelinating polyneuropathy, multifocal acquired sensory and motor axonopathy (MASAM).

Treatment

Goal: block the immune process Course: continue until maximal

improvement and then maintain. IVIg: 0.4g/kg qday x 5 days, then

monthly x 3 Plasma exchange Corticosteroids Mycophenolate mofetil, azothioprine,

cyclophosphamide, etanercept, rituximab

Sources Koller, H. et al. (2005) Chronic Inflammatory

Demyelinating Polyneuropathy. NEJM 352(13): 1343-1356.

Poncelet, AM. (1998) An Algorithm for the Evaluation of Peripheral Neuropathy. AFP, Feb 15th, 1998.

Said, G. (2006) Chronic Inflammatory Demyelinating Polyneuropathy. Neuromusc Disorders 16:293-303.

Sander, HW et al. (2003) Research Criteria for defining patients with CIDP. Neurology 60(Suppl 3):S8-S15.