Neurological diseases are placing an unprecedented burden on healthcare systems worldwide, making the need for new treatments more urgent than ever. While improving access to neurological care remains a global priority, ensuring patients have access to clinical research is equally important.
The scale of the challenge is clear. In 2021, more than 40% of the world’s population was living with a neurological disease, with stroke, migraine, and dementia among the most common. This burden has continued to grow; diabetic neuropathy has emerged as the fastest-growing neurological condition, while millions more people are now living with complicated neurological conditions following COVID-19.
Together, these trends point to a growing and increasingly complex patient population and reinforce the importance of continued research into better ways to prevent, manage, and treat neurological diseases.
Today, clinical trials face two important paradoxes. As neurological diseases become more common, trial populations are becoming less representative of the patients they aim to treat, while the growing number of patients does not necessarily translate into a larger pool of eligible participants.
In this article, we explore why these two paradoxes matter, and what they mean for the future of neurology clinical trials.
Underrepresentation & diversity in neurology clinical trials
Paradox 1: Neurological diseases affect everyone, but clinical trials don’t always reflect that diversity.
Key facts:
- Sex and gender differences shape neurological disease risk, with conditions like migraine, multiple sclerosis, and dementia more common in female patients, and stroke and Parkinson’s disease more common in males
- Over 80% of neurological deaths and disabilities occur in low- and middle-income countries
- Central and Western sub-Saharan Africa are among the regions with the highest burden of neurological disease, while high-income Asia Pacific and Australia have among the lowest
- High-income countries have up to 72-80 times more neurological specialists, creating unequal access to diagnosis, treatment, and research
This imbalance is also visible in clinical trials. A 2025 study found that in 459 epilepsy trials, nearly 83% of trial sites were located in high-income countries, while none were located in low-income countries. Africa and the Eastern Mediterranean were particularly underrepresented, with 40-145 times fewer trial sites than would be expected based on population and epilepsy burden. As a result, the populations most affected by neurological disease are frequently underrepresented in clinical research.
Digital recruitment can help expand reach, but it is not a complete solution. A US study on digital neurological research found that participants from disadvantaged neighborhoods were less likely to respond, while rural patients remained underrepresented, highlighting the barriers that digital approaches alone cannot overcome.
Sponsors therefore need to combine digital recruitment with strategies that address both access and practical barriers to participation. Community outreach and local partnerships can help connect with underserved populations, while practical support, such as patient transport, reimbursement for travel and childcare, home trial kits, and virtual visits, can reduce the burden of participation. By addressing these barriers alongside recruitment, sponsors can make trials more accessible to a broader and more representative patient population.
Increasing ageing populations and decreasing eligible patients
Paradox 2: more neurological patients doesn’t mean more eligible trial participants
Key facts:
- Rising case numbers are largely driven by population growth and longer life expectancy
- Older adults are more likely to experience multiple chronic conditions, frailty, polypharmacy, and cognitive impairment
- These same factors often make participation in clinical trials more complex or limit eligibility under traditional protocols
Countries across the globe have long seen this impact. For example, in Brazil, the proportion of elderly (aged 60+) has more than doubled between 1991 and 2022. (accompanied by a 34.6% increase in neurological mortality & 20.5% increase in DALYs). In China, neurological disorders affected nearly one-third of the population in 2021. The projections for the next 30 years suggest that neurological diseases will continue to grow across G7 countries, driven primarily by an ageing population.
Yet this growing patient population does not automatically translate into a larger pool of eligible trial participants. Older patients may be more likely to live with complex medical histories, take several medications, have mobility challenges, and require caregiver support, all of which can affect eligibility, increase screen failure rates, or make long-term participation more difficult.
This growing disconnect between disease prevalence and trial eligibility is becoming one of the defining challenges in neurological research.
For sponsors, success will increasingly depend on designing studies that better reflect real-world patient populations, identifying participants earlier in their disease journey, and reducing unnecessary barriers to participation where scientifically appropriate.
Looking ahead in neurology patient recruitment
The future of neurological research will depend on whether clinical trials evolve alongside the patients they are designed to serve.
The two paradoxes facing neurology are closely connected. On one hand, neurological disease disproportionately affects populations that remain underrepresented in clinical research. On the other, there is a rapid increase in disease burden while making patient recruitment increasingly complex. Together, these trends challenge traditional approaches to trial design and recruitment.
For sponsors, addressing these paradoxes means looking beyond recruitment numbers. It requires designing studies that reflect real-world patient populations, broadening access to research across diverse communities, and adapting protocols to the realities of older, and more medically complex participants.
The question is no longer whether more neurological clinical trials are needed, but whether today’s trials are ready for tomorrow’s patients.
Struggling to recruit for a neurology clinical trial?
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