Spinal Cord Tension: Causes, Symptoms, and Treatment
Gain insight into how a physically restricted spinal cord can impair nerve signals and learn about the approaches used to restore its necessary mobility.
Spinal cord tension is a mechanical condition where the spinal cord is pulled or stretched beyond its normal capacity. Housed within the protective spinal canal, the cord must move freely to accommodate body movements like bending and twisting. When this movement is restricted, the constant strain can be likened to a rubber band stretched too tightly, impairing the cord’s function and disrupting the nerve signals it carries.
The Link to Tethered Cord Syndrome
Spinal cord tension is the functional problem that arises from Tethered Cord Syndrome (TCS), a neurological disorder where the spinal cord is physically attached to surrounding tissues. This attachment, or tether, prevents the cord from moving freely. As the body grows or moves, the inelastic nature of these anchoring tissues means the spinal cord is pulled taut, which can compromise its blood supply and neurological function.
The causes of tethering are grouped into two categories. Congenital tethering is present from birth and is often associated with developmental conditions like spina bifida. Other congenital causes include an unusually thick or fatty filum terminale, the filament that anchors the end of the spinal cord to the tailbone.
Acquired cases of TCS develop later in life and are not related to a birth defect. These tethers can form from events that cause scar tissue to build up within the spinal canal. Causes include trauma to the spine, complications from spinal surgery, infections, or a tumor that adheres to the spinal cord.
Recognizing Key Symptoms
One of the most common signs is pain, particularly in the lower back, which worsens with activities that involve bending forward. This pain can radiate down into the legs, buttocks, and perineal area. Individuals may also experience sensory changes like numbness, tingling, or a pins-and-needles sensation in their legs and feet.
Motor function is frequently affected, causing progressive weakness in the legs and leading to changes in walking pattern or gait. In children, this can manifest as clumsiness or a deterioration in their ability to run. Foot and spinal deformities are also indicators, including high arches, curled toes, or scoliosis. Some individuals may experience a loss of muscle mass in their leg muscles.
Changes in bladder and bowel control are also associated with this condition. The tension on the lower spinal cord can disrupt nerve signals, leading to urinary incontinence, a frequent need to urinate, or chronic constipation. In some cases, these urological symptoms are the first signs that lead to a medical evaluation.
Skin markers on the lower back can indicate an underlying congenital tether, especially in children. While not present in all cases, their presence can be an early clue. These signs can include:
- A hairy patch
- A deep dimple
- Skin discoloration
- A fatty lump (lipoma) on the midline of the lower back
The Diagnostic Process
Diagnosis begins with a clinical evaluation, including a review of the patient’s medical history and symptoms. A physician will perform a physical and neurological examination to assess muscle strength, reflexes, sensation, and gait to identify patterns of weakness or sensory loss.
If a tethered cord is suspected, imaging studies are ordered to visualize the spinal cord. Magnetic Resonance Imaging (MRI) is the preferred method and can show the position of the conus medullaris, the tapered end of the spinal cord. In adults and older children, the conus ends at or above the L1-L2 vertebra; a position below this level indicates a tether.
The MRI also allows doctors to identify the specific cause of the tethering. It can reveal a thickened or fatty filum terminale, which should be a thin strand less than two millimeters in diameter. Other findings on an MRI include scar tissue, tumors, or other structural abnormalities anchoring the spinal cord.
Functional tests may also be used to assess the impact on body systems. For example, urodynamic studies evaluate bladder function by measuring pressure and urine flow. These studies help quantify the neurological impact on bladder control.
Approaches to Management and Treatment
For individuals with mild or stable symptoms, a conservative, non-surgical approach may be recommended. This often involves physical therapy to gently stretch the nerves and improve mobility. Pain management techniques, including medication, may also be used to alleviate discomfort. Regular monitoring with follow-up appointments and imaging ensures the condition does not worsen.
When symptoms are progressive or severe, surgical intervention is recommended. The surgical procedure is known as a “tethered cord release” or “detethering.” A surgeon makes an incision over the affected area, identifies the tethering element like a thickened filum terminale or scar tissue, and cuts it to free the spinal cord.
The objective of surgery is to halt the progression of neurological damage. Releasing the tension can restore blood flow to the spinal cord and prevent further injury. Many patients experience an improvement in symptoms, particularly pain and some motor function, after the procedure. Recovery and outcome can vary depending on the patient’s age and pre-existing neurological deficits.