Global Disparity in Occurrences of Traumatic Brain Injury and Spinal Cord Injury

Traumatic Brain Injury (TBI) and Spinal Cord Injury (SCI) are major causes of death and disability worldwide but the rate at which different geographical locations are affected varies wildly. All data indicates that low- and middle-income countries (LMICs) have the highest rate of deaths caused by injuries, possibly as high as 90%, as estimated by the World Health Organisation (WHO).

When we drill down into the incidences that lead to TBI, there is a strong link with Road Traffic Injuries (RTIs). That might account as to why LMICs experience proportionally up to three times the number of cases of traumatic brain injury than high-income countries. According to Corrado Iaccarino’s study, Epidemiology of Severe Traumatic Brain Injury (2018), TBIs from road traffic collisions were proportionately greatest in Africa and Southeast Asia (56% each) and lowest in North America (25%).

There are further regional differences in Traumatic Brain Injury and Spinal Cord Injury. TBI rates were highest in central Europe, eastern Europe and central Asia, and SCI rates were greatest in high-income North America and Asia-Pacific, was well as western Europe. Afghanistan and Middle East conflict-affected countries (Syria, Yemen, and Iraq) had the highest occurrence of SCI with Syria also showing the highest rate of TBI.

Looking at the differences in the main causes of TBI and SCI probably starts to explain the significant geographical variation in their incidences. Additionally, accessing healthcare and other resources may further explain some geographical variation.

• There is a higher prevalence of SCI in North America and western Europe: could this be related to survival bias in high spinal injury areas? Medical services and healthcare facilities for TBIs or SCIs are likely to lead to successful resuscitation. Otherwise, those patients may have died without receiving a diagnosis code.
• Central Europe, eastern Europe and central Asia have a high all-injury rate, estimated in the Global Burden of Diseases 2016, which correlates to their high rates of TBI.
• Sub-Saharan Africa and other low SDI countries witness lower rates of TBI and SCI, which largely corresponded with local patterns of falls and road injuries as reported in Global Burden of Diseases 2016.
• TBI cases in LMICs tend to be young adult pedestrians, cyclists or motorcyclists. Additionally, where armed violence and conflict is higher (Central America, the Middle East and Central Africa), assault and gunshot injuries massively contribute to TBI.

How do we know the scale of TBIs globally?

Several factors affect our understanding of the actual magnitude of TBIs. These include:

• Lack of consistent data recording; some high-income countries as well as LMI-countries do not have formal injury surveillance or reporting systems, such as trauma registries. Plus, TBI patients presenting mild to moderate injury are often not reported, and those with multiple trauma may be recorded under other causes of death. This all leads to false understanding of TBIs and SCIs and their burden on healthcare and diseases numbers worldwide.
• Most research into TBIs and SCIs is carried out in high-income countries using approaches that are often not attainable to LMICs, such as the biology of the disease and its progression, leading to greater understanding and uses of advanced technology for reconstructions, prosthesis and rehabilitation.

All research evidences the need to significantly advance TBI and SCI research worldwide. This has enormous challenges, particularly in LMICs and similarly austere environments, and will involve a wide field of experts beyond clinical practitioners and basic science researchers. A huge step forward would be locating and introducing technologies appropriate and affordable to each local environment, leading to more effective post-trauma treatments and rehabilitation.