Hi Willow,
Sorry that things are so uncertain for sure. I was just googling MMN without conduction blocks, and surprisingly there is a fair bit of info. One report said, "BACKGROUND: Conduction block is considered an essential finding for the distinction between motor neuropathies and lower motor neuron disorders. Only a small number of reports describe patients with multifocal motor neuropathies who lack overt conduction block, although in these cases other features of demyelination still suggest the presence of a demyelinating disorder. In contrast, a purely axonal multifocal motor neuropathy has not been described. METHODS: This report describes nine patients with slowly or nonprogressive multifocal motor neuropathies who had purely axonal electrodiagnostic features. RESULTS: GM1 antibodies titers were normal in all nine cases. Six patients were treated with either prednisone or IV immunoglobulin and three showed convincing improvement. CONCLUSIONS: These findings suggest an immune-mediated motor neuropathy with axonal electrophysiologic features that appears to be distinct from both multifocal motor neuropathy and established motor neuron disorders."
Another article went on to query whether there are two different types of MMN i.e. One with conduction blocks and one without blocks, and concluded IVIG worked for both. It says, "Assess if multifocal motor neuropathy (MMN) with and MMN without conduction block (CB) are similar or distinct diseases. METHODS: The authors reviewed the clinical features and responses to IV immunoglobulin (IVIg) treatment of patients with MMN with and without CB at diagnosis, after 4 years of follow-up and at the last examination. They included all patients showing clinical features of MMN who had been followed for at least 4 years: All had asymmetric purely motor weakness with a peripheral nerve distribution, without any sensory, bulbar, or respiratory signs and without any upper motor neuron involvement. RESULTS: Twenty patients had CB and 13 had no CB. Median follow-up time was 7 years. There were no differences between the two groups in term of age, sex, time from onset to diagnosis, anti-GM1 antibody titers, or CSF data. Nerve distribution, number of affected limb regions, predominant weakness in distal upper extremities, asymmetric weakness, cramps, fasciculations, and Medical Research Council sum-scores in upper and lower limbs were comparable at diagnosis, 4 years of follow-up, and last examination. Few significant differences were observed. Involvement of median nerve was less frequent at 4 years of follow-up (14/20 vs 4/13; p = 0.027) and at the last examination (17/20 vs 5/13; p = 0.009) in patients without CB. Proximal weakness was less frequent in patients with MMN without CB at the last examination (7/20 vs 0/13; p = 0.027). Fewer nerves were involved in patients without CB at the last examination (4.5 vs 2; p = 0.04). Efficacy of IVIg was similar in MNN patients without CB (8/13) and with CB (14/20; p > 0.05). CONCLUSION: After a median follow-up time of 7 years, patients with and without conduction block showed similar clinical features and a similar response to IV immunoglobulin treatment.
PMID: 16924010 [PubMed - indexed for MEDLINE]
Related Articles
* Multifocal motor neuropathy: clinical and immunological features and response to IVIg in relation to the presence and degree of motor conduction block. [J Neurol Neurosurg Psychiatry. 2002]
* Multifocal motor neuropathy: the diagnostic spectrum and response to treatment. [Neurology. 2007]
* [Multifocal motor neuropathy: a retrospective study of the response to high-dose intravenous immunoglobulin (IVIg) and current perspectives for diagnosis and treatment] [Bull Acad Natl Med. 2007]
Sounds like yet another opinion is indeed warranted. I would trust Al's recommendation.
Laurel
PS I would be interested in reading your story and symptoms if you have the energy to tell us.