[Congenital cervical spondylolisthesis].

Cervical spondylolysis with spondylolisthesis is a complex abnormality involving the posterior elements of the cervical vertebra, and anterolisthesis of the same vertebra. Cervical spondylolysis is defined as a corticated cleft between the superior and inferior articular facets of the articular "pillar", the cervical equivalent of the pars intraarticularis in the lumbar spine. The typical radiological features of this condition are as follows: 1. Spondylolysis (a break in the "pillar" on one or both sides) 2. Spina bifida of dysplastic vertebra 3. Affection of posterior intervertebral joints (abnormal inclination of the superior and inferior articular facets of the affected bones may present) Recognition of this congenital disorder and its differentiation from traumatic injury is extremely important in patients who have a history of recent cervical trauma.

[A case of juvenile-type distal and segmental muscular atrophy of upper extremities (Hirayama disease) with the isolated cervical fusion at the C3-C4 levels].

The case, 29-year-old male, had suffered from muscular weakness and atrophy of the bilateral forearms and hands with tremor of the bilateral fingers for about 13 years. A neurological examination showed normal muscle-stretch reflexes and no sensory disturbances. A cervical spinogram revealed a fusion at the C3-C4 levels and mild spondylotic changes. We clinically diagnosed him as juvenile-type distal and segmental muscular atrophy of upper extremities (Hirayama disease) with the isolated congenital cervical fusion. Magnetic resonance imaging demonstrated an enlargement of the anterior epidural space from the C4-C5 levels to the Th 1-Th 2 levels. This abnormal epidural space showed relatively high signal intensity partially with low signal intensity on the T2 weighted spin-echo image and decreased in signal on the T1 weighted spin-echo image. And the dural sac was shifted backward and narrowed. And the soft discs was slightly protruded at the level of C4-5, C5-6 and C6-7. These findings suggest the over swelling and the delayed blood flow of the internal vertebral venous plexus. In this case, the degeneration of the cervical spine and soft disc derived from the congenital cervical fusion seems to have caused the internal vertebral venous plexus congestion and then have damaged the anterior horn cells.

Acquired spondylolysis and spondylolisthesis in the young child.

The cause of spondylolysis and spondylolisthesis remains unknown. There is increasing evidence that the defect in the pars interarticularis is due to fatigue fracture rather than being of congenital origin. We describe the youngest patient on record with spondylolysis and spondylolisthesis in whom roentgenograms that showed no abnormality had previously been taken. This case supports the hypothesis that spondylolysis and spondylolisthesis are acquired and not congenital, even when discovered in a very young child.

Diastematomyelia and structural spinal deformities.

Sixty patients with diastematomyelia were seen over a thirty-year period and congenital scoliosis was found in 60 per cent. All of the patients had associated vertebral abnormalities and most (87 per cent) had a neural deficit. Myelography was helpful in the diagnosis, particularly prior to any procedure that might cause traction on the spinal cord. Laminectomy for removal of the spur was indicated when neural deficits were progressive or before corrective surgery on the spine, and in ten patients the operation alleviated neural sequelae. Observation of patients with diastematomyelia who have no neural deficit or a stable, non-progressing deficit is recommended.