[A clinical study on long-term outcome in patients with syringomyelia associated with Chiari malformation]

To investigate the long-term outcome in patients with syringomyelia associated with Chiari malformation (chronic tonsilar herniation), we investigated the actual factors of the patient's problems by a questionnaire for the patient. Replies to the questionnaires were obtained from 44 patients with syringomyelia who had been treated with expansive suboccipital cranioplasty with dural plasty (with plugging of the central canal in 20 patients). In 25 cases (68%) in whom the motor dysfunction of the upper extremities remained, the symptoms improved in 16 cases (43%) and were unchanged in 9 cases (24%). In 18 cases (64%) in whom the motor dysfunction of the lower extremities remained, the symptoms improved in 10 cases (36%) and were unchanged in 8 cases (29%). In 31 cases (78%) in whom the sensory disturbance remained, the symptoms improved in 19 cases (48%) and were unchanged in 12 cases (30%). The motor dysfunction of the upper extremities persisted significantly in more patients having a duration of illness over 2 years than in patients with those less than 2 years. Sensory disturbance persisted significantly in more patients with a duration of illness over 3 years than in patients with that less than 3 years. These results suggest that firstly, sensory disturbance (disturbance of the posterior horn) is most apt to remain, then motor dysfunction of the upper extremities (disturbance of the anterior horn) and followed by motor dysfunction of the lower extremities (disturbance of the pyramidal tract). We conclude that patients should be treated before having irreversible spinal cord disturbance.