Neuropathy, Myopathy, and NMD Flashcards

1
Q

What is a Mononeuropathy?

A

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

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2
Q

Wha are the 2 most common causes of mononeuropathies?

A

Trauma or Compression

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3
Q

Common cause of Ulnar Mononeuropathy?

A

Leaning or falling on the elbow

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4
Q

Common cause of Peroneal Mononeuropathy?

A

Injury to the lateral knee

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5
Q

Carpal Tunnel Syndrome

Describe the pathophysiology

A

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

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6
Q

Carpal Tunnel Syndrome

Clinical Symptoms

A

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

Thenar weakness and atrophy in very severe cases

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7
Q

Carpal Tunnel Syndrome

Treatment

A

Local rest

Anti-inflammatories

Splinting

Surgical decompression of the nerve

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8
Q

Describe Wallerian degeneration of nerves

A

Occurs at sites of severe nerve injury

Injury involves myelin and axons distal to the point of injury

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9
Q

Do nerves regenerate?

A

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

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10
Q

What is a polyneuropathy?

A

Disorder of multiple, major and small nerves

Characterized by an early sensory loss in distal limbs

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11
Q

Polyneuropathy

Clinical Symptoms

A

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

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12
Q

What are two general big causes of Polyneuropathy?

A

Axonal degeneration (more common)

Demyelination

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13
Q

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

A

Axonal degeneration – amplitude of waves are reduced

Demyelination – slowing of the nerve conduction

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14
Q

What is EMG testing?

A

Needle electromyography

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

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15
Q

When are nerve biopsies performed?

A

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

The patient is left with numbness after the biopsy

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16
Q

Polyneuropathy

Treatment

A

Address underlying causes (diabetes, alcohol)

Orthotic devices – improve ambulation

Physical therapy

Meds to improve paresthesia or dysesthesia

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17
Q

Guillan Barre Syndrome

Clinical Symptoms

A

Ascending, areflexic paralysis

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

18
Q

Guillan Barre Syndrome

What often precedes this syndrome? Describe the pathology.

A

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
Q

Guillan Barre Syndrome

Diagnosis

A

Evidence of demyelination seen on EMG (slowing of conduction)

Elevated protein in CSF, few if any WBCs

20
Q

Guillan Barre Syndrome

Prognosis and Treatment

A

Good prognosis with medical treatment

Plasmapheresis or IVIG may shorten illness and hasten recovery

21
Q

List some potential causes of Chronic Acquired Polyneuropathies

A
Diabetes
Hypothyroid
Uremia
Cancer
Myeloma
Rheumatoid arthritis
Lupus
Nutritional defects (Vit B)
Infection (leprosy)
Toxins (alcohol, lead)
22
Q

Hereditary Neuropathies

Clinical Symptoms

A

Onset usually in childhood

Distal sensorimotor deficits

Little/no paresthesia or dysthesia

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

23
Q

What is a myopathy?

A

Primary disease of muscle

24
Q

What is the first sign of myopathy?

A

PROXIMAL limb weakness and atrophy (shoulder and hip)

25
Q

Symptoms of Myopathy

A

Weakness
Fatigue, maybe with cramping

Proximal limb weakness (shoulders and hips)

Late loss of reflexes (after significant atrophy)

Intact sensation

26
Q

Myopathy

Diagnostic Methods

A

Review family history

Serum enzymes (CK) often elevated

EMG demonstrates muscle disorder

Muscle biopsy

27
Q

What is Polymyositis?

A

Inflammation and weakness of multiple muscles

28
Q

What are the causes of Polymyositis?

A

Viral infection

Drug reaction

Autoimmune

29
Q

Polymyositis

Diagnosis

A

EMG testing

Presence of inflammation and muscle fiber necrosis on muscle biopsy

30
Q

Polymyositis

Treatment

A

Immunosuppression (corticosteroids)

31
Q

Polymyositis

Clinical Symptoms

A

Proximal weakness (like a myopathy)

Rash around eyes or fingers

32
Q

What is Muscular Dystrophy?

A

Hereditary myopathy of variable progression and severity

33
Q

Duchenne’s Muscular Dystrophy

What is the inheritance? What is the pathological defect?

A

X linked inheritance

Absence of dystrophin (a crucial structural protein in muscle)

34
Q

Duchenne’s Muscular Dystrophy

Clinical Symptoms

A

More common in boys (X linked)

Proximal weakness

Calf pseudohypertrophy from muscle replaced by fat

Cardiorespiratory death by 3rd decade

35
Q

What is Gower’s Maneuver?

A

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
Q

What is Motor Neuron Disease (MND)?

A

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

37
Q

Spinal Muscular Atrophy

What cells are involved?

A

MND with Anterior horn involvement

38
Q

Spinal Muscular Atrophy

Clinical Symptoms

A

LMN signs of weakness, atrophy, areflexia, fasciculations

39
Q

Spinal Muscular Atrophy

Infantile form is…

A

Werdnig Hoffman

Terminal condition due to rapid development of diffuse weakness

40
Q

Amyotrophic Lateral Sclerosis

Describe the pathology

A

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

41
Q

Amyotrophic Lateral Sclerosis

Prognosis and Treatment

A

Worst prognosis (50% dead within 3 years)

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

42
Q

Amyotrophic Lateral Sclerosis

Clinical Symptoms

A

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