IM: AI Neuromuscular disorder (Dr Schee Ji Ping)

Question 1

1) Where is the weakness in (proximal vs distal) in peripheral nerve disease?

2) Does Peripheral nerve disease have
- Facial involvement? (Eg?)
- Ocular involvement? (Eg?)
- Bulbar involvement? (Eg?)

3) Is there respiratory involvement for any of the peripheral nerve disease?

4) Is there sensory involvement in peripheral nerve lesion?

Answer 1

1) Distal > proximal

2)
- Acutely (GBS)
- Acutely (MFS)
- Acutely (GBS/BBE/MFS)

3) Uncommon except for GBS

4) Yes, anterior horn cell disease, NMJ disease and myopathies don’t have sensory involvement

Question 2

** Relevant history in peripheral nerve disease**

What is the mnemonic 4D 4C and TIME?

Answer 2

4D
Diabetes Mellitus
Drink- alcohol
Drugs (Chemo drugs, cardiac meds etc.)
vitamin Deficiency (Vitamin B12)

4C
Charcot Marie Tooth disease
Connective tissue disease
Cancer
Chronic inflammatory demyelinating polyneuropathy (CIDP)

TIME
Toxin related
Infection
Metabolic
Endocrinopathy (Hypothyroidism)

Question 3

Epidemiology of Guillain-Barre syndrome

1) What common symptom history (2) precedes GBS in 2/3rds of the patients?

2) Campylobacter jejuni is isolated in 30% of cases. (T/F)

3) CMV is not seen. (T/F)

4) What local viruses can cause GBS? (2)

5) How many weeks prior to numbness presentation of GBS does patient have infection?

Answer 3

1) - URTI
- Diarrheal symptoms

2) True

3) False, CMV is seen in 10% of cases

4)
- Dengue
- Covid

5) 2-4 weeks

Question 4

Pathogenesis of Guillain-Barre syndrome

1) What is another name of GBS?

2) What is the pathogenesis of GBS?
- Describe three things that occur

3) What response is triggered when patient gets an infection that triggers GBS?

4) What antibodies are involved in GBS?

Answer 4

1) AIDP- Acute Inflammatory Demyelinating Polyneuropathy

2) Inflammation and demyelination of nerves
- Molecular mimicry
- Antiganglioside antibodies
- Complement activation (membrane attack complex (MAC))

3) A humoral immune and autoimmune response is triggered that causes nerve dysfunction

4) antiganglioside antibodies

Question 5

History of Guillain-Barre syndrome

1) What two infections are present prior to GBS?

2) What is the organism in GI infection that causes GBS in 30% of its patients?

3) Other association (risks) of developing GBS are:
- Vaccines (eg?)
- AI disease (eg?)
- Immunosuppressive drugs (eg?)
- Surgery

4) Viral infections associated with GBS? (4)

Answer 5

1) - URTI
- GI infective symptoms

2) Campylobacter jejuni

3)
- H1N1 vaccine
- SLE
- anti-TNF

4)
- EBV
- Zika
- CMV
- Varicella zoster virus

Question 6

1) What are the symptoms of GBS? (3)

2) Define GBS (2)

3) GBS was described in the year?

4) Progressive?
Symmetrical?
Ascending or descending?
Flaccid paraparesis?

Answer 6

1) symptoms:
- Numbness
- Paresthesia
- Burning pain in the limbs

2) Definiton:
- Syndrome of areflexic paralysis and
- Albuminocytologic dissociation in CSF

3) 1916

4) Progressive
Symmetrical
Ascending
Flaccid paraparesis

Question 7

Signs of GBS on physical examination?

• Facial weakness (1)
• Ocular weakness (2)
• Bulbar weakness (4)
• Neck weakness (1)
• Autonomic dysfunction (5)

Tone?
Weakness?
Reflex?
Sensory?
Proprioception?

Which symptom (1) take the longest to recover?

Answer 7

Facial weakness
- Smooth forehead (unable to bury eyelashes) - LMN facial palsy

Ocular weakness
- Diplopia
- Isolated cranial nerve palsy

Bulbar weakness
- Dysphagia
- Nasal speech
- Nasal regurgitation
- Choking

Neck weakness
- Especially neck flexion

Autonomic dysfunction
- Flushing
- Palpitation
- Labile BP
- Fluctuating HR
- Sphincter dysfunction

• Reduced tone
• Weakness: Distal>proximal
• Reflex: hypo/areflexia
• Sensory: subjective
• Proprioception: maybe
• Reflexes takes the longest to recover

Question 8

State 3 predictive factors in GBS that need for mechanical ventilaton.

Answer 8

• Bulbar symptoms
• Inability to raise the head or flex the arms
• Inadequate cough

Question 9

What is GBS disability score used for?

Range of score?

Assesses? (3)

Answer 9

• Assess severity of GBS
• Has score 0-6
• assesses patient’s walk over 10m, bed/chairbound/ ventilation

Question 10

Investigations for GBS

1) Why do FBC, Blood glucose, Electrolytes, RP and LFT?

2) What antibody serology investigated for GBS?

3) What is the finding in CSF analysis via Lumbar puncture that suggests GBS?

3a) What feature in CSF analysis will point towards infective or inflammatory pathologies?

Answer 10

1) Exclude infective and metabolic causes of GBS

2) Anti-ganglioside antibodies

3) CSF analysis for GBS:
- Elevated CSF protein
- Normal white cell count in CSF
(albumin-cytological dissociation)

4) Marked pleocytosis (>50cells/uL) suggests inflammatory or infective pathologies

Question 11

What are the two features (based on NINDS) required to diagnose GBS?

Answer 11

1) Progressive bilateral weakness of arms and legs
(initially legs only)

2) Hypo-/areflexia

Question 12

What are 4 (actual:14) features that doubt diagnosis of GBS?

Answer 12

• increased no. of PMN cells in CSF (>50x10^6/L)
• Hyperreflexia or clonus
• Sharp sensory level (SC injury)
• Nadir<24H

Question 13

What are 5 differential diagnosis of GBS?

Answer 13

1) Poliomyelitis
2) Myasthenia Gravis
3) Hypokalemic periodic paralysis
4) Botulism
5) Acute myopathy

Question 14

Management of GBS

1) Definitive management is either… (2)

2) To prevent complications:
a. Cardiac and pulmonary dysfunction
(monitor 5, treat with 3)
b. Pulmonary embolism

3) Can we treat patient with IVIG then plasma exchange in the same time period? Why?

Answer 14

1) Management
- Intravenous immunoglobulin (IVIG)
- Plasma exchange (catheter, Like dialysis)

2) Complications:
a. cardiac
- ECG
- BP monitoring
- Pulse O2
- Vital capacity
- Monitor swallowing
then, insert cardiac pacemaker, use mechanical ventilator and nasogastric tube placement

b. Prophylactic use of subcutaneous heparin (5000 units) and compression stockings (those whom are bedridden or chair-bound)

3) No, because plasma exchange will washout the immunoglobulins

Question 15

Management of GBS

1) Dosage of IVIG? and duration

2) Dosage of plasma exchange and duration

3) When should the treatment start preferably?

Answer 15

1) 0.4g/kg daily for 5 days

2) 200-250mL plasma/kg for 5 alternating days

3) Within 2-4 weeks from the onset of unable to walk unaided

Question 16

Management of GBS

1) Plasma exchange is unsuitable for? (1)

2) Possible complication from plasma exchange?

Answer 16

1) Patients with autonomic instability

2) Catheter-related sepsis

Question 17

OUTCOME of GBS

1) 60% of patients develop complications like (4)

2) What percent of patients recover from GBS and are able to walk

Answer 17

1) Complications
- Pneumonia
- Sepsis
- Pulmonary embolism
- GI bleed

2) 80% of patients will be able to walk within 6 months

Question 18

MANAGEMENT of GBS

1) What are the 4 long-term management component of GBS (rehab)?

Answer 18

1) Long-term management:
- Physical function (rehab with physiotherapist etc.)
- Fatigue (graded & supervised exercise program)
- Pain (Drugs for neuropathic pain)
- Psychological distress (Psychologist etc.)

Question 19

Myasthenia Gravis epidemiology

1) What is the type of distribution of MG? (1)

2) Ages at each spectrum which are at risk and age preference for each age range? (2)

Answer 19

1) Bimodal distribution

2) Ages:
- 20-30 years old: F>M
- >50 years old M>F

Question 20

MG pathogenesis

1) What is the name of the antibodies that cause MG? (1)

2) Where do these antibodies bind? (2)

3) What is the key points in the pathogenesis of MG (2)

Answer 20

1) Anti-acetylcholine receptor antibodies

2) Post-synaptic receptor
- at Neuromuscular junction (NMJ)

3) Reduced no. of AChR available at NMJ
- Functional block of AChR resulting in fewer competing receptors for binding of acetylcholine during NM transmission