Sphenopalatinum Test Block

What is a sphenopalatine ganglion test block?

A ganglion is a bundle of interconnected nerves that are important for pain in a certain area of the body. One such ganglion is known as the sphenopalatine ganglion and it is important in the treatment of some types of facial pain. Test blocks of this ganglion can help to relieve the pain. Before we perform a permanent block of this ganglion we first do a test block to see if this helps to relieve your pain. The sphenopalatine ganglion (see number 2 in Figure 1) is located next to the jaw (see number 1 in Figure 1) on the outer side of the face behind the nose and can be reached with a needle. In a test block of the sphenopalatine ganglion local anaesthetic is administered with a needle to this ganglion so that it can longer pass on pain signals.

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Figure 1. Side view of the skull. The box at bottom right is an enlargement (see text)..

 

What should I be aware of before undergoing sphenopalatine ganglion test block?

  • Any of the following situations should be reported to your pain specialist if he proposes sphenopalatine ganglion test block:
  • If you are pregnant: since X-ray equipment is used, pregnant women may not undergo a sphenopalatine ganglion test block and a new appointment has to be made.
  • If you are ill or have a fever on the day of treatment you cannot undergo a sphenopalatine ganglion test block, 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 that your pain specialist before the appointment for treatment is made. He will then consider whether the use of certain

How should I prepare for sphenopalatine ganglion test block?

  • No special preparations, such as an overnight bag, are necessary because the treatment is carried out on an outpatient basis.
  • You may eat before treatment and take your normal medication.
  • N.B.: this does not include blood thinners, as mentioned above.
  • Make sure you have someone to take you home, because you may not drive for 24 hours.

How does sphenopalatine ganglion test block work?

  • The treatment will be performed 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 monitors.
  • You will be positioned on the treatment table on your back.
  • The blood pressure and the amount of oxygen in your blood will be controlled during the treatment.
  • A drip will be placed in your hand.
  • The right place of the block is estimated with aid of fluoroscopy.
  • This place is marked on the skin with a felt pen.
  • The area around this site is then disinfected with a cold, red liquid.
  • The pain specialist covers the area with sterile drapes.
  • After a local anesthetic has been applied to the skin, the pain specialist, by means of fluoroscopy (via the television monitor), will insert the needles in the correct place.
  • The treatment is performed under light anaesthesia.
  • Some contrast fluid is also injected to enable the position of the needle to be clearly visible.
  • Then small electrical currents are administrated near the sphenopalatine ganglion.
  • You will feel a tingling sensation.
  • When you feel this, you must tell the treating pain specialist straight away, and not wait for it to become painful.
  • The pain specialist will ask you where you feel the sensation and you don't have to point the place with your finger.
  • By means of a special device, the pain specialist can read the distance from the needle to the sphenopalatine ganglion.
  • If the needle is in the right place the sphenopalatine ganglion test block is performed.
  • In sphenopalatine ganglion test blocks small amount of local anaesthetics are injected around the sphenopalatine ganglion nerves to temporarily block the nerves.
  • You will then be asked to get dressed and return to the waiting room.
  • After half an hour, your pain specialist will inquire whether the sphenopalatine ganglion test block clearly reduced your pain.
  • If this is not the case, you will have to make a new appointment with your own pain specialist to discuss further possible treatment options.
  • If the sphenopalatine ganglion test block clearly reduced your pain, then an appointment will immediately be made at the day centre for a permanent sphenopalatine ganglion block.

What are dangers and side effects of sphenopalatine ganglion test block?

After sphenopalatine ganglion test block, the following complications or side effects can occur:

  • It is possible that small blood vessel can be hit by the needle resulting in haemorrhage resulting in a bleeding nose or a haemorrhage of the cheek.
  • If the bleeding remain you have to contact the pain clinic.
  • The same is true in case you develop a fever over 38.5 Co, because in rare cases a meningitis can occur.
  • You immediately have to contact the hospital or the pain clinic and your GP to be treated as soon as possible with antibiotics.

When can I expect pain relief after the treatment?

  • Afterpains can occur following sphenopalatine ganglion test block. This may last a week but will eventually disappear.
  • The numbness will last several hours and your original pain will return.