Neuropathy, Myopathy, and NMD Flashcards Preview

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Flashcards in Neuropathy, Myopathy, and NMD Deck (42):
1

What is a Mononeuropathy?

A single, major nerve is involved with sensory or motor deficits related to its anatomical distribution

2

Wha are the 2 most common causes of mononeuropathies?

Trauma or Compression

3

Common cause of Ulnar Mononeuropathy?

Leaning or falling on the elbow

4

Common cause of Peroneal Mononeuropathy?

Injury to the lateral knee

5

Carpal Tunnel Syndrome
Describe the pathophysiology

If there is inflammation or swelling of the flexor tendons in the carpal tunnel, they can compress the median nerve and cause pain

May also be caused by fluid retention in pregnancy

6

Carpal Tunnel Syndrome
Clinical Symptoms

Tingling numbness of hand (thumb, index, middle, 1/2 ring finger)

Thenar weakness and atrophy in very severe cases

7

Carpal Tunnel Syndrome
Treatment

Local rest

Anti-inflammatories

Splinting

Surgical decompression of the nerve

8

Describe Wallerian degeneration of nerves

Occurs at sites of severe nerve injury

Injury involves myelin and axons distal to the point of injury

9

Do nerves regenerate?

CNS neurons are not good at regenerating, but PNS neurons may regenerate. Likelihood of regrowth is based on distance needed to travel and the degree of injury sustained

10

What is a polyneuropathy?

Disorder of multiple, major and small nerves

Characterized by an early sensory loss in distal limbs

11

Polyneuropathy
Clinical Symptoms

Spontaneous tingling

Pins and needles = Paresthesia

Unpleasant stimulation from non-painful stimuli = Dysesthesia

Distal limb weakness and atrophy

Early loss or decrease of muscle stretch reflexes

12

What are two general big causes of Polyneuropathy?

Axonal degeneration (more common)

Demyelination

13

How are axonal degeneration and demyelination discriminated on nerve conduction studies?

Axonal degeneration -- amplitude of waves are reduced

Demyelination -- slowing of the nerve conduction

14

What is EMG testing?

Needle electromyography

Electrical activity of muscles within individual motor units is assessed for denervation, reinnervation, or muscle disease

15

When are nerve biopsies performed?

Rarely. Only for significant neuropathy and typically only done for sensory nerves.

The patient is left with numbness after the biopsy

16

Polyneuropathy
Treatment

Address underlying causes (diabetes, alcohol)

Orthotic devices -- improve ambulation

Physical therapy

Meds to improve paresthesia or dysesthesia

17

Guillan Barre Syndrome
Clinical Symptoms

Ascending, areflexic paralysis

Acute polyneuropathy and weakness progressing quickly and at its worst by 4 wks

18

Guillan Barre Syndrome
What often precedes this syndrome? Describe the pathology.

Acute viral respiratory infection precedes the syndrome 50% of the time.

Misdirection of immune system to attack normal peripheral nerve myelin

Get inflammation and demyelination of the peripheral nerves or roots

19

Guillan Barre Syndrome
Diagnosis

Evidence of demyelination seen on EMG (slowing of conduction)

Elevated protein in CSF, few if any WBCs

20

Guillan Barre Syndrome
Prognosis and Treatment

Good prognosis with medical treatment

Plasmapheresis or IVIG may shorten illness and hasten recovery

21

List some potential causes of Chronic Acquired Polyneuropathies

Diabetes
Hypothyroid
Uremia
Cancer
Myeloma
Rheumatoid arthritis
Lupus
Nutritional defects (Vit B)
Infection (leprosy)
Toxins (alcohol, lead)

22

Hereditary Neuropathies
Clinical Symptoms

Onset usually in childhood

Distal sensorimotor deficits

Little/no paresthesia or dysthesia

May affect skeletal development (scoliosis, hammertoes, pes cavus)

23

What is a myopathy?

Primary disease of muscle

24

What is the first sign of myopathy?

PROXIMAL limb weakness and atrophy (shoulder and hip)

25

Symptoms of Myopathy

Weakness
Fatigue, maybe with cramping

Proximal limb weakness (shoulders and hips)

Late loss of reflexes (after significant atrophy)

Intact sensation

26

Myopathy
Diagnostic Methods

Review family history

Serum enzymes (CK) often elevated

EMG demonstrates muscle disorder

Muscle biopsy

27

What is Polymyositis?

Inflammation and weakness of multiple muscles

28

What are the causes of Polymyositis?

Viral infection

Drug reaction

Autoimmune

29

Polymyositis
Diagnosis

EMG testing

Presence of inflammation and muscle fiber necrosis on muscle biopsy

30

Polymyositis
Treatment

Immunosuppression (corticosteroids)

31

Polymyositis
Clinical Symptoms

Proximal weakness (like a myopathy)

Rash around eyes or fingers

32

What is Muscular Dystrophy?

Hereditary myopathy of variable progression and severity

33

Duchenne's Muscular Dystrophy
What is the inheritance? What is the pathological defect?

X linked inheritance

Absence of dystrophin (a crucial structural protein in muscle)

34

Duchenne's Muscular Dystrophy
Clinical Symptoms

More common in boys (X linked)

Proximal weakness

Calf pseudohypertrophy from muscle replaced by fat

Cardiorespiratory death by 3rd decade

35

What is Gower's Maneuver?

Have pt lay on floor belly down

Tell them to get up --> weak hip girdle causes them to crawl up on hands and legs before being able to rise

36

What is Motor Neuron Disease (MND)?

Disorders, sometimes hereditary, where degeneration of UMNs and LMNs occur with varying severity and progression rate

37

Spinal Muscular Atrophy
What cells are involved?

MND with Anterior horn involvement

38

Spinal Muscular Atrophy
Clinical Symptoms

LMN signs of weakness, atrophy, areflexia, fasciculations

39

Spinal Muscular Atrophy
Infantile form is...

Werdnig Hoffman
Terminal condition due to rapid development of diffuse weakness

40

Amyotrophic Lateral Sclerosis
Describe the pathology

Progressive degeneration of ALL motor neuron subgroups (UMNs and LMNs)

41

Amyotrophic Lateral Sclerosis
Prognosis and Treatment

Worst prognosis (50% dead within 3 years)

No curative treatment, but Riluzole (glutamate antagonist) may prolong survival by months

42

Amyotrophic Lateral Sclerosis
Clinical Symptoms

Start --> Regional weakness and atrophy of limb, which spreads and becomes bilateral

Diffuse fasciculations

Hyperreflexia

Spasticity

Babinski sign positive

Weakness affecting speech, swallowing, chewing, breathing

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