Dear collegue,

On 4 february 2002 I saw mr. O. Marchiori (date of birth 13-10-1933).
The question was whether the diagnosis CIDP should be considered and if so
whether treatment with IVIg is indicated after steroids had failed.
My conclusion is that CIDP is very unlikely and therefore IVIg is not
indicated. Against the diagnosis CIDP is:
-there is no areflexia.
-the conduction velocities in the arms are not in the demyelinating range.
-the CSF albumin is only moderately elevated.

Although this patient complains of tingling first in his left, later in his
right leg and although the left sural nerve is impaired at neurophysiological 
examinations, the sensory nerves appears not to be affected. The 
discrimination between a sharp and numb needle is perfect, there are no
vibration sense impairments and the sensation of moving his toes is intact.

I consider a pure motor syndrome as the most likely cause of his weakness
and atrophy of his legs. Therefore multifocal motor neuropathy (MMN) has to 
be considered. In favour of this diagnosis is his deterioration after 
treatment with steroids but there are several signs against this diagnosis as
well:
-MMN usually starts in the arms.
-the weakness is not strictly in the distribution of motor nerves.
-electrophysiological tests show no signs of conduction block.

IVIg can also be considered in MMN. Since I feel this diagnosis is unlikely 
I would not try this treatment.
Motor neuron disease is compatible with many of the disorder in mr Marchiori.
I would follow up this man with electrophysiological studies to see whether
signs of denervation arise in his arms and to look for signs of conduction
block. If there are signs of conduction block I would try treatment with IVIg.
Repeated clinical examinations may reveal Babinski signs or hyperreflexia in
that case the diagnosis will be clear. Perhaps it is now already time to
start with Riluzole.
I'm afraid we will finally arrive at the diagnosis of motor neuron disease.
If possible I would appreciate very much to be informed on the course of
this kind patient.

Sincerely yours,

prof. dr. M. Vermeulen,
neurologist 
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