1. Introduction
The Multiple Sclerosis (MS) is a chronic, autoimmune disease of the central nervous system (CNS), with more than 2 million prevalent cases of MS globally in 2016, which corresponded to a 10.4% increase in the age-standardized prevalence since 1990 [ 1 ], and highest prevalence rates are traditionally reported in Northern Europe and North America [ 2 ]. Conversely, the disease burden in Peru remains relatively low, with an estimated prevalence of 7.7 per 100,000 individuals [ 3 ]. Despite this lower regional prevalence, MS carries a significant public health impact globally, as it is the most frequent cause of non-traumatic disabling neurological disease affecting young adults [ 4 ].
The hallmark of MS pathology is the development of perivenular inflammatory lesions characterized by infiltrating CD8+ T cells, which ultimately leads to demyelination and axonal loss (plaque formation). While the initiating pathological mechanisms are heterogenous, the effector mechanisms become similar in the later stages of the disease. The clinical manifestations of MS are diverse and include acute or subacute motor weakness, unilateral visual loss (optic neuritis), sensory loss in the limbs or face, diplopia, gait disturbance, Lhermitte’s sign, vertigo, and bladder dysfunction [ 5 ]. MS is clinically classified into four main phenotypes: Clinically Isolated Syndrome (CIS), Relapsing-Remitting MS (RRMS), Secondary Progressive MS (SPMS), and Primary Progressive MS (PPMS). RRMS is reported as the most frequent initial phenotype, although 5–15% of patients present with PPMS, and most RRMS patients transition to SPMS after a period of 10 to 15 years [ 4 ]. The exact etiology of MS remains unclear, with evidence suggesting a complex interplay between various genetic and environmental risk factors [ 5 , 6 ]. Consistent with other autoimmune disorders, MS is more prevalent in women than in men, and is typically diagnosed between the ages of 20 and 40 years. Other identified risk factors include low vitamin D levels, smoking history, obesity, and prior Epstein-Barr virus infection [ 7 ].
Evidence characterizing the clinical presentation, demographics, and treatment response of MS patients in Latin America, and specifically in Peru [ 8 , 9 , 10 , 11 , 12 , 13 , 14 ], remain sparse. Recognizing the recent development of internationally adapted diagnostic criteria that incorporate the experience of diverse populations (including pediatric, Asian, and Latin American cohorts) [ 15 ], there is a critical need to contribute local epidemiological data. Therefore, this study aims to provide a comprehensive description of the demographic, clinical, and epidemiological characteristics of a patient series diagnosed with MS across three major hospitals in Lima, Peru.
2. Materials and Methods
This was a descriptive retrospective cohort study examining Peruvian patients diagnosed with Multiple Sclerosis (MS). The cohort was identified by reviewing medical records across three major hospitals located in Lima, Peru: Hospital Nacional Dos de Mayo, Hospital Nacional Alberto Sabogal Sologuren, and Hospital Nacional María Auxiliadora. Data were collected over a 10-year period, spanning from 1 January 2007, to 31 December 2017.
All clinical charts within the selected hospitals were reviewed against the following inclusion and exclusion criteria. Adult patients with a confirmed diagnosis of MS (any clinical phenotype) who were diagnosed using the contemporary consensus criteria at the time of evaluation (the 2005 McDonald criteria for patients diagnosed prior to 2010, and the 2010 McDonald criteria for those diagnosed from 2010 onward) and who had documented data available for at least 2 years within the respective institution were included. Demographic data (age, sex), clinical characteristics (year of diagnosis, smoking status, initial treatment, current treatment, clinical features at onset, and clinical features at the time of the current evaluation) were extracted from the electronic and/or paper medical records of each included patient. Data collection was performed using a standardized case record form (CRF).
For the statistical analysis, frequencies and percentages were used to describe categorical variables. Continuous variables were reported as medians and the interquartile range (IQR). All statistical computations were performed using the STATA statistical software package, version 15.1 (StataCorp, College Station, TX, USA).
3. Results
A total of 103 patients with Multiple Sclerosis (MS) were identified across the three hospitals. The majority of the cohort was female ( n = 60, 58.3%). The median age at disease onset was 38.4 years (Interquartile Range [IQR]: 28.9–46.5), with the age range spanning from 17.7 years to 70.9 years. The most common clinical phenotype at onset was RRMS ( n = 93, 90.3%), which remained the most frequent phenotype at the last recorded clinical evaluation ( n = 82, 79.6%). Twelve patients (12.9%) demonstrated progression from RRMS to SPMS by their last follow-up visit. No history of Epstein-Barr virus infection in early life was reported in this cohort. Cerebrospinal fluid (CSF) analysis revealed abnormal IgG oligoclonal band (OCB) positivity in 34 cases (63.4%). The general characteristics of the population at disease onset and the current evaluation are detailed in Table 1 .
The most frequent symptoms reported at disease onset were limb weakness ( n = 75/103, 72.8%), sensory symptoms ( n = 75/103, 72.8%), and blurred vision ( n = 42/100, 42.0%). At the time of the last evaluation, the most frequent symptoms were limb weakness ( n = 81/103, 78.6%), sensory symptoms ( n = 74/103, 71.8%), and spasticity ( n = 61/102, 40.2%). The full distribution of symptoms is presented in Table 2 .
The median relapse rate was 0.6 per year (IQR: 0.3–1.0). Regarding hospitalizations, one hospitalization per year was the most frequent frequency ( n = 43/88, 48.9%), with a stay of 5 days being the most common duration ( n = 19/89, 21.4%), largely driven by the administration of intravenous corticosteroids. Thirty-seven patients (35.9%) reported engaging in physical therapy.
Analysis of the Expanded Disability Status Scale (EDSS) showed that the median change between the EDSS score at onset and at the last evaluation was 0 (IQR: 0–0). When stratified by follow-up duration, patients with less than 10 years of follow-up maintained a median EDSS change of 0 (IQR: 0–0). However, those with 10 or more years of follow-up demonstrated a median reduction in EDSS score (median −1, IQR: −1 to 0). EDSS scores at onset and last evaluation, stratified by follow-up duration, are detailed in Table 1 .
Only 51 patients (49.5%) reported receiving any type of Disease-Modifying Therapy (DMT) at disease onset. The most frequent initial treatment was interferon beta ( n = 46/103, 44.7%), and this remained the most frequently recorded current treatment ( n = 35/103, 34.0%). Treatment duration was heterogeneous, with a median length of 5 years (IQR: 2.3–8.8), ranging from a minimum of 4 months to a maximum of 20 years. Patients primarily stayed on their initial first-line treatment unless they met criteria for treatment failure (defined as unmitigated clinical relapses or confirmed radiological progression).
Only three patients (2.8%) initiated therapy with a high-efficacy DMT at onset: Ocrelizumab ( n = 2, 1.9%) and Fingolimod ( n = 1, 0.9%). By the time of the last evaluation, 18 patients (17.5%) were registered as receiving a high-efficacy DMT, though all patients receiving these therapies, except for one on Fingolimod, were managed within the context of clinical trials. The remaining distribution of treatments is outlined in Table 3 . The vast majority of patients ( n = 91, 88.4%) reported adherence to their prescribed treatment. Regarding functional impact, 56 patients (54.4%) reported unemployment due to MS. Among those who required a caregiver ( n = 43), the majority were non-professional caregivers ( n = 41, 95.4%). The median current EDSS score was 4 (IQR: 3–5.5) for patients reporting unemployment and 5 (IQR: 3.5–5.5) for those requiring a caregiver.
4. Discussion
This 10-year retrospective study across three major referral hospitals provides a robust description of the MS population in Lima, Peru. Our results generally align with established international literature, specifically concerning the female predominance and the high frequency of the RRMS phenotype at both onset and follow-up [ 5 , 16 ]. Consistent with other reports, the PPMS phenotype was the second most common form encountered. However, we found a notably low frequency of reported smoking (7.3%) compared to global cohorts. This finding may reflect both the lower prevalence of smoking in Peruvian population and the inherent limitations of retrospective chart review, where non-standardized or absent documentation likely leads to an underestimation of this exposure. Furthermore, key established environmental and serological risk factors, such as obesity and prior exposure to Epstein-Barr virus (EBV), could not be assessed due to the absence of systematic recording in the medical charts.
The most frequent initial treatment in patients with MS in this cohort was found to be interferon beta (44.7%). These patients appear to show no change in their EDSS score when assessed at their last visit; however, the difference in follow-up length and disease stage at the final evaluation creates a high risk of bias in these results. Regarding interferon beta, a series of 20 patients reported in 2005 at a hospital in Lima demonstrates local experience with its use, finding 75% of patients relapse-free at the end of treatment. However, this evaluation was observational and carries a high risk of bias and other threats to the validity of the results [ 12 ]. Similarly, another study conducted in Peru ( n = 12) found that the early use of interferon in these patients showed no recurrence of optic neuritis (something found in 42% of our series), suggesting that early treatment can reduce the impact of such complications [ 17 ].
For patients with RRMS who exhibit non-aggressive disease onset or who are not identified as high-risk for initial treatment failure, the latest recommendations advise initiating therapy with conventional disease-modifying agents such as interferon beta, glatiramer acetate, or teriflunomide [ 6 ]. It is important to emphasize that early initiation of disease-modifying therapies in patients with RRMS is important to reduce the impact of disability, reduce relapses, and reduce inflammation and brain damage [ 18 , 19 , 20 ]. There is evidence of relapse reductions of 46–47% with ocrelizumab, 28–34% with interferon beta, 29% with glatiramer acetate, 54% with fingolimod, and 31% with teriflunomide [ 6 ]. In our study, where over 50% of patients lost their jobs due to MS and 41.7% require caregivers, we found that only 49.5% started any treatment at the onset of the disease. Therefore, it is crucial to emphasize the importance of initiating early therapy with disease-modifying therapies to alleviate the course of the disease and reduce the frequency of relapses.
To fulfill the diagnostic requirements of the McDonald criteria, every patient in this three-center cohort underwent at least two magnetic resonance imaging (MRI) protocols (brain and/or spinal cord) to formally confirm dissemination in space (DIS) and dissemination in space (DIT) while systematically ruling out alternative structural or inflammatory mimicking pathologies. However, because this study relies on a multi-center, 10-year retrospective chart review across differing institutional radiology platforms, highly granular, standardized quantitative neuroimaging parameters—such as precise T2/FLAIR lesion counts, baseline gadolinium-enhancing lesion volumes, or brain atrophy metrics—were not uniformly structured within the available historical medical records. While the lack of an integrated, quantitative neuroimaging database represents an acknowledged limitation of our retrospective design, it reflects a common real-world challenge in resource-limited public health settings where qualitative diagnostic confirmation takes clinical precedence over standardized volumetric tracking.
To better understand how the epidemiological and clinical landscapes of MS in Peru compare to broader trends, our findings can be contextualized within the existing local literature and standard international benchmarks: first, our cohort demonstrated a female predominance of 58.3%, similar with local and global reports [ 1 , 9 , 10 ]. Second, the median age at onset in our series was 38.5 years, aligning closely with similar Peruvian reports (35.0–33.7) [ 9 , 10 ]. The literature describing the status of MS in Peru remains sparse, underscoring the necessity of regional descriptive studies. Previous local investigations have established a baseline for the disease, with a 2009 study reporting a national prevalence of 7.7 per 100,000 persons [ 3 ], a figure subsequently refined by a capture-recapture analysis that estimated a point prevalence of 9.1 per 100,000 persons [ 10 ]; furthermore, this last study found RRMS as the predominant phenotype (79.3%) and highlighted interferon beta as the most frequent treatment (40.7%) during that period [ 10 ]. Our findings align strongly with these established patterns regarding phenotype distribution and symptomology. Earlier case series from Lima, including studies between 1993 and 2004 ( n = 55) and work from the Hospital Alberto Sabogal ( n = 24), consistently reported RRMS as the most common form, with frequent initial involvement being motor and sensory deficits, decreased visual acuity, and optic neuritis [ 14 , 21 ]. Furthermore, a prior analysis of 13 patients at the National Institute of Neurological Sciences (INCN) found a frequency of depression (38.5%) and cognitive impairment (1.45%) [ 11 ], observations that closely parallel our current results (depression 34.7%; cognitive dysfunction 25.3%).
However, our cohort contributes key important discrepancies. While previous local reports described onset ages ranging from 33 to 39 years, a broader series compiled from literature reported a mean age at diagnosis of 27 years [ 22 ], which is notably lower than the median of 38.5 years found in our study. More recent work from the INCN ( n = 121) detailed the high frequency of myelitis (35%) and brainstem syndrome (25%) at onset for RRMS patients, with brainstem syndrome identified as a predictor for earlier diagnosis [ 9 ]. Our large, multi-center cohort reinforces the consistency of the clinical picture across different Lima institutions while providing a more robust median age of onset and current data on the socio-economic burden and DMT utilization.
The inherent limitations of this study require cautious interpretation. As a descriptive study relying on a convenience sample from three referral hospitals, our findings may not be generalizable to the entire MS population across Peru. Nevertheless, the size of our cohort ( n = 103) represents one of the largest published series to date from Peru and includes data from major specialized centers. Data incompleteness represents a further limitation, common in chart reviews, with missing variables, including EBV exposure, serum Vitamin D levels, and specific genetic polymorphisms (e.g., HLA-DRB1*15:01). The lack of routine, comprehensive neuropsychological evaluations likely lead to an underestimation of cognitive impairment, a pervasive issue reported in MS literature globally (e.g., 28% impairment in one large German cohort [ 23 ]). Furthermore, we did not assess quality of life, which is known to be significantly impaired in MS patients compared to other chronic diseases and is critical for evaluating therapeutic success [ 24 , 25 ].
This study provides one of the largest available descriptions of the clinical and demographic characteristics of Multiple Sclerosis (MS) in Peru, confirming general similarities to international series but starkly highlighting the significant social and economic disability burden observed within this cohort. Given the substantial functional loss and high dependency rates reported, our results require a critical reassessment of the current therapeutic approach to ensure the early and sustained use of highly effective disease-modifying therapies (DMTs). While our findings underscore the clinical reality in a resource-limited setting, the high risk of bias inherent to the retrospective design demands further investigation. Implementation of prospective cohort studies employing standardized measurement tools and consistent follow-up protocols to robustly characterize, monitor, and optimize the management of MS patients across the Peruvian healthcare system are urgently needed.
Disclaimer/Publisher’s Note: The statements, opinions and data contained in all publications are solely those of the individual author(s) and contributor(s) and not of MDPI and/or the editor(s). MDPI and/or the editor(s) disclaim responsibility for any injury to people or property resulting from any ideas, methods, instructions or products referred to in the content.
Author Contributions
Conceptualization, methodology, formal analysis, investigation, data curation, and writing—review and editing: A.C.C., J.P.-V., E.A., E.S. and I.D.-P. All authors have read and agreed to the published version of the manuscript.
Institutional Review Board Statement
The study was conducted in accordance with the Declaration of Helsinki, and approved by the Institutional Review Board of each site: Hospital Nacional Alberto Sabogal Sologuren (NIT 684-2019-1644, approved 29 November 2019), Hospital Nacional Dos de Mayo (065-2019-CEIB-HNDM, approved 7 November 2019) and Hospital Nacional Maria Auxil-iadora (PRISMA IRB CE1158.19, approved 29 October 2019).
Informed Consent Statement
Patient consent was waived due to the retrospective and anonymous character of this study.
Data Availability Statement
Data supporting the findings of this study are not publicly available due to ethical restrictions. The data were obtained from retrospective reviews of medical charts and include sensitive patient information; therefore, sharing is restricted to ensure confidentiality and compliance with institutional and ethical regulations.
Conflicts of Interest
Authors Eduardo Alvarado and Edward Smith were employed by the company Roche Farma. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.
Abbreviations
The following abbreviations are used in this manuscript: MS Multiple sclerosis RRMS Relapsing-Remitting MS PPMS Primary Progressive MS CIS Clinically Isolated Syndrome SPMS Secondary Progressive MS CRF Case Record Form IQR Interquartile Range
References
1. Wallin M.T. Culpepper W.J. Nichols E. Bhutta Z.A. Gebrehiwot T.T. Hay S.I. Khalil I.A. Krohn K.J. Liang X. Naghavi M. Global, regional, and national burden of multiple sclerosis 1990–2016: A systematic analysis for the Global Burden of Disease Study 2016 Lancet Neurol. 2019 18 269 285 10.1016/s1474-4422(18)30443-5 30679040 PMC6372756
2. Simpson S. Jr. Blizzard L. Otahal P. Van der Mei I. Taylor B. Latitude is significantly associated with the prevalence of multiple sclerosis: A meta-analysis J. Neurol. Neurosurg. Psychiatry 2011 82 1132 1141 10.1136/jnnp.2011.240432 21478203
3. Darwin V.E. Castillo J.K. Barba C.C. Gutierrez A.C. Barbarán M.T. Ortiz A.B. Belaúnde A.G. Prevalencia de Esclerosis Múltiple en Lima-Perú Rev. Médica Hered. 2009 20 146 150
4. Dobson R. Giovannoni G. Multiple sclerosis—A review Eur. J. Neurol. 2019 26 27 40 10.1111/ene.13819 30300457
5. Jakimovski D. Bittner S. Zivadinov R. Morrow S.A. Benedict R.H. Zipp F. Weinstock-Guttman B. Multiple sclerosis Lancet 2024 403 183 202 10.1016/s0140-6736(23)01473-3 37949093
6. McGinley M.P. Goldschmidt C.H. Rae-Grant A.D. Diagnosis and Treatment of Multiple Sclerosis: A Review JAMA 2021 325 765 779 10.1001/jama.2020.26858 33620411
7. Alfredsson L. Olsson T. Lifestyle and Environmental Factors in Multiple Sclerosis Cold Spring Harb. Perspect. Med. 2019 9 a028944 10.1101/cshperspect.a028944 29735578 PMC6444694
8. Almubaslat F. Sanchez-Boluarte S.S. Diaz M.M. A review of neurological health disparities in Peru Front. Public Health 2023 11 1210238 10.3389/fpubh.2023.1210238 37744515 PMC10513391
9. Caparó-Zamalloa C. Castro-Suarez S. Cortez-Escalante J. Aguirre-Quispe W. Guevara-Silva E. Osorio-Marcatinco V. Meza-Vega M. Brainstem syndrome at onset is related to an early MS diagnosis in Peru: A national referral center cohort Heliyon 2021 7 e08069 10.1016/j.heliyon.2021.e08069 34765756 PMC8569397
10. Gonzales-Gamarra O. Alva-Diaz C. Pacheco-Barrios K. Aguirre-Quispe W. Malaga M. Inca J. Rojas E. Caparó-Zamalloa C. Montalvan M. Salcedo E. Multiple sclerosis in Peru: National prevalence study using capture-recapture analysis Mult. Scler. Relat. Disord. 2021 55 103147 10.1016/j.msard.2021.103147 34332455
11. Osorio-Marcatinco V. Castro-Suarez S. Meza-Vega M. Características del estado cognitivo de pacientes con esclerosis múltiple remitente-recurrente durante el brote en el Instituto Nacional de Ciencias Neurológicas 2014–2016 Rev. De Neuro-Psiquiatr. 2018 81 58 64 10.20453/rnp.v81i2.3331
12. Portillo-Vallenas R. Rojas-Huerto E. Inca-Parra J. Clinical control of multiple sclerosis patients treated with interferon beta in a hospital in Peru Rev. Neurol. 2005 41 575 576 16254867
13. Reyes Briceño J.C. Quiroz Cerna D. Montalván M. Epilepsia como manifestación de esclerosis múltiple: A propósito de un caso Rev. Cuerpo Méd. 1994 14 24 26
14. Vizcarra-Escobar D. Cava-Prado L. Tipismana-Barbarán M. Multiple sclerosis in Peru. A clinical-epidemiological description of a series of patients Rev. Neurol. 2005 41 591 595 16288421
15. Correale J. Abad P. Alvarenga R. Alves-Leon S. Armas E. Barahona J. Buzó R. Corona T. Cristiano E. Gracia F. Management of relapsing-remitting multiple sclerosis in Latin America: Practical recommendations for treatment optimization J. Neurol. Sci. 2014 339 196 206 10.1016/j.jns.2014.02.017 24607335
16. Reich D.S. Lucchinetti C.F. Calabresi P.A. Multiple Sclerosis N. Engl. J. Med. 2018 378 169 180 10.1056/NEJMra1401483 29320652 PMC6942519
17. Pecho J. Cruz A.G. Sanchez E. Perimetric and Fundoscopic Findings in Patients with Multiple Sclerosis Treated with Interferon Mult. Scler. J. 2012 18 1821 1879 10.1177/1352458512466528
18. Claflin S.B. Broadley S. Taylor B.V. The Effect of Disease Modifying Therapies on Disability Progression in Multiple Sclerosis: A Systematic Overview of Meta-Analyses Front. Neurol. 2018 9 1150 10.3389/fneur.2018.01150 30687214 PMC6335290
19. Metz L.M. Clinically Isolated Syndrome and Early Relapsing Multiple Sclerosis Continuum 2019 25 670 688 10.1212/con.0000000000000729 31162311
20. Tsivgoulis G. Katsanos A.H. Grigoriadis N. Hadjigeorgiou G.M. Heliopoulos I. Papathanasopoulos P. Kilidireas C. Voumvourakis K. Dardiotis E. The Effect of Disease Modifying Therapies on Disease Progression in Patients with Relapsing-Remitting Multiple Sclerosis: A Systematic Review and Meta-Analysis PLoS ONE 2015 10 e0144538 10.1371/journal.pone.0144538 26642051 PMC4671570
21. Renteria J. Cruz A.G. Corro E. Esclerosis Múltiple: Experiencia en el Hospital Alberto Sabogal, años 2003–2007 Rev. Per Neurol. 2007 11 35
22. Vizcarra Escobar D. Tipismana-Barbarán M. Descripción clínica de la esclerosis múltiple en Perú: Revisión de casos Rev. Per. Neurol. 2007 11 39 16288421
23. Renner A. Baetge S.J. Filser M. Ullrich S. Lassek C. Penner I.K. Characterizing cognitive deficits and potential predictors in multiple sclerosis: A large nationwide study applying Brief International Cognitive Assessment for Multiple Sclerosis in standard clinical care J. Neuropsychol. 2020 14 347 369 10.1111/jnp.12202 32056386
24. Hermann B.P. Vickrey B. Hays R.D. Cramer J. Devinsky O. Meador K. Perrine K. Myers L.W. Ellison G.W. A comparison of health-related quality of life in patients with epilepsy, diabetes and multiple sclerosis Epilepsy Res. 1996 25 113 118 10.1016/0920-1211(96)00024-1 8884169
25. Rudick R.A. Miller D. Clough J.D. Gragg L.A. Farmer R.G. Quality of life in multiple sclerosis. Comparison with inflammatory bowel disease and rheumatoid arthritis Arch. Neurol. 1992 49 1237 1242 10.1001/archneur.1992.00530360035014 1449401