At a glance
What it is
An umbrella term for conditions in which the lower end of the spinal cord is abnormally anchored, preventing it from moving freely upward within the spinal canal as the spine flexes or grows. The resulting traction stresses the delicate spinal cord tissue, particularly over time. Congenital causes include: tight (thickened) filum terminale, lipomeningomyelocele, split cord malformation, dermal sinus tract, and spinal cord cysts. Acquired causes include post-operative scar tissue, spinal tumour, and post-traumatic adhesions. Congenital forms are usually identified in childhood or adolescence during growth spurts; a minority are not diagnosed until adulthood. Nearly all adults with open spina bifida require lifelong monitoring for tethered cord.
Symptoms
Symptoms develop slowly but can become severe over time. Back pain that radiates to the legs, hips, and perineum — characteristically worsened by bending forward, sitting cross-legged ('Buddha-sitting'), or holding moderate weight at waist level (the '3-B sign'). Leg numbness, weakness, and muscle wasting. Bladder and bowel dysfunction: urgency, incontinence, or retention. Scoliosis — an early sign in children. Deteriorating neurological function over time rather than sudden onset. In adults with previously identified tethered cord, progressive worsening of any of these symptoms is an indication for surgical review.
Approach
MRI of the full spine is the key investigation: identifies the type and level of tethering and any associated anomalies (syringomyelia, Chiari malformation, hydrocephalus). Asymptomatic or minimally symptomatic adults may be observed with serial imaging. When symptoms are progressive or significant, surgical untethering (tether release) is recommended. The specific operation depends on the cause: filum section for tight filum, lipoma debulking and release for lipomyelomeningocele, lysis of post-operative adhesions for acquired tethering. The majority stabilise or improve after surgery. Re-tethering can occur and requires follow-up. Neuromodulation and physiotherapy support chronic pain and spasticity.
What tethered spinal cord is
The spinal cord normally ends (conus medullaris) at approximately the L1–L2 vertebral level in adults. It is attached to the sacrum by the filum terminale, a thin strand of fibrous tissue. Normally this strand is slender and elastic, allowing the cord to move freely within the canal during spinal flexion and extension.
When the cord is tethered, the filum is abnormally thickened or fatty, or the cord is attached directly to adjacent tissue by adhesions, a lipoma, a cyst, or a bony abnormality. As the spine moves — or as the child grows — the tethered cord is stretched. This traction produces metabolic stress and microvascular insufficiency in the terminal cord, damaging the sensory, motor, and autonomic neurones it contains.
**Congenital causes**
*Tight filum terminale* — the most common form in otherwise neurologically normal adults. The filum is thickened (> 2 mm on MRI) and fatty. Surgical section of the filum (a brief, low-risk procedure) reliably stops progression.
*Lipomyelomeningocele* — a fatty tumour (lipoma) grows into the spinal cord and nerve roots during embryonic development. The lipoma anchors the cord. Surgical debulking and release is more complex than simple filum section.
*Split cord malformation (diastematomyelia)* — the cord is divided into two hemicords by a bony or fibrous spur; each hemicord is tethered at the spur. Surgical removal of the spur untethers the cord.
*Spina bifida* — virtually all adults with open spina bifida have some degree of tethering related to closure surgery scars. Tethered cord is the most common reason for adult neurosurgical intervention in spina bifida.
**Acquired causes**
Post-operative epidural fibrosis (scar tissue after spinal surgery) can tether the cord or cauda equina roots. This is a recognised complication of spinal surgery and may present years after the original procedure.
**Surgery and outcome**
Tether release surgery opens the spinal canal from behind, identifies the cause of tethering, and divides or removes the offending structure under neurophysiological monitoring (to protect motor and sensory nerve roots in real time). The majority of patients stabilise or improve. Re-tethering occurs in a proportion, necessitating further surgery. Long-term neurological follow-up is essential.
Treatment options at Alimran Medical Center
Neuromodulation
Injection therapies
- Botox® injections
- Prolotherapy
- Ozone injection
- Trigger point injections
- Epidural steroid injections
Advanced therapies
Physiotherapy & rehabilitation
- Electrical stimulation
- Short and long wave therapy
- Laser therapy
- Ultrasound therapy
- Spasticity management and bladder rehabilitation
- SpineMED® system
- Sigma
Book a consultation
The secretary schedules first appointments during clinic hours; please have prior imaging, operative notes and a current medication list available at the time of the call.
This page provides general information about tethered spinal cord and is not a substitute for individual medical assessment. If your symptoms are severe or worsening, contact a clinician promptly.