The spinal cord extends from the base of the brain through the spinal canal to the lower back.
A tethered cord refers to a condition in which the lower spinal cord is restricted (“tethered”) and is not free to develop normally with in the spinal column. This can occur during fetal development or may be associated with build up of scar tissue after previous surgery in or around the spinal cord.
Signs and Symptoms of Tethered Spinal Cord
Signs and symptoms of tethered cord are not specific to this condition, meaning that other disorders may also result in these problems. However, if your child has any of the following, tethered cord should be considered:
- Leg or back pain
- Decrease in strength of legs or feet
- Loss of sensation in the legs
- Deformity of the legs or feet
- Stumbling or walking changes
- Difficulty or delay in toilet training
- Incomplete emptying of the bladder
- Changes in bladder and bowel control
- Curvature of the spine
- Skin abnormalities directly overlying the spinal cord – midline dimples, hairy patches, skin discoloration, skin tags or fatty lumps.
Diagnosis :
A diagnosis of tethered cord syndrome is made based upon identification of characteristic signs and symptoms (see the symptom section) that can neurologically locate the lesion to be above the attachment of the anomalies to the spinal cord. For this purpose, a detailed patient history and a thorough clinical evaluation and detailed MRI studies must be carried out. In children, typical imaging features such as a low lying spinal cord and a thickened filum terminale is confirmed by special imaging techniques such as magnetic resonance imaging (MRI) or computed tomography (CT) scan and ultrasound studies.
An MRI uses a magnetic field and radio waves to produce cross-sectional images of particular organs and bodily tissues. In addition, demonstration of spina bifida (bony defect of the lamina) supports a diagnosis of tethered cord syndrome.
In late teenagers and adults, the displacement of the filum located posterior to the cauda equina (a bundle of nerve roots that originate from the lower spinal cord) is a consistent finding. This important feature is proved by the combination of MRI, endoscopy and surgical findings. During CT scanning (a computer tomography) and MRI special techniques are used to create cross-sectional images of vertebrae and nervous system. In some cases, electromyography (EMG) and nerve conduction studies may be used to assess nerve function. EMG is a test that records electrical activity in skeletal (voluntary) muscles at rest and during muscle contractions. The abnormalities in this examination are only shown in patients with an advanced stage of tethered cord syndrome.
Standard Therapies
Treatment
In children, surgery to release “untether” the spinal cord is recommended to prevent or reverse progressive neurological symptoms. The type of surgery varies depending on the mechanical causes, such as an inelastic filum, myelomeningocele, lipomyelomeningocele, and dermal sinus. Accordingly, the surgical prognosis varies depending upon the presenting symptoms and tethering-producing anomalies. It has been said that treatment for adult patients with tethered cord syndrome is controversial However, it is clear that in both pediatric and adult patients who have firm evidence of tethered cord syndrome, prompt surgical intervention results in reversal, or at least stabilization, of symptoms in many cases.
Parents should talk to their physician and medical team about their child’s specific problems, associated symptoms and deformity of the spine and spinal cord. In an individual with only minimum complaint his/her physician may advise conservative treatment rather than surgery and will monitor the condition to see whether the symptoms progress Many experts of tethered cord syndrome recommend against surgery to individuals who present with the MRI finding of “cord elongation and thickened filum” but have no symptoms. Some neurosurgeons may prefer cutting the thickened filum in these cases for the prophylactic purpose.
The responses to treatment for tethered cord syndrome by repairing myelomeningocele or removal of scarring formation, varies from one person to another. After the repair, the spinal cord may become “retethered” and additional surgery may be recommended.
In individuals with severe arachnoiditis (adhesion of the meninges to the spinal cord) found by MRI or CT scan, careful evaluation of pain and neurological condition is required to find if surgical treatment is warranted. At surgery, release of arachnoid adhesion must be performed with meticulous technique. Or re-adhesion or extensive scar formation might follow the surgery. To circumvent this problem, two special surgical procedures have been advocated: 1) transection of the spinal cord to relieve severe back and leg pain, and 2) shortening of the spinal column by resection of one or two vertebrae to relieve spinal cord tension.