Is it really sciatica?
Sciatica is one of the most disabling and painful conditions someone can experience. Pain that travels down the leg is frequently a symptom a patient will describe, however more so than not, the pain is not due to sciatica. Yes, it is possible to experience pain referring down the leg and it not be due to the sciatic nerve. This is a good thing, as sciatica is certainly a condition that you would not wish on your worst enemy.
If you experience pain in your leg, then I would encourage you to book an appointment with your osteopath. An osteopath thinks and assesses holistically, and getting an accurate diagnosis and appropriate treatment for sciatica is essential. Finding out where and why you experience sciatica is critical, as it can impact rehabilitation and ultimately reduce unnecessary treatments to regions not causing the pain.
What is sciatica?
Sciatica is a symptom and not a specific diagnosis. Sciatica is pain that originates from the sciatic nerve and its nerve roots L4-S3. As these nerve roots are in the lower back (lumbar spine), the condition is also commonly referred to as lumbar radicular pain. Irritation of the nerve is usually due to compression somewhere along its pathway from the lower back (where the nerve roots are located), through to the buttock and down the back of the thigh, supplying the leg. People with sciatic pain typically will describe a shooting, burning sensation down their leg. This may be associated with pins and needles/numbness or tingling.
Although more commonly caused by compression of the nerve root, the sciatic nerve can be irritated by inflammation and even suffer from a lack of blood supply (ischemia). There is even thought to be an immune system response, leading to the onset of sciatica (infection is a potential cause). Compression of the neural tissue primarily is due to a lumbosacral disc bulge or herniation. However, compression can also be due to normal age-related spine changes (osteoarthritis/spondylosis) and tumours. This is one of the many reasons an early and accurate diagnosis is important. A lot of the time these irritants to the sciatic nerve are related and follow from the event of the other. The exact order of these events however remains unclear from our current knowledge on the condition.
Sciatica is complex and so is the pathophysiology of it. Research by Dower et al, 2019 discusses the pathology, which I will summarise. Mechanical mechanisms (compression of the nerve roots or neural tissue) have historically been thought to be the sole driver of developing sciatic pain. However, many studies have observed compression on imaging (CT scans and MRI) due to lumbar disc bulge/herniation, and the patient no longer or never experiencing symptoms. Furthermore, you can have nerve root compression and may only experience a tingling sensation and numbness. Mechanical compression mechanisms are thought to lead to ischemia of the nerve, which ultimately results in a loss of function of the nerve. Symptoms that signify a loss of nerve function include pins and needles or numbness and tingling. So, what causes the actual lancinating pain of sciatica?
Well chemical irritation from inflammatory and immune mediators is potentially the driver of this pain. How this inflammation occurs can be due to many reasons, however it is primarily due to the contents of the lumbar disc (from the bulge/herniation). It is believed the inflammatory and immune driver of pain is secondary to the mechanical mechanism of nerve root compression, from the disc injury. The contents of the disc known as the nucleus pulposus is highly inflammatory when they leave their normal environment. Inflammation drives the nerves to be hypersensitive to stimuli and ultimately effects the conduction of the nerves. The research supports the hypothesis that sensitised nerves (from inflammation) is what drives the horrible pain of sciatica.
There is evidence that in chronic cases of sciatica and neural tissue injury, there is an increased histology of immune cells and mediators of the immune system. These immune cells add to the increased sensitisation of the sciatic nerve roots and the whole nervous system. When we consider the symptom of pain in sciatica (radicular pain), the nerve is sensitised and has experienced a gain in function. A gain in function sounds good, but when we consider nerves, it just means it is firing painful nerve impulses.
How common is sciatica?
Sciatica is quite a prevalent symptom. Studies have reported it to have a lifetime prevalence of 43%! I mentioned earlier that most often it is initially caused by a lumbar disc herniation. It is reported to be involved in 85-90% of the time (Liu et al., 2023).
Why is a clinical diagnosis imperative when dealing with sciatica?
Like all injuries, just pushing through it is not recommended. Speak to a health professional for an appropriate assessment to get an accurate diagnosis early. Once a diagnosis is formed, you can be educated on the injury and the prognosis. The further the symptoms persist without adequate education and treatment, the longer the resolution may be. Furthermore, the longer the symptoms are present, the worse the pain and disability become. With these two factors increasing the risk of poor outcomes. Those who experience sciatica are also more likely to consume opioids and other forms of analgesia (Stynes et al., 2018). We know the dangers of chronic opioid use and when we look at the research for pharmaceuticals when treating sciatica, there is a lack of evidence supporting its effectiveness (Pinto et al., 2017).
When we consider the symptom sciatica, we need to determine if it is true sciatica! Pain referring down the leg from an injury beginning in the lumbar spine (lower back) may very well be sciatica. However, we can get referral from the joints in the spine, pelvis, hip, and the muscles and tendons of the lower back and hip. These can be considered somatic referrals. This referral will likely have pain worse in the site of injury, then it is in the legs. The referral will also less likely be described as burning, shooting or lancinating in nature. The pain may be duller in nature and will unlikely experience pins and needles, numbness, or tingling. Furthermore, the referral most often does not travel past the knee joint into the lower leg and foot.
Remember sciatica is known as a radicular pain, involving the gain of function of the nerve. It also may include loss of nerve function symptoms along with radicular pain. These symptoms are pins and needles, numbness, or tingling. If the pain is burning or shooting past the knee and the leg symptoms are worse than symptoms in the spine, that is sciatica.
Do you need surgery?
If a clinical diagnosis is made early and the appropriate treatment can commence, the prognosis for sciatica is extremely favourable to conservative management (osteopathy). Osteopathy will look to educate, reassure, and promote movement so that you can function whilst the condition heals. Within 4 months 90% of cases improve (Bailey et al., 2020). 71-74% are better within one year (Konstantinou et al., 2020). A third of individuals however will continue to experience symptoms for longer than one year (Liu et al., 2023).
If you are not responding to conservative management by 6-8 weeks, surgery is certainly an option. Surgery certainly carries more risks and costs, however in the short term it does have better outcomes for pain and disability than conservative care. However, surgery and conservative care are the same at one year!
Concluding Statement
Do not ignore your spine or leg pain! The earlier an accurate diagnosis is made and the earlier osteopathy can begin, the better chances you have of reducing long term severe pain and disability.
References