From the Departments of Neurology, Palo Alto VA
Medical Center and Stanford University (Dr. Katz), Palo Alto, CA;
University of Kansas Medical Center (Dr. Barohn), Kansas City;
University of Texas Southwestern Medical Center (Drs. Kojan, Wolfe,
Nations, and Saperstein), Dallas; and Brigham and Women's Hospital
(Dr. Amato), Harvard Medical School, Boston, MA.
Address correspondence and reprint requests to
Dr. Jonathan Katz, Department of Neurology (127), Department of
Veterans Affairs, 3801 Miranda Ave., Palo Alto, CA 94304; e-mail:
Background: Conduction block is considered an
essential findingfor the distinction between motor
neuropathies and lower motorneuron disorders. Only a
small number of reports describe patientswith multifocal
motor neuropathies who lack overt conductionblock,
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
Methods: This report describes nine patients with
slowly ornonprogressive multifocal motor neuropathies
who had purelyaxonal electrodiagnostic features.
Results: GM1 antibodies titers were normal in all
nine cases.Six patients were treated with either
prednisone or IV immunoglobulinand three showed
Conclusions: These findings suggest an
immune-mediated motorneuropathy with axonal
electrophysiologic features that appearsto be distinct
from both multifocal motor neuropathy and established
motor neuron disorders.
Neuropathies are a significant cause of morbidity worldwide, mainly
from diabetes mellitus, HIV infection and leprosy. Many are treatable with
immunosuppression or intravenous immunoglobulin. Tight glycaemic control
slows progression of diabetic neuropathy. Even when the underlying disorder
is untreatable, making a specific diagnosis and appropriate management to
avoid complications and neuropathic pain can be rewarding.