Background and PurposeNo previous studies have investigated the relationship between various anti-ganglioside antibodies and the clinical characteristics of Guillain-Barré syndrome (GBS) in Korea. The aim of this study was to determine the prevalence and types of anti-ganglioside antibodies in Korean GBS patients, and to identify their clinical significance.MethodsSerum was collected from patients during the acute phase of GBS at 20 university-based hospitals in Korea. The clinical and laboratory findings were reviewed and compared with the detected types of anti-ganglioside antibody.ResultsAmong 119 patients, 60 were positive for immunoglobulin G (IgG) or immunoglobulin M antibodies against any type of ganglioside (50%). The most frequent type was IgG anti-GM1 antibody (47%), followed by IgG anti-GT1a (38%), IgG anti-GD1a (25%), and IgG anti-GQ1b (8%) antibodies. Anti-GM1-antibody positivity was strongly correlated with the presence of preceding gastrointestinal infection, absence of sensory symptoms or signs, and absence of cranial nerve involvement. Patients with anti-GD1a antibody were younger, predominantly male, and had more facial nerve involvement than the antibody-negative group. Anti-GT1a-antibody positivity was more frequently associated with bulbar weakness and was highly associated with ophthalmoplegia when coupled with the coexisting anti-GQ1b antibody. Despite the presence of clinical features of acute motor axonal neuropathy (AMAN), 68% of anti-GM1- or anti-GD1a-antibody-positive cases of GBS were diagnosed with acute inflammatory demyelinating polyradiculoneuropathy (AIDP) by a single electrophysiological study.ConclusionsAnti-ganglioside antibodies were frequently found in the serum of Korean GBS patients, and each antibody was correlated strongly with the various clinical manifestations. Nevertheless, without an anti-ganglioside antibody assay, in Korea AMAN is frequently misdiagnosed as AIDP by single electrophysiological studies.

Background and Purpose This study aimed to determine the patterns and etiologies of acquired ocular motor nerve palsy (OMNP) diagnosed in neurology clinics. We also investigated the clinical features that may predict the causes other than microvascular ischemia in isolated OMNP. Methods We performed a prospective multicenter study that had recruited 298 patients with acquired OMNP from the neurology clinics of referral-based 9 university hospitals in Korea. We finally selected 235 patients with isolated OMNP and divided them into older (age ≥50 years, n =188) and younger (age <50 years, n =47) groups. We investigated the underlying etiologies of acquired OMNP. We also estimated the frequency of microvascular ischemia and other causes in isolated OMNP, and sought to determine the clinical features that can predict the causes other than microvascular ischemia. Results Abducens nerve palsy was the most common (40%) of the acquired OMNPs, followed by oculomotor nerve palsy (27%), trochlear nerve palsy (23%), and multiple OMNPs (10%). The etiologies included microvascular ischemia (47%), inflammatory (21%), stroke (5%), trauma (5%), neoplasm (3%), and others (2%), with the cause not being determined in 13% of the patients. Microvascular ischemia was the most common cause (83%) in patients aged ≥50 years with isolated OMNP, followed by inflammation (6%), stroke (6%), neoplasm (3%), and aneurysm (1%). Microvascular ischemia was more common in the older than the younger group (83% vs. 49%, p <0.001). The intensity of headache was the only risk factor for causes other than microvascular ischemia in isolated OMNP. Conclusions Vascular and inflammatory disorders are the most common causes of acquired OMNP diagnosed in neurology clinics. Microvascular ischemia was the predominant cause of isolated OMNP. Severe headache indicates causes other than microvascular ischemia in isolated OMNP.

ObjectiveTo assess the effect of vitamin D and calcium supplementation in preventing recurrences of benign paroxysmal positional vertigo (BPPV).MethodsWe performed an investigator-initiated, blinded-outcome-assessor, parallel, multicenter, randomized controlled trial in 8 hospitals between December 2013 and May 2017. Patients with confirmed BPPV were randomly assigned to the intervention (n=518) or the observation (n=532) group after a successful treatment with canalith repositioning maneuvers. The primary outcome was the annual recurrence rate (ARR). Patients in the intervention group had taken vitamin D 400 IU and 500 mg of calcium carbonate twice a day for one year when serum vitamin D level was lower than 20 ng/ml. Patients in the observation group were assigned to follow-ups without further vitamin D evaluation or supplementation.ResultsThe intervention group showed a reduction in the ARR [0.83 (95% CI: 0.74-0.92) vs. 1.10 (95% CI: 1.00-1.19) recurrences per one-person year] with an incidence rate ratio of 0.76 (95% CI: 0.66-0.87, p<0.001) and an absolute rate ratio of -0.27 (-0.40 to -0.14) from intention to treat analysis. The number needed to treat was 3.70 (95% CI: 2.50-7.14). The proportion of patients with recurrence was also lower in the intervention than in the observation group (37.8 vs. 46.7%, p=0.005).ConclusionsSupplementation of vitamin D and calcium may be considered in patients with frequent attacks of BPPV, especially when serum vitamin D is subnormal.Classification of Evidence:This study provides Class III evidence that for patients with BPPV, vitamin D and calcium supplementation reduces recurrences of BPPV.