Direction the operating theatre

Contrary to non-deficit LDHs, there are situations in which neurosurgeons do not doubt the need to intervene surgically due to a hernia. This is in the case when LDHs cause severe, important deficits causing paralysis, for example. This type of problem occurs, for example, when the patient is affected by a cauda equina or “horsetail” syndrome due to an LDH. “This is a very large hernia, located in L3-L4 for example, affecting the nerves in the lumbar canal. The nerves stemming from the spinal cord resemble a horse’s tail”, explains Dr. Annie Dubuisson. “For the patient, the compression of these nerves represents a real threat, including that of a sensory or motor deficit, with an impact on the sphincter muscles which can include a risk of incontinence. The ‘horsetail’ syndrome is categorically urgent”. She continues, “The patient who presents with such a clinical profile should be operated on within 24 hours”. A study carried out among 131 members of the Dutch Spine Society with regard to their treatment of LDHs confirmed that all the Dutch practitioners consider cauda equina syndrom form to be an urgent indication for surgery. Thus a majority of them operate on the patients concerned on the same day they are admitted to hospital.

And in the case of severe motor deficit caused by LDH, causing paralysis (and much more rare than non-deficit HDL), is it also necessary to intervene as quickly as possible? Unlike in the case of the horsetail syndrome, the answer is not so obvious. This is why the team from Liege wanted to know more...

The back or the knee?

The first precaution: “Every situation involving ‘foot drop’ does not necessarily signify that we are dealing with a paralyzing LDH”, explain the neurosurgeons. Indeed when a nerve located in the knee that makes it possible to lift the foot is affected; it can cause the same symptoms. Due to its fragility, this nerve can be damaged or compressed, this occurs among strawberry pickers who remain in a crouched position for a long time. “From the outset we are confronted by the urgency of diagnosis (for example by means of scan results), in order to make the connection between the anatomical picture and the location of the lesion. This differential diagnosis enables us to know whether the surgical indication of the back is adequate”, explains Prof. Didier Martin.

Most often, the deficit due to an LDH affects one leg due to a compression between L4 and L5, responsible for a weakness with regard to raising the foot. In any case, if it is clearly obvious that a falling leg (or any other serious repercussion) occurs due to a paralyzing LDH the clear necessity for a surgical intervention is unquestionable. But did the 24 patients who enrolled in the Liege-based study help to solve the debate as to whether there is a greater chance of recovery due to a rapid operation?

24 patients

The Liege series included 16 men and 8 women with an average age of 41.5 years. Among these, 8 had already experienced back problems. Two of them suffered from diabetes, 9 were smokers and 14 consumed alcohol on a daily basis. This data could be important: a study which appeared in December 2013 confirmed that the results of neurosurgery are less effective in smokers (of 10 cigarettes per day), for example with regard to healing of wounds. In the same way, the consumption of alcohol is generally considered as an unfavorable factor.

All the patients suffered either from back pain or radicular pain (along the route of the nerve) and they all presented a severe motor deficit most often affecting ankle flexions (with foot drop among 71% of them). 

Following clinical examination, at the end of the consultation, a decompression intervention was suggested to them because only decompression surgery can remove the different harmful mechanisms affecting the damaged nerve roots. 

The retrospective study took into account the data stemming from the emergency services, neurosurgery and/or pre-operation and anesthetic consultations. The authors therefore know the age of the patients, their sex, their profession, their sporting and leisure activities, their substance dependencies, their medical and surgical histories, the place of their first consultation (emergency services or GP consultation), their previous medical treatments and their complaints. They were aware of all the different examinations that had been carried out (a simple X-ray, a scan and/or MRI, and, in the case of 6 patients, an electrophysiology, that is to say an electrical study of the nerves and muscles).