AIDPCIDP MMN Stålberg

2. Incidence
• 1.5-2 per 100.000 /year
• all ages

3. Acute inflammatory polyneuropathies
• Subgroups Typically
• AIDP Acute infl demyelin. pnp Motor/sensory, relatively good progrnosis
• AMSAN Acute motor-sensory axonal pnp Motor/sensory, severe nerve damage
• AMAN Acute motor axonal pnp Weakness, normal sens, severe nerve
damage
• MFS Miller Fisher´s syndrom Ataxia (sens) and diplopia, often not weak

4. GBS; Symptoms
Predominantly weakness
– few or many muscle groups
– usually symmetic, but not always
– 1/6 need respirator
– 50% have cranical nerve involvement
•Sensory symptoms may dominate
– distal parestesia
– Deep sensibily most involved
– pain may be prominent

5. Findings
• reduced reflexes
– if refl are normal but no weakness, diagnosis ??
• ataxia (peripheral or brain stem)
• unclear papilledema
• autonomic dysfunction common
• sympatetic-orthostatic hypotension
• parasympatetic-tachycardia, bladder paresis, bowel
paresis
• can give mors subita

6. Time course
• The symptoms develop during days-weeks
• Progress < 2 weeks at 50%
• If progress > 8 weeks -> CIDP
• Recovery varies from weeks to months
– the slowest at axonal injury
• Mortality 5%
– autonomic dysfunction
– complications to immobilization
– 10% sequel
– 3% reoccur within weeks, months, years

7. Etiology och pathophysiology
• Autoimmune disease
– 2/3 comes after infection or surgery
– vaccinations
– malignant lymphoma
– aids
• Pathophysiology
– perivenulär patchy endoneural infiltration of mononuclear cells
– conduction block
– segmental demyelination
– axonal degeneration in severe cases

8. Impulse conduction block
MUSCLE
Two stimulation points;
Amplitude reduction = conduction block

9. F-response
MUSCLE
F-response is a recurrent response travelling from
stimulation to spinal cord and then to the muscle.
CV in entire nerve, also proximal part.
At conduction block, no transmission
in blocked nerve.
stim

10. A-waves
MUSCLE
A wave is usually generated in an abnormal
hyperexcitable axon

11. EDX vid GBS
Conduction block amplitude decay prox-dist, few F
Demyelination low CV, particularly MCV
Axonal degeneration low CMAP + denervation (EMG)
Motor hyperexcitability A-waves during 1-14 days
Sensory hyperexcitability not seen with routine EDX

12. May be due to
ion-channel interference
demyelination
Localization
mainly motor nerves
proximal or distal
symmetrical sometimes

13. Proximal, general or distal slowing
Prox slowing
MUSCLE
Generalized slowing
MUSCLE
Distal slowing
MUSCLE

14. Acute polyradiculitis
(Guillain-Barré Syndrome, GBS, AIDP)
Strategy
• demonstrate acute motor and sensory neuropathy
• demonstrate conduction block
• assess: severity, pathology, distribution

15. Acute polyradiculitis, GBS
-expected findings
Expected abnormal findings
Neurography, MCS
• conduction block
• F waves delayed and few
• DL prolonged
• reduced MCV, sometimes normal initially
• distal amplitude normal/low
Neurography, SCS
• reduced amplitude
EMG
• reduced IP, later acute neurogenic EMG findings
Autonomic tests
• often abnormal

16. Acute polyradiculitis (GBS, AIDP)
- procedure
Neurography
• MCS: n.med, n.uln, n.tib, n.per unilaterally
• SCS: n.radialis, n.suralis unilaterally
EMG
• < 10 days: not indicated (earlier onset ?)
• > 10 days: degree of axonal involvement
Autonomic tests
• RR-interval, SSR, pletysmography
Sensory thresholds (optional)
• temperature and vibration

17. Motor conduction block in GBS
-distal and prox CB
wrist
elbow
MCV F-waves
Median nerve
691104

18. Motor conduction block in GBS-
distal,proximal CB and general demyelination
ankle
knee
MCV F-waves
Fibular nerve
691104

19. Guillain Barré
Tibial nerve showing cond block below knee
340420

20. F-waves in GBS.
Proximal cond block
Normal GBS

21. A-waves
N Medianus

22. A-waves
N Medianus

23. A-waves
axon reflex extra discharge
(IDD)
ephaps M satellite

24. A waves
N Tibialis

25. A waves
N Tibialis

26. A- waves and GBSA- waves and GBS
15 year old girl

28. Uppsala: The final diagnosis if referral asks
GBS and EDX is normal
EDX normal Clinical EDX day
15/113 GBS?, myelopati, TIA 16d
GBS?? 43 d
CVL, vomiting 2d
Myosit, GBS, Ciprofloxacin (pain) 10d
(abnormal day3, normal day 7).
Transient GBS 3d
ADEM 7d
Diarrea after trip abroad 22d
Parestesia, 168d
increase refl, pain 14d
Vaccination 31d
lumbar pain MR uneg. 1d
Meningitis 14d
Inflammation in disc 22 d
GBS 6 y ago, now numbness, exclude GBS 20d
GBS för 8 y ago, now relaps? Prob not 8 år

29. Uppsala: The final diagnosis (referral, or a
clinical final diagnosis) if EDX at the first
occasion was interpreted as GBS
62 patients with EDX interpreted as GBS
Clinical final diagnosis GBS 60
Weakness, became GBS 1
Numbness – IVIG (GBS 2 years ago) became GBS
1

30. Referral GBS?
1:a EDX ”patol EDX” (unspec)
Which was the final diagnosis
GBS/GBS trol/GBS? 8
"non-GBS" 8
Encephalitis/myelitis 5
Unclear cases (weakness) 5
Root/Spinal Stenosis 4
Sensory loss 3
Lymphoma, antiHU 2
Central bleeding 2
Miller Fisher 1
Lyme disease 1
Critical illness myopathy 1
40/113 patienter

31. CIDP, clinical
• Signs of cranial nerve (CN) involvement (eg,
facial muscle paralysis or diplopia)
• Gait abnormalities
• Motor deficits (eg, symmetric weakness of both
proximal and distal muscles in upper and lower
extremities)
• Diminished or absent deep tendon reflexes
• Sensory deficits (typically in stocking-glove
distribution)
• Impaired coordination

32. CIDP, EDX
Electrodiagnostics - electromyography (EMG) and nerve
conduction study (NCS). In usual CIDP, the nerve
conduction studies show demyelination. These findings
include:
•a reduction in nerve conduction velocities;
•the presence of conduction block or abnormal temporal
dispersion in at least one motor nerve;
•prolonged distal latencies in at least two nerves;
•absent F waves or prolonged minimum F wave latencies in
at least two motor nerves. (In some case EMG/NCV can be
normal).

33. Chronic polyradiculitis
CIDP
Etiology
• probably prolonged autoimmune reaction
against peripheral nerves.
Strategy
• demonstrate subacute motor and sensory
neuropathy
• demonstrate conduction block
• assess: severity, pathology, distribution

34. CDPCDP
Distribution of conduction slowing
proximal even distal
AIDP/CIDP ++
CMT1 ++
anti MAG ++
modified from Attrian et al. Clin neurophys March 2001

35. length dependent dispersion
wrist
below elbow
above elbow

36. Multifocal Motor Neuropathy; MMNMultifocal Motor Neuropathy; MMN
Clinical featuresClinical features
•debut young adults, slow progression
•progressive weakness, even in non-atrophic muscles
•nerve distribution
•atrophy
•muscle cramps, fasciculations
•distal predominance
•no sensory disturbance
•reflexes diminished Stålberg

37. MMNMMN
ElectrodiagnosisElectrodiagnosis
•EMG shows denervation
•Nerve conduction:
reduced velocity
conduction block!
sensory normal
Stålberg

38. MMNMMN
wrist
elbow
Stålberg

39. MMNMMN
General commentsGeneral comments
•Symptoms similar to ALS!
In diagnosis of ALS, exclude MMN
by means of nerve conduction studies
Check for GM1 antibodies
•Is the disease a motor variant of pure motor CIDP?
Sometimes sensory nerves are involved
Nerve distribution
Conduction block
Effect of immunosuppresive treatment
Weakness also in non-atrophic muscles Stålberg

40. MMN/CIDP a comparison, Kimura textbook
MMN CIDP
pure motor frequent rare
mononeuritis multiplex yes no
remission/exacerbation no yes
generalized areflexia no yes
CSF protein often normal elevated
site with cond block forearm, brachial plexus entrapment sites
elevated anti-GM1 antibody frequent rare
choice of therapy immunosupp,IVIG steroids.plasmaex
IVIG