The 'Glasgow Outcome Scale' (GOS) is a scale so that patients with brain injuries, such as cerebral traumas can be divided into groups that allow standardised descriptions of the objective degree of recovery.
In 1973, Epstein identified lateral recess stenosis as another cause of canal narrowing 2). It was not until 1975 with the evolution of cross-sectional imaging and 1980's advances in CT and later MRI, that it became apparent that the soft tissue ligaments were a major cause of primary and also secondary stenosis.
In 1975 the Japanese Orthopaedic Association (JOA) introduced a score for the clinical neurological judgment of cervical myelopathy. In Japan and other Oriental countries this so-called JOA score is especially popular for judging the clinical progression of a disease known as ossification of the posterior longitudinal ligament (OPLL), which is very common in Japan.