The conus is considered abnormally low if it is at or below the L1-L2 disc space (Gupta, page 365).
Conditions associated with a tethered cord:
(1) neural tube defects
(1a) spinal dysraphism, which may be occult
(1b) diastematomyelia
(1c) lipomeningomyelocele
(2) lumbosacral lipoma (which may be a feature of occult spinal dysraphism)
(3) tight filum terminale
(4) fibrous adhesions
(5) neurenteric cyst
(6) dermal sinus tracts
(7) syringomyelia
Clinical findings:
(1) diffuse and non-dermatomal leg pain
(2) anorectal pain
(3) bladder dysfunction (frequency, urgency, stress incontinence, overflow incontinence)
(4) bowel dysfunction, including diarrhea
(5) in children, foot and spine deformities
(6) motor impairment of the lower extremities
(7) decreased sensation in the perineum and lower extremities
Symptoms may be precipitated by a sudden stretching of the conus associated with:
(1) trauma
(2) sexual intercourse
(3) child birth
(4) disc herniation
(5) lumbar spondylosis
(6) heavy lifting
(7) exercising
(8) prolonged sitting
