Introduction: Motor conduction impairment with conduction blocks (CBs) are typical electrodiagnostic findings in multifocal motor neuropathy (MMN), acute inflammatory demyelinating polyneuropathy (AIDP) variant of Guillain-Barré syndrome (GBS), chronic inflammatory demyelinating polyneuropathy (CIDP), hereditary neuropathy with liability to pressure palsies (HNPP); recently, a new electroclinical entity named “acute motor conduction block neuropathy (AMCBN)” has been proposed as incomplete form of the acute motor axonal neuropathy (AMAN)-GBS variant. Sensory nerve conduction is generally spared in MMN, AMAN and AMCBN. Several IgG or IgM anti-ganglioside antibodies have been found associated to different neuropathies till to become sometimes a serologic hallmark. We report a case of acute motor neuropathy with acute reversible conductionblocks and anti-GM1/GT1A/GT1B IgM complex antibodies.

Acute motor neuropathy with reversible conduction blocksand unusual anti-ganglioside complex IgM antibodies:

an uncommon Guillain-Barré syndrome case

Aste R.1, Tacconi P.2, Fadda E.3, Salaris E.1, Pische M.1, Floris E.1

(1) Department of Medical Care, Neurological Diagnostic Unit, H. San Martino - ASL Oristano - Oristano, Italy(2) Department of Neurological and Cardiovascular Sciences, Section of Neurology, University of Cagliari - AOU Cagliari - Cagliari, Italy(3) Department of Public Health, Clinical and Molecular Medicine, Multiple Sclerosis Centre, H. R. Binaghi - ASL Cagliari - Cagliari, Italy

References

American Association of Electrodiagnostic Medicine, Olney RK, Guidelines in electrodiagnostic medicine.

Consensus criteria for the diagnosis of partial conduction block. Muscle Nerve Suppl. 1999;8:S225-9.

Capasso M. et al. Acute motor conduction block neuropathy. Another Guillain-Barré syndrome variant. Neurology

2003; 61:617-622;

Fernàndez-Torre J.L. et al. Acute motor conduction block neuropathy pattern occuring in the course of an acute

inflammatory demyalinating polyradiculoneuropathy Clin Neurophysiol 2008; 38: 211-216;

Lefaucher J.P. Acute neuropathy with multiple motor conduction blocks: A variant of Guillain-Barré syndrom or

multifocal motor neuropathy with conduction blocks with acute onset? Clin Neurophysiol 2008; 38: 209-210;

Manganelli F et al. Case of acute motor conduction block neuropathy (AMCBN) Muscle Nerve 2009; 39: 224-226;

Uncini A. et al. Acute motor conduction block neuropathy por acute multifocal motor neuropathy: an attempt at

nosological systematization Muscle Nerve; 2010 Feb;41(2):283-5; author reply 285;

Dionisi S. et al. Target antigens in autimmune diabetes: pancreatic gangliosides. Ann.Ist.Super.Sanità, vol.33 n.3

(1997), pp. 433-435

Neurological examination showed mild heelwalking impairment, bilateral lower limb hyporeflexia, mild bilateral hand-grip weakness, mild stocking-glove hypoesthesia; cranial nerve exam was normal, nor patient complained about dysphagia or dyspnea. Serial nerve conduction studies showed a motor polyneuropathy with segmental demyelination and reversible partial CBs. No significant involvement of sensory conduction or reduction of distal compound motor action potential (CMAP) amplitude were observed. CSF examination revealed increased protein content (97.8 mg/dL) with normal cell count; immunoblotting disclosed high titers of anti-GM1, anti-GT1A and anti-GT1B IgM. The patient was treated with IVIg (0.4 mg/kg/day) for 5 days without a significant benefit until two months later when, after an initial clinical and instrumental motor worsening, she reported clini-

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Right median (A) and ulnar (B) motor nerve conduction 10, 40, 60, and 140 days after clinical onset.

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cal recovery and nerve conduction improvement occurred. CBs disappeared two months later; mild motor conduction slowing were still present in the distal segments of ulnar and median nerve six months after the onset.

Discussion and conclusions: In our patient the clinical course, the temporal relationship with a new-onset type 1 diabetes and the immunological profile were rather uncommon. The convergence of several pathogenetic mechanisms could explain the unusual clinical-immunological picture.

ASTE Rosa, MDS.S. Diagnostica NeurologicaP.O. San MartinoVia Rockfeller 09170 Oristano – ITALY

rosa.aste@gmail.com+39 0783 320090

ASLOristano - P.O. SAN MARTINOStruttura Semplice di Diagnostica Neurologica

Responsabile Dott. E. Salaris

Case report: A 24-year-old female was admitted to our department complaining of tingling and weakness in both hands. Three months earlier she was diagnosed with type 1 diabetes after a journey to Eritrea, where she complained of fever, diarrhea, weight loss and walking difficulties treated with antibiotics. No traumatic nerve injury nor new gastrointestinal symptoms were reported.

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Left median (A) and ulnar (B) motor nerve conduction 10, 40, 60, 80 and 140 days after clinical onset.

* patient underwent a single apheresis session

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