What is spinal cord test stimulation?
Spinal cord stimulation is also known as neurostimulation or ESES (Epidural Spinal Electrical Stimulation). In this procedure an electrode or lead (see figure) is used to apply small electric currents to certain nerve bundles in the spinal cord (number 4 in figure 1).
The vertebral column is made up of vertebrae (see number 1 in figure 1) in between which can be found the so-called intervertebral discs, which allow the vertebrae to move against one another. At the back of a vertebra are the so-called spinous processes (number 2 in the figure) and inside the vertebra is the vertebral canal. The vertebral canal contains the spinal cord (number 3 in the figure) that is surrounded by cerebrospinal fluid that in turn is surrounded by a hard membrane called the dura (number 4 in the figure). The space between this hard membrane and the bone of the vertebra is called the epidural space (number 5 in the Figure).
In spinal cord stimulation the electric currents ensure that fewer pain signals are sent to the brain via the spinal cord, thereby relieving your pain. The lead is inserted into the epidural space (number 5 in figure 1). The specific level of the spinal cord at which the lead (see figure) is placed inside the epidural space will depend on where you feel pain. Before you are given permanent spinal cord stimulation, a test period of stimulation is always carried out to see whether or not it reduces your pain symptoms.
Figure 1. Cervical vertebra seen from above (see text). At the bottom of the image a lead can be seen inside the epidural space (6).
Figure 2. X-ray of the vertebrae (2) taken from the front and showing the lead (1).
Figure 3. X-ray of the vertebrae (2) taken from the side and showing the lead (1).
What should I be aware of before undergoing spinal cord test stimulation?
Any of the following situations should be reported to your pain specialist if he proposes spinal cord test stimulation:
- If you are pregnant: since X-ray equipment is used, pregnant women may not undergo spinal cord test stimulation.
- If you are ill or have a fever on the day of treatment you cannot undergo spinal cord test stimulation, in which case a new appointment will have to be made.
- If you are allergic to iodine, bandages, anaesthetics or contrast fluids, you should notify your pain specialist before the appointment for treatment is made.
- If you are taking blood thinners, you should notify your pain specialist before the appointment for treatment is made. He will then consider whether the use of certain medications should be ceased temporarily.
How should I prepare for spinal cord test stimulation?
- No special preparations, such as an overnight bag, are necessary because the treatment is usually carried out on an outpatient basis, but we ask that you do not wear any jewellery, make-up, earrings or body piercing.
- The treatment requires that you have an empty stomach. This means that you cannot eat or drink anything from six hours before the treatment.
- You can take your medication in the morning.
- This does not include blood thinners, as mentioned above.
- You should stop taking any homeopathic medications one week before the treatment.
- It is advisable not to smoke or drink alcohol 24 hours before and after the treatment.
- During the treatment we ask that you do not wear make-up, nail polish, hair gel, jewellery, glasses, contact lenses or dentures.
- You must remove any earrings, body piercing or false nails yourself.
- Have a bath or shower beforehand and clean your teeth.
- Do not bring any valuables with you.
- Make sure you have someone to take you home, since you may not drive for 24 hours.
How does spinal cord test stimulation work?
- The treatment takes place in the surgical day-care centre, where you will be asked to change into a surgical gown. This gown closes at the back.
- A nurse will escort you to the treatment room, where there is a treatment table, an X-ray machine and television screens.
- You will be positioned on the treatment table on your front with a cushion under your stomach.
- Your blood pressure and the amount of oxygen in your blood will be monitored during the treatment.
- The intervention takes several hours.
- The X-ray machine is used to find the correct site for spinal cord test stimulation.
- This site is marked on the skin with a marker pen. The area around this site is then disinfected with a cold, red liquid.
- The pain specialist covers the area with sterile drapes in order to keep it sterile.
- After a local anesthetic has been applied to the skin, the pain specialist will insert the lead into the correct place by means of fluoroscopy (via the television monitor).
- Then small electrical currents are applied to the nerve bundles through the lead.
- You will experience a tingling feeling or sensation of pressure in the area where your pain is.
- If you notice this then you should inform the pain specialist treating you since this means that the lead is in the correct place.
- You do not have to point to the place with your finger.
- After this treatment you will be asked to make an appointment with the pain nurse at the Outpatient Pain Clinic.
- You will be asked to fill in a pain diary during the period of test stimulation.
- When you get home you do not have to stay in bed.
- Do not remove the plaster.
- The plaster may not get wet from showering or bathing.
- Review your own pain medication.
- The tingling feeling can come and go depending on the position of your body.
- The intensity can be adapted using the stimulator that you will take home with you.
What are the dangers and side effects of spinal cord test stimulation?
- There is always a risk of infection.
- In that case you will have a headache, nausea and vomiting.
- Contact the hospital straight away.
- There is a small risk of a haemorrhage around the spinal cord.
- In that case you will have severe back pain followed by a numb and paralysing feeling in your legs. Contact the hospital straight away.
- The lead can become dislodged so that the tingling feeling is no longer in the correct place.
- Contact the hospital straight away.
When can I expect to feel less pain after the treatment?
- Spinal cord stimulation does not cure your pain, but it helps to make the pain more bearable.
- You must also be aware of the fact that spinal cord stimulation may not work for you.
What is and is not permitted during the period of test stimulation?
- An MRI scan is not allowed.
- The stimulator must be turned off when driving.
- Take care with magnets such as those at airports.
- For this reason you should always carry your medical ID card with you.