A syndrome resulting from abnormal development of the
filum terminale resulting in persistent anchoring of the spinal cord conus
medullaris at or below the L2 level.
Occurs as part of inherited syndromes but has
not been described in isolation.
Normal regression of the distal embryonic spinal
cord produces a thread-like filum terminale attached to the coccyx when
differential growth of the conus medullaris occurs in the child. When this
regression is abnormal, it results in a thick rope-like filum that anchors
the conus at or below L2 level instead of the usual final L1 level. Usually
associated with spina bifida. This may coexist with diastematomyelia and Arnold-Chiari malformation.
Neurological signs may develop as a consequence of increased tension on the
cord compromising blood supply, particularly with flexion and extension.
Clinical signs confirmed by CT or MRI scan.
May be asymptomatic or present with progressive
neurological dysfunction of the lower cord. Asymmetric leg growth, talipes
cavus, muscle wasting. Bladder dysfunction, progressive scoliosis. Diffuse
pain. Midline skin lesion is usually observed in 70% of patients
affected. Hyperpigmentation, hemangioma, lipoma dermal pit are frequent
other physical characteristics of this syndrome.
Routine preoperative assessments. In
the presence of a significant scoliosis, respiratory evaluation, including
spirometry, should be obtained.
Usual considerations for prone position.
The use of intraoperative neuromonitoring for tethered cord release contributes
significantly to maintain functional integrity and is highly recommended.
May require catheterization; care with padding if bladder dysfunction or
scoliosis is present. Regional anesthesia is not contraindicated, however,
its indication must be assessed carefully for each patient because of the spina
bifida often associated.
There are no specific implications
with this condition.
Diastematomyelia: Characterized by pain,
weakness of legs, and incontinence. Surgical repair during infancy
Ali L, Stocks GM: Spina bifida, tethered cord, and regional anesthesia. Anaesthesia
Haslam R. Tetherd cord syndrome, in Behrman RE, Kliegman RM, Nelson WA, et
al. (eds): Nelson Textbook of Pediatrics. 14th ed. Philadelphia, WB Saunders, 1992: 1536-1537.
Kothbauer KF, Noval K: Intraoperative monitoring for tethered cord.
An update. Neurosurg Focus 16:18, 2004 (review).