"Intermittent ischaemia" of the cauda equina due to stenosis of the lumbar canal.

'Intermittent claudication' of the spinal cord was first described by Dejerine in 1911. In 1961, Blau and Logue described an unsual syndrome resulting from central protrusion of a lumbar intervertebral disc which gave rise to symptoms suggesting 'intermittent claudication of the cauda equina'. Since this report, a further series of cases has been described by Evans (1964). We have recently observed five cases of cauda equina compression in which the symptoms and signs were evoked or accentuated by exertion. Three patients were shown to have central disc protrusions in the lumbar region as described by Blau and Logue (1961). The purpose of this report is to describe two further patients with intermittent claudication of the cauda equina who presented with similar clinical features but in whom the radiological and operative findings were unusual.