Patients with tethered cord syndrome (TCS) rarely have symptomatic onset in adulthood. Twenty-three adult patients with TCS were studied with respect to the clinical, radiological, and pathological features of this syndrome. Specific circumstances involving either additional tugging of the already tight conus, narrowing of the spinal canal, or direct trauma to the back or buttocks precipitated symptomatic onset in 60% of patients. Diffuse and non-dermatomal leg pain, often referred to the anorectal region, was the most common presenting symptom. Progressive sensorimotor deficits in the lower extremities as well as bladder and bowel dysfunction were also common findings; but, unlike TCS in children, progressive foot and spinal deformities were not seen. As in TCS with onset in childhood, the most common tethering lesions were thickened filum, intradural lipoma, and fibrous adhesions. The degree of cord traction, rather than the type or distribution of the tethering lesions, probably determines the age of symptom onset: less severe traction remains asymptomatic in childhood but results in neurological dysfunction in later life due to repeated tugging of the conus during natural head and neck flexion, or when abnormal tension is aggravated by trauma or spondylotic canal stenosis. Metrizamide myelography revealed the diagnosis of tethered conus in most cases, but the addition of computerized tomographic imaging provided valuable structural details concerning the tethering lesion. The surgical outcome was gratifying in relation to pain and motor weakness but disappointing in the resolution of bowel and bladder dysfunction. Early diagnosis and adequate release of the tethered conus are the keys to successful management.
