Correction to: Case series of Creutzfeldt-Jakob disease in a third-level hospital in Quito.

Following publication of the original article [1], Andrés Damián Ortega Heredia requested that his name be corrected from.

Case series of Creutzfeldt-Jakob disease in a third-level hospital in Quito.

BACKGROUND: Creutzfeldt-Jakob disease is a rare and fatal neurodegenerative disorder that affects mammals and humans. The prevalence of this disease in the United States is 0.5 to 1 per million inhabitants. So far in Ecuador, we do not know what the prevalence or incidence is, and only one case report has been written. CASE PRESENTATION: We present a case series of Creutzfeldt-Jakob disease in a third-level hospital in Quito. The average age of symptom onset in our patients was 58.8 years. The male to female ratio was 1:1. Two patients began with cognitive/behavioral symptoms, while 4 patients began with focal neurological signs; 1 case with ataxia, 2 with gait disorders and 1 with vertigo and headache. All of the patients had the clinical features established by the World Health Organization. In addition, the entire cohort was positive for the 14-3-3 protein in cerebrospinal fluid, and had high signal abnormalities in caudate and putamen nucleus in DWI and FLAIR IRM. Only in one case, did we reach a definitive diagnosis through a pathological study. All other cases had a probable diagnosis. In this series of cases, 6 out of 6 patients died. The average time from the onset of the symptoms to death in this cohort was 13 months. CONCLUSION: This is the first report of a series of cases of Creutzfeldt-Jakob disease in Quito. Although definitive diagnosis must be histopathological, there are ancillary tests currently available that have allowed us to obtain a diagnosis of the disease.

New diagnostic criteria for neurocysticercosis: Reliability and validity.

OBJECTIVE: The diagnosis of neurocysticercosis (NCC) remains problematic because of the heterogeneity of its clinical, immunological, and imaging characteristics. Our aim was to develop and assess a new set of diagnostic criteria for NCC, which might allow for the accurate detection of, and differentiation between, parenchymal and extraparenchymal disease. METHODS: A group of Latin American NCC experts developed by consensus a new set of diagnostic criteria for NCC. A multicenter, retrospective study was then conducted to validate it. The reference standard for diagnosis of active NCC was the disappearance or reduction of cysts after anthelmintic treatment. In total, three pairs of independent neurologists blinded to the diagnosis evaluated 93 cases (with NCC) and 93 controls (without NCC) using the new diagnostic criteria. Mixed-effects logistic regression models were used to estimate sensitivity and specificity. RESULTS: Inter-rater reliability (kappa) of diagnosis among evaluators was 0.60. For diagnosis of NCC versus no NCC, the new criteria had a sensitivity of 93.2% and specificity of 81.4%. For parenchymal NCC, the new criteria had a sensitivity of 89.8% and specificity of 80.7% and for extraparenchymal NCC, the new criteria had a sensitivity of 65.9% and specificity of 94.9%. INTERPRETATION: These criteria have acceptable reliability and validity and could be a new tool for clinicians and researchers. An advantage of the new criteria is that they consider parasite location (ie, parenchymal or extraparenchymal), which is an important factor determining the clinical, immunological, and radiological presentation of the disease, and importantly, its treatment and prognosis. Ann Neurol 2016;80:434-442.

Abuse and other factors related to depression in older Ecuadorian adults.

Objective: To identify abuse and other risk factors associated with depression in older Ecuadorian adults using data from the 2012 Ecuador's Survey of Health, Welfare, and Aging (SABE). Methods: This cross-sectional study analyzed data from the 2012 SABE survey, which included 5235 adults aged 60 and above. The study evaluated residence, education level, ethnic self-identification, self-perceived health and memory, loneliness, cognitive status, and abuse. Depression was assessed using the Yesavage Depression Scale, short version (YDS-SV). Categorical variables were analyzed with the Chi-square test, differences between groups were calculated with the Kruskal-Wallis test, and multiple linear regression analysis was performed. A p-value of ≤0.05 was considered statistically significant. Results: The mean age was 71.39 ± 8.59 years and 55.10% of the sample were women. Abuse was absent in 72.1% (3.773) of the population. The Chi-square test indicated significant associations between depression and poor self-reported health (P = 0.000) and indigenous ethnicity (P = 0.000). Multiple linear regression analysis revealed that age (P < 0.001), abuse (p < 0.001), cognitive status (P = 0.002), and living alone (P = 0.034) significantly contributed to mood as assessed by the YDS-SV. No statistically significant association was found for perceived health status or place of residence (urban or rural). Conclusions: Risk factors associated with depression in older Ecuadorian adults include advanced age, living alone, cognitive decline, poor self-perception of health and cognition, and abuse.

Expanded and Independent Spanish Validation of the MDS-Non Motor Rating Scale.

Background: The Movement Disorder Society-sponsored Non-motor Rating Scale (MDS-NMS) assess the severity and disability caused by non-motor symptoms (NMS) in Parkinson's disease (PD). Objective: This article encapsulates the formal process for completing this program and the data on the first officially approved non-English version of the MDS-NMS (Spanish). Methods: The MDS-NMS translation program involves four steps: translation and back-translation; cognitive pre-testing to ensure that raters and patients understand the scale and are comfortable with its content; field testing of the finalized version; analysis of the factor structure of the tested version against the original English language version for the nine domains that could be analyzed in a confirmatory factor analysis. To be designated an "Official MDS translation," the confirmatory factor analysis Comparative Fit Index had to be ≥0.90. Results: The Spanish MDS-NMS was tested in 364 native-Spanish-speaking patients with PD from seven countries. For all subjects with fully computable data with all domains of the MDS-NMS (n = 349), the Comparative Fit Index was ≥0.90 for the nine eligible domains. Missing data were negligible and moderate floor effect (42.90%) was found for the Non-Motor Fluctuations subscale. Item homogeneity coefficient was adequate, and the correlation of the MDS-NMS domains with other measures for related constructs was acceptable (r s ≥ 0.50). Conclusions: The Spanish version of the MDS-NMS followed the IPMDS Translation Program protocol, reached the criterion to be designated as an Official Translation, and is now available on the MDS website.

A holistic approach to evaluating Parkinson's disease, using the Delphi method: a linear evaluation index.

BACKGROUND: Parkinson's disease (PD) is a chronic disease that presents a multitude of symptoms, with symptoms of both motor and nonmotor nature. The Delphi method is widely used to create consensuses among experts in a field of knowledge. OBJECTIVE: In order to reach a consensus on the values that should be assigned to the different motor and nonmotor manifestations of Parkinson's disease, a linear evaluation index (LEI) was created. Subsequently, the metric properties of this index were studied. METHODS: 120 consecutive patients with a Parkinson's diagnosis were chosen in accordance with the UKPDSBB criteria. The Delphi method was used to reach a consensus among experts regarding the values of each of the manifestations included. Subsequently, the following attributes were analyzed: quality and acceptability of the data; reliability, in terms of internal consistency, reliability index, Cronbach's alpha and standard error of measurement; and validity, in terms of convergent validity and validity for known groups. RESULTS: Twenty-five experts participated. The importance factor did not differ between the first round and the second round (chi-square test). We analyzed the responses that assigned percentage values to the 10 dimensions of the LEI. Both in the first and in the second round, the values of the scattering coefficient Vr were always close to 0. The homogeneity index was 0.36; the corrected-item total correlation values ranged from 0.02 to 0.7; Cronbach's α was 0.69; and the SEM was 4.23 (55.1%). CONCLUSIONS: The LEI was obtained through rigorous recommended methodology. The results showed adequate metric properties.

Living with chronic illness scale in Parkinson's disease: Longitudinal metric properties and meaningful change.

AIM: To analyze the responsiveness and interpretability of the Living with Chronic Illness Scale in patients with Parkinson's disease (LW-CI-PD). METHODS: Longitudinal, international study, with a convenience sample of 153 PD Spanish and Latin-American patients assessed at baseline and one year later. The LW-CI-PD and other clinical measures were applied. For responsiveness, Wilcoxon-Mann-Whitney test of differences, correlation of change between rating scales, standard error of difference, relative change, Cohen's effect size and standardized response mean of LW-CI-PD were computed. The minimally clinical important difference was calculated using anchor- (applying the Patient Global Impression of Severity) and distribution-based methods. A triangulation of interpretability indexes was performed to determine the range of the minimally clinical important difference values. RESULTS: The LW-CI-PD scored 65.7 (11.7, range: 33-101) at baseline, and 68.6 (10.3, range: 33-102) one year later (p < 0.001). Change in LW-CI-PD correlated -0.26 with change in psychosocial status, 0.18 with change in motor function and -0.15 with change in social support. Responsiveness statistics were: relative change = 4.5%; effect size = 0.25; standardized response mean = 0.46. Using PGI-S as anchor, 29 patients worsened, and the value of minimally clinical important difference for worsening in LW-CI-PD total score was 4.7. Minimally clinical important difference values using distribution-based methods were between 4.5 (1 standard error of measurement) and 10.4 (10% of total score), with a mean of 6.9. CONCLUSIONS: Our study suggest the LW-CI-PD is responsive to changes over time. The use of different methods for calculating the minimally clinical important difference allows to determine a range of the real change for the LW-CI-PD.

Adherence to treatment in Parkinson's disease: A multicenter exploratory study with patients from six Latin American countries.

BACKGROUND: Adherence to treatment in Parkinson's disease (PD) is compromised due to the need for multiple therapies, comorbidities related to aging, and the complexity of therapeutic schemes. In the present study, we aimed to explore adherence to treatment in groups of PD patients from six Latin-American (LA) countries and identify its associated demographic and clinical parameters. METHODS: A multicenter, cross-sectional, exploratory study was conducted from September 2016 to March 2017. Treatment adherence was assessed using the simplified medication adherence questionnaire (SMAQ), applied to patients and caregivers. Sociodemographic and clinical variables (MDS-UPDRS Part III-IV, MMSE, Beck Depression Inventory-II (BDI-II)) were recorded. RESULTS: Eight hundred patients from six LA countries were evaluated. Nonadherence was reported in 58.25% of the population, according to patients. The most frequent issues were forgetfulness and correct timing of doses. A high level of agreement in adherence prevalence and most SMAQ items were observed between patients and their caregivers. The nonadherent population had a significantly higher proportion of unemployment, free access to medication, troublesome dyskinesias and off-periods, lesser years of education, and worse motor, cognitive, and mood scores. In multiple logistic and linear regression analyses, MDS-UPDRS Part III, BDI-II, gender, free access to medication, treatment with dopamine agonists alone, years of education, excessive concerns about adverse effects, and beliefs about being well-treated remained significant contributors to adherence measures. CONCLUSION: Educational strategies, greater involvement of PD patients in decision-making, and consideration of their beliefs and values might be of great need to improve medication adherence in this PD population.

Metric properties of the mini-mental Parkinson and SCOPA-COG scales for rating cognitive deterioration in Parkinson's disease.

UNLABELLED: Parkinson's disease (PD) is a chronic neurodegenerative disorder that causes cognitive impairment and dementia in ∼30% of patients. OBJECTIVE: Compare metric qualities of Mini-Mental Parkinson (MMP) and scales for outcomes in Parkinson's disease-cognition (SCOPA-COG) with respect to their relative reliability, validity and ability to predict symptoms (mobility, quality of life, social repercussions, and mood) in PD patients. Outpatients (n=123, 78 males/45 females) diagnosed with PD were included in the study. A multilevel (hierarchical) modeling analysis was performed along with tests of reliability and validity to ascertain which of the two models better predicts symptoms related to PD. RESULTS: The MMP differed significantly between patients with Hoehn and Yahr (H&Y) stages 1, 2 or versus 4/5 (grouped together). The SCOPA-COG showed differences only between patients in H&Y stages 2 versus 4/5. Both scales were dependent on educational background and age. The SCOPA-COG had a higher coefficient of variation (0.303) than the MMP (0.184), indicating that it was the more discriminative of the two. CONCLUSIONS: The SCOPA-COG has some advantages over the MMP, the most important being a greater discriminative ability. Multilevel hierarchical analysis clarified the necessity of stratifying the PD population according to educational background, years of illness, and H&Y stage when using these scales.

Psychometric attributes of the rating scale for gait evaluation in Parkinson's disease.

BACKGROUND: The RSGE-PD-V2.0 is a specific measure for evaluation of gait impairment in PD. OBJECTIVE: To check the RSGE-PD-V2.0 metrics attributes. METHODS: In addition to demographic and historical data of PD, applied assessments were: Hoehn and Yahr staging (H&Y); impact in daily activities with Schwab and England scale (S&E); SCOPA Motor; mental status with Short portable mental status questionnaire (SPMSQ); quality of life with Parkinson's impact scale (PIMS), the Hamilton Depression Rating Scale-6 items (HDRS-6); and, the Clinical Impression of Severity Index-PD (CISI-PD). RESULTS: 151 PD patients were included (n = 102 (67.5%) were male). Most patients were in H&Y stage 3 (n = 78 (51.6%)). Mean of age and duration of disease was 68.4 and 7.6 years respectively. Mean values of L-Dopa doses was 652.6 mg/day. Mean values of SCOPA Motor were 29.1; SPMSQ: 1.8; HADS-6: 9.2; PIMS: 18.7;RSGE-PD-V2.0: 25.4; and, CISI-PD were 10.8. Full computable scores were 100%; Guttman's lambda, 0.954; and the item-total correlation, 0.408-0.830. Correlation coefficients (Spearman's rho) between RSGE-PD-V2.0 and H&Y, S&E, SCOPA Motor, PIMS and CISI-PD, were: 0.62; -0.75; 0.74; 0.46; and, 0.78 respectively. RSGE-PD-V2.0 scale significantly discriminated among PD severity levels (based on H&Y staging) Kruskal-Wallis (p < 0.000). CONCLUSIONS: Metric attributes of the RSGE-PD-V2.0 in this sample of study resulted in has sufficient and suitable satisfactory. We, therefore, believe that RSGE-PD-V2.0 is easy and a useful and recommendable specific tool for measuring gait disease in PD patients.

Cross-cultural evaluation of the modified Parkinson Psychosis Rating Scale across disease stages.

This study assessed the psychometric attributes of the modified Parkinson Psychosis Rating Scale (mPPRS). In an attempt to improve scale's scaling assumptions and content validity, all types of hallucinations were rated and all items were scored based on intensity. The scale was cross-culturally adapted to four Latin American countries (Argentina, Brazil, Ecuador, and Paraguay). Acceptability, internal consistency, factor structure, convergent and known-groups validity, and precision (standard error of measurement, SEM) were explored. A total of 388 patients with PD were included in the study (age, 64.5 +/- 10.7 years; 59.8% males; PD duration, 8.2 +/- 4.9 years). The mPPRS was highly usable in terms of missing values generated and scores distribution (total computable scores, 99.7%, ceiling effect, <15%). Scaling assumptions were acceptable as noted by the range of item-total correlations (0.14-0.55, only one coefficient below 0.2). Internal consistency was adequate for research use (Cronbach alpha, 0.7). Factor analysis identified two factors that accounted for 58.5% of the variance. Low correlation coefficients were found with cognitive function (SCOPA-Cog) and disease severity (CISI-PD) (r(S)

Parkinson's Disease Gravity Index: A Method by means of Optimal Scaling.

OBJECTIVE: This study has been designed with the aim of using optimal scaling to perform the allocation of scores and to be able to construct an indicator of the Parkinson's Disease Gravity Index. Scores were assigned to interrelated dimensions that share information about the patient's situation, to have an objective, holistic tool which integrates scores so that doctors can have a comprehensive idea of the patient's situation. Patients and Methods. 120 consecutive patients with Parkinson's diagnosis were chosen according to the United Kingdom Parkinson's Disease Society Brain Bank criteria. Subsequently, all the chosen dimensions were transformed into interval variables for which the formula proposed by Sturges was used. Once the dimensions were transformed into interval variables, optimal scaling was carried out. Subsequently, the following attributes were analyzed: quality and acceptability of the data; reliability: internal consistency, reliability index, Cronbach's alpha, and standard error of measurement; finally, validity: convergent validity and validity for known groups. RESULTS: There were no missing data. An appropriate Cronbach's alpha value of 0.71 was gathered, and all items were found to be pertinent to the scale. The item homogeneity index was 0.36. Precision evaluated with the standard error of measurement was 7.8. The Parkinson's Disease Gravity Index discriminant validity (validity for known groups), assessed among the different stages of Hoehn and Yahr scale by the Kruskal-Wallis test, showed major significance (X 2 = 32.7, p ≤ 0.001). CONCLUSIONS: The Parkinson's Disease Gravity Index has shown adequate metric properties.

Evaluation of the metric properties of the WHODAS 2.0, WHODAS-S, and RADS in the assessment of disability in Parkinsonian patients.

OBJECTIVES: Parkinson's disease is the second most prevalent progressive neurodegenerative disease and causes considerable disability in patients. We conducted a cross-sectional analytical study to examine the metric properties of the World Health Organization Disability Assessment Schedule 2.0 (WHODAS-2); the 12-item World Health Organization Disability Assessment Schedule (WHODAS-S) and the Rapid Assessment of Disability Scale (RADS) in assessing disability in Parkinsonian patients. PATIENTS AND METHODS: Patients with cognitive impairment, neurological disorder, or disability due to any condition other than PD were excluded. One hundred sixty-eight consecutive patients were assessed in ON state. The following attributes were evaluated: data quality and acceptability, reliability, and construct (convergent and known-groups) validity. Testretest reliability was analyzed in fifty-six patients. RESULTS: Out of 168 patients, 65.4% were men's, 96 (57.1%) at stage III of Hoehn and Yahr. One hundred fifty-one patients lived independently in the community, 102 lived with their spouses, 108 were retired, and 48 were still working. Cronbach's alpha exceeded the minimum requirement of 0.70 for the three scales. The SEM obtained was, also for the three scales, higher than the ½ of the standard deviation value. The validity for known groups showed that all domains were significantly different in both WHODAS-S and RADS. The stability of the scale was evaluated with the test-retest (ICC). The results for the WHODAS-2 ≤ 0.002; for the WHODAS-S were p ≤ 0.000]; and for the RADS were p ≤ 0.000]. CONCLUSION: The RADS is by far the fastest scale to use. All three scales showed suitable metric properties.

Cross-cultural validation of the Scales for Outcomes in Parkinson's Disease-Psychosocial questionnaire (SCOPA-PS) in four Latin American countries.

OBJECTIVE: To conduct a cross-national validation of the Scales for Outcomes in Parkinson's Disease-PsychoSocial questionnaire (SCOPA-PS) in four Latin American Countries. METHODS: Data quality (missing items), scale assumptions (item-test correlation), internal consistency (Cronbach's alpha, item homogeneity), factor structure, content validity, and precision (standard error of measurement, SEM) of the scale were explored, as was convergent validity with motor symptoms (Clinical Impression of Severity Index [CISI-PD], Scales for Outcomes in Parkinson's Disease-Motor Scale), emotional status (Hospital Anxiety and Depression Scale) and health-related quality of life (Parkinson Disease Questionnaire-39). Known-groups validity was studied by category of severity, based on Hoehn and Yahr staging (HY), CISI-PD, and disease duration. RESULTS: Three hundred thirty-one Parkinson's disease (PD) patients with usable data participated (mean age 64.7 years; 42.3% female; mean PD duration 8.5 years; HY, 1 to 5). Data quality (missing items <10%), scale assumptions (item-total correlation = 0.43 - 0.71) and internal consistency of SCOPA-PS (Cronbach's alpha = 0.87; item homogeneity = 0.38) were satisfactory. Factor analysis suggested a unifactorial structure. High convergent validity was found for depression (r(S) = 0.61), anxiety (r(S) = 0.62), and health-related quality of life (r(S) = 0.82). Known-groups validity analyses indicated a gradual influence of severity category and disease duration on SCOPA-PS scores (P < 0.0001). SEM value was 8.24 (7 to 12 in previous studies). These magnitudes may be indicative of the threshold for a real change and a minimum important difference. CONCLUSIONS: The Latin American versions of the SCOPA-PS displayed appropriate psychometric attributes.

Association between Blood Viscosity and Cardiovascular Risk Factors in Patients with Arterial Hypertension in a High Altitude Setting.

Background  Blood viscosity is a determinant of vascular resistance, and it is expected to contribute to blood pressure. Arterial hypertension (HTN), in addition to other cardiovascular risk factors, contribute to cardiac morbidity. Our study aimed to establish the association between cardiovascular risk factors including HTN and whole blood viscosity in Ecuadorian patients. Material and methods We studied 132 patients with the diagnosis of HTN. Fifteen cardiovascular risk factors were analyzed. The association between whole blood viscosity (WBV) and the number of cardiovascular risk factors was studied. The association between blood viscosity and risk factors was analyzed. Results  One hundred and thirty-two patients were analyzed. Blood viscosity was associated with a number of cardiovascular risk factors. Creatinine, uric acid, total cholesterol, and low-density lipoprotein (LDL) values were significantly higher in patients with high blood viscosity. Conclusion  Blood viscosity is a physiological variable associated with a number of cardiovascular risk factors in hypertensive patients. Such risk factors are related to renal function and lipid profiles. In high-altitude residents, polycythemia is common, and the consequences of high hematocrit on cardiovascular morbidity in this setting deserve special attention and warrant further research.

The Parkinson's Disease Sleep Scale-2 (PDSS-2): Validation of the Spanish Version and Its Relationship With a Roommate-Based Version.

BACKGROUND: Because of the prevalence and impact of sleep disorders in Parkinson's disease (PD), valid instruments for their evaluation and monitoring are necessary. However, some nocturnal sleep disorders may go unnoticed by patients themselves. OBJECTIVES: To validate a pan-Spanish version of the Parkinson's Disease Sleep Scale Version 2 (PDSS-2) and to test the relationships between the PDSS-2 and a PDSS-2 roommate version. METHODS: PD patients (n = 399) from seven Spanish-speaking countries were included. In addition to the tested PDSS-2 scales, valid measures for sleep disorders and both motor and nonmotor manifestations were applied. Acceptability, dimensionality, reliability, precision, and construct validity were explored, as well as discrepancies and agreement between the PDSS-2 and the roommate version. RESULTS: PDSS-2 showed negligible floor and ceiling effects. Four factors (57% of the variance) were identified. Reliability parameters were satisfactory: alpha = 0.84; item homogeneity coefficient = 0.27; corrected item total correlation = 0.28 to 0.61; and test-retest reliability (average kappa = 0.70; intraclass correlation coefficient [ICC] = 0.83). The standard error of measurement was 5.84, and correlations with other scales assessing nocturnal sleep were high (rS = 0.62-0.56). In comparison to the patient-based total score, the by proxy total score showed no significant difference, high correlation (rS = 0.70), and acceptable agreement (ICC = 0.69), but there were discrepancies in two or more points in 18% of item scores. CONCLUSIONS: The Spanish version of the PDSS-2 has shown satisfactory clinimetric attributes. Acceptability and precision data are presented for the first time. The PDSS-2 roommate version could be useful to complement the patient-based evaluation, but additional studies are needed.

Concurrent validation of the 21-item and 6-item Hamilton Depression Rating Scale versus the DSM-IV diagnostic criteria to assess depression in patients with Parkinson's disease: an exploratory analysis.

OBJECTIVE: The concurrent validity of this 6-item version of Hamilton Depression Rating Scale (HDRS-6) compared to the original 21-item tool (HDRS-21), using the DSM-IV criteria for major depression as the gold standard in patients with Parkinson's disease. METHODS: In analytical study were analyzed: Cronbach's alpha (alpha C), item-total correlation, the receiver operating characteristic curve (ROC) and their area under the curve (AUC), Finally, used the Fagan nomogram. RESULTS: The 115-patient sample with mean illness duration of 7.15 years. HDRS-21 achieved an alpha C of 0.83, HDRS-6 a value of 0.68. Eleven of the HDRS-21 items failed to reach a minimum value. HDRS-21 obtained its better AUC capacity of 0.94 (cut/score of 18/19); HDRS-6 got an AUC of 0.92 (cut/score of 7/8). The Fagan nomogram was (89-94% and 83-90%, respectively). CONCLUSIONS: Our results suggest that HDRS-6 is sufficient, valid and has a sound psychometric structure for use with Parkinson's disease patients.

Psychometric characteristics of PIMS--compared to PDQ-39 and PDQL--to evaluate quality of life in Parkinson's disease patients: validation in Spanish (Ecuadorian style).

OBJECTIVE: Analyze PIMS (Parkinson's impact scale) properties following the recommendations of the Scientific Advisory Committee of the Medical Outcomes Trust. METHODS: An analytical cross-sectional study to evaluate the psychometric qualities and scale assumptions of PIMS: quality of data, acceptability, reliability, validity, internal consistency, and construct validity. RESULTS: The sample included 131 patients with Parkinson's disease (PD), of which 39 (29.7%) were women. Psychometric qualities and scale assumptions, all of them are suitable. CONCLUSIONS: We therefore believe that PIMS is a useful and recommendable specific tool for measuring quality of life in PD patients.

Fatigue in Parkinson's disease: Metric properties of the fatigue impact scale for daily use (D-FIS), and its impact on quality of life.

OBJECTIVE: In Parkinson's disease patients, fatigue is a disabling non-motor symptom whose prevalence ranges from 28% to 58%. The Fatigue Impact Scale for Daily Use (D-FIS), one of the various scales for quantifying fatigue. The aim of our study was to analyze the metric properties of the D-FIS in PD subjects and assess the impact of fatigue on their quality of life. PATIENTS AND METHODS: The cohort in this study was comprised of 211 consecutive patients with a PD diagnosis regularly followed up at the Movement Disorders Unit of the Neurology Department at Carlos Andrade Marín Hospital (HCAM) in Quito, Ecuador, according to the United Kingdom PD Society Brain Bank criteria. Data Quality, Acceptability, Reliability, Stability (test-retest), Validity and Multiple linear regression analysis were determined. RESULTS: The final sample consisted of 138 men (65.4%) and 73 women. Forty-six percent of these (98 patients) were in stage II of H&Y. We obtained a Cronbach's α value of 0.912 and an ICC value of 0.79. D-FIS was strongly correlated with depression (Spearman rho [Srho] 0.60), anxiety (Srho 0.59), quality of life (Srho 0.67), and non-motor symptoms (Srho 0.66). The scale's discriminant validity, assessed among the different stages of H&Y by the Kruskal-Wallis test, showed major significance (X2 = 23.183, p ≤ 0.001). In the Multiple linear regression study, the resulting model proves that fatigue has a determining effect on quality of life. CONCLUSIONS: The D-FIS has good metric properties and demonstrates that fatigue significantly affects PD patients' quality of life and that its impact is independent from that of anxiety, depression, and sleep disorders.