No abstract

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 b 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 b 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,) 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.

To investigate the impact of metabolic syndrome (MetSD) on the development of intracranial atherosclerotic stroke, the authors evaluated the components of the MetSD in 512 patients with stroke. The MetSD was observed most frequently in patients with intracranial atherosclerosis (p = 0.007). In multiple regression analysis, the MetSD, but not conventional risk factors, was independently associated with intracranial atherosclerosis (p = 0.005). The results suggest that treatment of metabolic abnormalities may be an important prevention strategy for intracranial atherosclerosis.

We investigated the cognition enhancing effects of ginsenoside Rb1 and Rg1. Mice were trained in a Morris water maze following injection (i.p.) of Rb1 (1 mg/kg) or Rg1 (1 mg/kg) for 4 days. Both Rb1- and Rg1-injected mice showed enhanced spatial learning compared to control animals. The hippocampus, but not the frontal cortex, of treated mice contained higher density of a synaptic marker protein, synaptophysin, compared to control mice. Electrophysiological recordings in hippocampal slices revealed that Rb1 or Rg1 injection did not change the magnitude of paired-pulse facilitation or long-term potentiation. Our results suggest that Rb1 and Rg1 enhance spatial learning ability by increasing hippocampal synaptic density without changing plasticity of individual synapses.

The purpose of this study was to better understand the frequency and mechanisms of stroke recurrence after the stroke with no determined cause (NC). We prospectively studied consecutive patients with acute cerebral infarcts. We divided the patients into five groups (large artery disease [LAD], cardioembolism [CE], small artery disease [SAD], two or more causes [TMC], and NC) and registered recurrent strokes and prognosis for 1 year. Those in the NC group were compared with other subtypes. A total of 204 patients were included; 56 LAD, 22 CE, 62 SAD, 27 TMC, and 37 NC. During follow-up, there were 7 deaths and 31 first recurrent strokes. Patients of the NC group showed a significantly higher rate (30%) of recurrent stroke than those of other subtypes (LAD 16%; CE 14%; SAD 2%), and it was associated with the existence of mild stenosis (<50%) on relevant artery or the stenosis of greater than 50% on nonrelevant artery. Occlusive lesions other than significant stenosis of relevant artery may play an important role in the development of stroke recurrence in patients of the NC group. Therefore, from the therapeutic and prognostic point of view, the detection of such occlusive lesions in patients with cryptogenic stroke may be needed.