Spinal cord injury syndrome with motor sparing in the absence of all sensation

This paper describes the anatomic basis for the unusual presentation in a spinal cord injured subject of preservation of motor power in the absence of all sensation. The patient was examined at four hours, and daily thereafter, after a motorcycle accident in which he was thrown over the handle bars. He had trace ankle dorsi and plantar flexors, but light touch, pin, position, and vibratory sensation were absent below the level of C4 bilaterally. There was no physical evidence to differentiate whether he suffered a flexion or extension injury. Cervical spine films showed no evidence of fracture or dislocation, but anterior and posterior osteophytes involving C3 to C4, C4 to C5, and C5 to C6 were present. Magnetic resonance imaging showed evidence of cervical cord edema at C3 to C4 with possible hemorrhage and severe spinal stenosis at C3 to C4 and C4 to C5. This patient received a compression injury with resulting classic anterior spinal artery syndrome. Because of his spinal stenosis with a decreased anterior-posterior (AP) diameter of the canal, the posterior circulation was also compromised. The extensive pial anastomotic network provided relative sparing of the most peripheral components of the lateral corticospinal tracts. This case report demonstrates a unique clinical picture that cannot be anatomically classified by current American Spinal Injury Association (ASIA) standards as central cord syndrome. It can be explained by the lamination of the ascending and descending tracts in relation to the vascular supply of the cervical cord in conjunction with the narrowing of the AP diameter of the canal due to spinal stenosis.