Epidemiologic trends of multiple sclerosis in Puerto Rico (2013-2020).

BACKGROUND: Previous studies have demonstrated higher multiple sclerosis (MS) incidence and prevalence in Puerto Rico (PR) than in other Caribbean and Latin American countries. Our objectives are to update the epidemiologic trends in MS incidence and prevalence rates for PR from 2017 through 2020 and compare them to prior rate data from 2013 to 2016. METHODS: We used the Puerto Rico MS Foundation's registry (PRMS Registry) data to identify all newly diagnosed MS cases between January 2017 and December 2020. The study population included 568 MS patients, 406 women and 162 men living in PR. All individuals were 18 years and older and met the 2017 revised McDonald criteria for MS diagnosis. In addition, age- and sex-standardized incidence rates were estimated. RESULTS: A total of 568 new MS cases were diagnosed in Puerto Rico between 2017 and 2020. The 2020 MS cumulative prevalence for Puerto Rico was 95.3/100,000 (95% CI: 91.6, 99.1), higher than previously reported. The age- and sex-standardized MS incidence rate for Puerto Rico decreased from 6.5/100,000 (2017) to 6.3/100,000 (2020). The annual age-standardized MS incidence rates declined for females: from 9.5/100,000 (2017) to 8.2/100,000 (2020) but increased for males from 3.6/100,000 to 4.6/100,000 during the same period. CONCLUSION: These incidence and prevalence rates are among the highest reported among Caribbean and Latin American countries. A peak in the age- and sex-standardized MS incidence rate was observed after hurricane María (2018) and a decline during the first year of the COVID-19 pandemic (2020). Further investigation is needed to determine whether there was a causal relationship between the fluctuations observed and those natural events.

Impact of delayed treatment on exacerbations of multiple sclerosis among Puerto Rican patients.

BACKGROUND: There are limited data on multiple sclerosis (MS) patients in underserved groups, including Puerto Rico. In this study, we analyzed the characteristic of MS symptoms and number of relapses in Puerto Rican patients. We then compare these characteristics with MS patients from the US. The number of MS relapses is highly correlated with the treatment onset and adherence. Patients in Puerto Rico have been experiencing lengthy treatment delay. We will discuss the possible causes of such delay and its impact on MS prognosis. METHODS: This retrospective cohort study consisted of the evaluation of 325 medical records from MS patients attending the Caribbean Neurological Center from 2014 to 2019. We gathered symptoms and comorbidities data as binary objects. The treatment delay was calculated based on the mean value of days between diagnosis and treatment onset for these groups of patients. RESULTS: We found that on average, the treatment delay for MS patients in Puerto Rico (PR) to receive their medication was 120 days. The most common MS subtype was relapsing-remitting 72.8%, with a mean of 1.684 relapses per year. Initial symptoms were sensory 54%, visual 33.1%, motor 28.8%, coordination 23.2%, fatigue 9.7%, memory 7.3%, depression 6.5%, urinary 4.9%, gastrointestinal 2.4%, and sexual dysfunction 1.6%. The most common comorbidities were hypertension 18.4%, asthma 13.6%, and thyroid disease 12.8%. When we compared the comorbidities between the two populations, immune thrombocytopenia had the highest percent change with the value of almost 200% (0.001% of US patient vs. 0.8% of Puerto Rican MS patients). CONCLUSION: Patients from Puerto Rico had a 33% higher relapse rate compared to the one reported for MS patients in the US. This higher rate may be related to the long delay in receiving their medications. They also had a higher rate of complex comorbidities such as immune thrombocytopenia or thyroid disease. Our findings provide a proof of concept that delay in receiving medications can increase the number of relapses and complex comorbidities among MS patients.

Comprehensive review of neuromyelitis optica and clinical characteristics of neuromyelitis optica patients in Puerto Rico.

Neuromyelitis optica (NMO) is an immune-mediated inflammatory disorder of the central nervous system. It is characterized by concurrent inflammation and demyelination of the optic nerve (optic neuritis [ON]) and the spinal cord (myelitis). Multiple studies show variations in prevalence, clinical, and demographic features of NMO among different populations. In addition, ethnicity and race are known as important factors on disease phenotype and clinical outcomes. There are little data on information about NMO patients in underserved groups, including Puerto Rico (PR). In this research, we will provide a comprehensive overview of all aspects of NMO, including epidemiology, environmental risk factors, genetic factors, molecular mechanism, symptoms, comorbidities and clinical differentiation, diagnosis, treatment, its management, and prognosis. We will also evaluate the demographic features and clinical phenotype of NMO patients in PR. This will provide a better understanding of NMO and establish a basis of knowledge that can be used to improve care. Furthermore, this type of population-based study can distinguish the clinical features variation among NMO patients and will provide insight into the potential mechanisms that cause these variations.

Increasing Incidence and Prevalence of Multiple Sclerosis in Puerto Rico (2013-2016).

BACKGROUND: The incidence of multiple sclerosis (MS) has been increasing worldwide over the past decades. However, this upward trend has not been examined at the country level in Latin America and the Caribbean (LAC). The aims of this study are to examine trends of MS incidence over 4 years and to provide age- and gender-standardized incidence rate estimates for a Caribbean island. METHODS: Data from the Puerto Rico (PR) MS Foundation's registry was used to identify all newly diagnosed MS cases between 2013 and 2016. MS patients were 18 years and older and met the 2010 revised McDonald criteria. Age- and gender-standardized incidence rates were estimated. RESULTS: A total of 583 new MS cases were diagnosed in PR from 2013 to 2016. The age- and gender-standardized MS incidence rate for PR increased from 6.1/100,000 in 2013 to 6.7/100,000 in 2016. The annual age-standardized MS incidence rates for females rose from 8.4/100,000 in 2013 to 9.8/100,000 in 2016 and were higher than males, which remained around 3.7/100,000. CONCLUSION: Incidence estimates for PR were higher than other LAC countries but consistent with MS increases in other world regions. Our findings tend to rule out several prior potential environmental explanations for high MS incidence rates.

Incidence of Multiple Sclerosis in Puerto Rico, 2014: A Population-Based Study.

BACKGROUND: Multiple sclerosis (MS) affects millions of people worldwide. The estimates for MS incidence are difficult to obtain but are important for understanding MS etiology, developing prevention strategies, and service planning. This study is aimed at estimating the 2014 incidence of MS in Puerto Rico (PR). METHODS: The PR MS Foundation's registry was used as the data source. Neurologists, specialty pharmacies, MRI centers, health insurance companies, and the PR Department of Health identified MS cases missed by the registry. MS patients were 18 years and older and met the 2010 revised McDonald criteria. Age-standardized MS incidence rates and their corresponding 95% CIs were computed. RESULTS: A total of 144 new MS cases were diagnosed in 2014. The age-standardized MS incidence rate was 5.1/100,000 (95% CI 4.3-5.9). The incidence rate was 7.1/100,000 (95% CI 5.7-8.5) for females and 2.9/100,000 (95% CI 2.0-3.8) for males. MS cases were mostly females (72.9%) with a mean age of 41.0 years (±1.0). CONCLUSION: According to the country estimates, PR has a higher MS incidence than other Caribbean and Latin American countries, but a lower incidence compared to countries at higher latitudes. Our findings provide insights into the MS etiology in the Hispanic population that require additional research.