Brain injuries can cause many long-term morbidities, including cognitive, behavioral, and affective deficits and neurodegenerative diseases (Bajwa, Kesavan, and Mohan, 2018). Even mild brain injuries can pose long-term health issues to other systems in the body, such as hormonal and neural, and research on the change of these systems are still in the beginning stages (Bajwa, Kesavan, and Mohan, 2018). Increased awareness and research into brain injuries have illuminated the ongoing, often life-long post-brain injury process, which can affect other systems in the body and cause issues such as osteoporosis and other bone abnormalities (Bajwa, Kesavan, and Mohan, 2018).
Brain Injuries and Osteoporosis
Traumatic brain injuries can cause a change in physiological processes, which then lead to significant skeletal abnormalities over time (Bajwa, Kesavan, and Mohan, 2018). More research has focused on the mechanisms of the trauma and the events of the brain in the initial moments after a brain injury, but little is known about the actual long-term consequences of traumatic brain injuries (Bajwa, Kesavan, and Mohan, 2018). Researchers have recently discovered that neural signals from the brain aid in bone regulation. Damage to the brain can severely impact the regulatory molecules that control skeletal growth and maintenance (Bajwa, Kesavan, and Mohan, 2018).
An increased risk of osteopenia and osteoporosis was found in clinical studies participants categorizing the relationship between TBI and bone-related abnormalities. Osteopenia and osteoporosis are asymptomatic systemic skeletal diseases that cause micro-deterioration of bone tissue. In its most literal definition, osteoporosis means “porous bones,” and osteopenia is a more mild version of osteoporosis (Mortimer and Chung, 2013). Osteopenia is weaker than normal bones but not so weak that they fracture easily as they do when someone has osteoporosis (Walker, n.d.). This leads to bone fragility and, ultimately, bone fracture, which increases with age (Bajwa, Kesavan, and Mohan, 2018; Walker, n.d.). Changes in bone structure are caused by reduced bone mineral density (BMD) (which can be compounded by immobility) and other metabolism-related factors (Bajwa, Kesavan, and Mohan, 2018).
Brain Injuries and Bone Mass Density
Animal studies found that traumatic brain injury incidence significantly reduced bone mineral density in the cortical bone and decreased tibial trabecular bone mass regardless of mobility status (Bajwa, Kesavan, and Mohan, 2018). Stroke patients experience the highest rate of bone loss within the first year post-injury, with the most tremendous bone mass density loss in the paretic hip and upper limbs (Bajwa, Kesavan, and Mohan, 2018). A cross-sectional study of 112 young Irish acquired brain injury patients found that 41.1% had osteopenia and 21.4% and osteoporosis. The study concluded that both bone conditions are more common in this population when compared to the general population and have more risk for low bone density mass (Smith, Comiskey, and Carrolll, 2016). Adult TBI survivors have been found to have higher bone mass density loss in the femur and vitamin D deficiency; multiple stroke studies found a vitamin D deficiency in stroke survivors as well (Bajwa, Kesavan, and Mohan, 2018). The causal pathway for brain injury and vitamin D deficiency remains understudied in stroke patients, but it is believed that TBI reduces hormone activity, reducing vitamin D production and activity, which causes increased bone resorption and reduced microstructural integrity. This process drastically increases the risk for fractures (Bajwa, Kesavan, and Mohan, 2018).
Bone Health, Falls, and Fractures
Osteoporosis and osteopenia are also concerns because they are not only effects of brain injuries, but they can also cause falls and fractures, which can cause brain injuries as well. In the elderly population, in particular, osteoporosis can reduce bone strength, increasing the risk of fractures. Older women are more prone to rapid loss of bone mass post-menopause and are more susceptible to fractures (Elderly Fall Prevention, 2020). Post-stroke patients have 1.5-4 times the risk of hip fracture compared to non-stroke patients around the same age (Mortimer and Chung, 2013). Fractures are associated with additional strokes, increased mortality (18-33% in the 12 months post-fracture), and increased hospital length of stay (Mortimer and Chung, 2013; Elderly Fall Prevention, 2020).
Falls are the leading cause of traumatic brain injury in older adults, with the greatest incidence in 82-90 years old (Ziemer, n.d.). Worldwide, falls are the second leading cause of death, with 1 out of 5 falls causing serious injuries such as broken bones or a head injury and 3/4ths of falls requiring hospital admission (Ziemer, n.d.). Older adults are only 10% of traumatic brain injury patients but represent 50% of TBI-related deaths. Trauma to the head can cause multiple injuries, such as skull fracture, epidural hematoma, and subdural hematoma, and accounts for a 70% fatality rate for older adults above 65 years old (Elderly Fall Prevention, 2020). Older adults are more likely to suffer from recurrent falls after a TBI or a TBI after a fall (Elderly Fall Prevention, 2020).
How Power of Patients Can Help
Brain injury is a multi-faceted condition that leads to acute and long-term skeletal disorders that directly deteriorate bone integrity and function in brain injury survivors (Bajwa, Kesavan, and Mohan, 2018). Osteoporosis, falls, and brain injuries are inextricably linked, and more research is needed to understand the impact between these factors long-term after a brain injury. Additionally, attention needs to be focused on the older adult population, which sustains the highest brain injury death burden out of all ages. Power of Patients is committed to raising more awareness about the relationship between bone-related abnormalities, falls, and brain injuries. Sign up for our symptom and triggers-tracking dashboard at powerofpatients.com and begin tracking your brain injury and bone-related symptoms today!
Bajwa, N. M., Kesavan, C., & Mohan, S. (2018). Long-term Consequences of Traumatic Brain Injury in Bone Metabolism. Frontiers in neurology, 9, 115. https://doi.org/10.3389/fneur.2018.00115
Elderly Fall Prevention. (2020, September 27). Fall Related Injuries. Retrieved May 03, 2021, from https://elderlyfallprevention.com/fall-injuries/
Mortimer, D. S., MD, & Chung, K., DO. (2013, October 22). Osteoporosis and fractures after CNS injury. Retrieved May 03, 2021, from https://now.aapmr.org/osteoporosis-and-fractures-after-cns-injury/
Ziemer, A. (Ed.). (n.d.). Falls and Traumatic Brain Injury. Retrieved May 03, 2021, from https://www.physio-pedia.com/Falls_and_Traumatic_Brain_Injury
Smith, E., Comiskey, C., and Carroll, A. Prevalence of and risk factors for osteoporosis in adults with acquired brain injury. Ir J Med Sci. 2016 May;185(2):473-81. doi: 10.1007/s11845-016-1399-5. Epub 2016 Jan 19. PMID: 26787314.
Walker, W. (Ed.). (n.d.). Healthy Aging with Traumatic Brain Injury. Retrieved May 03, 2021, from https://www.physio-pedia.com/Healthy_Aging_with_Traumatic_Brain_Injury