Eun Hee Sohn

Prevalence of Anti-Ganglioside Antibodies and Their Clinical Correlates with Guillain-Barré Syndrome in Korea: A Nationwide Multicenter Study

Background and Purpose No 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. Methods Serum 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. Results Among 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. Conclusions Anti-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.

Relationship between changes of body mass index (BMI) and cognitive decline in Parkinson's disease (PD).

Decreased BMI has been reported that it may be associated with cognitive decline in the elderly. Weight loss is common in patients with PD. However, studies comparing cognitive changes according to BMI changes in PD have not been done yet. We performed this study to know a relationship between BMI changes and the rate of cognitive decline in PD. PD patients were recruited retrospectively. The patients (n=104) were divided into two groups according to BMI changes during initial 6 months of follow-up: decreased (n=52) vs. stable BMI groups (n=52). Cognitive functions were repeated until 36 months of follow-up using the Korean version of the Mini-Mental State Examination (K-MMSE) and the modified Mini-Mental State (3MS) test. We calculated the rate of cognitive decline (K-MMSE and 3MS score changes/month) and compared it between the two groups. The decreased BMI group showed lower level of cognitive function than that of stable BMI group, especially at the 36th month of follow-up (p<0.05). In addition, the rate of cognitive decline was also significantly faster in the decreased BMI group, particularly at the 36th month of follow-up (p<0.05). This study suggests that decreased BMI during initial 6 months of follow-up in PD might be a useful indicator for future risk of dementia and let clinicians predict faster rate of cognitive decline in patients with PD.

Longitudinal changes in clock drawing test (CDT) performance according to dementia subtypes and severity

UNLABELLED The CDT requires a patient to draw the face of a clock, insert all the numbers and set the hands for a specified time. This task engages a number of cognitive abilities including verbal understanding, memory, spatially coded knowledge, planning, concentration and visuoconstructive skills. Although CDT has been regarded as a simple and useful screening tool in dementia, little is known about the longitudinal changes in CDT performance and error types, according to dementia subtypes and their severity. MATERIALS AND METHODS Two hundred thirty-five consecutive patients with dementia (Alzheimer disease = AD, n=94, Parkinsons disease with dementia (PDD), n = 119, Vascular dementia = VaD, n = 22) were recruited from the memory clinic at Chungnam University hospital from January 2005 to July 2009. The Korean version of the mini-mental state examination (MMSE-K) and CDT were performed by all participants every 6 months. Scoring of the CDT performance was in accordance with the method of Mano and Wu. Error types of CDT were classified as follows: stimulus-bound response (SBR), conceptual deficit (CD), spatial and/or planning deficit (SPD) and perseveration error (PE). We divided patients into 3 groups by their initial MMSE-K score (severe, MMSE-K ≤ 17; moderate, 18 ≤ MMSE-K < 24; mild, 24 ≤ MMSE-K). Comparisons of CDT scores and error types in the three dementia subtypes and three cognitive groups were conducted. RESULTS Longitudinal changes on CDT and MMSE-K scores were not different between the three dementia subtypes. From the analysis of CDT error type, the most common error type was SPD in patients with mild to moderate dementia. In contrast, CD error was the most frequent in severe dementia group. The order of error frequency in all subjects from baseline to the last follow-up was as follows: SPD, CD, SBR and PE except CD was the most frequent error type in AD patients after 18 months from baseline. CONCLUSION Longitudinal analysis of error on CDT may reflect different characteristics of cognitive deterioration according to dementia subtypes and dementia stages.

Treatment of Alzheimer's Disease with Repetitive Transcranial Magnetic Stimulation Combined with Cognitive Training: A Prospective, Randomized, Double-Blind, Placebo-Controlled Study

Background and Purpose Repetitive transcranial magnetic stimulation (rTMS) has been examined as a potential treatment for many neurological disorders. High-frequency rTMS in particular improves cognitive functions such as verbal fluency and memory. This study explored the effect of rTMS combined with cognitive training (rTMS-COG) on patients with Alzheimers disease (AD). Methods A prospective, randomized, double-blind, placebo-controlled study was performed with 27 AD patients (18 and 8 in the treatment and sham groups, respectively, and 1 drop-out). The participants were categorized into mild [Mini-Mental State Examination (MMSE) score=21-26] and moderate (MMSE score=18-20) AD groups. The rTMS protocols were configured for six cortical areas (both dorsolateral prefrontal and parietal somatosensory associated cortices and Brocas and Wernickes areas; 10 Hz, 90-110% intensity, and 5 days/week for 6 weeks). Neuropsychological assessments were performed using the AD Assessment Scale-cognitive subscale (ADAS-cog), Clinical Global Impression of Change (CGIC), and MMSE before, immediately after, and 6 weeks after the end of rTMS-COG treatment. Results Data from 26 AD patients were analyzed in this study. There was no significant interactive effect of time between the groups. The ADAS-cog score in the treatment group was significantly improved compared to the sham group (4.28 and 5.39 in the treatment group vs. 1.75 and 2.88 in the sham group at immediately and 6 weeks after treatment, respectively). The MMSE and CGIC scores were also improved in the treatment group. Based on subgroup analysis, the effect of rTMS-COG was superior for the mild group compared to the total patients, especially in the domains of memory and language. Conclusions The present results suggest that rTMS-COG represents a useful adjuvant therapy with cholinesterase inhibitors, particularly during the mild stage of AD. The effect of rTMS-COG was remarkable in the memory and language domains, which are severely affected by AD.

Prognosis of ocular myasthenia in Korea: a retrospective multicenter analysis of 202 patients

OBJECTIVES The aims of this study were to obtain data on the frequency with which Korean patients with autoimmune myasthenia gravis (MG) present solely with ocular disturbances and progress to develop generalized disease and to identify the prognostic factors associated with secondary generalization. METHODS We conducted a retrospective multicenter survey in which a total of 376 adult patients who were newly diagnosed with MG from 2000 through 2005 were reviewed for analysis. Patients with ocular MG at the time of symptom presentation (n=202, 53.7%) were divided into two subgroups according to their prognosis: the patients whose disease remained ocular throughout the follow-ups were placed in the OMG-R group, and the patients who progressed to develop generalized disease were placed in the OMG-G group. Clinical characteristics and laboratory findings were compared between the two subgroups. RESULTS Secondary generalization developed in 47 (23.3%) of the 202 study subjects, mostly within the first 6 months after symptom presentation, while the disease remained ocular throughout the follow-up duration (median 11.8 months) in the remaining 155 patients (76.7%). AChR antibody, abnormal repetitive nerve stimulation tests (RNST) and thymoma were more frequently observed in the patients in the OMG-G group than in those in the OMG-R group (p<0.01 in all). In seropositive cases, the titers of AChR antibody were also significantly higher in the OMG-G group than in the OMG-R group (median, 3.8 nM vs. 6.4 nM; p<0.05). Cox proportional hazards regression analyses showed that early oral prednisolone treatment significantly reduced the risk of secondary generalization (HR, 0.24; 95% CI, 0.11-0.56), whereas abnormal AChR antibody (HR, 5.34; 95% CI, 1.60-17.8) and thymoma (HR, 2.32; 95% CI, 1.21-4.45) were predictive of the development of secondary generalization. CONCLUSIONS Our findings suggest that several factors, including the AChR antibody, thymoma, early corticosteroid treatment, and possibly latent neuromuscular abnormality revealed by RNST, may have an impact on the risk of developing generalized disease in Korean patients presenting with ocular myasthenia.

Comparison between Clinical Disabilities and Electrophysiological Values in Charcot-Marie-Tooth 1A Patients with PMP22 Duplication

Background and Purpose Charcot-Marie-Tooth disease (CMT) type 1A (CMT1A) is the demyelinating form of CMT that is significantly associated with PMP22 duplication. Some studies have found that the disease-related disabilities of these patients are correlated with their compound muscle action potentials (CMAPs), while others have suggested that they are related to the nerve conduction velocities. In the present study, we investigated the correlations between the disease-related disabilities and the electrophysiological values in a large cohort of Korean CMT1A patients. Methods We analyzed 167 CMT1A patients of Korean origin with PMP22 duplication using clinical and electrophysiological assessments, including the CMT neuropathy score and the functional disability scale. Results Clinical motor disabilities were significantly correlated with the CMAPs but not the motor nerve conduction velocities (MNCVs). Moreover, the observed sensory impairments matched the corresponding reductions in the sensory nerve action potentials (SNAPs) but not with slowing of the sensory nerve conduction velocities (SNCVs). In addition, CMAPs were strongly correlated with the disease duration but not with the age at onset. The terminal latency index did not differ between CMT1A patients and healthy controls. Conclusions In CMT1A patients, disease-related disabilities such as muscle wasting and sensory impairment were strongly correlated with CMAPs and SNAPs but not with the MNCVs or SNCVs. Therefore, we suggest that the clinical disabilities of CMT patients are determined by the extent of axonal dysfunction.

Current Status of the Diagnosis and Management of Amyotrophic Lateral Sclerosis in Korea: A Multi-Center Cross-Sectional Study

Background and Purpose Recently published, evidence-based guidelines should alter the management of amyotrophic lateral sclerosis (ALS)/motor neuron disease (MND). However, the newest recommendations for ALS/MND therapy are not reflected in actual clinical practice. We sought to evaluate the current status of the diagnosis and management of ALS in Korea. Methods The Korean ALS/MND research group was organized in 2010, involving more than 50 neurologists from neuromuscular centers in Korea. Participating centers collected data from April to September 2010 on the diagnosis and management of patients with ALS. Data forms from the ALS patient care database, which is a component of the ALS clinical assessment, research, and education program (http://www.outcomes-umassmed.org/ALS/), were modified and used for data collection. Results In total, 373 sporadic ALS cases from 35 centers were enrolled. The demographic features and clinical findings were similar to those in previous reports from other countries. The mean age at onset was 50-60 years, and a slight male predominance was observed. The enrolled patients predominantly showed focal onset of cervical or lumbosacral symptoms. Only about one-half of the indicated patients (31.4%) received a physicians recommendation for a parenteral gastrostomy, and 18.1% underwent the procedure. Noninvasive ventilation was recommended in 23% of patients, but applied in only 9.5% of them. Tracheostomy was performed in 12.7% of patients. Conclusions The demographic and clinical features of the diagnosis and management of ALS in Korea are similar to those reported in other countries; however, supportive management, as recommended in evidence-based guidelines, are not yet widely recommended or performed for patients with ALS in Korea.

A novel PYGM mutation in a Korean patient with McArdle disease: The role of nonsense-mediated mRNA decay

We have identified a compound heterozygous mutation of PYGM in a Korean patient with McArdle disease, which is composed of a novel single codon deletion (p.779delE) and a common nonsense mutation (p.R50X). Our study also showed an evidence of nonsense-mediated mRNA decay (NMD) caused by p.R50X mutation, supporting the importance of RNA processing defects in the molecular pathology of McArdle disease.

Autonomic and cognitive functions in Parkinson's disease (PD)

We performed this study to evaluate the relationship between the stages of PD and autonomic dysfunction, and to find an association between the autonomic dysfunction and cognitive impairment in PD. Sixty-three patients who met the criteria of the United Kingdom PD Society Brain Bank were enrolled prospectively. Clinical stages were using the Hoehn and Yahr (H&Y) staging and unified PD rating scale motor scores. Cognitive functions were evaluated using the mini-mental state examination (MMSE) and the modified MMSE (3MS) test. The scale for outcome in PD-autonomic (SCOPA-AUT) was used to evaluate autonomic symptoms. Severities of autonomic dysfunction were classified using the composite autonomic scoring scale (CASS). Fifty-four of the 63 patients (86%) had shown abnormalities on CASS. H&Y stages correlated with SCOPA-AUT (p<0.05) and 3MS and MMSE scores (p<0.05). H&Y stages were positively related with autonomic dysfunction, heart rate ratios during deep breathing and the quantitative sudomotor axon reflex test (QSART) scores. Autonomic dysfunction may be present from disease onset, whereas the rate of cognitive decline increases with disease progression. We recommend that both qualitative and quantitative autonomic evaluation from the early stage of disease and regular cognitive screening with disease progression might be useful to facilitate optimal management in PD.

When is facial diplegia regarded as a variant of Guillain-Barré syndrome?

A variant of Guillain‐Barré syndrome (GBS) with predominant manifestation of facial diplegia (FD) has been described recently. This study aimed to characterize and determine the incidence of this FD‐predominant GBS variant. The clinical and serological information of 900 consecutive patients were reviewed. In total, eight patients were identified between January 2007 and December 2010 as having FD accompanied by some features of GBS. These features were subjective sensory symptoms such as distal paresthesia (7/8, 88%), albumin‐cytological (A/C) dissociation (7/8, 88%), antecedent infection (6/8, 75%), and minor nerve conduction study (NCS) abnormalities (5/7, 71%). One patient presented with the typical NCS feature of demyelinating neuropathy. Only two patients exhibited areflexia (2/8, 25%). None of the patients possessed any anti‐ganglioside antibodies; however, the serum of two patients was positive for anti‐mycoplasma antibody (2/6, 33%). FD variant of GBS occurred in less than 1% of our dataset. FD can be a regional variant of GBS when it is accompanied by supporting features, such as subjective tingling, A/C dissociation, and minor NCS abnormalities.