Correlations in abnormal synergies between the upper and lower extremities across various phases of stroke.

The flexion synergy and extension synergy are a representative consequence of a stroke and appear in the upper extremity and the lower extremity. Since the ipsilesional corticospinal tract (CST) is the most influential neural pathway for both extremities in motor execution, damage by a stroke to this tract could lead to similar motor pathological features (e.g., abnormal synergies) in both extremities. However, less attention has been paid to the interlimb correlations in the flexion synergy and extension synergy across different recovery phases of a stroke. We used results of the Fugl-Meyer assessment (FMA) to characterize those correlations in a total of 512 participants with hemiparesis after stroke from the acute phase to 1 year. The FMA provides indirect indicators of the degrees of the flexion synergy and extension synergy after stroke. We found that, generally, strong interlimb correlations (r > 0.65 with all P values < 0.0001) between the flexion synergy and extension synergy appeared in the acute-to-subacute phase (<90 days). However, the correlations of the lower-extremity extension synergy with the upper-extremity flexion synergy and extension synergy decreased (down to r = 0.38) 360 days after stroke (P < 0.05). These results suggest that the preferential use of alternative neural pathways after damage by a stroke to the CST enhances the interlimb correlations between the flexion synergy and extension synergy. At the same time, the results imply that the recovery of CST integrity or/and the fragmentation (remodeling) of the alternative neural substrates in the chronic phase may contribute to diversity in neural pathways in motor execution, eventually leading to reduced interlimb correlations.NEW & NOTEWORTHY For the first time, this article addresses the asynchronous relationships in the strengths of flexion and extension synergy expressions between the paretic upper extremity and lower extremity across various phases of stroke.

Evidence of the existence of multiple modules for the stroke-caused flexion synergy from Fugl-Meyer assessment scores.

Stroke-caused synergies may result from the preferential use of the reticulospinal tract (RST) due to damage to the corticospinal tract. The RST branches multiple motoneuron pools across the arm together resulting in gross motor control or abnormal synergies, and accordingly, the controllability of individual muscles decreases. However, it is not clear whether muscles involuntarily activated by abnormal synergy vary depending on the muscles voluntarily activated when motor commands descend through the RST. Studies showed that abnormal synergies may originate from the merging and reweighting of synergies in individuals without neurological deficits. This leads to a hypothesis that those abnormal synergies are still selectively excited depending on the context. In this study, we test this hypothesis, leveraging the Fugl-Meyer assessment that could characterize the neuroanatomical architecture in individuals with a wide range of impairments. We examine the ability to perform an out-of-synergy movement with the flexion synergy caused by either shoulder or elbow loading. The results reveal that about 14% [8/57, 95% confidence interval (5.0%, 23.1%)] of the participants with severe impairment (total Fugl-Meyer score <29) in the chronic phase (6 months after stroke) are able to keep the elbow extended during shoulder loading and keep the shoulder at neutral during elbow loading. Those participants underwent a different course of neural reorganization, which enhanced abnormal synergies in comparison with individuals with mild impairment (P < 0.05). These results provide evidence that separate routes and synergy modules to motoneuron pools across the arm might exist even if the motor command is mediated possibly via the RST.NEW & NOTEWORTHY We demonstrate that abnormal synergies are still selectively excited depending on the context.

Predictors of Burden for First-Ever Stroke Survivor's Long-Term Caregivers: A Study of KOSCO.

Long-term changes in caregiver burden should be clarified considering that extended post-stroke disability can increase caregiver stress. We assessed long-term changes in caregiver burden severity and its predictors. This study was a retrospective analysis of the Korean Stroke Cohort for Functioning and Rehabilitation. Patients with an acute first-ever stroke were enrolled from August 2012 to May 2015. Data were collected at 6 months and 6 years after stroke onset. The caregiver burden was measured with a subjective caregiver burden questionnaire based on the Korean version of the Caregiver Burden Inventory. The caregivers' characteristics and patients' clinical and functional status were also examined at each follow-up. A high caregiver burden, which suggests a risk of burnout, was reported by 37.9% and 51.7% of caregivers at 6 months and 6 years post-stroke, respectively. Both the caregiver burden total score and proportion of caregivers at risk of burnout did not decrease between 6 months and 6 years. The patients' disability (OR = 11.60; 95% CI 1.58-85.08; p = 0.016), caregivers' self-rated stress (OR = 0.03; 95% CI 0.00-0.47; p = 0.013), and caregivers' quality of life (OR = 0.76; 95% CI 0.59-0.99; p = 0.042) were burden predictors at 6 months. At 6 years, only the patients' disability (OR = 5.88; 95% CI 2.19-15.82; p < 0.001) and caregivers' psychosocial stress (OR = 1.26; 95% CI 1.10-1.44; p = 0.001) showed significance. Nearly half of the caregivers were at risk of burnout, which lasted for 6 years after stroke onset. The patients' disability and caregivers' stress were burden predictors in both subacute and chronic phases of stroke. The findings suggest that consistent interventions, such as emotional support or counseling on stress relief strategies for caregivers of stroke survivors, may reduce caregiver burden. Further research is needed to establish specific strategies appropriate for Korean caregivers to alleviate their burden in caring for stroke patients.

Predictors of quality of life at 6 months in patients with mild stroke: A prospective observational cohort study.

OBJECTIVES: This study aimed to analyze the factors affecting the long-term quality of life of patients with mild stroke and evaluate the differences according to age and sex. MATERIALS AND METHODS: The Korean Stroke Cohort for functioning and rehabilitation data was used, and patients with mild stroke with a National Institute of Health Stroke Scale score of < 5 were included. Quality of life after 6 months was analyzed using EuroQol-5 dimensions. Demographic and clinical characteristics were evaluated, and factors affecting the quality of life at 6 months were analyzed. RESULTS: Age, current drinking, marital status, length of stay, and modified Rankin Scale, Fugl-Meyer assessment, Functional Independence Measure, and Geriatric Depression Scale scores affected the quality of life at 6 months in patients with mild stroke. Fugl-Meyer assessment score was a predictor for those aged < 65 years, while the functional ambulatory category was a predictor for those aged ≥ 65 years. Predictors of quality of life, excluding alcohol consumption, were comparable between male and female. CONCLUSIONS: Among patients aged <65 years, individuals who consumed alcohol, and those who showed better motor function and fewer comorbidities had a higher quality of life. Among patients aged ≥65 years, quality of life was higher in males, younger age, married individuals, those with diabetes, and those with a better walking ability. Among male, individuals who consumed alcohol had a higher quality of life. Rehabilitation treatment should prioritize improving modifiable factors to enhance the quality of life in patients with mild stroke.

Understanding of the Lower Extremity Motor Recovery After First-Ever Ischemic Stroke.

BACKGROUND: We aimed to verify the validity of the proportional recovery model for the lower extremity. METHODS: We reviewed clinical data of patients enrolled in the Korean Stroke Cohort for Functioning and Rehabilitation between August 2012 and May 2015. Recovery proportion was calculated as the amount of motor recovery over initial motor impairment, measured as the Fugl-Meyer Assessment of Lower Extremity score. We used the logistic regression method to model the probability of achieving the full Fugl-Meyer Assessment of Lower Extremity score, whereby we considered the ceiling effect of the score. To show the difference in the prevalence of achieving the full Fugl-Meyer Assessment of Lower Extremity score between 3 and 6 months poststroke, we constructed a marginal model through the generalized estimating equation method. We also performed the propensity score matching analysis to show the dependency of recovery proportion on the initial motor deficit at 3 and 6 months poststroke. RESULTS: We evaluated 1085 patients. The recovery proportions at 3 and 6 months poststroke were 0.67±0.42 and 0.75±0.39, respectively. A 1-unit decrease in the initial neurological impairment and the age at stroke onset increased the probability of achieving the full Fugl-Meyer Assessment of Lower Extremity score, which occurred at both 3 and 6 months poststroke. The prevalence of those who reach full lower limb motor recovery differs significantly between 3 and 6 months poststroke. We also found out that the recovery proportion at both 3 and 6 months poststroke is determined by the initial motor deficits of the lower limb. These results are not consistent with the proportional recovery model. CONCLUSIONS: Our results demonstrated that the proportional recovery model for the lower limb is invalid.

Assessment of Functional Near-infrared Spectroscopy by Comparing Prefrontal Cortex Activity: A Cognitive Impairment Screening Tool.

Many studies have suggested the possibility of using functional near-infrared spectroscopy (fNIRS) devices as neuroimaging tools in various patients. We aimed to evaluate whether fNIRS to measure the prefrontal cortex (PFC fNIRS) is suitable as a screening tool for cognitive impairments. Sixty participants, divided into normal, mild cognitive impairment, and dementia groups, were instructed to wear an fNIRS device during cognitive assessments to assess whether there is a significant difference in the PFC activity between the groups. A significant difference in PFC activity between the groups was observed during the verbal fluency test. Moreover, the PFC activity during the verbal fluency test significantly correlated with the existing cognitive screening tool score. These results suggested that PFC fNIRS can be used as a cognitive impairment screening tool for mild cognitive impairment and dementia. A larger sample size is needed to validate the potential of PFC fNIRS as a cognitive impairment screening tool.

Light-emitting diode irradiation induces AKT/mTOR-mediated apoptosis in human pancreatic cancer cells and xenograft mouse model.

The beneficial effects of light-emitting diode (LED) irradiation have been reported in various pathologies, including cancer. However, its effect in pancreatic cancer cells remains unclear. Herein, we demonstrated that blue LED of 460 nm regulated pancreatic cancer cell proliferation and apoptosis by suppressing the expression of apoptosis-related factors, such as mutant p53 and B-cell lymphoma 2 (Bcl-2), and decreasing the expression of RAC-ß serine/threonine kinase 2 (AKT2), the phosphorylation of protein kinase B (AKT), and mammalian target of rapamycin (mTOR). Blue LED irradiation also increased the levels of cleaved poly-(ADP-ribose) polymerase (PARP) and caspase-3 in pancreatic cancer cells, while it suppressed AKT2 expression and inhibited tumor growth in xenograft tumor tissues. In conclusion, blue LED irradiation suppressed pancreatic cancer cell and tumor growth by regulating AKT/mTOR signaling. Our findings indicated that blue LEDs could be used as a nonpharmacological treatment for pancreatic cancer.

Revisiting the Proportional Recovery Model in View of the Ceiling Effect of Fugl-Meyer Assessment.

Background and Purpose: The aim of this study was to verify the validity of the proportional recovery model in view of the ceiling effect of the Fugl-Meyer Assessment. Methods: We reviewed the medical records of patients enrolled in the Korean Stroke Cohort for Functioning and Rehabilitation between August 2012 and May 2015. Recovery proportion was defined as the actual change in Fugl-Meyer Assessment score of the upper extremity between 7 days and 6 months poststroke, relative to the initial neurological impairment. We then used logistic regression to identify clinical factors attributable to a ceiling effect of the Fugl-Meyer Assessment score of the upper extremity and propensity score matching to verify the validity of the proportional recovery rule. Results: We screened 10 636 patients and analyzed 849 patients (mean age, 65.4±11.9 years; female, 320 [37.7%]) with first-ever ischemic stroke. We found, through logistic regression analysis, that a one-unit increase in the initial neurological impairment and the age at stroke onset affected the odds ratio (1.0386 and 0.9736, respectively) of achieving the full Fugl-Meyer Assessment score of the upper limb at 6 months poststroke. We also demonstrated, through propensity score matching, that the difference in initial neurological impairment of the upper extremity resulted in discrepancy of the recovery proportion (0.92±0.20 [0­1] versus 0.81±0.31 [0­1], P<0.001). Conclusions: We demonstrated that the ceiling effect of the Fugl-Meyer Assessment score of the upper extremity is pronounced in patients with mild initial motor deficits of the upper extremity and that the recovery proportion varies according to the initial motor deficit of the upper limb using logistic regression analysis and propensity score matching, respectively. These results suggest that the proportional recovery model is not valid.

Status Of Dysphagia After Ischemic Stroke: A Korean Nationwide Study.

OBJECTIVE: To identify the incidence of dysphagia after ischemic stroke and determine factors affecting the presence of dysphagia. DESIGN: Retrospective case-control study. This was an interim analysis of a prospective multicenter Korean stroke cohort. SETTING: Acute care university hospitals. PARTICIPANTS: Patients (N=6000) with first-ever acute ischemic stroke. Patients were divided into 2 groups according to the presence or absence of dysphagia confirmed at 7 days after onset using the American Speech-Language-Hearing Association National Outcomes Measurement System (ASHA-NOMS) scale, which was determined after conducting screening or standardized tests. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Age at stroke onset, body mass index (BMI), premorbid modified Rankin Scale (mRS), brainstem lesions, National Institutes of Health Stroke Scale (NIHSS), poststroke mRS, and ASHA-NOMS swallowing level at poststroke day 7 were evaluated. RESULTS: Among patients with ischemic stroke, 32.3% (n=1940) had dysphagia at 7 days after stroke onset. At discharge, 80.5% (n=1561) still had dysphagia. The prediction model for the presence of dysphagia identified age at onset, underweight (BMI <18.5 kg/m2), premorbid mRS, brainstem lesions, and NIHSS as independent predictors. The odds ratio (OR) for the presence of dysphagia significantly increased with underweight (OR, 1.6684; 95% confidence interval [CI], 1.27-2.20), increased age at onset (OR, 1.0318; 95% CI, 1.03-1.04), premorbid mRS (OR, 1.1832; 95% CI, 1.13-1.24), brainstem lesions (OR, 1.6494; 95% CI, 1.39-1.96), and NIHSS (OR, 1.2073; 95% CI, 1.19-1.23). CONCLUSIONS: The incidence of dysphagia after ischemic stroke was 32.3%. The prediction model for the presence of dysphagia identified age, low BMI, premorbid disabilities, brainstem lesions, and NIHSS as predictive factors.

REPEATABILITY OF MACULAR MICROVASCULATURE MEASUREMENTS USING OPTICAL COHERENCE TOMOGRAPHY ANGIOGRAPHY ACCORDING TO TEAR BREAKUP TIME IN DRY EYE DISEASE.

PURPOSE: It is hypothesized that an unstable tear film would affect the quality and repeatability of optical coherence tomography angiography (OCTA). Therefore, OCTA repeatability according to tear break-up time (TBUT) was compared. METHODS: The 3 × 3 OCTA was performed twice and, the eyes were divided into 3 groups according to the TBUT (Group 1: TBUT ≤ 5 seconds, 43 eyes; Group 2: 5 seconds < TBUT ≤ 10 seconds, 35 eyes; Group 3: TBUT > 10 seconds, 34 eyes). The intraclass correlation coefficient, coefficient of variation, and test-retest SD were calculated and compared. RESULTS: The signal strengths of OCTA were 9.1 ± 1.2, 9.5 ± 0.8, and 9.5 ± 0.8 in each group from Groups 1, 2, and 3, respectively, which showed significant difference (P = 0.049). The intraclass correlation coefficient of vessel density were 0.733, 0.840, and 0.974 in Groups 1 to 3, respectively, and the values increased in the order of Groups 1, 2, and 3. The coefficient of variation were 6.41 ± 6.09, 3.29 ± 2.22, and 1.30 ± 1.17, and the test-retest SD were 0.83 ± 0.70, 0.47 ± 0.31, and 0.19 ± 0.17 in Groups 1, 2, and 3, respectively. The coefficient of variation and test-retest SD values decreased in the order of Groups 1, 2, and 3, and showed a significant difference (all, P < 0.05). CONCLUSION: The repeatability of OCTA tended to decrease with a shorter TBUT. When the TBUT is <5 seconds, care must be taken to interpret the OCTA results correctly.

Prevalence and Severity of Dysphagia Using Videofluoroscopic Swallowing Study in Patients with Aspiration Pneumonia.

INTRODUCTION: The purpose of this study was to identify the prevalence and severity of dysphagia in patients diagnosed with aspiration pneumonia, with and without neurologic disorders. METHODS: We retrospectively reviewed the medical records of inpatients with aspiration pneumonia who underwent a videofluoroscopic swallowing study (VFSS) for evaluation of dysphagia. Patients were divided into two groups based on the presence or absence of neurologic disorders. The prevalence and severity of aspiration and pharyngeal residue due to dysphagia were assessed using the penetration-aspiration scale (PAS) and pharyngeal residue grade (PRG). RESULTS: A total of 784 patients were enrolled; of these, 58.7% were males and the mean age was 76.12 ± 6.69. Penetration-aspiration-related dysphagia (PAS scores 3-8) was seen in 56.5% of all subjects, and 32.5% showed silent aspiration (PAS 8). Pharyngeal residue-related dysphagia (PRG scores 2-3) was seen in 65.2% of all patients, and the PAS and PRG were positively correlated. On dividing the subjects into two groups based on the presence of neurologic disorders, there was no significant difference in prevalence of the dysphagia between groups (PAS: p = 0.641; PRG: p = 0.872) with the proportion of silent aspiration (p = 0.720). CONCLUSION: In patients hospitalized for aspiration pneumonia, there was a high prevalence of dysphagia. There were no differences in the prevalence and severity of dysphagia in patients with aspiration pneumonia based on the presence or absence of a neurologic disorder. Therefore, diagnostic evaluation of dysphagia is necessary regardless of the presence of neurologic disorders.

Contralesional Application of Transcranial Direct Current Stimulation on Functional Improvement in Ischemic Stroke Mice.

BACKGROUND AND PURPOSE: The therapeutic use of transcranial direct current stimulation (tDCS), an adjuvant tool for stroke, induces long-term changes in cortical excitability, for example, the secretion of activity-dependent growth factors. We assessed the proper therapeutic configuration of high-definition tDCS (HD-tDCS) in the subacute stage of ischemic stroke and its underlying expression profiling of growth factors to propose a new method for ensuring better therapeutic effects. METHODS: Male C57BL/6J mice were subjected to middle cerebral artery occlusion, after which repetitive HD-tDCS (20 minutes, 55 µA/mm2, charge density 66 000 C/m2) was applied from subacute phases of their ischemic insult. Behavioral tests assessing motor and cognitive functions were used to determine suitable conditions and HD-tDCS stimulation sites. Gene expression profiling of growth factors and their secretion and activation were analyzed to shed light on the underlying mechanisms. RESULTS: Anodal HD-tDCS application over the contralesional cortex, especially the motor cortex, was more effective than ipsilesional stimulation in attenuating motor and cognitive deficits. In the HD-tDCS application over the contralesional motor cortex, positive changes in Bmp8b, Gdf5, Il4, Pdgfa, Pgf, and Vegfb were observed in the ipsilesional site. The expression of GDF5 (growth/differentiation factor 5) and PDGFA (platelet-derived growth factor subunit A) tended to similarly increase in both ipsi- and contralesional striata. However, higher expression levels of GDF5 and PDGFA and their receptors were observed in the peri-infarct regions of the striatum after HD-tDCS, especially in PDGFA expression. A higher number of proliferating or newly formed neuronal cells was detected in ipsilesional sites such as the subventricular zone. CONCLUSIONS: Application of anodal HD-tDCS over the contralesional cortex may enhance beneficial recovery through the expression of growth factors, such as GDF5 and PDGFA, in the ipsilesional site. Therefore, this therapeutic configuration may be applied in the subacute stage of ischemic stroke to ameliorate neurological impairments.

Effect of Cognitive Reserve on Risk of Cognitive Impairment and Recovery After Stroke: The KOSCO Study.

Background and Purpose- The theory of cognitive reserve (CR) was introduced to account for individual differences in the clinical manifestation of neuropathology. This study investigated whether CR has a modulating effect on cognitive impairment and recovery after stroke. Methods- This study is an interim analysis of the Korean Stroke Cohort for Functioning and Rehabilitation. A total of 7459 patients with first-ever stroke were included for analysis. Education, occupation, and composite CR scores derived from those 2 variables were used as CR proxies. Scores from the Korean version of the Mini-Mental State Examination analyzed for 30 months after stroke onset were analyzed. Results- Lower CR increased the risk of cognitive impairment after stroke. The odds ratio was 1.89 (95% CI, 1.64-2.19) in patients with secondary education and 2.42 (95% CI, 2.03-2.90) in patients with primary education compared with patients with higher education. The odds ratio was 1.48 (95% CI, 1.23-1.98) in patients with a skilled manual occupation and 2.01 (95% CI, 1.42-2.83) in patients with a nonskilled manual occupation compared with patients with a managerial or professional occupation. In the multilevel model analysis, the Korean version of the Mini-Mental State Examination total score increased during the first 3 months (1.93 points per month) and then plateaued (0.02 point per month). The slopes were moderated by the level of education, occupation, and composite CR score: the higher the level of education, occupation, or CR score, the faster the recovery. In the older adult group, the Korean version of the Mini-Mental State Examination scores showed a long-term decline that was moderated by education level. Conclusions- Education and occupation can buffer an individual against cognitive impairment caused by stroke and promote rapid cognitive recovery early after stroke. In addition, higher education minimizes long-term cognitive decline after stroke, especially in older patients. Clinical Trial Registration- URL: https://www.clinicaltrials.gov. Unique identifier: NCT03402451.

AIM2 inflammasome contributes to brain injury and chronic post-stroke cognitive impairment in mice.

Although over one-third of stroke patients may develop post-stroke cognitive impairment (PSCI), the mechanisms underlying PSCI remain unclear. We explored here, the involvement of post-stroke inflammasomes in long-term PSCI development, using a 45 min-middle cerebral artery occlusion (MCAO)/reperfusion-induced PSCI model. Immunohistological assessment on day 1, 3, and 7 was followed by cognitive function test 28 days post-stroke. Evaluation of inflammasome sensor gene expression in aged mouse brains showed dominant expression of absent in melanoma 2 (Aim2) in 6-, 12-, and 18-month-old mouse brains. AIM2 mRNA and protein increased until 7 days post-stroke. PSCI decreased anxiety in elevated plus maze test and impaired spatial learning and memory functions in Morris water maze test 28 days post-stroke. AIM2 and other inflammasome subunit immunoreactivities, including those for caspase-1, interleukin (IL)-1ß, and IL-18, were higher in the hippocampus and cortex of the PSCI than in those of the sham group 7 days post-stroke. AIM2 immunoreactivity of the PSCI group was primarily co-localized with Iba-1 (microglial marker) and CD31 (endothelial cell marker) immunoreactivities but not NeuN (neuronal marker) and GFAP (astrocyte marker) immunoreactivities, suggesting that microglia or endothelial cell-induced AIM2 production mediated PSCI pathogenesis. Additionally, inflammasome-induced pyroptosis might contribute to acute and chronic neuronal death after stroke. AIM2 knockout (KO) and Ac-YVAD-CMK-induced caspase-1 inhibition in mice significantly improved cognitive function and reversed brain volume in the hippocampus relative to those in stroke mice. Conclusively, AIM2 inflammasome-mediated inflammation and pyroptosis likely aggravated PSCI; therefore, targeting and controlling AIM2 inflammasome could potentially treat PSCI.

Characteristics of the Foveal Microvasculature in Asian Patients with Dry Age-Related Macular Degeneration: An Optical Coherence Tomography Angiography Study.

PURPOSE: To evaluate changes in the foveal microvasculature in patients with dry age-related macular degeneration (dry AMD) using optical coherence tomography angiography (OCTA). METHODS: Eighty-three eyes with dry AMD and 83 age- and sex-matched normal eyes were enrolled. A 3 × 3 mm2 OCTA (Zeiss HD-OCT 5000 with AngioPlex; Carl Zeiss Meditec, Dublin, CA, USA) scan was used to acquire images. Vessel density (VD), perfusion density (PD), and the foveal avascular zone (FAZ) of the superficial capillary plexus were analyzed. RESULTS: The VD of the full area, central area, and inner ring of the dry AMD patients (18.61, 8.41, and 20.45, respectively) were significantly lower than those of the controls (20.06, 11.09, and 22.51, respectively). The PD of the full area, central area, and inner ring of the dry AMD patients (0.34, 0.15, and 0.37, respectively) were also significantly lower than those of the controls (0.36, 0.19, and 0.40, respectively). The FAZ area and perimeter in the dry AMD patients (0.29 mm2 and 2.47 mm, respectively) were larger than those in the controls (0.23 mm2 and 2.09 mm, respectively). The FAZ circularity index in the dry AMD patients was smaller than that in the controls (0.61 vs. 0.66). Using univariate linear regression, age, best-corrected visual acuity (BCVA), central macular thickness (CMT), and ganglion cell-inner plexiform layer (GC-IPL) thickness were associated with both VD and PD of the full area. Using multivariate analysis, only GC-IPL thickness was significantly associated with the VD and PD of the full area (p = 0.001 and p = 0.004, respectively). CONCLUSIONS: OCTA revealed changes in the foveal microcirculation of patients with dry AMD. Age, BCVA, CMT, and GC-IPL thickness should be considered when analyzing the OCTA data of patients with dry AMD. GC-IPL thickness is particularly important during clinical evaluation of VD and PD in patients with dry AMD.

Quantitative Analysis of EEG Power Spectrum and EMG Median Power Frequency Changes after Continuous Passive Motion Mirror Therapy System.

Robotic mirror therapy (MT), which allows movement of the affected limb, is proposed as a more effective method than conventional MT (CMT). To improve the rehabilitation effectiveness of post-stroke patients, we developed a sensory stimulation-based continuous passive motion (CPM)-MT system with two different operating protocols, that is, asynchronous and synchronous modes. To evaluate their effectiveness, we measured brain activation through relative and absolute power spectral density (PSD) changes of electroencephalogram (EEG) mu rhythm in three cases with CMT and CPM-MT with asynchronous and synchronous modes. We also monitored changes in muscle fatigue, which is one of the negative effects of the CPM device, based on median power frequency (MPF) and root mean square (RMS). Relative PSD was most suppressed when subjects used the CPM-MT system under synchronous control: 22.11%, 15.31%, and 16.48% on Cz, C3, and C4, respectively. The absolute average changes in MPF and RMS were 1.59% and 9.78%, respectively, with CPM-MT. Synchronous mode CPM-MT is the most effective method for brain activation, and muscle fatigue caused by the CPM-MT system was negligible. This study suggests the more effective combination rehabilitation system for MT by utilizing CPM and magnetic-based MT task to add action execution and sensory stimulation compared with CMT.

Longitudinal Changes in Peripapillary Retinal Nerve Fiber Layer Thickness in High Myopia: A Prospective, Observational Study.

PURPOSE: To determine longitudinal change of peripapillary retinal nerve fiber layer (pRNFL) thickness in patients with high myopia without ophthalmic disease. DESIGN: Prospective observational study. PARTICIPANTS: Participants were divided into 2 groups: a high myopia group (80 eyes) that included eyes with an axial length ≥26.0 mm and a control group (80 eyes) that included eyes with a spherical equivalent (SE) between +3.0 and -6.0 diopters (D). Both groups were further divided into age subgroups by decade: 20s, 30s, 40s, and 50s. Each subgroup included 20 eyes. METHODS: After the initial visit, pRNFL thickness measurements were performed 2 times more with at least 1-year intervals between examinations using spectral-domain OCT. The mean pRNFL thickness was fitted with linear mixed models. MAIN OUTCOME MEASURES: The pRNFL thickness and rate of pRNFL thickness reduction. RESULTS: The mean patient age and thickness of the pRNFL at the first visit were 39.5±12.5 years and 90.16±9.06 µm, and 41.5±12.2 years and 96.80±9.50 µm in the high myopia and control groups, respectively. The high myopia group showed a significant reduction in mean pRNFL thickness between the first and second visits, and between the second and third visits (P < 0.001 and P = 0.002, respectively). For individuals aged 50 to 59 years, the reduction rate was -1.69 and -0.63 µm/year in the high myopia and control groups, respectively; the interaction between group and duration was significant (P = 0.014). The reduction rate in individuals aged 40 to 49 years was -1.70 and -0.48 µm/year in the 2 groups, respectively; the interaction was also significant (P = 0.031). Among those aged 30 to 39 years and 20 to 29 years, no such significant interactions were observed (-0.95 vs. -0.57 µm/year, P = 0.086 and -0.31 vs. -0.19 µm/year, P = 0.858, respectively). CONCLUSIONS: Highly myopic eyes had a significantly greater decrease in pRNFL over 2 years than normal eyes. In addition, the reduction rate of pRNFL thickness was greater in older patients with high myopia, whereas similar values were shown in normal controls except individuals aged 20 to 29 years.

PRIMARY CORE VITRECTOMY TECHNIQUE BEFORE CATARACT SURGERY IN COMBINED PHACOVITRECTOMY FOR EYES WITH DENSE VITREOUS HEMORRHAGES.

PURPOSE: To investigate the efficacy and safety of a primary core vitrectomy technique for combined phacovitrectomy in eyes showing a poor red reflex because of dense vitreous hemorrhage before cataract surgery. METHODS: A total of 156 eyes from 156 patients, who underwent combined phacovitrectomy because of cataract and dense vitreous hemorrhage, and who were followed up for at least 6 months were included. The patients were divided into a primary phacoemulsification group (Group A, 80 eyes) who underwent phacoemulsification first followed by total vitrectomy and a primary vitrectomy group (Group B, 76 eyes) who underwent core vitrectomy first followed by cataract surgery and followed by total vitrectomy. A conventional 23-gauge combined phacovitrectomy was performed in all patients. The operation time, including the total continuous curvilinear capsulorhexis time and total cataract surgery time, and the incidence of surgery-related complications were evaluated in the two groups. RESULTS: Diabetic retinopathy was the most common cause for vitreous hemorrhage in both groups (Group A: 51 eyes; Group B: 39 eyes). The total continuous curvilinear capsulorhexis time (P = 0.001) and total cataract surgery time (P = 0.036) were significantly shorter in Group B than in Group A. Among the complications, radial tears occurred more frequently in Group A than Group B, but these differences were not statistically significant (P = 0.211). Pupil size reduction during cataract surgery was greater in Group B than in Group A (P = 0.034). There were no significant differences in posterior capsular ruptures or posterior capsular opacities between the two groups. Other postoperative complications were not observed in either group until 6 months after surgery. CONCLUSION: Primary core vitrectomy combined with phacovitrectomy of patients who had dense vitreous hemorrhage helped to obtain a good red reflex and enabled surgeons to perform successful cataract surgery. In addition, primary core vitrectomy was an easy and safe technique, which reduced the surgery time and surgery-related complications. This surgical technique would, therefore, be helpful to vitreoretinal surgeons.

Neural Compensatory Response During Complex Cognitive Function Tasks in Mild Cognitive Impairment: A Near-Infrared Spectroscopy Study.

The present pilot study was aimed at conducting a comparative analysis of the level of activation in the prefrontal cortex among a normal elderly group and amnestic and nonamnestic mild cognitive impairment (MCI) groups and investigating the presence of neural compensatory mechanisms according to types of MCI and different cognitive tasks. We performed functional near-infrared spectroscopy (fNIRS) along with cognitive tasks, including two-back test, Korean color word Stroop test, and semantic verbal fluency task (SVFT), to investigate hemodynamic response and the presence of neural compensation and neuroplasticity in the prefrontal cortex of patients with amnestic and nonamnestic MCI compared with a healthy elderly group. During the two-back test, there was no significant difference in the bilateral region-of-interest (ROI) analysis in the three groups. During the Stroop test, right-sided hyperactivation compared to the left side during the task was shown in the nonamnestic MCI and normal groups with statistical significance. Mean acc∆HbO2 on the right side was highest in the nonamnestic MCI group (0.30 µM) followed by the normal group (0.07 µM) and the amnestic MCI group (-0.10 µM). Otherwise, intergroup ROI analysis of acc∆HbO2 in these activated right sides showed no significant difference. During the VFT test, there was no significant difference in the bilateral region-of-interest analysis in the three groups. The highest mean acc∆HbO2 was shown in the normal group (0.79 µM) followed by the nonamnestic MCI group (0.52 µM) and the amnestic MCI group (0.21 µM). Otherwise, there was no significant difference between groups. The hemodynamic response during fNIRS showed different findings according to MCI types and cognitive tasks. Among the three tasks, the Stroop test showed results that were suggestive of neural compensatory mechanisms in the prefrontal cortex in nonamnestic MCI.

Modulating Brain Connectivity by Simultaneous Dual-Mode Stimulation over Bilateral Primary Motor Cortices in Subacute Stroke Patients.

Repetitive transcranial magnetic stimulation (rTMS) or transcranial direct current stimulation (tDCS) has been used for the modulation of stroke patients' motor function. Recently, more challenging approaches have been studied. In this study, simultaneous stimulation using both rTMS and tDCS (dual-mode stimulation) over bilateral primary motor cortices (M1s) was investigated to compare its modulatory effects with single rTMS stimulation over the ipsilesional M1 in subacute stroke patients. Twenty-four patients participated; 12 participants were assigned to the dual-mode stimulation group while the other 12 participants were assigned to the rTMS-only group. We assessed each patient's motor function using the Fugl-Meyer assessment score and acquired their resting-state fMRI data at two times: prior to stimulation and 2 months after stimulation. Twelve healthy subjects were also recruited as the control group. The interhemispheric connectivity of the contralesional M1, interhemispheric connectivity between bilateral hemispheres, and global efficiency of the motor network noticeably increased in the dual-mode stimulation group compared to the rTMS-only group. Contrary to the dual-mode stimulation group, there was no significant change in the rTMS-only group. These data suggested that simultaneous dual-mode stimulation contributed to the recovery of interhemispheric interaction than rTMS only in subacute stroke patients. This trial is registered with NCT03279640.