Comparison of UPDRS III score between young and late onset Parkinson disease after deep brain stimulation: A meta-analysis.

PURPOSE: Parkinson disease (PD) is a common age-related neurodegenerative disease. Subthalamic nucleus deep brain stimulation (DBS) is a safe and effective surgical treatment for medically resistant advanced PD. However, the relationship between the age at PD onset and the efficacy of subthalamic nucleus DBS surgery remains unclear. Thus, we conducted a meta-analysis to compare motor symptom improvements after DBS for the treatment of young-onset and late-onset PD. METHODS: We systematically searched the Medline and Embase databases (from inception to March 2023) for English publications. All published studies comparing the outcomes (Unified Parkinson's Disease Rating Scale part III [UPDRS III] scores) of DBS between the young-onset Parkinson disease (YOPD) and late-onset Parkinson disease (LOPD) groups were identified. The effect size was defined as the standardized mean difference (Hedge g) with 95% confidence intervals. The standardized mean difference was calculated by dividing the difference in UPDRS III scores between old and young patients by the pooled and weighted standard deviations. The meta-analysis was performed using R Statistical Software version 4.2.2 (The R Foundation for Statistical Computing). RESULTS: Six studies were eligible for inclusion. The standardized mean difference of UPDRS III score between young and old patients ranged from -0.54 to 1.43 with a pooled difference of 0.0932 (95% confidence intervals: - 0.4666 to 0.6530, I2 = 86.77%). Subgroup analyses were performed with a cutoff age of 65 years and did not show a significant difference in UPDRS III scores between patients with YOPD and LOPD (0.1877, -0.6663 to 1.0417). CONCLUSIONS: The efficacy of DBS in patients with YOPD and LOPD showed similar improvements in the UPDRS score; hence, DBS should be considered, if necessary, regardless of the onset age of PD.

Neuropsychological, neuroimaging and autopsy findings of butane encephalopathy.

BACKGROUND: Butane is an aliphatic hydrocarbon used in various commercial products. While numerous reports of sudden cardiac-related deaths from butane inhalation have been described, butane-associated acute encephalopathy has rarely been reported. CASE PRESENTATION: A 38-year-old man presented with cognitive dysfunction after butane gas inhalation. Neuropsychological test results showed impairments in verbal and visual memory, and frontal executive function. Diffusion weighted MRI revealed symmetric high-signal changes in the bilateral hippocampus and globus pallidus. FDG-PET demonstrated decreased glucose metabolism in the bilateral precuneus and occipital areas and the left temporal region. At the 8-month follow-up, he showed still significant deficits in memory and frontal functions. Diffuse cortical atrophy with white matter hyperintensities and extensive glucose hypometabolism were detected on follow-up MRI and FDG-PET, respectively. Brain autopsy demonstrated necrosis and cavitary lesions in the globus pallidus. CONCLUSIONS: Only a few cases of butane encephalopathy have been reported to date. Brain lesions associated with butane encephalopathy include lesions in the bilateral thalamus, insula, putamen, and cerebellum. To the best of our knowledge, this is the first report on bilateral hippocampal and globus pallidal involvement in acute butane encephalopathy. The pathophysiology of central nervous system complications induced by butane intoxication is not yet fully understood. However, the direct toxic effects of butane or anoxic injury secondary to cardiac arrest or respiratory depression have been suggested as possible mechanisms of edematous changes in the brain after butane intoxication.

Hospitals' Adoption of Mobile-Based Personal Health Record Systems and Patients' Characteristics: A Cross-Sectional Study Analyzing National Healthcare Big Data.

Insufficient information exists on the associations between hospitals' adoption of mobile-based personal health record (mPHR) systems and patients' characteristics. This study explored the associations between patients' characteristics and hospitals' adoption of mPHR systems in Korea. This cross-sectional study used 316 hospitals with 100 or more beds as the unit of analysis. Previously collected data on mPHR adoption from May 1 to June 30, 2020 were analyzed. National health insurance claims data for 2019 were also used to analyze patients' characteristics. The dependent variable was mPHR system adoption (0 vs 1) and the main independent variables were the number of patients, age distribution, and proportions of patients with cancer, diabetes, and hypertension among inpatients and outpatients. The number of inpatients was significantly associated with mPHR adoption (adjusted odds ratio [aOR]: 1.174; 1.117-1.233, P < .001), as was the number of outpatients (aOR: 1.041; 1.028-1.054, P < .001). The proportion of inpatients aged 31 to 60 years to those aged 31 years and older was also associated with hospital mPHR adoption (aOR: 1.053; 1.022-1.085, P = .001). mPHR system adoption was significantly associated with the proportion of inpatients (aOR: 1.089; 1.012-1.172, P = .024) and outpatients (aOR: 1.138; 1.026-1.263, P = .015) with cancer and outpatients (aOR: 1.271; 1.101-1.466, P = .001) with hypertension. Although mPHR systems are useful for the management of chronic diseases such as diabetes and hypertension, the number of patients, younger age distribution, and the proportion of cancer patients were closely associated with hospitals' introduction of mPHR systems.

Preliminary Study on Natural Killer Cell Activity for Interferon-Gamma Production after Gamma Knife Radiosurgery for Brain Tumors.

OBJECTIVE: High-dose radiation is well known to induce and modulate the immune system. This study was performed to evaluate the correlation between clinical outcomes and changes in natural killer cell activity (NKA) after Gamma Knife Radiosurgery (GKS) in patients with brain cancer. METHODS: We performed an open-label, prospective, cross-sectional study of 38 patients who were treated with GKS for brain tumors, including metastatic and benign brain tumors. All of the patients underwent GKS, and blood samples were collected before and after GKS. NKA was measured using an enzyme-linked immunosorbent assay kit, to measure interferon-gamma (IFNγ) secreted by ex vivo-stimulated NK cells from whole blood. We explored the correlations between NK cell-produced IFNγ (NKA-IFNγ) levels and clinical parameters of patients who were treated with GKS for brain tumors. RESULTS: NKA-IFNγ levels were decreased in metastatic brain tumor patients compared to those with benign brain tumors (p<0.0001). All the patients who used steroid treatment to reduce brain swelling after GKS had an NKA-IFNγ level of zero except one patient. High NKA-IFNγ levels were not associated with a rapid decrease in brain metastasis and did not increase after GKS. CONCLUSION: The activity of NK cells in metastatic brain tumors decreased more than that in benign brain tumors after GKS.

Long-Term Outcomes of Bilateral Subthalamic Nucleus Deep Brain Stimulation for Patients With Parkinson's Disease: 10 Years and Beyond.

BACKGROUND: Deep brain stimulation (DBS) of the subthalamic nucleus (STN) represents an effective treatment for severe Parkinson's disease (PD), but little is known about the long-term benefit. OBJECTIVE: To investigate the survival rate and long-term outcome of DBS. METHODS: We investigated all 81 patients including 37 males and 44 females who underwent bilateral STN DBS from March 2005 to March 2008 at a single institution. The current survival status of the patients was investigated. Preoperative and postoperative follow-up assessments were analyzed. RESULTS: The mean age at the time of surgery was 62 (range 27-82) years, and the median clinical follow-up duration was 145 months. Thirty-five patients (43%) died during the follow-up period. The mean duration from DBS surgery to death was 110.46 ± 40.8 (range 0-155) months. The cumulative survival rate is as follows: 98.8 ± 1.2% (1 year), 95.1 ± 2.4% (5 years), and 79.0 ± 4.5% (10 years). Of the 81 patients, 33 (40%) were ambulatory up to more than 11 years. The Unified Parkinson's Disease Rating Scale (UPDRS) score was significantly improved until 5 years after surgery although it showed a tendency to increase again after 10 years. The patient group with both electrodes located within the STN showed a higher rate of survival and maintained ambulation. CONCLUSION: STN DBS is a safe and effective treatment for patients with advanced PD. This study based on the long-term follow-up of large patient populations can be used to elucidate the long-term fate of patients who underwent bilateral STN DBS for PD.

Serum progranulin is not associated with rs5848 polymorphism in Korean patients with neurodegenerative diseases.

Low serum progranulin (PGRN) is known to be associated with granulin (GRN) gene mutation and T alleles of GRN rs5848 polymorphism. However, there have been only a few Asian studies exploring these. We investigated the serum PGRN levels, rs5848 genotypes, and their relations with cerebrospinal fluid (CSF) Alzheimer's disease (AD) biomarkers in the Korean population. Serum PGRN levels, GRN rs5848 polymorphism, and GRN mutations were evaluated in 239 participants (22 cognitively unimpaired participants and 217 patients with neurodegenerative diseases). CSF AD biomarkers were also evaluated in 214 participants. There was no significant difference in the serum PGRN levels among the diagnostic groups. We could not find any GRN mutation carrier in our sample. The differences in the frequencies of the rs5848 genotypes among the clinical groups or the effects of the rs5848 genotypes on serum PGRN were not observed. There was no correlation between the serum PGRN level or rs5848 genotype and CSF AD biomarkers. Neither the T allele nor the TT genotype had an effect on the development of AD. Our results showed that serum PGRN levels were not associated with rs5848 genotypes, indicating that multiple single nucleotide polymorphisms might affect PGRN concentrations in an ethnicity-specific manner.

User perception of medical service robots in hospital wards: a cross-sectional study.

BACKGRUOUND: Recently, there have been various developments in medical service robots (MSRs). However, few studies have examined the perceptions of those who use it. The purpose of this study is to identify user perceptions of MSRs. METHODS: We conducted a survey of 320 patients, doctors, and nurses. The contents of the survey were organized as follows: external appearances, perceptions, expected utilization, possible safety accidents, and awareness of their responsibilities. Statistical analyses were performed using t-test, chi-square test, and analysis of variance. RESULTS: The most preferred appearance was the animal type, with a screen. The overall average score of positive questions was 3.64±0.98 of 5 points and that of negative questions was 3.24±0.99. Thus, the results revealed that the participants had positive perceptions of MSR. The overall average of all expected utilization was 4.05±0.84. The most expected utilization was to guide hospital facilities. The most worrisome accident was exposure to personal information. Moreover, participants thought that the overall responsibility of the robot user (hospital) was greater than that of the robot manufacturer in the case of safety accidents. CONCLUSION: The perceptions of MSRs used in hospital wards were positive, and the overall expected utilization was high. It is necessary to recognize safety accidents for such robots, and sufficient attention is required when developing and manufacturing robots.

Atypical Young-onset Dementia in Cerebral Thromboangiitis Obliterans: A Case Report.

Young-onset dementia (YOD, age at onset below 45 y) has a broad differential diagnosis. We describe a 41-year-old man with atypical manifestations of YOD syndrome in cerebral thromoboangiitis obliterans (CTAO). Extensive antemortem workup including clinical assessment, laboratory investigations, neuroimaging, and genetic testing did not elucidate a diagnosis. Postmortem neuropathologic examination revealed cortical sickle-shaped granular atrophy, resulting from numerous remote infarcts and cortical microinfarcts that mainly affected the bilateral frontal and parietal lobe, confirming CTAO. Although CTAO is a rare cause of vascular dementia, it should be considered as one of the differentials in patients with YOD with a history of heavy smoking and presence of symmetric damages of watershed-territory on neuroimaging.

Drop Attack Treated by Microvascular Decompression of the Superior Vestibular Nerve.

We report a case of cochleovestibular neurovascular compressive syndrome (CVCS)-induced drop attack treated with microvascular decompression (MVD) of the superior vestibular nerve. This report discusses the merits of surgical intervention through a review of related literature. A 58-year-old woman was referred to our clinic with a chief complaint of intermittent, strong, right-sided tinnitus lasting for a few seconds immediately prior to drop attack. Magnetic resonance imaging (MRI) showed bilateral neurovascular contact between the anterior inferior cerebellar artery (AICA) and the vestibulocochlear nerve. Based on MRI findings, history of present illness, and response to anticonvulsants, CVCS was suspected, and surgical decompression on the right side was subsequently performed. The patient became asymptomatic immediately after the surgery, and the vestibular-evoked myogenic potentials were normalized. No recurrence was reported during a 1-year follow-up period.

Preclinical mouse model of optical coherence tomography for subcortical brain imaging without dissection.

The purpose of this study was to investigate the feasibility of using optical coherence tomography (OCT) to identify internal brain lesions, specifically intracerebral hemorrhage, without dissection. Mice with artificially injected brain hematomas were used to test the OCT system, and the recorded images were compared with microscopic images of the same mouse brains after hematoxylin and eosin staining. The intracranial structures surrounding the hematomas were clearly visualized by the OCT system without dissection. These images reflect the ability of OCT to determine the extent of a lesion in several planes. OCT is a useful technology, and these findings could be used as a starting point for future research in intraoperative imaging.

Long-term Outcome of Microscopic Transsphenoidal Surgery for Prolactinomas as an Alternative to Dopamine Agonists.

BACKGROUND: Although long-term dopamine agonist (DA) therapy is recommended as a first-line treatment for prolactinoma, some patients may prefer surgical treatment because of the potential adverse effects of long-term medication, or the desire to become pregnant. This study aimed to determine whether surgical treatment of prolactinomas could be an alternative to DA therapy. METHODS: In this retrospective study, 96 consecutive patients (74 female, 22 male) underwent primary pituitary surgery without long-term DA treatment for prolactinomas at a single institution from 1990 to 2010. All patients underwent primary surgical treatment in the microscopic transsphenoidal approach (TSA). RESULTS: The median age and median follow-up period were 31 (16-73) years and 139.1 (12.2-319.6) months, respectively. An initial overall remission was accomplished in 47.9% (46 of 96 patients, 33 macroadenomas, and 13 microadenomas) of patients. DA dose reduction was achieved in all patients after TSA. A better remission rate was independently predicted by lower diagnostic prolactin levels and by a greater extent of surgical resection. Overall remission at the last follow-up was 33.3%, and the overall recurrence rate was 30.4%. The permanent complication rate was 3.1%, and there was no mortality. CONCLUSION: TSA can be considered a safe and potentially curative treatment for selective microprolactinomas as an alternative to treatment with a long-term DA.

Clinical outcome prediction from analysis of microelectrode recordings using deep learning in subthalamic deep brain stimulation for Parkinson`s disease.

BACKGROUND: Deep brain stimulation (DBS) of the subthalamic nucleus (STN) is an effective treatment for improving the motor symptoms of advanced Parkinson's disease (PD). Accurate positioning of the stimulation electrodes is necessary for better clinical outcomes. OBJECTIVE: We applied deep learning techniques to microelectrode recording (MER) signals to better predict motor function improvement, represented by the UPDRS part III scores, after bilateral STN DBS in patients with advanced PD. If we find the optimal stimulation point with MER by deep learning, we can improve the clinical outcome of STN DBS even under restrictions such as general anesthesia or non-cooperation of the patients. METHODS: In total, 696 4-second left-side MER segments from 34 patients with advanced PD who underwent bilateral STN DBS surgery under general anesthesia were included. We transformed the original signal into three wavelets of 1-50 Hz, 50-500 Hz, and 500-5,000 Hz. The wavelet-transformed MER was used for input data of the deep learning. The patients were divided into two groups, good response and moderate response groups, according to DBS on to off ratio of UPDRS part III score for the off-medication state, 6 months postoperatively. The ratio were used for output data in deep learning. The Visual Geometry Group (VGG)-16 model with a multitask learning algorithm was used to estimate the bilateral effect of DBS. Different ratios of the loss function in the task-specific layer were applied considering that DBS affects both sides differently. RESULTS: When we divided the MER signals according to the frequency, the maximal accuracy was higher in the 50-500 Hz group than in the 1-50 Hz and 500-5,000 Hz groups. In addition, when the multitask learning method was applied, the stability of the model was improved in comparison with single task learning. The maximal accuracy (80.21%) occurred when the right-to-left loss ratio was 5:1 or 6:1. The area under the curve (AUC) was 0.88 in the receiver operating characteristic (ROC) curve. CONCLUSION: Clinical improvements in PD patients who underwent bilateral STN DBS could be predicted based on a multitask deep learning-based MER analysis.

Successful Motor Evoked Potential Monitoring in Cervical Myelopathy : Related Factors and the Effect of Increased Stimulation Intensity.

OBJECTIVE: Intraoperative neurophysiological monitoring (IONM) has been widely used during spine surgery to reduce or prevent neurologic deficits, however, its application to the surgical management for cervical myelopathy remains controversial. This study aimed to assess the success rate of IONM in patients with cervical myelopathy and to investigate the factors associated with successful baseline monitoring and the effect of increasing the stimulation intensity by focusing on motor evoked potentials (MEPs). METHODS: The data of 88 patients who underwent surgery for cervical myelopathy with IONM between January 2016 and June 2018 were retrospectively reviewed. The success rate of baseline MEP monitoring at the initial stimulation of 400 V was investigated. In unmonitorable cases, the stimulation intensity was increased to 999 V, and the success rate final MEP monitoring was reinvestigated. In addition, factors related to the success rate of baseline MEP monitoring were investigated using independent t-test, Wilcoxon rank-sum test, chi-squared test, and Fisher's exact probability test for statistical analysis. The factors included age, sex, body mass index, diabetes mellitus, smoking history, symptom duration, Torg-Pavlov ratio, space available for the cord (SAC), cord compression ratio (CCR), intramedullary increased signal intensity (SI) on magnetic resonance imaging, SI length, SI ratio, the Medical Research Council (MRC) grade, the preoperative modified Nurick grade and Japanese Orthopedic Association (JOA) score. RESULTS: The overall success rate for reliable MEP response was 52.3% after increasing the stimulation intensity. No complications were observed to be associated with increased intensity. The factors related to the success rate of final MEP monitoring were found to be SAC (p<0.001), CCR (p<0.001), MRC grade (p<0.001), preoperative modified Nurick grade (p<0.001), and JOA score (p<0.001). The cut-off score for successful MEP monitoring was 5.67 mm for SAC, 47.33% for the CCR, 3 points for MRC grade, 2 points for the modified Nurick grade, and 12 points for the JOA score. CONCLUSION: Increasing the stimulation intensity could significantly improve the success rate of baseline MEP monitoring for unmonitorable cases at the initial stimulation in cervical myelopathy. In particular, the SAC, CCR, MRC grade, preoperative Nurick grade and JOA score may be considered as the more important related factors associated with the success rate of MEP monitoring. Therefore, the degree of preoperative neurological functional deficits and the presence of spinal cord compression on imaging could be used as new detailed criteria for the application of IONM in patients with cervical myelopathy.

Personal experience with microvascular decompression and partial sensory rhizotomy for trigeminal neuralgia.

BACKGRUOUND: Trigeminal neuralgia (TN) is a severe, paroxysmal pain in the distribution of the fifth cranial nerve. Microvascular decompression (MVD) is the most widely used surgical treatment for TN. We undertook this study to analyze the effects of and complications of MVD and to refine the surgical procedure for treating TN. METHODS: A total of 88 patients underwent for TN underwent surgery at our hospital. Among them, 77 patients underwent MVD alone, and 11 underwent partial sensory rhizotomy (PSR) with or without MVD. The medical records of these patients were retrospectively analyzed for patient characteristics, clinical results, offending vessels, and complications if any. RESULTS: The mean follow-up duration was 43.2 months (range, 3-216 months). The most common site of pain was V2+V3 territory (n=27), followed by V2 (n=25) and V3 (n=23). The most common offending vessels were the superior cerebellar artery and anterior inferior cerebellar artery in that order. The overall rate of postoperative complications was 46.1%; however, most complications were transient. There were two cases of permanent partial hearing disturbance. In the MVD alone group, the cure rate was 67.5%, and the improvement rate was 26.0%. Among 11 patients who underwent PSR with or without MVD, the cure rate was 50.0%, and the improvement rate was 30.0%. CONCLUSION: The clinical results of MVD were satisfactory. Although the outcomes of PSR were not as favorable as those of pure MVD in this study, PSR can be considered in cases where there is no significant vascular compressive lesion or uncertainty of the causative vessel at the surgery.

Bilateral Subthalamic Nucleus Deep Brain Stimulation under General Anesthesia: Literature Review and Single Center Experience.

Bilateral subthalamic nucleus (STN) Deep brain stimulation (DBS) is a well-established treatment in patients with Parkinson's disease (PD). Traditionally, STN DBS for PD is performed by using microelectrode recording (MER) and/or intraoperative macrostimulation under local anesthesia (LA). However, many patients cannot tolerate the long operation time under LA without medication. In addition, it cannot be even be performed on PD patients with poor physical and neurological condition. Recently, it has been reported that STN DBS under general anesthesia (GA) can be successfully performed due to the feasible MER under GA, as well as the technical advancement in direct targeting and intraoperative imaging. The authors reviewed the previously published literature on STN DBS under GA using intraoperative imaging and MER, focused on discussing the technique, clinical outcome, and the complication, as well as introducing our single-center experience. Based on the reports of previously published studies and ours, GA did not interfere with the MER signal from STN. STN DBS under GA without intraoperative stimulation shows similar or better clinical outcome without any additional complication compared to STN DBS under LA. Long-term follow-up with a large number of the patients would be necessary to validate the safety and efficacy of STN DBS under GA.

Comparison of Amyloid in Cerebrospinal Fluid, Brain Imaging, and Autopsy in a Case of Progressive Supranuclear Palsy.

Cerebrospinal fluid (CSF) amyloid-beta 1-42 (Aß1-42) and amyloid positron emission tomography (PET) are the 2 main Alzheimer disease amyloid biomarkers that have been validated in neuropathologically confirmed Alzheimer disease cases. Although many studies have shown concordance of amyloid positivity or negativity between CSF Aß1-42 and amyloid PET, several studies also reported discrepancies between these 2 Aß biomarkers. We conducted a comparison of CSF Aß1-42 level, amyloid PET, and autopsy findings in a case with progressive supranuclear palsy in which biomarker acquisition and postmortem pathologic examination were conducted almost at the same time. Our case with antemortem CSF Aß1-42 (+)/amyloid PET (-) who was pathologically confirmed with Aß pathology in the cerebral cortex may indicate CSF Aß1-42 is more sensitive for assessing in vivo Aß than amyloid PET.

Comparison of Diagnostic Performances Between Cerebrospinal Fluid Biomarkers and Amyloid PET in a Clinical Setting.

The diagnostic performances of cerebrospinal fluid (CSF) biomarkers and amyloid positron emission tomography (PET) were compared by examining the association and concordance or discordance between CSF Aß1-42 and amyloid PET, after determining our own cut-off values for CSF Alzheimer's disease (AD) biomarkers. Furthermore, we evaluated the ability of CSF biomarkers and amyloid PET to predict clinical progression. CSF Aß1-42, t-tau, and p-tau levels were analyzed in 203 individuals [27 normal controls, 38 mild cognitive impairment (MCI), 62 AD dementia, and 76 patients with other neurodegenerative diseases] consecutively recruited from two dementia clinics. We used both visual and standardized uptake value ratio (SUVR)-based amyloid PET assessments for analyses. The association of CSF biomarkers with amyloid PET SUVR, hippocampal atrophy, and cognitive function were investigated by linear regression analysis, and the risk of conversion from MCI to AD dementia was assessed using a Cox proportional hazards model. CSF p-tau/Aß1-42 and t-tau/Aß1-42 exhibited the best diagnostic accuracies among the CSF AD biomarkers examined. Correlations were observed between CSF biomarkers and global SUVR, hippocampal volume, and cognitive function. Overall concordance and discordance between CSF Aß1-42 and amyloid PET was 77% and 23%, respectively. Baseline positive CSF Aß1-42 for MCI demonstrated a 5.6-fold greater conversion risk than negative CSF Aß1-42 .  However, amyloid PET findings failed to exhibit significant prognostic value. Therefore, despite presence of a significant correlation between the CSF Aß1-42 level and SUVR of amyloid PET, and a relevant concordance between CSF Aß1-42 and amyloid PET, baseline CSF Aß1-42 better predicted AD conversion.

Prediction of future weight change with dopamine transporter in patients with Parkinson's disease.

Fluctuating body weight is a commonly reported nonmotor feature in patients with Parkinson's disease (PD). We hypothesised that striatal dopamine transporter (DAT) density at the time of diagnosis might play an important role in weight regulation in patients with PD. DAT density was measured from 123I-FP-CIT single-photon emission computed tomography. Region-of-interest analyses were performed to measure the specific binding of 123I-FP-CIT to DAT, and the putamen-to-caudate nucleus ratio (PCR) was calculated. Body weight was measured at baseline (W0) and at 48 months (W48). We classified subjects into three groups: weight loss, stable, and weight gain. In final analyses, 163 patients (106 men, 57 women) were included. PCR significantly differed by group in men, but not in women or across all patients. In men, PCR was slightly negatively associated with the percentage change in weight. No such correlation was found across all patients or in women. In univariate and multivariate logistic regression analyses, low PCR was associated with future weight gain in men with PD but not in women. In conclusion, striatal DAT availability at the time of diagnosis could predict subsequent weight change in men with PD.