The list of diseases and conditions that are classified as Central Nervous System (CNS) disorders is extensive. Challenges in this therapeutic area start with the effort which is needed to develop treatments for such a wide and varied range of neurological disorders. CNS clinical trials are the starting point of the struggle to improve the lives of so many patients around the world.
However, medical researchers still face many challenges in designing and implementing clinical studies to develop new drugs for CNS treatments. In this article, we will explore the 3 top challenges and show how the implementation of Decentralized Clinical Trials (DCTs) can help researchers overcome these obstacles. First, let us start with a brief definition of the CNS therapeutic area and the role of clinical trials.
Central Nervous System Disorders
The nervous system, which is composed of the central and the peripheral nervous system, is the part of the human body which coordinates our body’s activities. The brain, spinal cord, eyes and sensory organs are some of the organs of the nervous system.
The nervous system can be subject to trauma, infections, degeneration, structural defects, tumors, blood flow disruption and autoimmune disorders. Some examples of known disorders that affect the nervous system are:
- Vascular disorders such strokes and hemorrhage
- Infections such meningitis and polio
- Structural disorders such as carpal tunnel syndrome and peripheral neuropathy
- Functional disorders such as chronic headache and epilepsy
- Degeneration disorders such as Parkinson and Alzheimer diseases
There is more than one medical specialty that treats Central Nervous System disorders. Neurologists, neurosurgeons, psychologists, psychiatrists and physical therapists, among others, can help in the treatment of the many kinds of CNS disorders.

The Role of CNS Clinical Trials
According to the World Health Organization (WHO), hundreds of people worldwide suffer from neurological disorders (which include central and peripheral nervous systems disorders). Strokes and epilepsy are relatively common: more than 6 million people die of strokes each year, and more than 50 million have epilepsy. Alzheimer disease is the most common cause of dementia, which affects 47.5 million people in the world.
These numbers help demonstrate how urgent and essential medical research in CNS is. Clinical trials are part of this effort and are constantly being conducted to help bring new treatments for CNS diseases to the market. The role of these studies, like other kinds of clinical trials, is to test the safety and efficacy of drugs and medical devices before they can be approved by regulatory authorities and enter the market.
The 3 Top Challenges in Conducting CNS Clinical Trials
Conducting clinical research often involves many challenges and the collective effort of a whole team of medical researchers and other specialists. Regulatory compliance and patient recruitment are among the most common concerns of new companies that are just beginning to participate in the discovery and development of new drugs and medical devices.
Most manufacturers, though, choose to partner with a Contract Research Organization to receive specialized guidance on navigating these challenges.
In this section, we list the 3 most common challenges faced by companies conducting Central Nervous System clinical trials, and we also give our insights on how decentralized clinical trials (DCTs) can improve patient’s and researcher’s experience and enhance the trial’s outcomes. First, let us start with a definition of decentralized clinical trials.
What are DCTs ?
As the name suggests, DCTs are conducted in more than one location, rather than exclusively in a single study center (as happens with traditional clinical trials). These other locations may be the patient’s home, their preferred local health center or a laboratory closer to them.
DCTs rely on digital health technologies to enable remote patient monitoring and communication with them. There is a wide range of tools, software and devices which enable decentralized trials, such as wearable activity trackers, blood pressure monitors and interactive mobile applications.
Challenge #1: Patient Recruitment and Retention
We have mentioned that patient recruitment is a common challenge in clinical research. Because of characteristics that are specific to CNS diseases, this challenge affects CNS clinical trials more than trials in other therapeutic areas.
Despite the extensive list of disorders that affect many people worldwide, the eligible population is smaller compared to other areas. Many CNS patients are also mentally dependent (such as the case of neurodegenerative diseases) or have limited mobility and disposition, which are factors that complicate their recruitment to take part in trials.
Consequently, clinical trials with CNS patients are often impacted by delays because the recruitment rate goal could not be met. Increased costs are also a consequence of difficulty in patient recruitment, as the trial will have to be in place, and the site maintained, for a longer time than initially planned.
How to Overcome This Challenge with DCTs ?
The main benefit of DCTs regarding patient recruitment and retention is reducing the patient’s burden, and also the burden on their caregivers, improving the conditions for their participation. Implementing a DCT to conduct CNS research can:
- Allow the recruitment of patients from a wider area through digital advertising
- Improve communication and comprehension of the study’s objectives and outcomes through digital training and electronic consent
- Enhance and facilitate data collection using electronic patient-reported outcomes (ePROs), offering patients the convenience of participating from the comfort of their own homes
- Reduce the need for travel, as some of the activities may be done remotely, encouraging patients with limited mobility to enroll.
Challenge #2: CNS stigma
The stigma around CNS disorders can make patients hesitant to enroll in trials and even to search for relevant studies to join. Some of CNS conditions are considered “taboo” and many people are still scared or ashamed of talking about their health issues. This is common to patients with dementia and CNS disorders with psychiatric symptoms.
CNS patients may hesitate to join clinical trials because they fear being judged or stereotyped. Stigma can also affect patient retention and data collection, because participants may withhold information for fear of disclosing personal information and they lack motivation to keep participating.
How to Overcome This Challenge with DCTs ?
The main benefit of DCTs regarding the stigma challenge is the increased privacy offered by remote and digitally enhanced studies. Implementing a DCT to conduct CNS clinical trials can:
- Give participants the possibility of interacting with researchers and medical professionals through video calls or messaging. For some patients, this will help them to feel more comfortable to talk about their symptoms, since they are distant and in an environment that they trust (their home)
- Help patients who fear being judged to be more accurate in their symptoms reporting, since digital questionnaires can be more easily anonymized, and it is easier to prove that their information is being securely held
Challenge #3: Patient’s safety
This challenge is a consequence of the difficulty in engaging patients faced by researchers conducting clinical trials involving CNS disorders. Because these trials usually focus on critical functions of the brain and nervous systems, ongoing communication is essential to ensure the patient’s safety.
Patients who refrain from reporting their symptoms regularly or who drop out of the study are a concern to the study team. It is difficult to keep them safe if they do not engage with the medical professionals who oversee their health at the moment.
How to Overcome This Challenge with DCTs ?
The main benefit of DCTs regarding the safety challenges is enhanced remote monitoring, which can help doctors keep track of vital functions even if the patient is not communicating enough naturally. Implementing DCTs to conduct CNS clinical trials can:
- Allow patients to use their own devices (bring your own device – BYOD) to monitor and report symptoms more easily
- Provide the medical team with automated continuous or point-in-time data collection, allowing immediate detection of adverse events and reactions
- Make the research and medical support teams more readily available through video calls and messaging, should the patient need to contact them for urgent assistance

Summary
- The nervous system, which is composed of the central e the peripheral nervous system, is the part of the human body which coordinates our body’s activities
- It can be subject to trauma, infections, degeneration, structural defects, tumors, blood flow disruption and autoimmune disorders
- Clinical trials are constantly being conducted to help bring new treatments for CND diseases to the market. The role of these studies, like other kinds of clinical trials, is to test the safety and efficacy of drugs and medical devices before they can be approved by regulatory authorities and enter the market.
- DCTs are clinical trials that are conducted in more than one location, rather than exclusively in a single study center (as happens with traditional clinical trials).
- The 3 most common challenges faced by companies conducting CNS clinical trials are patient recruitment and retention, the CNS stigma and ensuring patient’s safety. Overcoming these challenges can be easier when the research team is aware of the benefits of decentralized clinical trials, which employ the best of technology advancements to make fully remote or hybrid studies possible.