Chronic low back pain (CLBP) has been found to be one of the most common and crucial clinical, economic, and public health problems when looking at chronic pain disorders worldwide (1). It is widely regarded as a multifactorial disorder which can be complicated to treat. Current treatment strategies for people with CLBP are often based on a biomechanical (e.g. treatment of involved joints, muscles, ligaments) or pharmacological model (e.g. NSAIDS, painkillers) without addressing the underlying pain mechanism. Research shows that there are brain changes in CLPB and understanding these changes can help improve care for not only the pain symptoms but also side effects of CLBP such as poor sleep and fear avoidance behaviour(2).
What are the brain changes?
Many people with chronic low back pain lack a clear origin of symptoms, or the cause of symptoms is not severe enough to explain the severity of pain that the body is experiencing. In these patients (estimated about 25% of people with CLBP), the reason behind their presentation is often central sensitisation. Central sensitisation the brain and spinal cord has undergone changes where more pain is perceived with less provocation. These people are not only more sensitive to actions/things that should hurt but can also respond with pain to ordinary touch or pressure. Research now indicates that regardless of how the initial injury occurred, central sensitisation is the factor behind the chronicity of pain and dysfunction. MRI studies have shown reorganisation of neuron networks in several brain regions and also increased activity in areas that are responsible for processing pain(3). This is particularly evident in the amygdale which is known as the “fear-memory centre” of the brain. It not only plays an important role in negative emotions such as anger, but research has also identified it as a catalyst of central sensitisation.
Vicious Cycle
Due to this change, even preparing for a previous pain inducing movement (such as bending over) is enough to activate the fear-memory centre and produce pain, for some people, even visualising these movements can trigger feelings of pain in their back. This pain then provides feed back to create more pain memories and increase the hypersensitivity(4).
One of the most common side effects of chronic pain is disrupted sleep. Sleep deprivation leads to low-grade inflammation, which is why even a single night of sleep deprivation in a healthy individual can result in generalised soreness and increased anxiety. This soreness and anxiety also feeds back to the fear-memory centre and creates a vicious loop of negative feedback to the brain.
What should I do?
It is important to remember that central sensitisation is not an accurate representation of tissue injury. This does not mean the pain is not real, but simply the pain does not make sense – it’s an over the top, exaggerated interpretation of something that your brain has deemed is dangerous. Pain is meant to be a warning from your brain to your body and central sensitisation is a condition where the warning system has gone hyperactive. The good news is there is increasing evidence supporting that the brain and nervous system changes found in people with CLBP are not permanent and to a degree can be reversed by effective therapies. If you have chronic back pain that just doesn’t seem to make sense, it is very important to address not just the biomechanical component but also the side effects and emotional component. Whichever therapy you choose, your brain and nervous system needs to feel safe and be soothed. At a very basic level, feeling pain is your brain’s judgment of how safe you body is. If your brain perceive something as dangerous, it’ll send out pain signals, if it doesn’t, the pain will slowly ease.
Lydia Feng is a chiropractor at Health Space Kings Cross. Enquire about low back pain with her on 02 8354 1534.
References:
(1) Hoy, D., March, L., Brooks, P. et al, The global burden of low back pain: estimates from the Global Burden of Disease 2010 Study. Ann Rheum Dis. 2014;73:968–974.
(2) Nijs J, Clark J, Malfliet A, Ickmans K, Voogt L, Don S, den Bandt H, Goubert D, Kregel J, Coppieters I, Dankaerts W. In the spine or in the brain? Recent advances in pain neuroscience applied in the intervention for low back pain. Clin Exp Rheumatol. 2017;35 Suppl 107(5):108–115.
(3)Konno S, Sekiguchi M. Association between brain and low back pain. Journal of Orthopedic Science. 2018 23 (1): 3-7
(4) Malfliet A, Coppieters I, Van Wilgen P, Kregel J, De Pauw R, Dolphens M, Ickmans M. Brain changes associated with cognitive and emotional factors in chronic pain: A systematic review. European Journal of Pain. 2017; 21 (5): 769-786
