Psychometric properties and construct validity of the Parkinson's Disease-Cognitive Rating Scale (PD-CRS) in Colombia.

Background: Cognitive impairment is frequent among people living with Parkinson's disease: up to 40% of patients exhibit symptoms of mild cognitive impairment and 25% meet the criteria for dementia. Parkinson's Disease Cognitive Rating Scale (PD-CRS) is one of the recommended scales by the Movement Disorders Society Task Force for level 1 screening of dementia. However, its psychometric properties have not been studied in the Colombian population. Methods: A cross-sectional study was conducted on 100 patients with Parkinson's disease diagnosed by a movement disorders neurologist. Patients were evaluated with PD-CRS and MoCA. Principal component analysis was conducted, and then confirmatory factor analysis was implemented through the maximum-likelihood method. Internal consistency was evaluated using Cronbach α. Convergent and divergent validity were also calculated and concurrent validity with the MoCA was assessed. Results: 62% were males. Their median age was 68 years (IQR 57-74) and the median disease duration was 4 years (IQR 2-9). 77% were classified in early stages (Hoehn and Yahr stage ≤ 2), while the MDS-UPDRS part III score was 25 (IQR 15.5-38). In the principal component factor analysis, the pattern matrix unveiled a mnesic and a non-mnesic domain. Confirmatory factor analysis showed similar explanatory capacity (λ ≥ 0.50) for items other than naming (λ = 0.34). Cronbach's α for the full 9-items instrument was 0.74. MoCA and PD-CRS total scores were correlated (ρ = 0.71, p = 0.000). Assuming a cut-off score of 62 points, there is an agreement of 89% with the definition of dementia by MoCA for Colombia (κ = 0.59; p = 0.000). Conclusion: PD-CRS has acceptable psychometric properties for the Colombian population and has significant correlation and agreement with a validated scale (MoCA).

Machine Learning Classifiers to Evaluate Data From Gait Analysis With Depth Cameras in Patients With Parkinson's Disease.

Introduction: The assessments of the motor symptoms in Parkinson's disease (PD) are usually limited to clinical rating scales (MDS UPDRS III), and it depends on the clinician's experience. This study aims to propose a machine learning technique algorithm using the variables from upper and lower limbs, to classify people with PD from healthy people, using data from a portable low-cost device (RGB-D camera). And can be used to support the diagnosis and follow-up of patients in developing countries and remote areas. Methods: We used Kinect®eMotion system to capture the spatiotemporal gait data from 30 patients with PD and 30 healthy age-matched controls in three walking trials. First, a correlation matrix was made using the variables of upper and lower limbs. After this, we applied a backward feature selection model using R and Python to determine the most relevant variables. Three further analyses were done using variables selected from backward feature selection model (Dataset A), movement disorders specialist (Dataset B), and all the variables from the dataset (Dataset C). We ran seven machine learning models for each model. Dataset was divided 80% for algorithm training and 20% for evaluation. Finally, a causal inference model (CIM) using the DoWhy library was performed on Dataset B due to its accuracy and simplicity. Results: The Random Forest model is the most accurate for all three variable Datasets (Dataset A: 81.8%; Dataset B: 83.6%; Dataset C: 84.5%) followed by the support vector machine. The CIM shows a relation between leg variables and the arms swing asymmetry (ASA) and a proportional relationship between ASA and the diagnosis of PD with a robust estimator (1,537). Conclusions: Machine learning techniques based on objective measures using portable low-cost devices (Kinect®eMotion) are useful and accurate to classify patients with Parkinson's disease. This method can be used to evaluate patients remotely and help clinicians make decisions regarding follow-up and treatment.

Espectro clínico y tratamiento del trastorno cognoscitivo y demencia asociada a la enfermedad de Parkinson / Clinical spectrum, evaluation and treatment of cognitive disorder and dementia associated with Parkinson's disease

RESUMEN La prevalencia del deterioro cognitivo mínimo en pacientes con EP está en un rango de 20-50 %. La prevalen-cia puntual de la demencia asociada a la enfermedad se estima en alrededor del 25-30 °% con un incremento proporcional en relación con la edad y el tiempo de evolución de la enfermedad. El perfil clínico puede ser heterogéneo y hace referencia a la alteración en los diferentes dominios que supone un substrato neurobiológico diferente. La disfunción ejecutiva suele ser más frecuente en etapas tempranas de la enfermedad, aunque también hay perfiles clínicos corticales. Hay síntomas neuropsiquiátricos como la depresión, la ansiedad y el discontrol de impulsos que pueden afectar la cognición. La valoración rutinaria de las actividades de la vida diaria y el desempeño funcional se ha relacionado con el grado de compromiso así como con el rendimiento cognitivo global. Pacientes en estadios avanzados y candidatos a la cirugía de estimulación cerebral profunda requieren la evaluación neuropsicológica para seguimiento e identificación de potenciales riesgos o contraindicaciones cognitivas, comportamentales y/o emocionales. Las conclusiones del consenso de cognición son: 1) el deterioro cognitivo mínimo es común en los pacientes, incluso en estadios tempranos; 2) el perfil clínico es heterogéneo, aunque la disfunción ejecutiva es más frecuente; 3) la valoración inicial permite detectar perfiles de riesgo a demencia; 4) deben usarse instrumentos validados para esta población; 5) los síntomas neuropsiquiátricos pueden afectar el desempeño del paciente, y 6) la valoración de la independencia funcional permite explorar el impacto de la cognición en la cotidianidad.

SUMMARY The prevalence of minimal cognitive impairment in patients with PD is between 20-50 °%. The prevalence of dementia associated with the disease is estimated at around 25-30 °% with a proportional increase in relation to age and time of disease progression. The clinical profile can be heterogeneous and refers to the alteration in the different domains that a different neurobiological substrate supposes. Executive dysfunction is usually more frequent in the early stages of the disease, although there are also clinical cortical profiles. There are neuropsychiatric symptoms such as depression, anxiety and impulse control disorders that can affect cognition. The routine assessment of activities of daily living and functional performance has been related to the degree of commitment as well as to the overall cognitive performance. Patients in advanced stages and candidates for deep brain stimulation surgery require neuropsychological evaluation to monitor and identify potential risks or cognitive, behavioral and/or emotional contraindications. The conclusions of the consensus of cognition are 1. Minimal cognitive deterioration is common in patients even in early stages, 2. The clinical profile is heterogeneous, although executive dysfunction is more frequent, 3. An initial assessment allows detecting risk profiles to dementia, 4. Validated instruments should be used for this population, 5. Neuropsychiatric symptoms can affect the patient's performance and 6. The assessment of functional independence allows for exploring the impact of cognition in everyday life.

Age Matters: Objective Gait Assessment in Early Parkinson's Disease Using an RGB-D Camera.

BACKGROUND: Gait alterations are hallmarks for the diagnosis and follow-up of patients with Parkinson's disease (PD). In normal conditions, age could affect gait dynamics. Although it is known that objective assessment of gait is a valuable tool for diagnosis and follow-up of patients with PD, only few studies evaluate the effect of aging on the gait pattern of patients with PD. OBJECTIVE: The purpose of this study was to assess differences in gait dynamics between PD patients and healthy subjects and to investigate the effects of aging on these differences using a low-cost RGB-D depth-sensing camera. METHODS: 30 PD patients and 30 age-matched controls were recruited. Descriptive analysis was used for clinical variables, and Spearman's rank correlation was used to correlate age and gait variables. The sample was distributed in age groups; then, Mann-Whitney U test was used for comparison of gait variables between groups. RESULTS: PD patients exhibited prolonged swing (p=0.002) and stance times (p < 0.001) and lower speed values (p < 0.001) compared to controls. This was consistent in all age groups, except for the one between 76 and 88 years old, in which the controls were slower and had longer swing and stance times. These results were statically significant for the group from 60 to 66 years. CONCLUSION: Gait speed, swing, and stance times are useful for differentiating PD patients from controls. Quantitative gait parameters measured by an RGB-D camera can complement clinical assessment of PD patients. The analysis of these spatiotemporal variables should consider the age of the subject.

Assessment transcallosal Diaschisis in a model of focal cerebral ischemia in rats.

OBJECTIVE: To evaluate transcallosal changes after a local ischemic injury in rats by using the monoclonal marker anti-NeuN (Mouse anti-neuronal nuclei). METHODS: Twenty-eight adult, male, Wistar rats were subjected to focal injury in the right hemisphere. The technique used was the experimental model of focal ischemic injury through intraluminal suture of the middle cerebral artery. Analyses were made for the five groups: after the lesion (control), at 24 h, 96 h, 10 days and 20 days. Exofocal neuronal damage was inferred from neuronal immunoreactivity changes to NeuN. RESULTS: In the cortex contralateral to the lesion, immunoreactivity was diminished. This finding was most notable in the supra-granular sheets 24 h post ischemia. After 96 h, there was a generalized diminishment of the inmmunoreactivity in the supra and infra-granular sheets. At 10 and 20 days, the tissue recovered some immunoreactivity to NeuN, but there were some changes in the VI layer. CONCLUSION: The immunoreactive changes to NeuN support the process of inter-hemispheric diaschisis. Changes in immunoreactivity could indicate metabolic stress secondary to the disruption in connectivity to the site of lesion.

OBJETIVO: Evaluar los cambios exofocales transcallosos después de lesión isquémica focal en ratas, mediante marcación inmunohistoquímica con el anticuerpo monoclonal anti-NeuN (Mouse Anti-Neuronal Nuclei). MÉTODOS: Se intervinieron 28 ratas machos Wistar adultas. Mediante el modelo experimental de isquemia cerebral focal del territorio de la arteria cerebral media por filamento intraluminal, se les ocasionó una lesión focal en el hemisferio derecho. Posteriormente se evaluó el hemisferio contralateral, marcando la población neuronal con el anticuerpo monoclonal anti-NeuN. Se definieron cinco grupos de evaluación: uno de control, 24 horas, 96 horas, 10 días y 20 días. Se evaluaron los cambios neuronales exofocales después de la lesión con base en la observación de los cambios en la inmunoreactividad de las neuronas al NeuN. RESULTADOS: Se redujo la inmunoreactividad en la corteza contralateral a la lesión. Este fenómeno fue más notable en las capas supragranulares después de 24 h post isquemia. Después de 96 h hubo una disminución generalizada de la inmmunoreactivity en las capas supra e infragranulares. A los 10 y 20 días, el tejido recobró alguna inmunoreactividad NeuN, estos cambios se dieron en la capa VI. CONCLUSIONES: Los cambios inmunorreactivos a NeuN apoyan el proceso de diasquisis interhemisférica. Los cambios en la inmunorreactividad podrían indicar estrés metabólico secundario a la interrupción en la conectividad con el sitio de la lesión.

Assessment transcallosal Diaschisis in a model of focal cerebral ischemia in rats / Evaluación de la diásquisis transcallosa en un modelo de isquemia cerebral focal en ratas

Objective: To evaluate transcallosal changes after a local ischemic injury in rats by using the monoclonal marker anti-NeuN (Mouse anti-neuronal nuclei). Methods: Twenty eight adult, male, Wistar rats were subjected to focal injury in the right hemisphere. The technique used was the experimental model of focal ischemic injury through intraluminal suture of the middle cerebral artery. Analyses were made for the five groups: and after the lesion (control), at 24 h, 96 h, 10 days and 20 days. Exofocal neuronal damage was inferred from neuronal immunoreactivity changes to NeuN. Results: In the cortex contralateral to the lesion, immunoreactivity was diminished. This was most notable in the supragranular layers 24 h post ischemia. After 96 h, there was a generalized diminishment of the inmmunoreactivity in supra and infragranular layers. At 10 and 20 days, the tissue recovered some NeuN immunoreactivity, but there were set changes in the VI layer. Conclusion: The immunoreactive changes to NeuN support the process of interhemispheric diaschisis. Changes in immunoreactivity could indicate metabolic stress secondary to the disruption in connectivity to the site of lesion.

Objetivo: Evaluar los cambios exofocales transcallosos después de lesión isquémica focal en ratas, mediante marcación inmunohistoquímica con el anticuerpo monoclonal anti-NeuN (Mouse Anti-Neuronal Nuclei). Métodos: Se intervinieron 28 ratas machos Wistar adultas. Mediante el modelo experimental de isquemia cerebral focal del territorio de la arteria cerebral media por filamento intraluminal, se les ocasionó una lesión focal en el hemisferio derecho. Posteriormente se evaluó el hemisferio contralateral, marcando la población neuronal con el anticuerpo monoclonal anti-NeuN. Se definieron cinco grupos de evaluación: uno de control, 24 h, 96 h, 10 días y 20 días. Se evaluaron los cambios neuronales exofocales después de la lesión con base en la observación de los cambios en la inmunoreactividad de las neuronas al NeuN. Resultados: Se redujo la inmunoreactividad en la corteza contralateral a la lesión. Este fenómeno fue más notable en las capas supragranulares después de 24 h post isquemia. Después de 96 h hubo una disminución generalizada de la inmmunoreactivity en las capas supra e infragranulares. A los 10 y 20 días, el tejido recobró alguna inmunoreactividad NeuN, estos cambios se dieron en la capa VI. Conclusiones: Los cambios inmunorreactivos a NeuN apoyan el proceso de diasquisis interhemisférica. Los cambios en la inmunorreactividad podrían indicar estrés metabólico secundario a la interrupción en la conectividad con el sitio de la lesión.