Chronic Inflammatory Demyelinating Polyneuropathy

 05 November 2004

Slowly progressive, sometimes relapsing, demyelinating sensorimotor polyneuropathy affecting limbs.

Mean age of onset 45

Slight predominance in males

6 – 9 months from onset to time of diagnosis

75% present with symmetrical, sensorimotor neuropathy.

CLINICAL

Kenneth et al. Chronic Inflammatory Demyelinating Polyneuropathy: Clinical features and response to treatment in 67 consecutive patients with and without monoclonal gammopathy. Neurology 1997; 48: 321-7.

Working criteria

1.   Progressive or relapsing sensorimotor, or only motor or sensory, dysfunction of more than 1 limb of a peripheral nerve nature, developing over at least 8 weeks with hypo or areflexia.

2.   Neurophysiology

a.    <70% conduction velocity

b.    >150% distal latency

c.     absent or prolonged F waves

d.    partial conduction block

3. CSF: albuminocytologic dissociation.

Routine tests: FBE, UCE, ESR, ANA, CK, TFT, serum & urine electrophoresis, HIV, hepatitis serology, B12, glucose.

TREATMENT

MAINSTAY:

1.   IVIG 0.4 gm/kg/d for 5 days.

2.   Plasmapharesis

3.   Prednisolone 1mg/kg/d

All have 66% response rate.

If no initial response with IVIG or plasmapharesis, out of this group 35% will respond with second or third course of same treatment.

May have to trial steroids for up to 2 months before response.

If no response with 1 form of main treatment, may get response with other form of mainstay of treatment.

May require multiple repeat treatments individually timed to achieve stabilisation of relapsing disease or addition of second mainstay treatment (ie plasmapharesis & steroids).

Azathioprine often added on to prednisolone but no evidence for this to be of any benefit.

Kenneth et al. Chronic Inflammatory Demyelinating Polyneuropathy: Clinical features and response to treatment in 67 consecutive patients with and without monoclonal gammopathy. Neurology 1997; 48: 321-7.

PREDICTORS OF RESPONSE TO IVIG

More than 90% will respond if all five factors present.

1.   Disease duration <1 year.

2.   Progression of weakness until treatment.

3.   Absence of discrepancy in weakness between arms & legs.

4.   Areflexia of the arms.

5.   Slowing of motor conduction velocities in median nerve.

Angelika et al. Treatment of chronic inflammatory demyelinating polyneuropathy with intravenous immunoglobulin. Neurology 51(Suppl 5) S16-19, December 1998.

SECOND LINE TREATMENT

Alpha-interferon: several reported cases in young patients

Sabatelli et al. Interferon-alpha may benefit steroid unresponsive chronic inflammatory demyelinating polyneuropathy. Journal of Neurology, Neurosurgery & Psychiatry. 58(5):638-9

Gorson et al. Improvement following interferon-alpha 2A in chronic inflammatory demyelinating polyneuropathy. Neurology 48(3):777-80, 1997 March.

Cyclophosphamide in conjunction with prednisolone (no trial showing efficacy).

Cyclosporin A (promising but no trial)

Hodgkinson et al. Cyclosporin A in the treatment of chronic inflammatory demyelinating polyneuropathy. Journal of Neurology, Neurosurgery & Psychiatry. 1990;53:327-30.