Isolated bulbar palsy with anti-GM3 and GT1b antibodies

Isolated acute bulbar palsy has been described as one of the more rare variants of Guillain-Barré syndrome. IgG anti-ganglioside antibodies are associated with axonal subtypes of Guillain-Barré syndrome as well as Fisher syndrome. However, IgG against GM3 and GT1b in relation to bulbar palsy is uncommon. In this case report, we describe a 64 year-old male patient presenting with isolated bulbar weakness and generalized hyporeflexia without limb weakness. Serological testing for antiganglioside antibodies was positive for IgG anti-GM3 and -GT1b, suggesting the association of these antibodies with isolated bulbar palsy. Neurology Asia 2013; 18(3) : 319 – 321 Address correspondence to: Somsak Tiamkao, Department of Medicine, Faculty of Medicine, Khon Kaen University, Khon Kaen, 40002, Thailand. Tel: 66-43-363-664, Fax: 66-43-348-399, E-mail: [email protected] INTROUDUCTION Gangliosides are a family of glycosphingolipids containing sialic acid that are commonly found in the nervous system, and IgG anti-ganglioside antibodies have been associated with the pathogenesis of Guillain-Barré syndrome (GBS) and its variant Fisher syndrome (FS). FS is characterized by external ophthalmoplegia, ataxia and areflexia. However, patients with FS and GBS can also demonstrate bulbar weakness. Isolated bulbar palsy has been described to be a lesser variant of FS although both conditions are rare. Another rare variant of GBS, pharyngeal–cervical–brachial weakness is associated with bulbar palsy and proximal upper limb weakness. These conditions are associated with ganglioside antibodies, specifically GT1a, GQ1b and GD1a. Rojas-Garcia et al. retrospectively reviewed the association of antiganglioside antibodies against terminal NeuNAc (alpha2-3) Gal in over 3,000 patients from 1998 to 2007. The antiGM3, GD1a and GT1b combination was found in only 10 patients (Table 1). Eight of out of 10 patients had symptoms of bulbar involvement. All 10 patients were male with an average age of 60.4 years (range 35-74 years). Five patients (no. 1-5) who presented with acute symptoms, had a history of upper respiratory tract infection, and were positive for IgG antibodies, while the other 5 patients (no. 6-10) had chronic symptoms with positive IgM antibodies on testing. Frequent symptoms were dysphagia or dysphonia. Other symptoms included vocal cord paralysis, nasal voice, ophthalmoplegia, ptosis, and bilateral facial paresis. The patients with acute symptoms (cases 2, 3, 5) received intravenous immunoglobulin (IVIG) and recovered. Case no. 4 received IVIG, prednisolone and had plasma exchange with no improvement. The three patients (no. 8-10) with chronic presentations were treated. Case no. 8 received IVIG and fully recovered. Cases 9 and 10 received IVIG, prednisolone and plasma exchange, but neither showed improvement. Their antibodies against terminal NeuNAc (alpha2-3) Gal epitope were rare and may relate to bulbar involvement. Rojas-Garcia et al. reported a patient with acute oropharyngeal, facial diplegia and tongue palsy in 2006. CSF examination revealed albumincytological dissociation following infection of the upper respiratory tract. High titers of anti-GM3, GD1a and GT1b IgG were detected suggesting the association with acute bulbar palsy. Koga et al. compiled data from clinical records of 602 patients who were diagnosed as having GBS,FS, Bickerstaff’s brainstem encephalitis, and acute ophthalmoparesis in order to find a correlation between early bulbar palsy and antiganglioside antibodies. They found that anti-GT1a and antiGM-1b antibodies supported the diagnosis of GBS and GBS variant. Anti-GM1b IgG and IgM, however, did not significantly correlate with bulbar palsy. Neurology Asia September 2013 320 In this report, we describe the rare presentation of a patient with isolated bulbar palsy associated with anti-GM3 and anti-GT1b antibody.