Isolated posterior column dysfunction: An unusual presentation of spondylotic myelopathy

Two patients with previously unreported clinically evident myelopathy cause d by herniated intervertebral disks are described. These patients had isola ted posterior column dysfunction in the lower extremities without motor def icits, abnormal reflexes, spinothalamic sensory abnormalities, or sphincter changes. The level of cord compression was significantly more cranial than suggested by clinical localization, and the results of initial radiographi c studies were unremarkable. Study of posterior column dysfunction using so matosensory evoked potentials was helpful in localizing the lesions and gui ding appropriate neuroradiologic studies.