Abstracts of the 8th Meeting of the Italian Peripheral Nerve Study Group: 61

Abstract

We describe a patient affected by MMN with CB exhibiting unusual progression and clinical features. MMN is a chronic immune mediated demyelinating neuropathy characterized by slowly progressive painless asymmetrical weakness usually in distal limb muscles. GM1 antibodies are found in high titer in 22%‐ 84% of cases. Electrophysiological findings are CB not at usual sites of compression, abnormal temporal dispersion and F‐waves, normal or near‐normal sensory conduction studies. This 63 year old woman was referred for evaluation of one year and half duration weakness which began in right upper limb and progressed to contralateral and to lower extremities. On first admission (July 2001) neurological examination showed normal cranial nerves and sensory testing, severe asymmetric weakness mainly proximal in the upper extremities and distal in the lower. There were atrophy of small hand muscles and weak deep reflexes. She denied sensory symptoms. There were no upper motor neuron signs. Laboratory tests including CK, tumor marker, CSF, anti‐GM1 antibodies were unremarkable. Electrophysiological study was consistent with MMN with CB. Patient underwent IVIG (0.4 g/kg/daily for five days) and PE without significant improvement. In October 2002, her conditions rapidly worsened: she became quadriplegic, unable to swallow, to chew and to protrude her tongue. Admitted to ICU because of respiratory failure, tracheotomy was performed. Repeated searches for GM1 antibodies gave negative results. CSF was still normal. IVIG was administered twice with partial benefit although severe disability persisted. The case presented has notable features: the rapid monophasic progression to quadriplegia within two years and half, the acute worsening in absence of precipitating events and of systemic illness, the severe involvement of cranial nerves and respiratory muscles. The late response to IVIG is in favor of an immune mediated disorder despite the absence of GM1 antibodies.