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Flashcards in Peripheral Neuropathies Deck (58)
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1

Define polyneuropathy

Symmetric distal sensory loss with burning or weakness

2

Etiologies of polyneuropathy

Adverse effect of medication
Manifestation of systemic disease

3

Pathogenesis of Guillain-Barre Syndrome

Acute immune-mediated group of polyneuropathies, usually provoked by preceding infection
Acute inflammatory demyelinating polyneuropathy (AIDP)

4

Types of infections which commonly bring on Guillain-Barre Syndrome

Campylobacter jejuni
Respiratory tract infection
CMV
EBV

5

Guillain-Barre antibodies to what

Gangliosides which cause axonal injury or immune response to myelin

6

Guillain-Barre Clinical Features

Ascending symmetric muscle weakness
Severe respiratory muscle weakness (intubation)
Paraesthesia's common
Sensory abnormalities frequently mild
Severe back pain
Dysautonia

7

What is Dysautonia?

Tachycardia alternating with bradycardia, urinary retention, HTN alternating with hypotension, orthostatic hypotension, ileus, loss of sweating

8

Guillian Barre Syndrome Diagnostics

Lumbar puncture
Electromyography (EMG)
Nerve conduction studies
Glycolipid antibodies to gangliosides

9

Features that make Guillian-Barre Syndrome doubtful

Sensory level
Marked, persistent asymmetry of weakness
Severe/persistent bowel/bladder dysfunction
More than 50 WBC in the CSF

10

Define Bell's Palsy

Acute peripheral facial palsy of unknown origin

11

Bell's Palsy Anatomy

Fibers for motor output to facial muscles
Parasympathetic fibers to the lacrimal, submandibular, & sublingual salivary glands
Afferent fibers for taste from the anterior 2/3 of tongue
Somatic afferents for external auditory canal and pinna

12

Pathogenesis of Bell's Palsy

Most common- herpes simplex
Other infectious causes: EBV, adenovirus, rubella, mumps, influenza B, herpes zoster, coxsackie virus
Ischemia

13

Clinical Presentation of Bell's Palsy

Sudden onset
Unilateral facial paralysis
Eyebrow saggio
Inability to close the eye
Disappearance of the nasolabial fold
Mouth drawn to the non affected side
Decreased tearing

14

Physical Exam for Bell's Palsy

Assess facial movement
General physical and neurologic exam
Attention to external ear for vesicles or scabbing
Attention to parotid for mass lesions

15

Bell's Palsy Course

Onset over hours to 2 days
Progressive with maximal paralysis within 3 weeks of onset
Recovery of some degree of function by 6 months

16

Bell's Palsy Management

Glucocorticoid therapy

17

Patient Information for Bell's Palsy

Usually caused by a virus
As nerve cell swells, it becomes compressed & it's protective covering breaks down
Takes time to recover

18

What is Myasthenia Gravis?

Autoimmune disorder characterized by weakness and fatiguability of skeletal muscle

19

Pathogenesis of Myasthenia Gravis

Autoantibodies against acetylcholine receptors (AChR-Ab)
Decrease # of acetylcholine receptors due to binding
Destruction of receptors by a compliment-mediated process
T cells bind to acetylcholine receptors and activate B cells
Most have thyme abnormalities

20

Bimodal distribution of Myasthenia Gravis

Female- 20-30s
Male- 60-80s

21

Key Symptoms of Myasthenia Gravis

Fluctuating skeletal muscle weakness
Worsened by contractile force
True muscle fatigue not tiredness

22

Ocular Symptoms of Myasthenia Gravis

Ptosis
EOM often involved leading to diplopia
Ptosis increases with sustained upward gaze or by holding up the opposite eyelid

23

Bulbar Symptoms of Myasthenia Gravis

Weakness with prolong chewing, jaw weakness
Dysarthria
Dysphagia
Nasal regurgitation of liquids

24

Facial Symptoms of Myasthenia Gravis

Patient appears expressionless
"Lost their smile"
Weakness of orbicular Doris muscle
Weakness of orbicular oculi

25

Neck and Limb Symptoms of Myasthenia Gravis

Weight of head overcome extensors
Limbs proximal weakness
Wrist & finger extensors & foot dorsiflexors

26

Respiratory Symptoms of Myasthenia Gravis

Respiratory insufficiency
Pending respiratory failure

27

Myasthenia Gravis Clinical Course

Early symptoms transient
Gets worse throughout the day

28

Myasthenia Gravis Diagnostics

Serologic testing immunologic assay
Electrophysiologic studies

29

Electrophysiologic Studies

Repetitive nerve stimulation studies
Single fiber electromyography

30

Treatment for Myasthenia Gravis

Anticholinesterase agents
Chronic immunotherapies
Rapid immunotherapies
Surgery