Neuropathies and Neuromuscular Junction Disorder

How common is neuropathy?

25%-30% of Americans

What are the types of neuropathy?

• mononeuropathy

• radiculopathy

• autonomic neuropathy

• amyotrophy

• polyneuropathy

What are the examples of mononeuropathy?

• bell palsy

• carpal tunnel syndrome.

What is radiculopathy?

nerve root dysfunction

What is autonomic neuropathy affecting?

affecting the peripheral nerves that automatically regulate body processes.

What is amyotrophy?

proximal neuropathy

True or False: If there's weakness in more than one nerve, it can still be bell's palsy.

False

What is another name for Bell palsy?

Idiopathic facial paralysis

What nerve is affected in Bell palsy?

Weakness of the peripheral cranial nerve VII (this is a cranial mononeuropathy)

What is the most common form of facial paralysis?

Bell Palsy.

What is the incidence of Bell palsy?

25 cases per 100,000

At what ages does Bell palsy peak?

Peaks at ages 20–40

What does Bell palsy cause?

Causes abrupt onset of unilateral upper and lower face weakness/paralysis

When does maximum weakness occur in Bell palsy?

Maximum weakness within 48 hours

What pain may precede Bell palsy?

post auricular pain preceding by a day or two

What are other s/s of Bell palsy?

• loss of taste

• drooling

• Hyperacusis of affected side

What are the causes of Bell palsy?

• Idiopathic

• HSV 1 reactivation - likely most common cause

• VZV reactivation may be the second most common cause,

• Other viruses - EBV, Inactivated intranasal influenza vaccine

What are the risk factors for Bell palsy?

PREGNANCY AND DIABETES

What type of diagnosis is Bell palsy?

Diagnosis of exclusion

How is Bell palsy clinically diagnosed?

Clinically made in a patient with:

1. A typical presentation

2. No risk factors or preexisting symptoms for other causes of facial paralysis

3. Absence of herpes zoster in the external ear canal (Ramsay-Hunt)

4. A normal neurologic examination with the exception of the facial nerve

What is the diagnosis of Bell palsy?

clinical

What tests are used in atypical presentations of Bell palsy?

ESR, Blood Glucose, Lyme Titer, HIV, TFTs

When is NCS/EMG used in Bell palsy?

if there is complete paralysis to determine degree of injury

What may MRI Brain show in Bell palsy?

inflammation of facial nerve or may indicate a mass

When is CSF used in Bell palsy?

occasionally

What is the DDx for Bell palsy?

• Lyme disease

• Ramsay Hunt syndrome

• Sarcoidosis, GBS, Leprosy

• Melkersson-Rosenthal syndrome

• Acoustic neuromas

• Pontine lesions - stroke, MS, tumors,

• Temporal bone invasion by tumors.

What Lyme disease signs make it a DDx for Bell palsy?

unilateral or bilateral (main differentiating factor).

What causes Ramsay Hunt syndrome?

herpes zoster virus.

What accompany's Ramsay Hunt syndrome?

vesicular eruption in the sensory distribution of the seventh nerve in the ipsilateral ear.

What eye treatments are used in Bell palsy?

Artificial tears and ointment

What eye protection is used in Bell palsy?

Eye patch (Not tape to close eye due to risk of corneal scratching if it slips)

What other eye protection is used in Bell palsy?

Eye protection - glasses or goggles

If a pt presents with Bell palsy for 3 days, what is used?

glucocorticoids.

What glucocorticoid treatment is used after 3 days of bell palsy onset?

prednisone 60-80mg per day x 1 week.

What is the role of antivirals in Bell palsy?

The addition of antiviral is controversial (not used alone)

What antivirals may be used in Bell palsy?

Valcyclovir / Acyclovir

When are antivirals used in Bell palsy?

Used if facial palsy is severe

How is Bell palsy treated if caused by Lyme disease?

treated with antibiotics

What percentage of Bell palsy patients recover completely?

80-90% completely recover in 6-12 weeks

What indicates a better prognosis in Bell palsy?

Better prognosis if paralysis is incomplete in 1st week

How does EMG guide prognosis in Bell palsy?

if denervation persists after 10 days, symptoms will likely last longer or even be permanent

What factors indicate a worse prognosis in Bell palsy?

Worse prognosis in patients older than 60, or with concomitant systemic disease

What percentage of Bell palsy patients have recurrence?

4-14% will have recurrence

What is another name for trigeminal neuralgia?

tic douloureux

What type of neuropathy is trigeminal neuralgia?

A cranial neuropathy

What does trigeminal neuralgia cause?

Causes severe facial pain in trigeminal distribution—typically on one side of the face

What type of pain occurs in trigeminal neuralgia?

Chronic and severe, shooting or electric shock-like pain

How long does trigeminal neuralgia pain last?

Lasts a few seconds to a minute

What triggers trigeminal neuralgia pain?

Spontaneous triggered by touching the face, chewing, smiling, brushing teeth, wind on the face

Who is more often affected by trigeminal neuralgia?

women more often affected than men

What causes trigeminal neuralgia?

• vascular compression of the nerve

• tumors or AVMs

• demyelination from multiple sclerosis

• injury to the nerve

What is the diagnosis for trigeminal neuralgia?

MRI/ MRA brain

What is the treatment for trigeminal neuralgia?

carbamazepine or oxcarbazepine

What are the surgical options for trigeminal neuralgia?

• Microvascular decompression

• Brain stereotactic radiosurgery (Gamma knife)

• rhizotomy.

What does rhizotomy do in surgery for trigeminal neuralgia?

destroy nerve fibers to reduce pain (causes some facial numbness).

What is neuropathy?

dysfunction of a nerve or nerves

What are the lower extremity mononeuropathies?

common peroneal mononeuropathy and lateral femoral cutaneous neuropathy

What are the different radiculopathies?

C6, C8, L5, S1 radiculopathy

What is another name for lateral femoral cutaneous neuropathy

meralgia paresthetica

How do you treat carpal tunnel syndrome?

• Usually, conservative treatment with wrist braces first

• if unresponsive, surgery (microvascular depression of a nerve)

What are some causes of lateral femoral cutaneous neuropathy?

compression and obesity

What can lateral femoral cutaneous neuropathy cause?

dysesthesia and sensory loss of lateral thigh

What are s/sxs of C6 radiculopathy?

• neck pain

• paresthesias to thumb and index fingers

• decreased brachiorachial reflex

• weakness in C6 innervated muscles (brachioradialis and wrist extension weakness)

What are the most common reasons for radiculopathies?

herniated disc, spinal stenosis, etc

What are s/sxs of C8 radiculopathy?

• low cervical neck pain

• paresthesias to ring and little fingers

• weakness in C8 innervated muscles (weakness with finger flexion)

What are s/sxs of L5 radiculopathy?

• low back pain

• paresthesias to top of foot

• intact DTRs

• weakness in L5 innervated muscles (great toe extension weakness)

What are s/sxs of C6 radiculopathy?

• LBP/buttock pain

• paresthesias down posterior leg to littel toe

• decreased achilles reflex

• weakness in S1 innervated muscles (ankle plantar flexion weakness)

What reflex is absent, and what is attached in an L4 radiculopathy?

Patellar absent, achilles intact

What is median neuropathy associated with?

carpal tunnel syndrome (entrapment at the wrist)

What should be reviewed in median neuropathy?

Review s/s

What is the most common location of ulnar neuropathy compression?

compression at the elbow (ulnar groove) * this is the most common location

What is entrapment at the cubital tunnel called?

“cubital tunnel syndrome”

Where else can ulnar neuropathy be compressed?

Compression at the wrist

What do symptoms depend on in ulnar neuropathy?

symptoms depend on location of injury

Where can radial neuropathy occur?

in the axilla (classically caused by crutches that are too long)

What causes radial neuropathy in the spiral groove?

caused by humeral fracture or compression aka “Saturday night palsy”

What do symptoms of radial neuropathy depend on?

symptoms depend on location of injury

What is another name for common peroneal mononeuropathy?

common fibular nerve injury

Where is compression most common in common peroneal mononeuropathy?

Compression at the fibular neck most common (lateral knee)

What are causes of common peroneal mononeuropathy?

• trauma (ex knee dislocation)

• compression

• prolonged bed rest

• chronic leg crossing

What are the s/s of common peroneal mononeuropathy?

paresthesias in lateral lower leg, dorsal foot or first toe webspace

What is the treatment for common peroneal mononeuropathy?

ankle foot orthosis (AFO) and PT

What type of polyneuropathy is described in peripheral polyneuropathy?

Distal symmetric sensory and sensorimotor polyneuropathy (DSPN)

What sensory loss pattern is seen in peripheral polyneuropathy?

“Glove-stocking” sensory loss

Where does sensory loss begin in peripheral polyneuropathy?

Sensory loss begins in the toes and progresses over time

How does sensory loss spread in peripheral polyneuropathy?

Spreads up legs and to fingers and arms

What are the s/sxs of peripheral polyneuropathy?

• Tingling, burning

• deep aching pain

• Decreased or absent distal DTRs

• Weakness develops over time.

Why is it important to find the cause of peripheral polyneuropathy?

Need to find cause to treat it appropriately!

What are the categories of causes of peripheral polyneuropathy?

Can be acquired from a disease process (most common

What are causes of acquired neuropathies?

• diabetes

• kidney disorders

• cancer

• hypothyroidism

• alcohol

• nutritional deficiency

• meds and poisons

• infections

• autoimmune disorders

• vascular and vasculitic disorders.

What nutritional deficiencies can cause acquired neuropathy?

B1, B6, B9, B12, Niacin, Vit E, Copper

What meds and poisons can cause acquired neuropathy?

• chemo

• heavy metals

• industrial solvents

What infections can cause acquired neuropathy?

• HIV

• Herpes

• Syphilis

• Lyme

• Leprosy

What autoimmune disorders can cause acquired neuropathy?

• GBS

• SLE

• RA

• Sjogren syndrome

What percentage of people with diabetes develop diabetic neuropathy?

occurs in 60% to 70% of people with diabetes

What is the most common type of diabetic neuropathy?

Distal symmetric sensory or sensorimotor polyneuropathy DSPN - most common

What are other neuropathies that can occur in diabetes?

• autonomic

• diabetic amyotrophy (radiculoplexus neuropathy)

• cranial neuropathies

• other mononeuropathies.

What do NCS show in diabetic neuropathy?

NCS show reduced amplitudes and mild-moderate slowing of conduction velocities

How is diabetic neuropathy diagnosed?

NCS.

What can decrease risk or improve diabetic neuropathy?

Tight control of glucose can decrease risk of developing neuropathy or improve the neuropathy