Baseline neurological exposome characteristics in a nationwide community-based screening cohort for movement disorders in marginalized and integrated Roma populations

Technical Summary: Baseline Neurological Exposome in a Nationwide Roma Screening Cohort

Problem Statement
Movement disorder research, particularly regarding Parkinson's disease (PD), suffers from a significant lack of diversity, with clinical cohorts and trials overwhelmingly dominated by White participants. This gap is critical for the Roma population, Europe's largest ethnic minority (~10–14 million), who are virtually absent from epidemiological studies. Roma communities, particularly those in marginalized, segregated settlements, are exposed to a distinct "neurological exposome" characterized by biomass combustion, poor sanitation, unprotected water sources, overcrowded housing, and chronic psychosocial stress. These environmental and socioeconomic factors may heighten susceptibility to neurodegeneration, yet the specific baseline exposome profiles of Roma populations undergoing movement disorder screening remain undocumented.

Methodology
The study presents a cross-sectional, community-based participatory screening program conducted across Slovakia between January 2023 and February 1, 2026. The cohort consists of 541 Roma participants divided into two strata:

1. Marginalized Roma (MT): 350 participants recruited via door-to-door screening by trained community health workers in over 450 segregated settlements.
2. Integrated Roma (IT): 191 participants recruited through neurology outpatient clinics, general practitioners, and patient organizations.

Data Collection and Classification:

• Screening Tool: All participants completed a structured, non-diagnostic questionnaire assessing self-reported motor symptoms (slow movements/stiffness, involuntary movements, balance issues, tremor, gait disturbance).
• Grouping: Participants were classified as "screen-positive" (MP for marginalized, IP for integrated) or "screen-negative" (MHC for marginalized healthy controls, IHC for integrated healthy controls). In marginalized communities, field workers reviewed complaints; in integrated communities, neurologists performed or supervised this classification. Screen-negative individuals with motor-like complaints were often judged to have musculoskeletal rather than neurological origins.
• Exposome Assessment: A standardized questionnaire captured data across multiple domains:
  • Socioeconomic: Education, employment, disability pension, marital status.
  • Housing/Environment: Dwelling type, household size, room count, water sources (tap vs. unprotected springs), sanitation (sewage connection, flush toilet).
  • Exposures: Indoor combustion fuels (wood, gas, electricity), tobacco exposure (household and personal), dietary patterns (dairy, processed meat, produce, sweets), physical activity, and psychosocial stressors (debt, hunger, fear for children).
  • Medical History: Access to neurological/genetic care, family history, and parental consanguinity.

Key Results

• Cohort Demographics: The marginalized group (MT) was generally younger, had lower educational attainment, and higher rates of long-term unemployment compared to the integrated group (IT).
• Exposome Disparities (Marginalized vs. Integrated): The marginalized stratum exhibited a significantly more adverse exposome profile. Key differentiators included:
  • Housing: MT participants lived in larger, more crowded households, often in temporary or shack housing, exclusively using unprotected water sources (springs/streams) and lacking sewage connections.
  • Combustion: Wood-burning was the dominant heating and cooking fuel for MT, whereas IT participants more frequently used radiators, gas, or electricity.
  • Lifestyle & Stress: MT participants reported higher tobacco exposure, physical inactivity, household hunger, and debt-related stress.
  • Healthcare Access: IT participants had significantly better access to specialist neurological and genetic care.
• Screen-Positive vs. Screen-Negative: Within both strata, screen-positive individuals clustered at the more adverse end of the exposome spectrum compared to their screen-negative counterparts.
  • In the marginalized group, screen-positive (MP) participants were younger, less educated, had higher disability pension rates, lived in fewer rooms per household, relied more heavily on wood heating, and were less physically active than MHC.
  • In the integrated group, screen-positive (IP) participants showed more pronounced differences from IHC, including lower education, higher disability rates, greater reliance on wood for heating/cooking, and markedly lower physical activity.
• Motor Symptoms: Screen-positive groups reported higher burdens of motor symptoms. In marginalized communities, symptoms were frequent across both MP and MHC groups (often attributed to musculoskeletal issues in the latter), whereas in integrated communities, symptoms were concentrated in the IP group.

Significance and Claims
This study provides the first systematic description of a neurological exposome within a nationwide Roma movement disorder screening cohort. The authors claim that their findings highlight two primary contributions:

1. Documentation of Disparities: The research quantifies the dense clustering of environmental and social risk factors (biomass combustion, inadequate sanitation, chronic stress) in marginalized Roma settlements, suggesting this population is embedded in environments that may increase susceptibility to neurodegeneration.
2. Exposome Gradient: The data indicates that individuals screening positive for movement symptoms, regardless of whether they are marginalized or integrated, tend to occupy the "high-risk" end of the exposome spectrum. This suggests a potential link between cumulative environmental disadvantage and early movement-related complaints.

The paper modestly frames these findings as a baseline for future research rather than definitive diagnostic conclusions. It emphasizes that the current data represents screening-level signals, not confirmed neurological diagnoses. The authors posit that future work integrating standardized neurological examinations and genomic analyses is necessary to disentangle the interplay between genetic susceptibility (including founder mutations and consanguinity common in Roma populations) and these environmental drivers. The ultimate goal is to clarify how neurological disease emerges from the interaction of environmental adversity, social structure, and inherited risk, thereby addressing the homogeneity in current movement disorder research.