Frontal functional connectivity and disease duration interactively predict cognitive decline in Parkinson's disease

OBJECTIVE

Cognitive decline does not always follow a predictable course in Parkinson's disease (PD), with some patients remaining stable while others meet criteria for dementia from early stages. Functional connectivity has been proposed as a good correlate of cognitive decline in PD, although it has not been explored whether the association between this connectivity and cognitive ability is influenced by disease duration, which was our objective.

METHODS

We included 30 patients with PD and 15 healthy controls (HC). Six cognitive domains were estimated based on neuropsychological assessment. Phase-based connectivity at frontal and posterior cortical regions was estimated from a resting EEG.

RESULTS

The PD group showed significant impairment for the executive, visuospatial, and language domains compared with HC. Increased connectivity at frontal regions was also found in the PD group. Frontal delta and theta connectivity negatively influenced general cognition and visuospatial performance, but this association was moderated by disease duration, with increased connectivity predicting worse performance after 8 years of disease duration.

CONCLUSION

Subtle neurophysiological changes underlie cognitive decline along PD progression, especially around a decade after motor symptoms onset.

SIGNIFICANCE

Connectivity of EEG slow waves at frontal regions might be used as a predictor of cognitive decline in PD.

Determinants and impact of alexithymia on quality of life in Parkinson's disease

INTRODUCTION

Alexithymia is a neuropsychiatric symptom conceptualized as difficulty identifying and describing feelings. Although associated with other non-motor symptoms, mainly neuropsychiatric, alexithymia may present as an isolated symptom in persons with Parkinson's Disease (PwP). The objective of the study is to identify determinants of alexithymia and its association with quality of life (QoL) in Parkinson's disease.

METHODS

Subjects with Parkinson's disease were recruited. The following instruments were applied: Movement Disorders Society Unified Parkinson's Disease Rating Scale (MDS-UPDRS), Non-Motor Symptoms Scale (NMSS), Montreal Cognitive Assessment (MoCA), Toronto alexithymia scale (TAS-20) and Parkinson's Disease Questionnaire (PDQ-8). Matched healthy controls were screened using TAS-20. Clinical and demographical variables were compared between alexithymic and non-alexithymic. Regression models were used to find determinants of alexithymia. Impact of alexithymia on QoL was estimated with a linear regression model.

RESULTS

98 patients were included. 56.1% PwP and 28.8% controls were alexithymic (p<0.001). Education level (OR 0.86) and NMSS urinary score (OR 1.09) determined alexithymia as well as TAS-20 score. Alexithymia was an independent determinant of QoL.

CONCLUSIONS

Alexithymia is a prevalent independent non-motor symptom in PwP with impact on QoL. Low education level and urinary symptoms are important determinants of alexithymia.

Incidencia y distribución geográfica de la enfermedad de Parkinson en México

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Neurological manifestations in coronavirus disease 2019

Coronavirus disease 2019 (COVID-19), an infection caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is currently hitting the world in the form of a pandemic. Given that some reports suggest that this infection can also occur with neurologic manifestations, this narrative review addresses the basic and clinical aspects concerning the nervous system involvement associated with this disease. More than one third of patients hospitalized for COVID-19 can present with both central and peripheral neurological manifestations. The former include dizziness and headache, while the latter include taste and smell disturbances. Other reported neurological manifestations are cerebrovascular disease and epileptic seizures. According to published reports, neurological disorders are not uncommon in COVID-19 and can sometimes represent the first manifestation of the disease; therefore, neurologists should consider this diagnostic possibility in their daily practice. Since maybe not all COVID-19 neurological manifestations are due to SARS-CoV-2 direct effects, it is important to monitor the rest of the clinical parameters such as, for example, oxygen saturation. Similarly, follow-up of patients is advisable, since whether neurological complications may develop lately is thus far unknown.

Malnutrition and Associated Motor and Non-motor Factors in People with Parkinson's Disease

BACKGROUND

People with Parkinson's disease (PwP) are at higher risk of developing malnutrition. Several factors have been suggested to be involved including motor symptoms, non-motor symptoms, and treatment-related complications.

OBJECTIVE

The objective of the study was to analyze the combined effect of motor, non-motor, and pharmacological factors in the risk of malnutrition in PwP.

METHODS

Eighty-seven consecutive PwP were included in the study. Clinical data and pharmacological treatment were collected. Nutritional status was assessed using the Mini-Nutritional Assessment (MNA) questionnaire. Movement Disorder Society Unified Parkinson's Disease Rating Scale (MDS-UPDRS), Non-motor Symptoms Scale (NMSS), Hamilton Depression Rating Scale HAM-D, and Montreal Cognitive Assessment were applied.

RESULTS

Thirty (34.4%) PwP were at risk of malnutrition and seven had malnutrition (8%). Abnormal nutritional status was associated with lower education, higher MDSUPDRS Parts I, II, and III and total scores, and higher scores in the NMSS domain of sleep disorders and fatigue. MDS-UPDRS motor score remained as a determinant of abnormal nutritional status, defined as MNA < 23.5, with an odds ratio 1.1 (95% confidence interval 1.01-1.10, p = 0.02).

CONCLUSION

The main factor associated with nutritional status was severity of the motor symptoms as assessed by the MDS-UPDRS Part III. Non-motor symptoms and treatment-related complications were not associated with malnutrition.

Neuropsychiatric profile of patients with craniocervical dystonia: A case-control study

OBJECTIVE

Depression, anxiety, and obsessive-compulsive disorder have been widely reported in patients with dystonia. On the other hand, cognitive impairment, frontal lobe function, impulsiveness and pseudobulbar affect are less studied. The objective of the study is to assess these neuropsychiatric symptoms along with the quality of life of subjects with craniocervical dystonia.

PATIENTS AND METHODS

A cross-sectional study was carried out in patients with craniocervical dystonia. Sex- and age-matched healthy controls were included. Neuropsychiatric assessment included the Montreal Cognitive Assessment (MoCA), Frontal Assessment Battery (FAB), Barrat Impulsiveness Scale (BIS-11), Center for Neurologic Study-Lability Scale (CNS-LS), Anxiety Rating Scale (HAM-A), Hamilton Depression Rating Scale (HAM-D), and the 12-item Short Form Health Survey (SF-12).

RESULTS

A total of 44 patients with craniocervical dystonia and 44 controls were included. The mean age was 57 ± 13.7 years. Depression (56.1 % vs 9.1 %, p < 0.001), anxiety (56.8 % vs 6.8 %, p < 0.001), and pseudobulbar affect (31.8 % vs 9.1 %, p = 0.02) were more common in the dystonia group in comparison to controls. No difference between groups was found in impulsiveness (p = 0.65), MoCA score (p = 0.14) or executive dysfunction (p = 0.42). Quality of life was worst in the dystonia group with 90.9 % (p = 0.03) and 61.4 % (p < 0.001) of the subjects scoring under average in the Physical Composite Score (PCS) and Mental Composite Score (MCS) of the SF-12.

CONCLUSION

MoCA scores ≤18, pseudobulbar affect, depression and anxiety are more prevalent in subjects with craniocervical dystonia in comparison to sex- and age-matched healthy controls. Regarding quality of life, MCS is more affected that the PCS in subjects with dystonia.

Factores asociados con deterioro cognitivo en una cohorte mexicana multicéntrica de Parkinson: estudio transversal comparativo

Introduction

Cognitive impairment is common in Parkinson's disease and represents a risk for dementia. Identifying associated factors will help implement early interventions and study its progression.

Objective

To identify factors associated with cognitive impairment.

Method

Cross-sectional study of 306 subjects with Parkinson's disease who were assessed for 12 months. Demographics and clinical variables were analyzed as explanatory variables, and cognitive impairment as outcome variable. Significant variables were used to construct a cognitive impairment predictive model.

Results

Cognitive impairment was reported in 43.8%. Female gender (p = 0.001, odds ratio [OR] = 1.77), age at diagnosis (p < 0.001, mean deviation [MD] = 5.7), level of education (p < 0.001, MD = -2.9), disease duration (p = 0.003, MD = 1.7), MDS-UPDRS part III score (p < 0.001, MD = 9.7), presence of anxiety (p = 0.007, OR = 2.11), hallucinations (p = 0.029, OR = 2.27) and freezing of gait (p = 0.048, OR = 1.91) were predictors for cognitive impairment. The use of type B monoamine oxidase inhibitors was associated with less cognitive impairment (p = 0.001).

Conclusions

Predictive factors that were consistent with those previously reported were identified. Prospective studies are required in order to clarify the effect of type B monoamine oxidase inhibitors on cognition.

Falls in persons with Parkinson's disease: Do non-motor symptoms matter as much as motor symptoms?

ABSTRACT Falls are common among persons with Parkinson's disease (PD). On the other hand, predicting falls is complex as there are both generic and PD-specific contributors. In particular, the role of non-motor symptoms has been less studied. Objective: The objective of this study was to identify the role of non-motor predictors of falling in persons with PD (PwP). Methods: A cross-sectional study was carried out in PwP recruited from a movement disorders clinic. Clinical and demographical data were collected. All PwP were assessed using the Movement Disorders Society Unified Parkinson's Disease Rating Scale (MDS-UPDRS) and the Non-Motor Symptoms Scale (NMSS). Variables were assessed at the bivariate level. Significant variables were put into a logistic regression model. Results: A total of 179 PwP were included. Overall, 16.8% of PwP had fallen in the past 12 months, with 53.3% of them being recurrent fallers. The mean number of monthly falls was 2.5 ± 3.3. Factors associated with falling in the bivariate analysis included the disease duration, Hoehn and Yahr stage, MDS-UPDRS part I and II, postural instability/gait disturbance (PIGD) subtype, NMSS urinary domain, NMSS miscellaneous domain, and non-motor severity burden (all p-values < 0.05). After multivariate analysis, only the disease duration (p = 0.03) and PIGD (p = 0.03) remained as independent risk factors. Conclusion: Disease duration and the PIGD subtype were identified as relevant risk factors for falls in PwP Non-motor symptoms appear to have a less important role as risk factors for falls.

Progressive supranuclear palsy as differential diagnosis of Parkinson's disease in the elderly

INTRODUCTION

Progressive supranuclear palsy (PSP) is a syndrome characterized by progressive parkinsonism with early falls due to postural instability, typically vertical gaze supranuclear ophthalmoplegia, pseudobulbar dysfunction, neck dystonia and upper trunk rigidity as well as mild cognitive dysfunction. Progressive supranuclear palsy must be differentiated from Parkinson's disease taking into account several so-called red flags.

MATERIALS AND METHODS

We report a case series hallmarked by gait abnormalities, falls and bradykinesia in which Parkinson's disease was the initial diagnosis.

RESULTS

Due to a torpid clinical course, magnetic resonance imaging (MRI) was performed demonstrating midbrain atrophy, highly suggestive of progressive supranuclear palsy.

CONCLUSION

The neuroradiological exams (magnetic resonance imaging, single photon emission computer tomography, and positron emission tomography) can be useful for diagnosis of PSP. Treatment with levodopa should be considered, especially in patients with a more parkinsonian phenotype.

Motor and non-motor wearing-off and its impact in the quality of life of patients with Parkinson's disease

OBJECTIVES

The wearing-off phenomenon is common in patients with Parkinson's disease. Motor and non-motor symptoms can fluctuate in relation to the "on/off" periods. To assess the impact of motor and non-motor wearing-off on activities of daily living and quality of life of patients with PD.

METHODS

A cross-sectional study was carried out. All patients were evaluated using the Movement Disorders Society Unified Parkinson's Disease Rating Scale. Wearing-off was assessed using the Wearing-Off Questionnaire-19, and quality of life was assessed using the Parkinson's Disease Questionnaire-8.

RESULTS

A total of 271 patients were included; 73.4% had wearing-off; 46.8% had both motor and non-motor fluctuations. Patients with both motor and non-motor wearing-off had a worst quality of life compared with those with only motor fluctuations (p = 0.047).

CONCLUSIONS

Motor and non-motor fluctuations have an impact on activities of daily living and quality of life. Non-motor wearing-off may have a higher impact.

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 (r_S = 0.62-0.56). In comparison to the patient-based total score, the by proxy total score showed no significant difference, high correlation (r_S = 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.

Diagnostic Utility of [11C]DTBZ Positron Emission Tomography In Clinically Uncertain Parkinsonism: Experience of a Single Tertiary Center

Background

The use of single-photon emission computed tomography and positron emission tomography (PET) has proven to be helpful in differentiating Parkinson's disease (PD) from other movement disorders with a sensitivity of up to 95%.

Objective

The objective of this study was to determine the accuracy of [11C]DTBZ PET imaging in patients with clinically uncertain parkinsonism from a tertiary referral center in Mexico City.

Materials and Methods

Patients who underwent [11C]DTBZ PET brain scan due to clinically uncertain parkinsonism where divided into two groups: PD or non-PD. A scan was considered positive when visual assessment revealed a decrease in [11C]DTBZ uptake typical for PD; a scan was considered negative when visual assessment showed no decrease in [11C]DTBZ uptake or showed a decrease in tracer uptake in a non-PD pattern. Sensitivity, specificity, and positive and negative predictive values were calculated using a 2 × 2 table, with a 95% confidence interval.

Results

A total of 39 patients were included in the study. 14 PET studies were deemed positive and 25 PET studies were deemed negative; 12 true positives and 23 true negatives were found. This yielded a sensitivity of 92.9% (95% CI, 66.1-99.8), specificity of 92% (95% CI, 74-99), PPV of 86.7% (95% CI, 63.1-96.1), and NPV of 95.8% (95% CI, 79.1-98.4).

Conclusions

The [11C]DTBZ PET has an excellent accuracy for differentiating idiopathic PD from other disorders.

[Breve recorrido histórico de la enfermedad de Parkinson a 200 años de su descripción]

The original description of what currently is known as Parkinson's disease was published 200 years ago. During both these centuries, knowledge on symptomatology, pathophysiology, genetics and pharmaceutical and surgical treatment has significantly increased; however, this nosological entity continues to be of imprecise origin and progressive evolution. In the present review, the historical events that contributed to describe and improve the understanding of this disease are summarized.

Two-hundred Years Later: Is Parkinson's Disease a Single Defined Entity?

An Essay on the Shaking Palsy, by James Parkinson, was published in 1817. Later, Jean-Martin Charcot better described some of the motor features of the disease and named the condition as "La Maladie de Parkinson." As understanding about the disease progressed, aided by both clinical expertise and technological developments, the definition of what is Parkinson's disease has evolved. Motor phenotype, non-motor symptoms, monogenic mutations, genetic risk factors, disease subtyping, and data-driven clusters, among other concepts, have given rise to the hypothesis that Parkinson's disease may be not one well-defined entity but several different diseases encompassed as a levodopa-responsive Parkinsonism. This review present and discusses several of these factors and how they may support or not the notion of Parkinson's being one or more diseases. In summary, current evidence appears to be insufficient at this moment to clarify this issue. Parkinson's disease will continue to be an evolving concept over the years to come.

Huntington's disease-like disorders in Latin America and the Caribbean

Diseases with a choreic phenotype can be due to a variety of genetic etiologies. As testing for Huntington's disease (HD) becomes more available in previously resource-limited regions, it is becoming apparent that there are patients in these areas with other rare genetic conditions which cause an HD-like phenotype. Documentation of the presence of these conditions is important in order to provide appropriate diagnostic and clinical care for these populations. Information for this article was gathered in two ways; the literature was surveyed for publications reporting a variety of genetic choreic disorders, and movement disorders specialists from countries in Latin America and the Caribbean were contacted regarding their experiences with chorea of genetic etiology. Here we discuss the availability of molecular diagnostics for HD and for other choreic disorders, along with a summary of the published reports of affected subjects, and authors' personal experiences from the regions. While rare, patients affected by non-HD genetic choreas are evidently present in Latin America and the Caribbean. HD-like 2 is particularly prevalent in countries where the population has African ancestry. The incidence of other conditions is likely determined by other variations in ethnic background and settlement patterns. As genetic resources and awareness of these disorders improve, more patients are likely to be identified, and have the potential to benefit from education, support, and ultimately molecular therapies.

Brain oscillations reveal impaired novelty detection from early stages of Parkinson's disease

The identification of reliable biomarkers for early diagnosis and progression tracking of neurodegenerative diseases has become an important objective in clinical neuroscience in the last years. The P3a event-related potential, considered as the neurophysiological hallmark of novelty detection, has been shown to be reduced in Parkinson's disease (PD) and proposed as a sensitive measure for illness duration and severity. Our aim for this study was to explore for the first time whether impaired novelty detection could be observed through phase- and time-locked brain oscillatory activity at early PD. Twenty-seven patients with idiopathic PD at early stages (disease duration <5 years and Hoehn and Yahr stage <3) were included. A healthy control group (n = 24) was included as well. All participants performed an auditory involuntary attention task including frequent and deviant tones while a digital EEG was obtained. A neuropsychological battery was administered as well. Time-frequency representations of power and phase-locked oscillations and P3a amplitudes were compared between groups. We found a significant reduction of power and phase locking of slow oscillations (3-7 Hz) for deviant tones in the PD group compared to controls in the P3a time range (300-550 ms). Also, reduced modulation of late induced (not phase locked) alpha-beta oscillations (400-650 ms, 8-25 Hz) was observed in the PD group after deviant tones onset. The P3a amplitude was predicted by years of evolution in the PD group. Finally, while phase-locked slow oscillations were associated with task behavioral distraction effects, induced alpha-beta activity was related to cognitive flexibility performance. Our results show that novelty detection impairment can be identified in neurophysiological terms from very early stages of PD, and such impairment increases linearly as the disease progresses. Also, induced alpha-beta oscillations underlying novelty detection are related to executive functioning.