Tethered spinal cord syndrome (TSCS) is a neurological condition in which the spinal cord is abnormally stretched or anchored by thick filum terminale, lipomas, or scar tissue. Imposing progressive mechanical tension, ischemia, and metabolic stress, management relies on high-resolution MRI diagnostic evaluation and microsurgical untethering surgery.
Tethered Spinal Cord Definition and Pathophysiology
Tethered spinal cord syndrome occurs when the spinal cord is abnormally fixed or anchored to surrounding dural or skeletal structures by fibrous bands, lipomas, or postoperative scar tissue, restricting its normal physiological ascension during spinal growth. This abnormal mechanical tension can:
- Reduce microvascular blood flow and oxidative metabolism within the conus medullaris
- Stretch spinal nerve roots and lumbosacral neural pathways
- Increase cellular metabolic stress and ischemia
- Cause progressive motor, sensory, and urological dysfunction
Common associated conditions:
- Spina bifida occulta, myelomeningocele, and lipomeningocele
- Congenital split cord malformations and dermal sinus tracts
- Thickened, fibrotic, or adherent filum terminale
- Postoperative scar tissue, particularly following prior myelomeningocele repair
It forms a key dysraphic condition closely evaluated alongside related pediatric dysraphisms, dysraphic entities like diastematomyelia, and pediatric lesions like pediatric spinal tumors.
Epidemiology
TSCS can affect both pediatric and adult populations, with early childhood growth spurts and adolescence being the most frequent periods for clinical presentation and diagnosis.
Males and females are equally affected. Although relatively rare, prompt diagnostic identification and neurosurgical intervention are critical to prevent permanent neurological deficits and preserve functional mobility.
Symptoms
Clinical presentation varies based on patient age, the severity of mechanical cord traction, and secondary skeletal involvement:
In Children
- Gait instability, difficulty walking, and progressive lower extremity weakness
- Foot deformities (such as pes cavus, clubfoot, or leg length discrepancy)
- Progressive spinal deformities, particularly rapid scoliosis
- Neurogenic bladder and bowel dysfunction (enuresis, urinary tract infections)
- Chronic back or lumbosacral pain, cutaneous stigmata (dimples, hypertrichosis)
In Adults
- Persistent, severe lower back pain radiating into the legs and perineum
- Neurogenic claudication, causing leg weakness or numbness during walking
- Progressive motor weakness and sensory dermatomal loss
- Urinary urgency, frequency, incontinence, or neurogenic bowel impairment
- Spinal alignment changes and worsening scoliosis
Diagnosis and Evaluation
Accurate diagnosis of TSCS requires detailed clinical assessment paired with specialized neuroimaging:
Clinical & Urodynamic Examination
Detailed testing of lower limb motor power, deep tendon reflexes, and sensory levels. Urodynamic studies evaluate bladder compliance, detrusor sphincter dyssynergia, and subclinical neurogenic bladder dysfunction.
Magnetic Resonance Imaging (MRI)
The gold standard diagnostic tool. Spine MRI visualizes low-lying conus medullaris (located at or below the L2 level), thickened filum terminale (>2 mm), spinal lipomas, and dural tethering bands.
Ultrasound, CT & Electrophysiology
High-frequency spinal ultrasound offers dynamic conus movement assessment in infants. Thin-slice CT details associated osseous defects (spina bifida, bony spurs). EMG/NCS studies assess nerve root conduction impairment.
Treatment
The primary objectives of treatment for tethered spinal cord syndrome are to release mechanical cord tension, preserve or restore neurological function, and relieve pain:
1. Surgical Treatment (Microsurgical Untethering)
Microsurgical untethering surgery is the definitive treatment for patients demonstrating progressive pain, neurological deterioration, bladder/bowel dysfunction, or lower limb deformities.
Through a precise laminectomy or laminoplasty, neurosurgeons dissect fibrotic bands, resect spinal lipomas, or transect a thickened filum terminale to free the conus medullaris and allow normal cord movement.
2. Conservative Management
In completely asymptomatic or neurologically stable patients discovered incidentally, careful non-surgical monitoring with periodic clinical and MRI evaluations may be considered.
Analgesics, NSAIDs, physical rehabilitation, and close pediatric neurosurgical follow-up support conservative observation protocols.
Frequently Asked Questions
What is tethered spinal cord syndrome (TSCS)?
It is a neurological disorder where the spinal cord is abnormally attached or anchored to surrounding tissues at the base of the spine, preventing its normal movement and causing mechanical tension.
What is a low-lying conus medullaris on MRI?
Normally, the end of the spinal cord (conus medullaris) rests above the L1-L2 vertebral level. On MRI, a conus located at or below L2 is a primary indicator of a tethered spinal cord.
What are the signs of tethered cord in children?
Common signs in children include gait difficulties, foot deformities, progressive scoliosis, back or leg pain, bladder/bowel accidents, and skin marks on the lower back (like a tuft of hair or deep dimple).
How does untethering surgery work?
Untethering surgery is a microsurgical procedure where the neurosurgeon carefully releases the attachments (such as cutting a thick filum terminale or resecting a lipoma) to free the spinal cord from mechanical tension.
Can adults develop tethered spinal cord syndrome?
Yes. Adults may present with symptoms due to trauma, progressive spinal degeneration, or late presentation of mild congenital tethering, causing leg pain, weakness, and urinary issues.
Can a tethered spinal cord re-tether after surgery?
Yes, re-tethering can occasionally occur years after surgery due to postoperative scar tissue formation. Regular neurological follow-up helps detect and manage re-tethering early.