Management of the lumbosacral radicular syndrome (sciatica)

Advisory report | 16-11-1999

LRS is usually the result of a herniated disc, but there can be other causes, such as stenosis of the spinal canal or a nerve root canal. The Committee decided to examine this issue not from the point at which an anatomic diagnosis of herniated disc is made, but from the point where a patient consults his or her doctor complaining of symptoms consistent with the condition.
It is estimated that there are between 60 000 and 75 000 new cases of LRS in the Netherlands each year. A number of factors are associated with an increased risk of LRS. These are early adulthood and middle age, above-average height and severe physical strain, especially in conjunction with rotation of the trunk. The direct and indirect costs are believed to total maximally 2.6 billion guilders a year.

The Committee concludes that the natural history of the condition is usually favourable. Within three months of first consulting their doctors, about 60 per cent of patients are no longer experiencing problems at work or in their private lives. After a year, the figure rises to 70 per cent. Furthermore, a high proportion of those who continue to experience problems do improve considerably. Significantly, the Committee also concluded that it is not presently possible to identify those who are likely to suffer significant ongoing problems early on the basis of reported symptoms or by diagnostic imaging. It is also important to recognise that back problems are very prevalent even in the absence of LRS; the Committee would counsel against allowing such problems to be regarded as part of LRS or its residual effects. Back problems should be treated separately, typically as non-specific back pain.

LRS can be diagnosed in cases where the patient complains of the characteristic irradiating pain and a positive result of one or more neurological tests indicating nerve root tension or neurological deficit. However, the standard straight leg raising test (Lasègue, for nerve root tension) is not particularly sensitive or specific. Most tests for neurological deficit are quite specific but few are at all sensitive. Nevertheless, in practice, a doctor can increase both sensitivity and specificity by combining several tests. Testing is also important for ascertaining the anatomical level of the nerve root compression. LRS should not be confused with non-radicular or referred pain irradiating in the leg.

The Committee is of the opinion that further diagnostic procedures are indicated only where the patient’s medical history or a physical examination suggests that the LRS may have a cause other than a herniated disc, or where surgery is indicated. Where the use of diagnostic imaging is considered appropriate, MRI (magnetic resonance imaging) is the preferred option.

The treatment of LRS is primarily aimed at pain relief and conservation or restoration of normal day-to-day activities. In view of the fact that, despite the frequently worrying nature of the condition, the prognosis for LRS is generally quite good, great importance is attached to the provision of information. Unfortunately, the effect of giving information and counselling has not been studied specifically among LRS patients. However, various studies have looked at the provision of such support to people suffering from other pain syndromes. Inferences can reasonably be made from the findings of these studies. Hence, it may be assumed that adequate and unambiguous information about what is wrong (the nature of the condition) and what the patient can expect (the prognosis), together with trustworthy counselling, can reduce the anxiety and uncertainty felt by the patient and thus ease the pain. With a view to increasing the quality and clarity of the information given to LRS patients, the Committee would like to see first-line and second-line policy protocols developed by general practitioners, physiotherapists and specialists. Doctors and physiotherapists should encourage patients to continue with normal day-to-day activities as far as possible. The prevention of chronic pain problems is an important secondary objective for information and counselling.

The Committee concludes that insufficient data is currently available to allow the efficacy of the various forms of medicinal pain relief to be properly assessed. Research into the efficacy of treatments intended to relieve pain in LRS is regarded as desirable by the Committee.

Lack of detailed knowledge regarding the causal and prognostic factors that are relevant to LRS is an obstacle to object-oriented intervention in the natural history of the condition. The Committee does not believe that any particular forms of non-invasive therapy have been shown to aid recovery. Bed rest is not regarded as efficacious by the Committee. On the other hand, the efficacy of guidance by a physiotherapist is felt to warrant investigation.

Where patients are referred for surgery, too, the primary objective is pain relief and conservation or restoration of normal day-to-day activities. When assessing whether surgery is needed, a distinction is made between patients with and without serious neurological deficit. The Committee is of the opinion that only a diagnosis of cauda equina constitutes an absolute indication that emergency surgery is required. The Committee regards serious or progressive motor loss (paresis) a relative indication for the use of surgery. In that case the urgency of the indication is also dependent on the impediments felt by the patient. The effect of surgical intervention on the course of milder forms of paresis is felt to warrant investigation in randomised trials comparing surgery with non-invasive treatment.

Comparative research among patients without serious neurological deficit has shown that surgery is more efficacious than chemonucleolysis and placebo in selected circumstances, where there is serious and prolonged pain despite the use of appropriate pain relief therapies, where progress towards natural recovery is unduly slow or where the impediments due to the pain are too great for the patient to bear. However, there is insufficient evidence to support any firm conclusions regarding either the exact circumstances under which surgery is indicated or the timing of surgical intervention. For most LRS patients, surgery is not indicated. In the Committee’s view, invasive treatment should be used only once other forms of non-invasive treatment have been tried without success. Not enough is yet known about the problems potentially associated with surgery, such as surgical failure, recidivism and the occurrence of side effects. The Committee would accordingly like to see research conducted into the circumstances under which surgery is indicated and into the timing and adverse effects of surgery.

More than a quarter of all LRS patients are referred by their GPs for first-line assistance - usually to a physiotherapist. Fewer than 20 per cent are referred for second-line assistance. Surgery for herniated discs is more common in the Netherlands than in other Western countries. This may to some extent be a reflection of the average height and of the age distribution of the Dutch population. However, the main causes of this discrepancy are almost certainly social factors and the preferences of doctors and patients. The Committee is of the opinion that more information is required regarding the preferences of doctors and patients and regarding the influence that these preferences have on the selection of appropriate courses of action.

In conclusion, there are considerable gaps in scientific understanding with respect to the effectiveness of diagnosis and treatment of LRS. Also, the Committee was unable to determine to what extent current knowledge is utilised by medical practitioners. Research is recommended to systematically make good the gaps identified by the Committee. Part of such a research programme should be devoted to the implementation of guidelines.