Neuro /Bells Palsy/TN/Myasthenia Gravis

Question 1

Amygdala

Answer 1

fear and aggression, facial evaluation, social processing, (and odor processing)

Question 2

Cerebellum

Answer 2

implicit/procedural/motor memory

Implicit memory is skills, action, and emotional conditioning

Question 3

Prefrontal Cortex

Answer 3

memory encoding and retrieval

Question 4

Limbic System

Answer 4

Involved in emotional responses:
-controls emotional experience and expression
-can modify the way a person acts
-produces such feelings of fear, anger, pleasure & sorrow
-recognizes life threatening disruptions in a person’s physical or psychological condition and counters them

Initiates fight-or-flight (SNS) system
-Guides a person into behavior that may increase chances for survival

Question 5

choroid plexus

Answer 5

500 mL CSF formed each day (mainly) by choroid plexus in lateral ventricles.

Question 6

Cerebellum

Answer 6

General Functions:
Muscle memory
Balance (proprioception)
Equilibrium (vestibular)
Muscle Tone
Coordination
Motor Learning

Question 7

Bulbar Nerves

Answer 7

CN IX
CN X
CN XI
CN XII
-common “function” of chewing, swallowing, head/neck movement

Question 8

Lower motor neuron

Alpha motor neurons

Answer 8

To extrafusal muscle fibers
Force generating contractions

Question 9

lower motor neuron

gamma motor neuron

Answer 9

To intrafusal muscle fibers
Muscle tension and reflex contractions

Question 10

Bell Phenomenon

Answer 10

Left eye rolls upward and inward

Question 11

Answer 11

bells palsy

Question 12

Answer 12

bells palsy

Question 13

Bell palsy essentials of dx

Answer 13

-Sudden onset of lower motor neuron facial palsy.
Deficits evolve in 72 hours
-Hyperacusis or impaired taste may occur.
-No other neurologic abnormalities.

Question 14

Bell palsy other potential findings (pain)

Answer 14

Post auricular pain
Concurrent or prodrome

Trigeminal neuralgia ~ 8%

Question 15

Bells palsy

Sx onset and prognosis

Answer 15

Deficits evolve in 72 hours

Recovery of normal facial function occurs in majority

Question 16

Bell Palsy: Epi

Answer 16

• Most common etiology of unilateral facial nerve palsy
• Usually adults, peak ages 20-40
• Men and women equally affected
• More often on right side of face
• Rarely occurs in summer
• DM, immunocompromise, preeclampsia

Question 17

Bells palsy

etiology

Answer 17

HSV hypothesis: after causing primary infection on lips (cold sores), virus travels up sensory nerve axons and resides in geniculate ganglion. At times of stress, virus reactivates and causes local damage to myelin.

Autopsy studies have shown HSV in geniculate ganglion of patients with Bell palsy.

Other potential causes: Lyme disease, syphilis, EBV infection, CMV, HIV; inflammation alone; microvascular disease (DM andHTN). Has also been known to follow recent URI.

May be secondary to autoimmune reactions that cause facial nerve to demyelinate.

Question 18

bells palsy

Patho

Answer 18

Question 19

bell palsy

Dx

Answer 19

Unilateral facial palsy of acute onset
Evolved within 72 hours
Ipsilateral postauricular pain/mild to moderate otalgia/hyperacusis or phonophobia
Hypo or dysgeusia
Subjective tongue and facial hypoesthesia
Pfizer vaccine

Question 20

Facial palsy of known etiology (e.g. Lyme Disease), or a palsy that is progressive, waxing and waning or affects facial zones in an uneven fashion—

Answer 20

is NOT Bells Palsy

Question 21

Bells palsy

PE

Answer 21

Focused neuro exam, complete head and neck exam including detailed CN exam, otoscopy, and tuning fork exams - Except for ipsilateral facial palsy, the exam should be unremarkable

Question 22

Bells palsy

Upper vs Lower motor neuron

Answer 22

Question 23

possible bells palsy?

Uneven distribution?

Vesicles (auditory canal or auricle)?

Answer 23

Suggestive of neoplasm –> imaging

Zoster

Question 24

bell palsy

red flags

Answer 24

Question 25

# Bells palsy Dx testing

Answer 25

Imaging when indicated to rule out stroke or neoplasm Lyme testing if known tick bite or travel to tick endemic area

Question 26

# bell palsy Tx

Answer 26

Question 27

# bells palsy eye protection

Answer 27

Artificial tears during the day, tape shut at night with lubricant

Question 28

# bell palsy Severe cases Tx

Answer 28

For severe cases: Refer to a Neuro-ophthalmologist and Neurologist for further evaluations and treatments > surgery???

Question 29

# bell palsy prognosis and follow up

Answer 29

Question 30

# Trigeminal Neuralgia Essentials of Dx

Answer 30

**Brief episodes of stabbing facial pain**. [attacks following sensory distribution of CN V, usually right sided] Pain is in the territory of the second and third division of the trigeminal nerve. Pain exacerbated by touch.

Question 31

# trigeminal neuralgia International Headache Society criteria

Answer 31

Question 32

# trigeminal neuralgia Patients can localize their pain precisely

Answer 32

Question 33

# Trigeminal neuralgia triggers

Answer 33

Chewing, talking, smiling Drinking cold or hot fluids Touching, shaving, brushing teeth, blowing nose Encountering cold air from open automobile window Patients carefully avoid rubbing the face or shaving trigger area, in contrast to other facial pain syndromes, in which they massage the face or apply heat or ice Many patients try to hold face still while talking, to avoid precipitating an attack

Question 34

Answer 34

trigeminal neuralgia

Question 35

# trigeminal neualgia more about TN pain

Answer 35

Question 36

# Trigeminal neuralgia Epi

Answer 36

More likely biologic females than biologic males Usually begins after age 40, typically 60-70 years HTN is risk factor

Question 37

# TN Dx

Answer 37

Characteristic pain distinguishes it from other causes Labs and imaging not always needed May use labs as baseline for monitoring treatment drug effects Imaging if lesion is suspected

Question 38

Question 39

# TN Tx

Answer 39

AEDs: Carbamazepine and oxcarbazepine Inhibit neuronal sodium channel activity, reducing excitability of neurons Gabapentin, esp in patients with M Modulation of excitatory transmitters involved in pain Lamotrigine Inhibits release of glutamate (excitatory amino acid) and inhibits neuronal sodium channel activity, which stabilizes neuronal membranes, reducing excitability

Question 40

# TN Surgical Tx (3)

Answer 40

Microvascular decompression Gamma Knife treatment damages trigeminal nerve to stop transmission of pain signals Radiofrequency damages trigeminal nerve to stop transmission of pain signals

Question 41

# Tn complications of surgery

Answer 41

Complications of surgery include permanent anesthesia over face or disabling, spontaneous postop pain (can be worse than original trigeminal neuralgia, and often untreatable) Many patients require pain medication even after surgery

Question 42

# TN prognosis

Answer 42

Tends to be chronic Treatments may fail

Question 43

Answer 43

Myasthenia Gravis (MG)

Question 44

# Myasthenia Gravis (MG) general

Answer 44

**Autoimmune disorder of postsynaptic membrane at neuromuscular junction** Characteristics rare presents at any age males and females fatigable muscle weakness: eyelids (ptosis common) and EOM fatigue face, neck, extremities & respiratory muscles

Question 45

# Myasthenia Gravis S/Sx

Answer 45

Partial paralysis of eye movements (ophthalmoparesis), double vision (diplopia), and droopy eyelids (ptosis) are usually among the first symptoms. >50% present with ocular symptoms of ptosis and/or diplopia. Of those who present with ocular sx, half will develop generalized disease within two years.  Weakness and fatigue in neck and jaw also can occur early (Bulbar weakness — impairment of function of CN IX, X, XI, XII) — dysarthria, dysphagia, difficulty holding up the head. About 15% of patients.

Question 46

# Myasthenia gravis generalized Sx

Answer 46

**weakness spreads from face/neck to upper limbs, hands, then lower limbs.** (difficult to lift arms overhead, rise from sitting position, walk long distances, climb stairs, grip heavy objects). Limb weakness alone in 5%

Question 47

# MG Patho

Answer 47

**Immune system attacks Ach receptors on muscle,** so muscle can no longer contract in response to Ach release from motor neurons

Question 48

# Mg Ice Pack test

Answer 48

part of neuro exam if ptosis; based on principle that neuromuscular transmission improves at lower muscle temperatures. Assess ptosis, fill surgical glove with ice, place on closed lid for two minutes; remove ice and reassess ptosis; improvement is positive test result.

Question 49

# MG Edrophonium ("Tensilon") test (historical)

Answer 49

Drug = acetylcholinesterase inhibitor with rapid onset (30 to 45 seconds) and short duration of action (5 to 10 minutes); prolongs presence of acetylcholine in neuromuscular junction and results in immediate increase in muscle strength.

Question 50

# MG blood Work up

Answer 50

**Serum anti-AChR antibodies** positive in 80-90% with generalized MG **Anti-muscle-specific tyrosine kinase (MuSK) antibodies** positive in up to 70% of anti-AChR negative patients facial, respiratory, proximal muscle weakness Seronegative for both antibodies ~10% Consider screening for concurrent thyroid disease

Question 51

# MG electrical work up

Answer 51

EMG testing: repetitive nerve stimulation shows decremental change in amplitude of muscle response

Question 52

# MG Imaging

Answer 52

CT or MRI: thymus gland abnormality (thymoma)

Question 53

# MG Tx Meds and surgical

Answer 53

* Symptomatic (acetylcholinesterase inhibition) to increase amount of acetylcholine (ACh) available at neuromuscular junction * Chronic immunosuppressive therapies (glucocorticoids) to target underlying immune dysregulation * Rapid but short-acting immunomodulating treatments (therapeutic plasma exchange and intravenous immune globulin [IVIG]) * Surgical treatment (thymectomy)

Question 54

# MG Mild disease management

Answer 54

* no treatment * pyridostigmine (cholinesterase inhibitor) * add corticosteroids if unresponsive to inhibitor

Question 55

# MG Crisis (severe weakness, respiratory failure) Tx

Answer 55

* intubation and mechanical ventilation * plasma exchange/IV immunoglobulin

Question 56

# MG Moderate disease Tx

Answer 56

pyridostigmine + immunosuppressant (steroids, cyclosporine, tacrolimus)

Question 57

# MG Thymectomy

Answer 57

patients with thymoma (any age) May not benefit MuSK antibody+ patients patients with generalized MG and AChR antibodies < 60 years of age