Dysphagia In Multiple Sclerosis Patients: Diagnostic And Evaluation Strategies

Can Voice Parameters Provide Cutoff Values to Predict Dysphagia in Individuals with Multiple Sclerosis?

In dysphagia assessment, along with well-defined measurements and signs, voice parameters can potentially support clinical decision as a marker, but more evidence is needed. This study aims to determine the voice parameters that can predict the risk of dysphagia and to determine optimal cutoff values in individuals with multiple sclerosis (IwMS). Seventy-six adults participated in the study, including 39 IwMS and 37 healthy individuals (HI). The study used the Dysphagia in Multiple Sclerosis Questionnaire (DYMUS), Gugging Swallowing Screen (GUSS), and Voice Handicap Index (VHI-10) and recorded voice samples using Praat programme. Voice recordings were taken pre- and post-swallowing. The voice parameters analysed are fundamental frequency (F0), standard deviation F0 (SD F0), jitter (local), shimmer (local), and harmonic-to-noise ratio (HNR). Roc analysis was performed to examine the diagnostic accuracy performance of the risk for dysphagia/penetration. The parameters of IwMS pre-swallowing differed significantly from those of HI on the VHI-10, DYMUS, GUSS scores, and jitter (local), shimmer (local), and HNR. IwMS but not HI exhibited significant differences in shimmer (local) and HNR between the pre- and post-swallowing measurements. In IwMS, GUSS revealed significant differences in shimmer (local) pre- and post-swallowing between the groups with and without dysphagia/penetration. In the ROC analysis results, the area under the curve (AUC) for shimmer (local) pre-swallowing was 73.1% (cutoff = 1.69); post-swallowing, it was 78.6% (cutoff = 1.57). In conclusion, IwMS can be associated with differences in shimmer (local) and HNR parameters, low quality of life-related to voice, and dysphagia/penetration risk. The AUC values for shimmer (local) in IwMS pre- and post-swallowing may help to strengthen diagnostic decisions of dysphagia risk.

The leukotriene receptor antagonist montelukast as a potential therapeutic adjuvant in multiple sclerosis - a review

Multiple Sclerosis (MS) is a multifactorial autoimmune disease of the central nervous system (CNS). It is characterized by a heightened activation of the immune system with ensuing inflammation, demyelination and neurodegeneration with consequences such as motor, sensory, cognitive, as well as autonomic dysfunctions. While a range of immune-modulatory drugs have shown certain efficacy in alleviating pathology and symptoms, none of the currently available therapeutics regenerates the damaged CNS to restore function. There is emerging evidence for leukotrienes and leukotriene receptors being involved in the various aspects of the MS pathology including neuroinflammation and de/remyelination. Moreover, leukotriene receptor antagonists such as the asthma drug montelukast diminish inflammation and promote regeneration/remyelination. Indeed, montelukast has successfully been tested in animal models of MS and a recent retrospective case-control study suggests that montelukast treatment reduces relapses in patients with MS. Therefore, we propose montelukast as a therapeutic adjuvant to the standard immune-modulatory drugs with the potential to reduce pathology and promote structural and functional restoration. Here, we review the current knowledge on MS, its pathology, and on the potential of leukotriene receptor antagonists as therapeutics for MS.

Mapping research trends regarding the mechanism of dysphagia from 1993 to 2023: a bibliometrics study and visualization analysis

As a common consequence of various neurogenic disorders, dysphagia has a significant impact on the quality of life for patients. To promote the development the field of swallowing, it will be helpful to clarify the pathological and therapeutic mechanisms of dysphagia. Through visual analysis of related papers from 1993 to 2023 in the Web of Science Core Collection (WoSCC) database, the research status and development trend of the pathogenesis of dysphagia were discussed. The co-occurrence study was finished using CiteSpace 6.2 R4 software, including keywords, countries, institutions, and authors. Finally, 1,184 studies satisfied the inclusion requirements. The findings of the visualization analysis suggested that aspiration and gastroesophageal reflux disease would be the areas of greatest interest for researchers studying the mechanism of dysphagia. As for the latest occurred research trends, fMRI, signals and machine learning emerging into the field of view of researchers. Based on an analysis of country co-occurrence, United States, Japan and China rank the top three, in terms of the number of publications on dysphagia. University System of Ohio is the organization that has published the most amount of articles regarding the mechanism of dysphagia. Other highly published schools in the top three include State University System of Florida and Northwestern University. For the prolific authors, German, Rebecca Z published the most articles at present, whose own research team working closely together. Several closely cooperating research teams have been formed at present, including the teams centered around German, Rebecca Z, Warnecke, Tobias and Hamdy Shaheen. This study intuitively analyzed the current research status of the mechanism of dysphagia, provided researchers with research hotspots in this field.

The impact of physical therapy on dysphagia in neurological diseases: a review

A neurogenic dysphagia is dysphagia caused by problems with the central and peripheral nervous systems, is particularly prevalent in conditions such as Parkinson's disease and stroke. It significantly impacts the quality of life for affected individuals and causes additional burdens, such as malnutrition, aspiration pneumonia, asphyxia, or even death from choking due to improper eating. Physical therapy offers a non-invasive treatment with high efficacy and low cost. Evidence supporting the use of physical therapy in dysphagia treatment is increasing, including techniques such as neuromuscular electrical stimulation, sensory stimulation, transcranial direct current stimulation, and repetitive transcranial magnetic stimulation. While initial studies have shown promising results, the effectiveness of specific treatment regimens still requires further validation. At present, there is a lack of scientific evidence to guide patient selection, develop appropriate treatment regimens, and accurately evaluate treatment outcomes. Therefore, the primary objectives of this review are to review the results of existing research, summarize the application of physical therapy in dysphagia management, we also discussed the mechanisms and treatments of physical therapy for neurogenic dysphagia.

Relationship Between Subjective Questionnaires and Videofluoroscopy of Dysphagia Evaluation: A Systematic Review and Meta-Analysis

BACKGROUND

Early detection of dysphagia is important for preventing aspiration pneumonia. Although videofluoroscopy is currently the primary diagnostic tool for dysphagia, access to this tool may be limited because of radiation exposure risk, high cost, and other factors.

PURPOSE

In this study, a meta-analysis was used to determine the strength of the correlation between dysphagia detection outcomes obtained using subjective questionnaires and videofluoroscopy.

METHODS

The PubMed and Embase databases were searched for original articles up to December 2022. Studies published in English that used cross-sectional designs to assess the correlation between subjective questionnaires and videofluoroscopy were considered eligible for inclusion. The search terms used included "dysphagia," "questionnaire," and "videofluoroscopy." Two reviewers critically appraised and extracted the correlation coefficient r values. In addition, a random-effects meta-analysis was conducted. The Q statistic was used to assess the heterogeneity among the included studies. Publication bias was checked using the funnel plot and Egger's tests. Multilevel analysis was used to determine sensitivity to consider within-study correlations. In addition, subgroup analyses were conducted based on type of questionnaire, head and neck cancer, and English-speaking regions.

RESULTS

The meta-analysis included five studies and 856 patients using the Eating Assessment Tool-10 and one study and 27 patients using the Sydney Swallow Questionnaire. The results of the random-effects meta-analysis showed a moderate relationship between the subjective questionnaires and videofluoroscopy ( r = .35, 95% CI [0.20, 0.48]). Similar results were also obtained using multilevel analysis ( r = .34, 95% CI [0.25, 0.42]). No publication bias was found for any of the studies ( p = .88). In the subgroup analyses, a moderate relationship between Eating Assessment Tool-10 and videofluoroscopy ( r = .31, 95% CI [0.19, 0.42]) and an ultrahigh relationship between Sydney Swallow Questionnaire and video-fluoroscopy ( r = .74, 95% CI [0.50, 0.87]) were found. Furthermore, moderate associations were observed within each head and neck cancer and English-speaking regions subgroup. However, no significant differences were found between these two subgroups.

CONCLUSIONS

These results indicate the subjective questionnaires considered in this study share a moderate relationship with videofluoroscopy. Subjective questionnaires may be used as an auxiliary tool by nurses and homecare givers for the early assessment of dysphagia risk in patients.

Adaptation and validation of the Greek version of the Speech Pathology-Specific Questionnaire for Persons with Multiple Sclerosis (SMS)

PURPOSE

The aim of the present study was to adapt and validate the Speech Pathology-Specific Questionnaire for Persons with Multiple Sclerosis (SMS) into the Greek language.

METHOD

The study sample consisted of 124 people with multiple sclerosis (PwMS) and 50 healthy controls (HCs). All PwMS underwent cognitive assessment using the Brief International Cognitive Assessment for Multiple Sclerosis (BICAMS). Both PwMS and HCs completed the SMS, the Eating Assessment tool (EAT-10), the Voice Handicap Index (VHI), and the Stroke and Aphasia Quality of Life Scale-39 (SAQOL-39).

RESULT

Significant difference was found between PwMS and HCs for the EAT-10, SAQOL-39, the total SMS, and the SMS subscales. Discriminant validity analyses revealed a statistically significant difference between PwMS and HCs for the total and subscales SMS. Convergent validity analyses between the total SMS and the SMS subscales, and scores on the BICAMS, EAT-10, SAQOL-39, and VHI in PwMS were significantly correlated, with exception of the SMS Speech/Voice with the Symbol Digit Modalities Test (SDMT) and the Greek Verbal Learning Test-II (GVLT-II). Scores on the EAT-10, SAQOL-39, and VHI in PwMS were also correlated with the total SMS and the SMS subscales in PwMS, HCs, and the total sample. Construct validity analyses revealed that the total SMS and the SMS subscales were significantly correlated with the Expanded Disability Status Scale (EDSS) and years of education, while no associations were found with regards to age, MS subtype (relapsing-remitting MS [RRMS] vs progressive MS [PMS]), disease duration, or sex. The internal consistency of all items was excellent in PwMS and the total sample (Cronbach's alpha was >0.7 after deletion of one item), with the exception of two items, which still fell within the acceptable range (>0.6) for PwMS and the total sample.

CONCLUSION

The Greek version of the SMS is a reliable and valid patient-reported outcome measure to assess speech-language and swallowing pathology related symptoms in PwMS, and can be used for research and clinical purposes.

Multiple Sclerosis Is Associated With Achalasia and Diffuse Esophageal Spasm

Background/Aims

Multiple sclerosis (MS) is an inflammatory disease characterized by the demyelination of primarily the central nervous system. Diffuse esophageal spasm (DES) and achalasia are both disorders of esophageal peristalsis which cause clinical symptoms of dysphagia. Mechanisms involving dysfunction of the pre- and post-ganglionic nerve fibers of the myenteric plexus have been proposed. We sought to determine whether MS confers an increased risk of developing achalasia or DES.

Methods

Cohort analysis was done using the Explorys database. Univariate logistic regression was performed to determine the odds MS confers to each motility disorder studied. Comparison of proportions of dysautonomia comorbidities was performed among the cohorts. Patients with a prior diagnosis of diabetes mellitus, chronic Chagas' disease, opioid use, or CREST syndrome were excluded from the study.

Results

Odds of MS patients developing achalasia or DES were (OR, 2.09; 95% CI, 1.73-2.52; P < 0.001) and (OR, 3.15; 95% CI, 2.89-3.42; P < 0.001), respectively. In the MS/achalasia cohort, 27.27%, 18.18%, 9.09%, and 45.45% patients had urinary incontinence, gastroparesis, impotence, and insomnia, respectively. In the MS/DES cohort, 35.19%, 11.11%, 3.70%, and 55.56% had these symptoms. In MS patients without motility disorders, 12.64%, 0.79%, 2.21%, and 21.85% had these symptoms.

Conclusions

Patients with MS have higher odds of developing achalasia or DES compared to patients without MS. MS patients with achalasia or DES have higher rates of dysautonomia comorbidities. This suggests that these patients have a more severe disease phenotype in regards to the extent of neuronal degradation and demyelination causing the autonomic dysfunction.

Effect of Metabolic and Bariatric Surgery on the Clinical Course of Multiple Sclerosis in Patients with Severe Obesity: a Systematic Review

Multiple sclerosis (MS) is an autoimmune inflammatory condition affecting the central nervous system (CNS). A systematic review following the PRISMA guidelines was performed to explore the effect of metabolic and bariatric surgery (MBS) on the clinical course and outcomes in patients with multiple sclerosis. Eleven articles examining 394 patients were included in the final analysis. The mean MS duration at the time of surgery was 7.6 ± 4.6 years, and the mean postoperative follow-up was 35.5 ± 5.3 months. MBS leads to the same weight loss with the same complication rate as in patients without MS. Most of patients experienced improvement in clinical course of MS after MBS, compared to non-surgical group. However, there is a risk for MS exacerbation in a number of patients after MBS; they should not be disadvantaged from having MBS, since surgery leads to the same weight loss outcomes with the same complication rate as in patients without MS.

Survival and functional outcomes after total glossectomy with total laryngectomy: Case series from a high-volume tertiary institution

OBJECTIVES

Total glossectomy with total laryngectomy (TGTL) is indicated for some cases of advanced oral squamous cell carcinoma. However, this procedure is rarely performed, as quality of life outcomes are often considered poor. Consequently, few studies to date have reported survival and functional outcomes in patients undergoing TGTL. Here, we present the largest cases series to date of TGTL patients and provide relevant data on survival and functional outcomes.

METHODS

Patients met inclusion criteria if they underwent TGTL (concurrent or staged) indicated for head and neck squamous cell carcinoma. Patient demographics and disease characteristics, survival outcomes, functional oral intake scores, time to oral intake, gastrostomy tube dependence, and communication methods post-surgery were retrospectively extracted from the electronic medical record.

RESULTS

Survival in patients undergoing TGTL was poor. Most patients in this study were eventually approved for some oral intake of restricted consistencies but remained gastrostomy tube dependent for most of their nutritional needs. Baseline oral intake was suboptimal in most patients but often re-achieved approximately 12 months following surgery. Communication methods following surgery included writing, text-to-speech, and augmentative and alternative communication devices.

CONCLUSION

Our data provide new insights comparing survival and functional outcomes of patients undergoing TGTL. Additional investigation particularly on patient-perceived quality of life following TGTL is needed to better understand the risks and benefits for patients who are candidates for TGTL.

Cross-cultural Adaption, Validation and Factor Analysis of the Persian Version of the Eating Assessment Tool: EAT-10

The eating assessment tool (EAT-10) is a self-reported questionnaire to assess the patient's perception of swallowing difficulties. The aim of this study was to cross-culturally adapt and determine validity and reliability of the Persian version of the EAT-10 (P-EAT-10) in patients with oropharyngeal dysphagia. The EAT-10 was translated into Persian language and cross-culturally adapted. One hundred patients with dysphagia (mean age ± SD = 44.44 ± 14.69 years) participated. The test-retest reliability (time interval = 7 days) was assessed in 50 patients. Intraclass correlation coefficient (ICC), standard error of measurement (SEM) and smallest detectable change (SDC) were analyzed. The Persian version of functional oral intake scale (FOIS-P) was also recorded to assess construct validity. One hundred healthy subjects completed the P-EAT-10 for clinical validity. Factor analysis was performed to determine the P-EAT-10 structure. There were no missing responses and floor or ceiling effects. Internal consistency was high (Cronbach's α 0.91). Item-total correlations exceeded acceptable standard of 0.3 for the all items (0.62-0.83). The test-retest reliability was excellent [(ICC)agreement 0.96]. The SEM and SDC were 2.61 and 7.23, respectively. Construct validity was confirmed by a significant correlation between the P-EAT-10 and FOIS-P scores (r = 0.84). Clinical validity was supported by a significant discrimination between patients and healthy subjects (t = 29.97, P < 0.001). Factor analysis indicated 2 components for the P-EAT-10. The P-EAT-10 is a valid and reliable tool and can be used in clinic and research for the assessment of oropharyngeal dysphagia in Persian-speaking patients.

Neurorehabilitation in Multiple Sclerosis-A Review of Present Approaches and Future Considerations

Multiple sclerosis is an increasingly prevalent disease, representing the leading cause of non-traumatic neurological disease in Europe and North America. The most common symptoms include gait deficits, balance and coordination impairments, fatigue, spasticity, dysphagia and an overactive bladder. Neurorehabilitation therapeutic approaches aim to alleviate symptoms and improve the quality of life through promoting positive immunological transformations and neuroplasticity. The purpose of this study is to evaluate the current treatments for the most debilitating symptoms in multiple sclerosis, identify areas for future improvement, and provide a reference guide for practitioners in the field. It analyzes the most cited procedures currently in use for the management of a number of symptoms affecting the majority of patients with multiple sclerosis, from different training routines to cognitive rehabilitation and therapies using physical agents, such as electrostimulation, hydrotherapy, cryotherapy and electromagnetic fields. Furthermore, it investigates the quality of evidence for the aforementioned therapies and the different tests applied in practice to assess their utility. Lastly, the study looks at potential future candidates for the treatment and evaluation of patients with multiple sclerosis and the supposed benefits they could bring in clinical settings.

A Comparative Assessment of the Diagnosis of Swallowing Impairment and Gastroesophageal Reflux in Canines and Humans

Swallowing impairment is a highly prevalent and clinically significant problem affecting people and dogs. There are myriad causes of swallowing impairment of which gastroesophageal reflux is the most common in both species. Similarities in anatomy and physiology between humans and canines results in analogous swallowing disorders including cricopharyngeus muscle achalasia, esophageal achalasia, hiatal herniation, and gastroesophageal reflux with secondary esophagitis and esophageal dysmotility. Accordingly, the diagnostic approach to human and canine patients with swallowing impairment is similar. Diagnostic procedures such as swallowing fluoroscopy, high-resolution manometry, pH/impedance monitoring, and endolumenal functional luminal imaging probe can be performed in both species; however, nasofacial conformation, increased esophageal length, and the difficulty of completing several of these procedures in awake dogs are inherent challenges that need to be considered. Human patients can convey their symptoms and respond to verbal cues, whereas veterinarians must rely on clinical histories narrated by pet owners followed by comprehensive physical examination and observation of the animal eating different food consistencies and drinking water. Dogs may also be unwilling to drink or eat in the hospital setting and may be resistant to physical restraint during diagnostic procedures. Despite the species differences and diagnostic challenges, dogs are a natural animal model for many oropharyngeal and esophageal disorders affecting people, which presents a tremendous opportunity for shared learnings. This manuscript reviews the comparative aspects of esophageal anatomy and physiology between humans and canines, summarizes the diagnostic assessment of swallowing impairment in both species, and discusses future considerations for collaborative medicine and translational research.

Pneumonia in Nervous System Injuries: An Analytic Review of Literature and Recommendations

Pneumonia is one of the most common complications in intensive care units and is the most common nosocomial infection in this setting. Patients with neurocritical conditions who are admitted to ICUs are no exception, and in fact, are more prone to infections such as pneumonia because of factors such as swallow dysfunction, need for mechanical ventilation, longer length of stay in hospitals, etc. Common central nervous system pathologies such as ischemic stroke, traumatic brain injury, subarachnoid hemorrhage, intracerebral hemorrhage, neuromuscular disorders, status epilepticus, and demyelinating diseases can cause long in-hospital admissions and increase the risk of pneumonia each with a mechanism of its own. Brain injury-induced immunosuppression syndrome is usually considered the common mechanism through which patients with critical central nervous system conditions become susceptible to different kinds of infection including pneumonia. Evaluating the patients and assessment of the risk factors can lead our attention toward better infection control in this population and therefore decrease the risk of infections in central nervous system injuries.

Self-perceived dysphagia in non-invasively ventilated COVID-19 patients

PURPOSE

COVID-19 is known to present with a wide range of clinical symptoms. COVID-19-related dysphagia has been frequently investigated in patients who were critically ill and mechanically ventilated, but not in those with less severe presentations. This study aims to identify the frequency, characteristics, and severity of self-perceived oropharyngeal dysphagia in non-intubated COVID-19 patients.

METHODS

In this cross-sectional study, data were collected from patients using a self-administered questionnaire that included the Eating Assessment Tool (EAT-10).

RESULTS

The study included 359 participants with a median age of 34 (range: 18-65) years. Self-perceived dysphagia (EAT-10 total score > 2) was identified in 64.62%, and their median EAT-10 total score was 13 (range 3-40). The most prevalent symptoms were painful swallowing, affected pleasure of eating, stressful swallowing, and coughing while eating. Age, gender, and hospitalization were not statistically significantly associated with the presence of dysphagia, while re-infection, duration, and severity of COVID-19 diagnosis were. The EAT-10 total score was higher in moderate and severe COVID-19 cases as compared to mild cases, and showed a statistically significant inverse correlation with the duration of COVID-19 (r = - 0.267).

CONCLUSION

Self-perceived dysphagia was prevalent in non-intubated COVID-19 patients. Its severity was related to that of COVID-19 and its duration.

The Preventive Effect of Dysphagia Screening on Pneumonia in Acute Stroke Patients: A Systematic Review and Meta-Analysis

(1) Background: Dysphagia is common in acute stroke patients and is a major risk factor for aspiration pneumonia. We investigated whether the early detection of dysphagia in stroke patients through screening could prevent the development of pneumonia and reduce mortality; (2) Methods: We searched the PubMed, Embase, Cochrane Library, and Scopus databases for relevant studies published up to November 2021. We included studies that performed dysphagia screening in acute stroke patients and evaluated whether it could prevent pneumonia and reduce mortality rates. The methodological quality of individual studies was evaluated using the Risk Of Bias In Non-randomized Studies of Interventions tool, and publication bias was evaluated by the funnel plot and Egger's test; (3) Results: Of the 6593 identified studies, six studies met the inclusion criteria for analysis. The screening group had a significantly lower incidence of pneumonia than the nonscreening group did (odds ratio (OR), 0.60; 95% confidence interval (CI), 0.42 to 0.84; p = 0.003; I2, 66%). There was no significant difference in mortality rate between the two groups (OR, 0.61; 95% CI, 0.33 to 1.13; p = 0.11; I2, 93%); (4) Conclusions: Early screening for dysphagia in acute stroke patients can prevent the development of pneumonia.

Screening of dysphagia in relapsing-remitting multiple sclerosis patients in Montenegro

OBJECTIVES

To perform screening of dysphagia in Montenegrin multiple sclerosis (MS) patients. Dysphagia is often neglected problem in patients with MS.

METHODS

We included 104 patients with relapsing-remitting MS who completed 3 questionnaires: dysphagia in multiple sclerosis (DYMUS), eating assessment tool-10 (EAT-10) and swallowing disturbance questionnaire (SDQ). Our study was performed in the clinic for neurology of the Clinical Center of Montenegro (Podgorica, Montenegro) and Polyclinic Neuron (Bijelo Polje, Montenegro) between November 2020 and December 2020.

RESULTS

Self-reported prevalence of this symptom in our group was simmilar to previously reported results. We did not find correlation between DYMUS and expanded disability status scale (EDSS), as it was reported before. Time spent from disease onset to diagnosis is strongly correlated with reported SDQ results. The population of dysphagia-patients is statistically significantly older compared to the non-dysphagia patients, and statistically higher mean values in this population of our subjects were proven on all 3 questionnaires used.

CONCLUSION

The importance of this issue is not just because it warns of potientially malnutrion in MS patients, but also important factor in therapy choosing algorithm in the era of orally used immunomodulatory drugs.

Prevalence and Risk Factors of Dysphagia in Patients with Multiple Sclerosis

Dysphagia is one of the most common symptoms in multiple sclerosis (MS) patients. It can reduce the quality of life and increase the risk of mortality by developing complications such as aspiration pneumonia. The present study was conducted to estimate the prevalence of dysphagia in MS patients and investigate the associations between dysphagia and disease characteristics. The Persian version of the DYMUS questionnaire was used to assess dysphagia in 865 patients with MS, including 738 (85.3%) relapsing-remitting MS (RRMS), 106 (12.3%) secondary progressive MS (SPMS), and 21 (2.4%) primary progressive MS (PPMS). Also, demographic and clinical data, including age, sex, smoking status, Expanded Disability Status Scale (EDSS) score, disease duration, disease-modifying therapies exposure, initial symptoms of MS, were recorded. The mean (SD) age was 37.95(9.25) years, and 83.1% of the participants were female. The prevalence of dysphagia was estimated to be 25.4% among all patients. According to the DYMUS questionnaire results, the prevalence of dysphagia in RRMS, SPMS, and PPMS patients was 22.2%, 44.3%, and 42.9%, respectively. After multivariate analysis the current EDSS score (OR = 1.197, CI: 1.062, 1.350, p = 0.003), cerebellar impairment (OR = 1.335, CI: 1.450, 4.716, p = 0.004) and motor dysfunction (OR = 1.651, CI: 1.004, 2.715, p = 0.048) emerged as the risk factors for dysphagia. Since dysphagia, as previously mentioned, is a common symptom in multiple sclerosis, particularly in SPMS and PPMS courses, active screening for this condition is recommended in all patients, particularly those with identified risk factors.