As our global population grows older, the rise in neurological conditions has become a major challenge for healthcare professionals around the world.¹ This article discusses the prevalence of these conditions, the benefits of high-quality neurological testing procedures, and promising future trends in the field of neurological testing.

Prevalence and growth of neurological conditions worldwide

More people are enjoying longer lifespans than before.¹ This has led to a significant increase in the elderly population worldwide.¹ By 2030, one in six people will be aged 60 and older.² What’s more, by 2050, the number of people over 60 is expected to have more than doubled, and the number of people over 80 is expected to have tripled.^1,2 

Of course, with older age comes health problems, ranging from the usual aches and pains to much more serious and debilitating conditions, like dementia, Alzheimer’s disease or Parkinson’s disease.^2-5 The growing prevalence of degenerative neurological conditions combined with the number of elderly people needing care are major concerns for healthcare and social services.^1,2,6

Adding to the burden on the neurological healthcare system is the fact that millions of people every year suffer traumatic brain injuries (TBIs).^7,8 These injuries cause long-lasting neurological problems in the people affected.^7,8

The Global burden of neurological disease and brain injuries

Alzheimer’s disease

• Alzheimer’s is a brain disorder that causes memory and cognitive skills to worsen over time.^4,9 It’s a common cause of dementia (loss of cognitive function) in older adults.^4,9 
• It’s estimated that 416 million people around the world have Alzheimer’s disease in various stages of progression – that’s 22% of all people aged 50 and older.¹⁰

Dementia

• Dementia is a general term for several neurological diseases that affect memory, thinking and the ability to perform simple daily tasks.³ 
• An estimated 55 million people worldwide have dementia, with nearly 10 million new cases every year.^3,11

Parkinson’s disease

• Parkinson’s disease is a degenerative brain condition that affects thinking skills and motor skills. It causes tremors, slow movement and problems with balance.⁵ 
• An estimated 8.5 million people are living with Parkinson’s disease.¹¹ While this is much lower than the prevalence of Alzheimer’s and other types of dementia, the rates of disability and death caused by Parkinson’s are growing faster than those caused by any other neurological disorder.^5,11
• In 2019 Parkinson’s disease caused 5.8 million patient disabilities (an 81% increase from 2000) and 329,000 deaths (more than a 100% increase since 2000).¹¹

Traumatic brain injury

• TBI isn’t a disease, it’s an injury caused by trauma to the brain – like a blow to the head or an object penetrating the skull and brain (for example, in a car accident).^7,8,13 Depending on the type of injury, TBI can affect the brain in different ways, and often affects cognitive function.^7,8,13
• It’s estimated that there are 69 million new cases of TBI every year.⁸ While the overall incidence of TBI is highest in North America, TBIs caused by road accidents are highest in Africa and Southeast Asia.⁸

The state of neurological testing

It’s important to diagnose a neurological disease as early as possible, because early treatment helps to slow down the progression of the disease, meaning the patient can stay healthier and live independently for longer, with fewer support needs.⁶ Patients treated early typically have a lower risk of complications and disability, as well as lower treatment costs.¹⁵

In the case of a TBI, quick diagnosis is also important to help prevent a repeated injury, which can further damage the brain if the patient hasn’t recovered from their first injury.^15b (This is known as “second impact syndrome”.^15b) Repetitive injuries can cause dementia later in life or may even be fatal.^15b

An increase in neurological disease cases means an increased demand for accurate diagnostic testing⁶ and there are currently several tests that can be used to do so.^6,16 These include cognitive, behavioral and imaging tests, as well as the examination of samples taken from the patient. CT, EEG and MRI scans are examples of imaging tests.¹⁶ In vitro diagnostics (IVD) testing methods are an example of sample analysis.^6,16

Common sample analysis methods:

• Spinal tap/lumbar puncture: A special needle is injected into the lower back, to draw a sample of cerebrospinal fluid (CSF) for testing.¹⁶  
• Brain biopsy: A small sample of brain tissue is removed so it can be examined.¹⁷ 
• IVD testing: A sample of blood or tissue is taken and tested for the presence and amounts of certain biomarkers (proteins) which can indicate the presence of a disease or condition.⁶ Cardiovascular disease, for example, is an IVD testing area where the use of biomarkers is well established.

Challenges when testing for neurological disease and injury

Imaging tests often require large, expensive machines, making it difficult for smaller clinics and under-funded facilities to perform the tests.⁶ Tests using samples of tissue, blood or other fluids (such as IVD tests) are simpler and more cost-effective.⁶

However, when it comes to IVD testing, there’s a lot we still don’t understand about degenerative neurological conditions, and our knowledge about the biomarkers that indicate the presence of these conditions is less established, compared to other areas like heart disease or kidney disease.⁶ To date, there are only a few markers that are scientifically proven to indicate the presence of neurological disease.⁶

Blood tests provide a non-invasive, affordable alternative

Procedures like spinal taps and biopsies are highly invasive, which is why easier sampling methods – such as blood tests – are so useful when testing for neurological disease.⁶ 

The fact that more blood based immunoassay tests are becoming available for neurological disease diagnosis is important, because taking samples for these tests can be performed across many settings, including in clinics and even in the patient’s own home.⁶ Blood based tests also make repeat sampling and disease monitoring easier.⁶

However, blood samples contain far lower concentrations of biomarkers than spinal fluid samples – sometimes 40 times less!⁶ So a blood test must be exceptionally sensitive to give an accurate result.

The concentrations of a specific biomarker may vary between patients. Currently, there’s no one definitive biomarker level that would point to a positive or negative result – it depends on the individual patient. Therefore, biomarker level measurements can aid in diagnosis with other testing methods, but are currently more useful in monitoring the progress of illness or effects of therapy when measuring the changes in biomarker levels over time.

To design a sensitive, specific IVD test, it’s therefore absolutely critical to use high-quality materials, and that’s where Medix Biochemica is making a difference.⁶

Medix Biochemica's neurological testing reagents

Medix Biochemica develops and manufactures a wide portfolio of IVD raw materials (such as antibodies and antigens), which can be used in IVD assay development from both CSF and blood samples.⁶ We also provide biospecimens (such as blood and CSF from diagnosed patients and healthy controls), which help with the test-development process.⁶

What sets Medix Biochemica apart? 

Neurological IVD tests often require the use of two antibodies (they’re known as ‘sandwich assays’). We can offer pairing recommendations to help you choose the best combination of antibodies for your tests.⁶

At Medix Biochemica we focus heavily on testing, ensuring that each product is of the highest quality.⁶ We measure many different qualities in our reagents, including:

• Sensitivity: The ability to recognize clinically relevant levels of a substance.¹⁸ Especially with neurological markers, we focus on finding the highest sensitivity antibodies that can enable detecting the low concentrations of biomarkers in blood.
• Specificity: The ability to target and bind to a specific target.¹⁸
• Dynamic range: The range of antigen concentration that can be reliably measured in a paired antibody assay.⁶
• Cross-reactivities: The possibility that an antibody might detect other proteins that are not relevant to the test.⁶
• Kinetics: The speed at which the antibodies bind to the protein being detected, and whether the protein stays bound.⁶

View an example of our Product Specification sheets.

This extensive quality-assurance process ensures excellent product performance and reduces the risk of a false-positive result. 

Here's what our customers can expect from us:⁶ 

• Ready-made validated antibodies that save time to market
• Bulk-level production without any compromise in quality or batch-to-batch consistency
• Large amounts of reagents produced at a rapid pace
  

Future trends in neurological testing

In recent years, we’ve started to see some exciting new trends in neurology and neurological testing emerging. 

For example, more companies are developing blood-based tests and minimally invasive saliva tests to detect dementia, Alzheimer’s and other degenerative conditions affecting the brain.^6,19,20 Some of these tests may also be used to predict the onset of a neurological disease before symptoms begin.^19,20 

These newer tests and technologies have revolutionary implications, as they make early diagnosis easier, more affordable and less invasive, which ultimately leads to improved patient outcomes.⁶

The Medix Biochemica team looks forward to providing continued support to our IVD customers in the innovative field of neurological testing development, and keeping you up to date on advances in the IVD testing space.

Neurological testing reagents available from Medix Biochemica:^21-26 

• Neurofilament Light (NfL)
• S100B
• Neuron specific enolase (NSE)
• Alpha synuclein
• Glial fibrillary acidic protein (GFAP)
• Ubiquitin carboxy terminal hydrolase (UCHL1)

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References: 

1. Béjot Y, Yaffe K. Ageing population: a neurological challenge. NED. 2019;52(1-2):76-77. doi:10.1159/000495813. 
2. Ageing and health. World Health Organization. Accessed April 20, 2023. https://www.who.int/news-room/fact-sheets/detail/ageing-and-health. 
3. Dementia. World Health Organization. Accessed April 20, 2023. https://www.who.int/news-room/fact-sheets/detail/dementia.
4. Alzheimer’s disease fact sheet. National Institute on Aging. Accessed April 20, 2023. https://www.nia.nih.gov/health/alzheimers-disease-fact-sheet.
5. Parkinson disease. World Health Organization. Accessed April 20, 2023. https://www.who.int/news-room/fact-sheets/detail/parkinson-disease.
6. Expert opinion. Interview with Maiju Palokangas, Sr. Product Manager, Immunodiagnostic reagents, Medix Biochemica, and Emilia Galli, R&D Manager, Medix Biochemica. 14 April 2023. 
7. Georges A, M Das J. Traumatic brain injury. In: StatPearls. StatPearls Publishing; 2023. Accessed April 20, 2023. http://www.ncbi.nlm.nih.gov/books/NBK459300/.
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9. What is Alzheimer’s disease? Alzheimer’s Association. Accessed April 20, 2023. https://www.alz.org/alzheimers-dementia/what-is-alzheimers.
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11. Shin JH. Dementia epidemiology fact sheet 2022. Ann Rehabil Med. 2022;46(2):53-59. doi:10.5535/arm.22027.
12. Launch of WHO’s Parkinson disease technical brief. World Health Organization. Accessed April 20, 2023. https://www.who.int/news/item/14-06-2022-launch-of-who-s-parkinson-disease-technical-brief.
13. Traumatic brain injury (TBI). National Institute of Neurological Disorders and Stroke. Accessed April 20, 2023. https://www.ninds.nih.gov/health-information/disorders/traumatic-brain-injury-tbi. 
14. Seventy-fifth World Health Assembly. World Health Organization. Provisional agenda item 14.1. A75/10 Add.5. 27 April 2022.
15. Di Luca M, Nutt D, Oertel W, et al. Towards earlier diagnosis and treatment of disorders of the brain. Bull World Health Organ. 2018;96(5):298-298A. doi:10.2471/BLT.17.206599.
16. Diagnostic tests for neurological disorders. Health Encyclopedia University of Rochester Medical Center. Accessed April 20, 2023. https://www.urmc.rochester.edu/encyclopedia/content.aspx?contenttypeid=85&contentid=P00811.
17. Schott JM, Reiniger L, Thom M, et al. Brain biopsy in dementia: clinical indications and diagnostic approach. Acta Neuropathol. 2010;120(3):327-341. doi:10.1007/s00401-010-0721-y.
18. Expert opinion. Interview with Laura-Leena Kiiskinen, Vice President Innovation and Business Development, Medix Biochemica. November 21, 2022.
19. Blood test for early Alzheimer’s detection. National Institutes of Health (NIH). Accessed April 21, 2023. https://www.nih.gov/news-events/nih-research-matters/blood-test-early-alzheimer-s-detection.
20. Lee M, Guo JP, Kennedy K, et al. A method for diagnosing Alzheimer’s disease based on salivary amyloid-β protein 42 levels. J Alzheimers Dis. 2017;55(3):1175-1182. doi:10.3233/JAD-160748.
21. Vinny PW, Vishnu VY, Padma Srivastava MV. Artificial Intelligence shaping the future of neurology practice. Med J Armed Forces India. 2021;77(3):276-282. doi:10.1016/j.mjafi.2021.06.003.