Lumbar stenosis is any narrowing of the spinal or root canal. Stenosis is classified as congenital or acquired, central or lateral, local, segmental or generalized. The cardinal clinical symptom is neuroge- nic claudication: after a certain period of standing in an upright position or after walking a certain distance root pain develops or paraesthesias which radiate into one or both extremities and are followed by weakness. The condition is worse after a backwards bend. Anteflexion, sitting or lying down lead to regression of the complaints. The predominant age of onset of complaints is the sixth decade. The objective finding at rest may be normal, about one third of all patients report permanent weakness of the lower extremities. Stretching manoeuvres are negative. For the development of neurogenic clau- dications the stenosis must be present at least at two levels. The pathophysiological basis of claudica- tions is a vascular ischaemic block of the caudal fibres caused by venous congestion of the venous plexuses. The gold standard of imaging methods is lumbosacral contrast radiculography which reveals complete or partial block of the passage of contrast material through the stenotic portion. At present non-invasive methods are enforced: native CT of the spine, MRI and MR radiculography. Treatment in mild and medium forms without progression is consernative: exercise, ortheses, calcitonin administra- tion, in severe forms with progression surgery is the therapeutic method.

        Key words: lumbar spinal stenosis, neurogenic claudication