Sciatica is relatively uncommon, with a prevalence ranging from 5 to 10 percent among patients with back pain. Therefore, if I consult 10 patients with low back pain, it's likely that 1 of them may have sciatica. (This frequency may vary in specialized clinics.) However, in general clinical practice, every third to fifth patient we see is diagnosed with sciatica. This scenario is comparable to seeing 1 or 2 different Ferraris during my commute every day while living in India.
So, either we are in mist of a sciatica epidemic or we are over diagnosing sciatica. As you all know i think we are overdiagnosis sciatica. I believe the increase in sciatica diagnosis has coincided with unchecked privatization and increase in taking fancy photos of the spine. In our practice, we observe that all patients with low back pain undergo MRI scans without considering pretest probability. Consequently, this results in the discovery of more disc pathology without corresponding clinical correlates.
Let's discuss how we can effectively diagnose radiculopathy (sciatica) in patients.
Remember when a patient presents with sciatica, it indicates that the lesion is affecting the nerve directly, and therefore, the patient should exhibit symptoms related to this nerve involvement.
The first information to remember is even if the “image” shows the nerve root is pressed by a herniate disc it does not mean the patient is suffering from sciatica or has radiculopathy. Why? well, simple answer is that’s not how biology works. and then there is the seeing is not believing but to investigate thoroughly. So what should we investigate when i “assume” the patient might be suffering from radiculopathy?
There is no one sign or test to diagnose a patient as having sciatica. It is usually via a combination of listening to the patient and physical examination.
History of fall and sudden onset of pain in the back and leg can be a common finding. Please note patients can also get sciatica without this history.
character of pain can also give you a clue if it is radiculopathy. Many patients characterise the pain as burning along the lower limb. It's crucial to have a clear understanding of what "burning" pain means in the patient's own language or terms. This sensation is often similar to what diabetic patients typically complain of in their feet (as diabetic neuropathy is also a form of radiculopathy). However, it's important to remember that this presentation is not universal and may vary among individuals.
Most likely, no specific position provides relief from the pain associated with radiculopathy Whilst examination combined movements or individual movements are universally painful. Radiculopathy pain stems from a chemical reaction causing irritation of the nerve root, which remains unaffected by changes in movements. However, it's important to remember that this presentation is not universal and may vary among individuals.
Patients quaintly of the pain is usually high as measured with VAS. Unlike pain from from non specific back pain in radiculopathy the pain is usually severe. However, it's important to remember that this presentation is not universal and may vary among individuals.
Assess for sensory and motor weakness in the affected limb. If a nerve is affected, it typically presents not only as pain but also as sensory or motor deficits. It's important to note that a saddle-type sensory loss may require an immediate neurosurgical referral as it is considered a red flag. However, it's important to remember that this presentation is not universal and may vary among individuals.
The pain associated with sciatica typically does not significantly improve after taking a painkiller or undergoing physiotherapy. If a patient experiences even slight relief after engaging in exercises or receiving passive treatments, it is less likely to be sciatica. Due to the multifaceted nature of the pain, sciatica often does not respond well to physical therapy or drug therapy.
if many of the above features are present then a SLR can help you be more confident of your diagnosis of sciatica. As a stand alone test it is pretty useless like a MRI.
Please remember sciatica is a clinical diagnosis based on physical examination
When multiple findings mentioned above are positive, we can have confidence that the patient may be suffering from sciatica. It is not based on a single test, history, or imaging study. In fact, an MRI is not typically indicated for diagnosing a patient with sciatica and should only be performed when the patient is referred for surgery. If we follow these then may be we will make better diagnosis and treatment.
It's important to emphasize that there is no specific treatment for sciatica. If someone is offering you a treatment for sciatica, whether it is acupuncture (referred to as dry needling) or manual therapy, they are likely a charlatan. Sadly powerful opioids which prescribed like candies for patients with sciatica is also bad, i mean bad.
The best treatment is advice to be active which is easier to write than to teach and make patient understand and wait for resolution.
further reading
Physical examination for lumbar radiculopathy due to disc herniation in patients with low‐back pain