Nam Jong Paik

Effects of Combined Peripheral Nerve Stimulation and Brain Polarization on Performance of a Motor Sequence Task After Chronic Stroke.

BACKGROUND AND PURPOSEnRecent work demonstrated that application of peripheral nerve and cortical stimulation independently can induce modest improvements in motor performance in patients with stroke. The purpose of this study was to test the hypothesis that combining peripheral nerve stimulation (PNS) to the paretic hand with anodal direct current stimulation (tDCS) to the ipsilesional primary motor cortex (M1) would facilitate beneficial effects of motor training more than each intervention alone or sham (tDCS(Sham) and PNS(Sham)).nnnMETHODSnNine chronic stroke patients completed a blinded crossover designed study. In separate sessions, we investigated the effects of single applications of PNS+tDCS, PNS+tDCS(Sham), tDCS+PNS(Sham), and PNS(Sham)+tDCS(Sham) before motor training on the ability to perform finger motor sequences with the paretic hand.nnnRESULTSnPNS+tDCS resulted in a 41.3% improvement in the number of correct key presses relative to PNS(Sham)+tDCS(Sham), 15.4% relative to PNS+tDCS(Sham), and 22.7% relative to tDCS+PNS(Sham). These performance differences were maintained 1 and 6 days after the end of the training.nnnCONCLUSIONSnThese results indicate that combining PNS with tDCS can facilitate the beneficial effects of training on motor performance beyond levels reached with each intervention alone, a finding of relevance for the neurorehabilitation of motor impairments after stroke.

Quantification of the path of center of pressure (COP) using an F-scan in-shoe transducer

By tracking the path of the center of pressure (COP) during the stance phase, the balance and pattern of progression can be determined. The path of COP is frequently used in clinical practice, although it is not quantified. In this study, an F-scan pressure sensitive insole system was used to quantify the path of COP. The COP of initial contact and the average during the stance phase corresponded to the center of the heel and to the center of the total plantar surface, respectively. The COP displacement corresponded to 83% of foot contact length and 18% of forefoot contact width. When the longitudinal axis of the insole was plotted as the Y-axis and the transverse axis of the insole as X-axis, the slopes of the COP coordinates during stance phase was 6 degrees inward. Velocities of the COP during each functional rocker action were even and 22-27 cm/s. The changes of quantified COP parameters according to the biomechanical alteration of the foot were confirmed by high-heeled gait.

Lack of Association Between Apolipoprotein E Polymorphism and Vascular Dementia in Koreans

To investigate an association of vascular dementia (VD) with the apolipoprotein E (APOE) polymorphism, the APOE polymorphism of 100 VD patients, 100 age- and gender-matched Alzheimer disease (AD) patients, and 200 age- and gender-matched nondemented control (NC) subjects was genotyped. The distribution of APOE polymorphism was compared. Neither the APOE ε4 allele nor the APOE ε2 allele was more prevalent in the VD patients compared with the NC subjects (P > .1 by the χ 2 test), which was the case when both men and women were analyzed separately (P > .1 by the χ2 test) and when young patients (75 years old or less) and old patients (more than 75 years old) were analyzed separately (P > .1 by the χ2 test). The estimated statistical power was over 0.80 when the odds ratios (OR) for VD conferred to the APOE ε4 are assumed to be higher than 2.2 and the type I error probability is set at 0.05, which is much higher than the power of the previous studies on the VD/APOE association. In conclusion, the results suggested that APOE ε4 allele does not confer the risk for VD, and even if it does, it does so very modestly.

Effect of the Presence of Brain-Derived Neurotrophic Factor Val66Met Polymorphism on the Recovery in Patients With Acute Subcortical Stroke

Objective To investigate the effect of brain-derived neurotrophic factor (BDNF) Val66Met polymorphism on the recovery after subcortical stroke, using the modified Rankin Scale (mRS). Methods Subcortical stroke patients with copies of BDNF Val66Met polymorphism (n=7) were compared to their controls (n=7) without a copy of BDNF Val66Met polymorphism after matching for initial severity, location and type of stroke. The mRS scores at 1 and 3 months after discharge from the neurorehabilitation unit were compared between the groups. Results A repeated measures ANOVA for mRS revealed significant interaction between time and group (F(2, 24) =37.2, p<0.001) and a significant effect of time (F(2, 24)=10.8, p<0.001), thereby reflecting significant differences between the Met allele (+) group and the Met allele (-) group. There was a significant difference in mRS scores at 3 months post-discharge between the two groups (p=0.01) although no difference was evident in mRS scores at 1 month post-discharge between the two groups. There were significant improvements between mRS scores on admission and mRS scores at 1 month post-discharge (p=0.02), and between mRS scores at 1 month post-discharge and mRS scores at 3 months post-discharge (p=0.004) in the Met allele (-) group. Conclusion BDNF Val66Met polymorphism may be associated with worse functional outcome in Korean patients with subcortical stroke. Therefore, BDNF Val66Met polymorphism should be considered as an important prognostic factor for recovery and responses to rehabilitation therapies after stroke in Korean patients. There is a need for developing different rehabilitation strategies for the population with BDNF Val66Met polymorphism. Further studies assessing different outcomes for various functional domains of stroke recovery are needed to clarify the role of BDNF Val66Met polymorphism.

Remifentanil Attenuates Muscle Fasciculations by Succinylcholine

Purpose The present visual and electromyographic study was designed to evaluate muscle fasciculations caused by succinylcholine in adults pretreated with either remifentanil 1.5 µg/kg or saline. Materials and Methods The effect of remifentanil on succinylcholine-induced muscle fasciculations was studied using a double-blind method in 40 adults. After i.v. pretreatment with either remifentanil 1.5 µg/kg (remifentanil group, n = 20) or an equivalent volume of i.v. saline (saline group, n = 20), patients were anaesthetized with a 2.0 mg/kg of i.v. propofol followed by i.v. succinylcholine 1.0 mg/kg. Intensity and duration of muscle fasciculation following i.v. succinylcholine administration were recorded. Electromyography (EMG) was used to quantify the extent of muscle fasciculation following i.v. succinylcholine injection. Myalgia was evaluated 24 hours after induction time. Serum potassium levels were measured five minutes after i.v. succinylcholine administration and creatine kinase (CK) levels 24 hours after induction time. Results Compared to saline treated controls, remifentanil decreased the intensity of muscle fasciculations caused by i.v. succinylcholine [fasciculation severity scores (grade 0 to 3) were 2/1/12/5 and 3/13/4/0 (patients numbers) in the saline group and the remifentanil group, respectively, p < 0.001]. The mean (SD) maximum amplitude of muscle action potential (MAP) by EMG was smaller in the remifentanil group [283.0 (74.4) µV] than in the saline group [1480.4 (161.3) µV] (p = 0.003). Postoperative serum CK levels were lower in the remifentanil group (p < 0.001). Postoperative myalgia was not different between the two groups. Conclusion Remifentanil 1.5 µg/kg attenuated intensity of muscle fasciculations by succinylcholine.

Clinical and sonographic risk factors for hemiplegic shoulder pain: A longitudinal observational study.

OBJECTIVEnTo identify baseline risk factors associated with hemiplegic shoulder pain during the first 6 months after a stroke and to investigate changes in these risk factors over time.nnnDESIGNnLongitudinal observational study.nnnPATIENTSnA total of 94 patients with first-ever unilateral stroke lesion within 1 month after stroke.nnnMETHODSnClinical, radiological and sonographic evaluations were performed at baseline. Hemiplegic shoulder pain was assessed at 1, 3 and 6 months post-stroke. Associations between baseline factors and hemiplegic shoulder pain during the first 6 months and hemiplegic shoulder pain at 1, 3 and 6 months poststroke were analysed.nnnRESULTSnPoor arm motor function, indicated by a poor National Institutes of Health Stroke Scale item 5 score (odds ratio (OR)u2009=u20093.0; 95% confidence interval (CI)u2009=u20091.1-7.7) and the presence of supraspinatus tendon pathology (ORu2009=u20094.2; 95% CIu2009=u20091.4-12.9), were associated with hemiplegic shoulder pain. While patients with adhesive capsulitis, glenohumeral subluxation, or long head of biceps tendon effusion showed a higher prevalence of hemiplegic shoulder pain at 1 month after stroke, those with supraspinatus tendon pathology showed a higher prevalence at 3 and 6 months.nnnCONCLUSIONnPatients at high risk of hemiplegic shoulder pain with severe arm paralysis and supraspinatus tendon pathology require more careful attention during the rehabilitation period.

A new method to measure caudal motor conduction time using magnetic stimulation

Although central motor conduction time (CMCT) has been used for the diagnosis of lumbosacral spinal stenosis (LSSS), its diagnostic value is limited due to the short length of the involved segment compared to the long length of the total conduction distance. To overcome this, we introduce a new method to measure the caudal motor conduction time (caudal MCT) using magnetic stimulation. Magnetic stimulation was applied to the vertex and the T12 and S1 spinous processes for transcortical, thoracic, and sacral stimulation, respectively, and compound muscle action potentials were recorded simultaneously from the rectus abdominis (RA) and the right and left abductor hallucis (AH) muscles using three channels. CMCT was calculated by the latency difference in the AH response between transcortical and sacral stimulation, and between transcortical and thoracic stimulation for RA. Caudal MCT was calculated by subtracting CMCT for RA from that for AH. Caudal MCT was delayed in patients with LSSS compared to normal persons. We suggest that measuring caudal MCT may be useful for the diagnosis of LSSS, but its diagnostic sensitivity and specificity requires prospective study. Muscle Nerve, 2004

A Supporting Platform for Semi-Automatic Hyoid Bone Tracking and Parameter Extraction from Videofluoroscopic Images for the Diagnosis of Dysphagia Patients.

Conventional kinematic analysis of videofluoroscopic (VF) swallowing image, most popular for dysphagia diagnosis, requires time-consuming and repetitive manual extraction of diagnostic information from multiple images representing one swallowing period, which results in a heavy work load for clinicians and excessive hospital visits for patients to receive counseling and prescriptions. In this study, a software platform was developed that can assist in the VF diagnosis of dysphagia by automatically extracting a two-dimensional moving trajectory of the hyoid bone as well as 11 temporal and kinematic parameters. Fifty VF swallowing videos containing both non-mandible-overlapped and mandible-overlapped cases from eight patients with dysphagia of various etiologies and 19 videos from ten healthy controls were utilized for performance verification. Percent errors of hyoid bone tracking were 1.7xa0±xa02.1% for non-overlapped images and 4.2xa0±xa04.8% for overlapped images. Correlation coefficients between manually extracted and automatically extracted moving trajectories of the hyoid bone were 0.986xa0±xa00.017 (X-axis) and 0.992xa0±xa00.006 (Y-axis) for non-overlapped images, and 0.988xa0±xa00.009 (X-axis) and 0.991xa0±xa00.006 (Y-axis) for overlapped images. Based on the experimental results, we believe that the proposed platform has the potential to improve the satisfaction of both clinicians and patients with dysphagia.

Korean Brain Rehabilitation Registry for Rehabilitation of Persons with Brain Disorders: Annual Report in 2009

This first annual report provides a description of patients discharged from rehabilitation facilities in Korea based on secondary data analysis of Korean Brain Rehabilitation Registry V1.0 subscribed in 2009. The analysis included 1,697 records of patients with brain disorders including stroke, traumatic brain injury, brain tumor and other disorders from 24 rehabilitation facilities across Korea. The data comprised 1,380 cases of stroke, 104 cases of brain injury, 55 cases of brain tumor, and 58 cases of other brain diseases. The functional status of each patient was measured using the Korean version of the Modified Barthel Index (KMBI). The average change in the KMBI score was 15.9 for all patients in the inpatient rehabilitation facility. The average length of stay for inpatient rehabilitation was 36.9 days. The transfer rates to other hospitals were high, being 62.4% when all patients were considered. Patients with brain disorders of Korea in 2009 and measurable functional improvement was observed in patients. However, relatively high percentages of patients were not discharged to the community after inpatient rehabilitation. Based on the results of this study, consecutive reports of the status of rehabilitation need to be conducted in order to provide useful information to many practitioners.

Inpatient stroke rehabilitation outcomes in Korea derived from the Korean Brain Rehabilitation Centers' online database system for the years 2007 to 2011.

The purpose of this report was to provide information for patients receiving inpatient rehabilitation after stroke and to identify the possible factors influencing functional outcome after inpatient rehabilitation. Stroke patients (n = 5,212) who were discharged from the Departments of Rehabilitation Medicine (RM) of university hospitals and rehabilitation hospitals from 2007 through 2011 were participants. Prevalence, age, transfer time after onset, length of stay (LOS), functional status at admission and discharge were analyzed. In all stroke subjects, cerebral infarctions (67%) were more common than hemorrhages. Cerebral infarctions in the middle cerebral artery territory were most common, while the basal ganglia and cerebral cortex were the most common areas for hemorrhagic stroke. The LOS decreased from 45 to 28 days. Transfer time after onset decreased from 44 to 30 days. Shorter transfer time after onset was correlated with better discharge functional status and shorter LOS. Initial functional status was correlated with discharge functional status. In ischemic stroke subtypes, cerebellar and brainstem strokes predicted better outcomes, while strokes with more than one territory predicted poorer outcomes with more disabilities. In hemorrhagic stroke subtypes, initial and discharge functional status was the lowest for cortical hemorrhages and highest for brainstem hemorrhages. This report shows that LOS and transfer time after onset has been decreased over time and initial functional status and shorter transfer after onset are predictors of better functional outcome at discharge.