Paraproteinaemic demyelinating neuropathy

Paraproteinaemic demyelinating neuropathy (PDN) is sometimes described as:

z	chronic demyelinating neuropathy associated with a benign paraprotein;
z	CIDP associated with paraprotein;
z	CIDP with paraproteinaemia.

Antibody-producing bone marrow cells go out of control and produce large numbers of the same antibody. The antibody (or immunoglobulin) sometimes damages nerve fibres causing a peripheral neuropathy.

Some doctors regard the clinical, electrophysiological and pathological features of the demyelinating paraproteinaemic neuropathies and of CIDP as closely similar and almost indistinguishable.

These neuropathies are usually late-onset in terms of age and are mixed motor and sensory, although the severity of sensory loss tends to be greater compared with CIDP. So there is usually more pain but less severe weakness and impairment.

 

Most patients respond to corticosteroids, cytotoxic drugs, or plasma exchange.

Group member Ken Sawyer has created a Web site of information on PDN. The GBS Support Group accepts no responsibility for linked sites.

Multifocal motor neuropathy

Multifocal motor neuropathy (MMN) mimics motor neurone disease (MND/ALS). Research has shown it to be a chronic demyelinating neuropathy and some regard it as a rare variant of CIDP. However, there are differences that are more prominent than the similarities.

MMN patients commonly have asymmetric weakness of the distal (far) muscles, while in CIDP, proximal (near) symmetric weakness is more common. The remitting and relapsing course that may occur in CIDP is uncommon in MMN. Patients with MMN rarely have significant sensory symptoms, unlike CIDP. Increased protein level in the cerebrospinal fluid of MMN patients is rare.

Treatment by IVIg or cyclophosphamide is shown to be effective.

Lewis-Sumner syndrome or MADSAM

The Lewis-Sumner syndrome is also known as MADSAM — multifocal acquired demyelinating sensory and motor neuropathy. It is a chronic condition with similarities to multifocal motor neuropathy but with enough differences, especially in treatment, to have acquired its own definition. Some report it to be an assymetrical variant of CIDP.

MMN and MADSAM respond to IVIG. Some MADSAM sufferers respond to prednisolone whilst most MMN sufferers do not.

Chronic axonal neuropathy

Chronic axonal neuropathies are common, particularly as a result of diabetes or alcoholism. However, the medical literature does report cases of immune-mediated chronic axonal neuropathy though there are suggestions that this is a secondary result of myelin damage that ultimately appears to be the primary cause of the condition.

Sub-acute inflammatory demyelinating polyradiculoneuropathy (SIDP)

GBS is defined when the nadir (worst point) occurs within four weeks of first symptoms. Usually it is much less. CIDP is defined when the nadir comes after eight weeks. Usually it take much longer. An illness peaking peaking after four weeks but before eight weeks may be called subacute etc and will be treated as CIDP or GBS depending on which it best resembles.

 

 

 

 

 

 

If after reading this guide you still have anxieties and unanswered questions, telephone our helpline on 0800 374803 (UK) or 0033 1529 415278 (RoI). Alternatively, you can e-mail us or register for support on-line

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GBS Support Group, LCC Offices, Eastgate, Sleaford, Lincs, NG34 7EB Tel: 01529 304615 E-mail: admin@gbs.org.uk Web site: www.gbs.org.uk © GBS Support Group

January 2005

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