Common clinical course of cervical myelopathy (CM) is chronic. But there are some cases with so called “sudden onset type CM”, which shows rapid progression without the history of trauma or OPLL. We reported 12 cases of sudden onset type CM treated by surgery. They were evaluated by plain lateral X-ray views and the Japanese Orthopedic Association Score before and after treatment. And they were compared with 49 popular chronic cases treated by surgery.
The results of this paper showed that; 1) There was little disturbance of activity of the daily life before the onset. And each case had severe symptoms of CM with sudden onset in an activity of daily life; 2) The older cases had more severe symptoms than chronic cases. But the result of the surgical treatment is better than the chronic cases; 3) All of the 12 cases had cervical spinal canal stenosis with the minimal anteroposterior diameter of the canal being less than 12mm. We thought that it is the base of the sudden onset type CM.
