Introduction: Lower motoneurone syndromes (SMNI) have been defined by their clinical pattern, anomalies in nerve conduction and the presence of antiglycolipid antibodies. The possible response to immunotherapy is another characteristic which makes these syndromes interesting.
Patients and methods: We studied the clinical and electrophysiological data, clinical progress and response to treatment of a series of six patients, with a pure lower motoneurone syndrome, with a follow up period of between 5 and 13 years.
Conclusions: The clinical phenotype of our patients was: male, middle aged, the clinical topography showed only lower motoneurone involvement, predominantly or exclusively limited to the upper limbs, asymmetrical, distal rather than proximal, with a chronic course progressing initially but later becoming stable. From the electrophysiological point of view some of our cases were of SMNI. In these the conduction block was not permanent although there were signs of axon loss and multifocal demyelination. Response to treatment with intravenous immunoglobulins was seen in patients with anti GMI antibodies of IgM type and recent signs of clinical deterioration, whether there were conduction blocks present or not. In the cases which responded to this treatment there was tolerance and dependence following repeated transfusions of IV IgG.