Neuropathy, Myopathy and MNDs

Question 1

What are the general causes of mononeuropathies?

Answer 1

trauma or compression

Examples: ulnar neuropathy from leaning/falling on elbow, peroneal neuropathy from and injury to the lateral knee

Question 2

What types of damage occur to nerves in mononeuropathies?

Answer 2

focal demyelination of the nerve where it tends to be compressed, accompanied by axonal damage if the lesion is more severe

Question 3

Which is the most common mononeuropathy?

Answer 3

Carpal Tunnel - compression of the medial nerve

Question 4

What is the treatment for carpal tunnel?

Answer 4

local rest, anti-inflammatories, splinting —> surgical decompression of the nerve.

Question 5

What are the earliest signs of a polyneuropathy?

Answer 5

Sensory loss of impairment in DISTAL limbs (feet, and then hands - due to relative length of fibers)

• Stocking and Glove

Question 6

What are secondary signs seen in polyneuropathy (other than impaired distal limb sensory loss)

Answer 6

Paresthesia - spontaneous tingling “pins and needles” and dysesthesia (unpleasant sensation from non-noxious stimuli)

Question 7

How are reflexes affected by polyneuropathy?

Answer 7

They are lost/decreased early on

Question 8

How/which muscles are affected by polyneuropathy?

Answer 8

Distal limb weakness and atrophy

Question 9

What are two different types of causes of polyneuropathies?

Answer 9

1) hereditary

2) Toxic neuropathies (due to certain occupations, hobbies, chemo etc…(

Question 10

What are some diagnostic tools for finding the cause of different polyneuropathies?

Answer 10

1) Blood tests to ID treatable neuropathies
2) Nerve conduction testing and electromyography
3) Nerve biopsy in special cases

…often cause remains unknown

Question 11

What is the most common cause of polyneuropathy?

Answer 11

Axonal degeneration - possibly from inadequate axonal plasma flow

Demyelination may occur secondarily

Question 12

In a nerve conduction study, a primary slowing of nerve conduction velocity suggests what type of nerve damage?

Answer 12

Demyelination

Question 13

In a nerve conduction study, a primary decrease in nerve conduction amplitude suggests what type of nerve damage?

Answer 13

Axonal loss

Question 14

What types of medications are used to relieve painful sensory disturbances associated with polyneuropathy?

Answer 14

topical creams/ointments

oral anticonvulsants or antidepressants

Question 15

What is the paralysis pattern seen in Guillain barre?

Answer 15

Ascending paralysis

Question 16

How are reflexes affected in Guillain barre?

Answer 16

Reflexes are absent (areflexia)

Question 17

What is the etiology of Guillain barre?

Answer 17

GB usually follows an acute viral infection (or campylobacter jejuni) and results in misdirection of the immune system against normal peripheral nerve myelin

-If the damage is severe, secondary axonal loss may occur

Question 18

How is Guillain barre diagnosed?

Answer 18

EMG evidence of demyelination

CSF shows elevated proteins with few/no WBCs

Question 19

What intervention may shorten the time course and hasten the recovery of Guillain barre?

Answer 19

IVIG

Question 20

What orthopedic abnormalities generally accompany hereditary polyneuropathies?

Answer 20

Scoliosis, hammartoes, pes cavus

Question 21

When do hereditary polyneuropathies usually become symptomatic?

Answer 21

Childhood

Question 22

How are hereditary polyneuropathies treated?

Answer 22

No curative treatments available- give assistive orthotics and devices as needed

Question 23

What is a myopathy?

Answer 23

Primary disease of a muscle

Question 24

What are the major clinical findings of myopathies?

Answer 24

PROXIMAL limb weakness and atrophy (shoulders and hips)

Question 25

How are reflexes affected in a myopathy?

Answer 25

LATE LOSS of reflexes --> after significant muscle atrophy occurs

Question 26

How is sensation affected by a myopathy?

Answer 26

Unaffected- it doesn't affect the nerves

Question 27

How might a myopathy be diagnosed? (list 4 ways)

Answer 27

Family hx (for things like muscular dystrophY) Serum CK levels are elevated EMG demonstrates disorder of muscles Muscle biopsy

Question 28

What is polymyositis?

Answer 28

Inflammmation and weakness of multiple muscles following a viral infections or a drug reaction

Question 29

What is the most common cause of polymyositis in the US?

Answer 29

Autoimmune!

Question 30

What are the symptoms of polymyositis?

Answer 30

``` Proximal weakness (over weeks to months) Rash around eyes and fingers may occur (in dermatomyositis) ```

Question 31

How is polymyositis treated/

Answer 31

Corticosteroids or other immunosuppressant drugs

Question 32

What is the genetic inheritance pattern of Duchenne's Muscular Dystrophy?

Answer 32

X-linked

Question 33

What is the genetic mutation/gene affected by Duchennes?

Answer 33

There is a virtual absence of dystrophin- a critical structural protein in muscle tissue. It also affects respiratory and cardiac muscle

Question 34

What is calf pseudohypertrophy?

Answer 34

Muscle in calves are replaced by fat and connective tissue.

Question 35

What is the prognosis of Duchenne' s muscular dystrophy?

Answer 35

Cardiac failure by third decade.

Question 36

What is a motor neuron disease?

Answer 36

These are disorders- occasionally hereditary- where degeneration of UMNs or LMNs or both occurs with varying severity and rate of progression that's a shitty description.

Question 37

What are the symptoms of spinal muscular atrophy (anterior horn cell involvement)

Answer 37

LMN signs of weakness, atrophy, areflexia and fasciculations

Question 38

What is Werdnig Hoffman Syndrome?

Answer 38

Floppy baby syndrome- infantile onset of spinal muscular atrophy. fatal.

Question 39

What are the hallmark symptoms of ALS?

Answer 39

UMN AANNNDD LMN symptoms. Especially UMN lesion symptoms + fasciculations ====r ALS

Question 40

What is Riluzole?

Answer 40

Riluzole is a drug used to treat ALS. It is a glutamate antagonist and is thought to increase the lifespan of people with ALS by inhibiting the "over-excitement of neurons by glutamate" TBH its not a great drug and 50% of people will ALS still die within 3 yrs of respiratory failure or complications of diffuse weakness.