Parkinson’s disease (PD) is a common neurodegenerative disease that is a growing public health challenge. Estimates of the burden of PD have focused on data from high-income countries, with lower-income countries poorly described. We reviewed and examined the prevalence of PD reported by studies in low- to upper-middle-income countries. A systematic literature search was performed in the Medline/PubMed, Embase, LILACS, and Web of Science databases. Age group, sex, and geographic region were considered when analyzing the data. Of the 4327 assessed articles, 57 met the inclusion criteria for qualitative review, and 36 were included in the meta-analysis. Heterogeneity measures were high both as a whole and in each geographic region. Data analysis by geographic region showed that reported prevalence differed across regions, ranging from 49 per 100,000 (Sub-Saharan Africa) to 1081 per 100,000 (Latin America and the Caribbean). There was an increasing prevalence of PD with advancing age (per 100,000): 7 in 40–49 years, 158 in 50–59 years, 603 in 60–69 years, 1251 in 70–79 years, and 2181 in over the age of 80. The prevalence of PD in men and women was similar. There was a greater PD prevalence in populations with a higher 5-year GDP per capita and a higher life expectancy. Our findings suggest a higher prevalence of PD in lower and upper-middle-income countries than previously reported. Comparisons between regions are difficult, as the sociocultural differences and lack of methodological standardization hinder understanding key epidemiological data in varied populations.

Movement disorders are increasingly described in hospitalized and milder cases of SARS-CoV-2 infection, despite a very low prevalence compared to the total patients. We reviewed the scientific literature published in English, spanning from the initial descriptions of COVID-19 until January 25, 2021, in the PubMed/MEDLINE database. We identified 93 new-onset movement disorders cases (44 articles) from 200 papers screened in the database or reference lists. Myoclonus was present in 63.4% (n = 59), ataxia in 38.7% (n = 36), action/postural tremor in 10.8% (n = 10), rigid-akinetic syndrome in 5.38% (n = 5), oculomotor abnormalities in 20.4% (n = 19), catatonia in 2.1% (n = 2), dystonia in 1.1% (n = 1), chorea in 1.1% (n = 1), functional (psychogenic) movement disorders in 3.2% (n = 3) of the reported COVID-19 cases with any movement disorder. Encephalopathy was a common association (n = 37, 39.78%). Comprehensive neurophysiological, clinical, and neuroimaging descriptions of movement disorders in the setting of SARS-CoV-2 infection are still lacking, and their pathophysiology may be related to inflammatory, postinfectious, or even indirect mechanisms not specific to SARS-CoV-2, such as ischemic-hypoxic brain insults, drug effects, sepsis, kidney failure. Cortical/subcortical myoclonus, which the cited secondary mechanisms can largely cause, seems to be the most common hyperkinetic abnormal movement, and it might occur in association with encephalopathy and ataxia. This brief review contributes to the clinical description of SARS-CoV-2 potential neurological manifestations, assisting clinical neurologists in identifying features of these uncommon syndromes as a part of COVID-19 symptomatology.

Parkinson’s disease (PD) is a common neurodegenerative disease associated with cognitive impairment. The Montreal Cognitive Assessment (MoCA) has been used as a recommended global cognition scale for patients with PD, but there are some concerns about its application, partially due to the floor and ceiling effects. Objective: To explore the floor and ceiling effects on the MoCA in patients with PD in Brazil. Methods: Cross-sectional study with data from patients with PD from five Brazilian Movement Disorders Clinics, excluding individuals with a possible diagnosis of dementia. We analyzed the total score of the MoCA, as well as its seven cognitive domains. The floor and ceiling effects were evaluated for the total MoCA score and domains. Multivariate analyses were performed to detect factors associated with floor and ceiling effects. Results: We evaluated data from 366 patients with PD and approximately 19% of individuals had less than five years of education. For the total MoCA score, there was no floor or ceiling effect. There was a floor effect in the abstraction and delayed memory recall domains in 20% of our sample. The ceiling effect was demonstrated in all domains (80.8% more common in naming and 89% orientation), except delayed recall. Education was the main factor associated with the floor and ceiling effects, independent of region, sex, age at evaluation, and disease duration. Conclusion: The floor and ceiling effects are present in specific domains of the MoCA in Brazil, with a strong impact on education. Further adaptations of the MoCA structure for underrepresented populations may reduce these negative effects.

Sir, We have read with great interest the article published by Gallea et al. (2013), in the November 2013 issue of Brain , regarding the pathophysiological basis of the rare disease named congenital mirror movements (Srour et al. , 2010; Depienne et al. , 2012), that might serve as a model to recognize new aspects of bimanual motor control (Gallea et al. , 2011). We have recently seen a patient with congenital mirror movements and have coincidently studied this disorder using a clinical, neurophysiological and neuroimaging protocol similar to those used by Gallea et al. (2013). This case was presented as a video session at the 5th Meeting of the Movement Disorders Scientific Department of the Brazilian Academy of Neurology, in August 2013, but has not yet been published. Our patient is a 32-year-old right-handed male, with synkinetic distal movements of distal limbs since early childhood, with stable course, and no other movement disorders or neurological abnormalities. The involuntary movements led him to labour impairment as he works as a postman and has difficulties in performing bimanual tasks such as writing on a clipboard or handling a mobile telephone or keyboard. Interestingly, a late acquisition of running abilities was his only neurodevelopmental delay; his parents reporting a preference for jumping instead of running in early childhood \[which may be similar to the Kanga mice hopping gait, with spontaneous mutation in the deleted in colorectal carcinoma ( Dcc ) gene\] (Finger et al. , 2002). His clinical manifestations were classified in the Woods and Teuber Mirror Movements Scale (Woods and Teuber, 1978) as …