Lumbar Spinal Stenosis: Syndrome, Diagnostics and Treatment

From Nature Reviews Neurology

Eberhard Siebert, MD; Harald Prüss, MD; Randolf Klingebiel, MD; Vieri Failli, PhD; Karl M. Einhäupl, MD; Jan M. Schwab, MD, PhD

Abstract

Lumbar spinal stenosis (LSS) comprises narrowing of the spinal canal with subsequent neural compression, and is frequently associated with symptoms of neurogenic claudication.
To establish a diagnosis of LSS, clinical history, physical examination results and radiological changes all need to be considered.
Patients who exhibit mild to moderate symptoms of LSS should undergo multimodal conservative treatment, such as patient education, pain medication, delordosing physiotherapy and epidural injections.
In patients with severe symptoms, surgery is indicated if conservative treatment proves ineffective after 3-6 months.
Clinically relevant motor deficits or symptoms of cauda equina syndrome remain absolute indications for surgery.

The first randomized, prospective studies have provided class I-II evidence that supports a more rapid and profound decline of LSS symptoms after decompressive surgery than with conservative therapy.

In the absence of a valid paraclinical diagnostic marker, however, more evidence-based data are needed to identify those patients for whom the benefit of surgery would outweigh the risk of developing complications. In this Review, we briefly survey the underlying pathophysiology and clinical appearance of LSS, and explore the available diagnostic and therapeutic options, with particular emphasis on neuroradiological findings and outcome predictors.

Introduction
The term lumbar spinal stenosis (LSS) refers to the anatomical narrowing of the spinal canal and is associated with a plethora of clinical symptoms.

The annual incidence of LSS is reported to be five cases per 100,000 individuals, which is fourfold higher than the incidence of cervical spinal stenosis.
The characteristic symptom of LSS is neurogenic claudication, which was a term coined by Dejerine (1911) and defined by von Gelderen (1948) and, later, Verbiest (1954).
In his report, von Gelderen described neurogenic claudication as "localized, bony discoligamentous narrowing of the spinal canal that is associated with a complex of clinical signs and symptoms comprising back pain and stress-related symptoms in the legs (claudication)".

This characterization is still in use today. LSS has become the most common indication for lumbar spine surgery, in part because of the increasing quality and availability of radiological imaging.
The increasing frequency of LSS surgery also reflects the elevated demand for mobility and flexibility in the aging population. Propagated by the increasing prevalence of this condition, controlled, evidence-based advice for individual treatment decisions is starting to emerge.

LSS can be classified according to etiology (primary and secondary stenoses) and to anatomy (central, lateral or foraminal stenosis), as summarized in Box 1 .
Primary stenosis is caused by congenital narrowing of the spinal canal, whereas secondary stenosis can result from a wide range of conditions, most often chronic degeneration, which leads to a destabilized vertebral body. Other causes of secondary stenosis include rheumatoid diseases, osteomyelitis, trauma, tumors, and, in rare cases, Cushing disease or iatrogenic cortisone application.


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