Movement disorders in Latin America

The epidemiology of Parkinson's disease

The epidemiology of Parkinson's disease shows marked variations in time, geography, ethnicity, age, and sex. Internationally, prevalence has increased over and above demographic changes. There are several potential reasons for this increase, including the decline in other competing causes of death. Whether incidence is increasing, especially in women or in many low-income and middle-income countries where there is a shortage of high-quality data, is less certain. Parkinson's disease is more common in older people and men, and a variety of environmental factors have been suggested to explain why, including exposure to neurotoxic agents. Within countries, there appear to be ethnic differences in disease risk, although these differences might reflect differential access to health care. The cause of Parkinson's disease is multifactorial, and involves genetic and environmental factors. Both risk factors (eg, pesticides) and protective factors (eg, physical activity and tendency to smoke) have been postulated to have a role in Parkinson's disease, although elucidating causality is complicated by the long prodromal period. Following the establishment of public health strategies to prevent cardiovascular diseases and some cancers, chronic neurodegenerative diseases such as Parkinson's disease and dementia are gaining a deserved higher priority. Multipronged prevention strategies are required that tackle population-based primary prevention, high-risk targeted secondary prevention, and Parkinson's disease-modifying therapies for tertiary prevention. Future international collaborations will be required to triangulate evidence from basic, applied, and epidemiological research, thereby enhancing the understanding and prevention of Parkinson's disease at a global level.

Overview of management of infection-related movement disorders with focus on specific-infections

Infections are important treatable causes of secondary movement disorders (MD) that can have heterogeneous presentations. According to various studies, infection-related movement disorders (IRMD) account for around 10-20% of secondary MD. Certain infections have a predilection for causing various MD, and some MD phenomenologies, such as acute cerebellar ataxia and opsoclonus-myoclonus-ataxia syndromes (OMAS), suggest a strong possibility of an underlying infectious cause. The underlying pathophysiology is multifaceted, including direct neuronal damage due to neurotropism, granulomas, abscesses causing structural damage, and inflammatory and autoimmune responses triggered by infections. Understanding the prevalence, spectrum, and pattern of these IRMD and common infections that are responsible helps in early diagnosis, and instituting appropriate, timely treatment, thereby improving the overall prognosis and avoiding unnecessary investigations. In this review, we aim to provide a brief overview of common infections associated with MD, common clinical presentations of IRMD, their underlying pathophysiology, and overall approach to their treatment, with a focus on specific treatments of prevalent and treatable IRMD.

Prevalence and impact of neuropsychiatric symptoms in normal aging and neurodegenerative syndromes: A population-based study from Latin America

BACKGROUND

Neuropsychiatric symptoms (NPSs) are common in neurodegenerative diseases; however, little is known about the prevalence of NPSs in Hispanic populations.

METHODS

Using data from community-dwelling participants age 65 years and older enrolled in the 10/66 study (N = 11,768), we aimed to estimate the prevalence of NPSs in Hispanic populations with dementia, parkinsonism, and parkinsonism-dementia (PDD) relative to healthy aging. The Neuropsychiatric Inventory Questionnaire (NPI-Q) was used to assess NPSs.

RESULTS

NPSs were highly prevalent in Hispanic populations with neurodegenerative disease; approximately 34.3%, 56.1%, and 61.2% of the participants with parkinsonism, dementia, and PDD exhibited three or more NPSs, respectively. NPSs were the major contributor to caregiver burden.

DISCUSSION

Clinicians involved in the care of elderly populations should proactively screen for NPSs, especially in patients with parkinsonism, dementia, and PPD, and develop intervention plans to support families and caregivers. Highlights Neuropsychiatric symptoms (NPSs) are highly prevalent in Hispanic populations with neurodegenerative diseases. In healthy Hispanic populations, NPSs are predominantly mild and not clinically significant. The most common NPSs include depression, sleep disorders, irritability, and agitation. NPSs explain a substantial proportion of the variance in global caregiver burden.

Prevalence of parkinsonism and Parkinson disease in urban and rural populations from Latin America: A community based study

Background

Age and gender specific prevalence rates for parkinsonism and Parkinson's disease (PD) are important to guide research, clinical practice, and public health planning; however, prevalence estimates in Latin America (LatAm) are limited. We aimed to estimate the prevalence of parkinsonism and PD and examine related risk factors in a cohort of elderly individuals from Latin America (LatAm).

Methods

Data from 11,613 adults (65+ years) who participated in a baseline assessment of the 10/66 study and lived in six LatAm countries were analyzed to estimate parkinsonism and PD prevalence. Crude and age-adjusted prevalence were determined by sex and country. Diagnosis of PD was established using the UK Parkinson's Disease Society Brain Bank's clinical criteria.

Findings

In this cohort, the prevalence of parkinsonism was 8.0% (95% CI 7.6%-8.5%), and the prevalence of PD was 2.0% (95% CI 1.7%-2.3%). PD prevalence increased with age from 1.0 to 3.5 (65-69vs. 80 years or older, p < 0.001). Age-adjusted prevalence rates were lower for women than for men. No significant differences were found across countries, except for lower prevalence in urban areas of Peru. PD was positively associated with depression (adjusted prevalence ratio [aPR] 2.06, 95% CI 1.40-3.01, I ² = 56.0%), dementia (aPR 1.57, 95% CI 1.07- 2.32, I ² = 0.0%) and educational level (aPR 1.14, 95% CI 1.01- 1.29, I ² = 58.6%).

Interpretation

The reported prevalence of PD in LatAm is similar to reports from high-income countries (HIC). A significant proportion of cases with PD did not have a previous diagnosis, nor did they seek any medical or neurological attention. These findings underscore the need to improve public health programs for populations currently undergoing rapid demographic aging and epidemiological transition.

Funding

The funding source had no role in the design and conduct of the study; collection, management, analysis, and interpretation of the data; preparation, review, or approval of the manuscript; and decision to submit the manuscript for publication.

A systematic review and mixed treatment comparison of monotherapy in early Parkinson's disease: implications for Latin America

Parkinson's disease (PD) is the second most common neurodegenerative disease. There are no clinical trials comparing all available pharmacological therapies for the treatment of early PD. The objective of this review is to indirectly analyze the efficacy of antiparkinson drugs currently available in Latin America. A systematic review was performed exploring only placebo-controlled randomized trials comparing antiparkinson monotherapy (levodopa, pramipexole, rasagiline, or selegiline) in patients with PD on Hoehn and Yahr stages I through III published from January 1994 to May 2014. The primary outcome was the mean change in the Unified PD Rating Scale (UPDRS) I, II and III. A mixed treatment comparison analysis (indirect comparisons) through a random-effects model was performed. Levodopa demonstrated the highest effects in terms of UPDRS score improvement both from baseline and when compared to other treatments. Levodopa showed a 60.1% probability of granting the greatest reduction in UPDRS I, II and III.

Factors influencing the clinical expression of intermediate CAG repeat length mutations of the Huntington's disease gene

Our aim is to elucidate the clinical variables associated with the development of manifest HD in patients with intermediate CAG repeat lengths. 2,167 participants were seen throughout 44 research sites in the United States, Canada or Australia over a five-year natural history observational study (2006-2011) (Trial # NCT00313495). The Chi-square test and a generalised linear model were used to examine the differences in demographics and cognitive tests among three groups of CAG repeat length. The mixed model was then used to examine the time effect on cognitive assessments by CAG groups. No patient with CAG repeat length 27-35 developed manifest HD, whereas three patients with 36-39 did. Total motor score, maximal chorea score and maximal dystonia score were significantly different at baseline (p < 0.001) for each measure between those patients with a repeat length 27-35 versus those 36-39; as were total functional assessment, independence scale and total functional capacity (p < 0.001). Being aged 65 years or more (OR 5.81, 95 % CI 0.37-90.58, p = 0.02) and smoking (OR 13.99, 95 % CI 2.03-96.44, p = 0.007) were related to manifest HD in patients with CAG 36-39; those with an associated university degree or higher education were less frequently diagnosed as manifest HD (OR 0.10, 95 % CI 0.02-0.54, p = 0.007). Age, smoking and lower education achievement were found to be significantly associated with higher odds of manifest HD in patients with intermediate CAG repeat length mutations.

Movement Disorders Among Adult Neurological Outpatients Evaluated over 20 Years in Guayaquil, Ecuador

There is little information available on the evolutive pattern of patients with movement disorders in developing countries. We analyzed 579 consecutive adults with movement disorders and prospectively evaluated them at our institution (Department of Neurological Sciences, Kennedy Clinic, Guayaquil, Ecuador) from 1990 to 2009. Mean age was 62.9±17.5 years, and 50.8% were men. Patients presented with tremor/rigidity (55%), involuntary movements (23.5%) and abnormalities of stance and gait (21.5%). Overall, 45% of our patients had degenerative disorders of the nervous system. We found significant increases in the relative prevalence of tremor/rigidity and abnormalities of stance and gait, and this reflected an increase in the number of patients with degenerative diseases over the study years. We found a dynamic pattern of movement disorders over the years. Today, causes and relative prevalence of these conditions in our population is more similar to that reported from the developed world than it was 20 years ago.