Pain may be defined as an unpleasant sensory and emotional experience associated with actual or potential tissue damage.
Pain is the body’s mechanism of self-preservation acting as a warning to indicate that harm or damage is happening or about to happen.
Chronic Pain Conditions
Chronic pain conditions can stem from structural abnormalities of the spine or nerves, although pain may also occur due to multiple other causes. Some of the most common chronic pain conditions that we manage as Neurosurgeons are:
- Trigeminal neuralgia
- Nerve injury pain/neuropathic pain
- Failed back surgery syndrome
- Complex regional pain syndromes
- Occipital neuralgia
- Cancer-related pain
- Degenerative disease of the spine / Spinal stenosis / Disc herniation – see common spine conditions (David please have this as a hyperlink to that page)
- Lumbar and cervical pain / sciatica / brachalgia – see common spine conditions (David please have this as a hyperlink to that page)
- Carpal tunnel syndrome / Ulnar neuropathy – see Peripheral nerve decompression (have this as a hyperlink to the peripheral nerve decompression page)
Trigeminal neuralgia is sudden, severe facial pain. It is often described as a sharp shooting pain or similar to an electric shock in the jaw, teeth or gums. It usually occurs in short, unpredictable attacks that can last from a few seconds to about two minutes. The attacks are abrupt and stop suddenly also. The pain can be severe interfering with the normal activities of daily living.
Painful episodes may be triggered by chewing, talking, brushing teeth, shaving or light pressure on the face.
In most cases trigeminal neuralgia affects part or all of one side of the face, with the pain usually felt in the lower part of the face. Very occasionally it can affect both sides of the face, although not usually at the same time.
The first line treatment for trigeminal neuralgia is usually drug therapy. Certain medications can help reduce or control pain including Carbamazepine, Baclofen, Gabapentin and others.
If drugs fail to control the pain or if they produce intolerable side effects, intervention may be needed. A variety of surgical techniques are available to treat trigeminal neuralgia. The goal of some of these procedures is to damage or destroy part of the trigeminal nerve that is causing the pain. This can lead to numbness in the face to a varying degree. Some of the surgical options are:
- Percutaneous (through the skin) surgical techniques e.g. Balloon compression, radiofrequency rhizotomy.
Balloon compression is performed by inserting a tiny balloon through a thin tube. Once at the root of the trigeminal nerve, the balloon is inflated with enough pressure to damage the nerve and block pain signals.
Radiofrequency rhizotomy involves treating trigeminal neuralgia through the use of electrocoagulation (heat) to the root of the trigeminal nerve.
- Open surgical procedures: Microvascular decompression (MVD):
Generally this is the most effective method to treat trigeminal neuralgia. However, it is also the most invasive because an opening must be made in the skull to expose the trigeminal nerve root. The surgeon can then locate the blood vessel that may be compressing the nerve and gently dissect it away from the point of compression. The blood vessel is kept separated from the nerve with a small pad (Teflon).
- Stereotactic radiosurgery is also an option in which computer-guided focused radiation is aimed precisely to the root of the trigeminal nerve. Relief may take several weeks to begin. The procedure is painless and is usually done without anesthesia.
Please see further information at the Trigeminal Neuralgia Association UK: https://www.tna.org.uk
Failed back surgery syndrome and spine cord stimulation
Failed Back Surgery Syndrome is a condition in which there is new or persistent pain following spine surgery for degenerative disease. This may include lower back pain, leg pain, or leg numbness. The cause of pain is difficult to determine from clinical evaluation and diagnostic imaging.
The term refers to a condition of continuing pain and is not meant to imply there was necessarily a problem during surgery. This is true in many cases, but it remains important that a comprehensive spine surgeon opinion is obtained to rule out other causes for the pain.
If correctable structural problems are identified, additional surgery may be recommended to address these issues. This may include facet joint or sacroiliac joint radiofrequency ablation for the median nerves, spinal fusion, or sacroiliac joint fusion. If the pain generator is suspected to be the facet or sacroiliac joints, then diagnostic injections, physiotherapy or manipulation may be recommended.
Treatment for failed back surgery syndrome symptoms may include pain medications, diagnostic nerve blocks, physiotherapy or a pain management programme.
Sometimes no correctable cause of the patient’s symptoms is identified. In these cases, spinal cord stimulation may be used for pain control. This is a neuromodulation method in which low voltage electrical stimulation is applied through one or more leads with small electrical contacts placed near the nerves (such as the spine or the peripheral nerves beyond the spine along the lower back). If pain is reduced during an initial trial, then a small battery is implanted to provide ongoing stimulation. Spine cord stimulation works by stopping painful impulses from reaching the brain.
Another neuromodulation treatment option is intrathecal drug delivery. Rather than rely on medication taken by mouth, this involves placement of a catheter that delivers pain medication directly to the affected area.
Spine cord stimulation maybe recommended for the following conditions:
- Neuropathic Pain, this is pain caused by an insult or injury to the nerves rather than by damage to the other tissues, such as the joints and muscles.
- Failed back surgery syndrome
- Complex regional pain syndrome (CRPS)
CRPS is a condition, which causes chronic pain in an arm or leg. It usually develops after an injury, but the pain is more severe and lasts much longer than would be expected from the injury itself.
The main symptom of CRPS is a burning, stabbing, stinging or throbbing pain in the affected limb. It may also become very sensitive to touch. The area may have skin temperature or colour changes and there maybe a decrease or increase in sweat from the involved region with changes in nail and hair growth. The limb may swell, leading to stiffness, and many people report that the limb feels strange.
There are two types of CRPS:
Type 1: This type occurs after an illness or injury that didn’t directly damage the nerves in your affected limb. The majority of complex regional pain syndrome is this type. It is also known as reflex sympathetic dystrophy syndrome (RSD),
Type 2: This type has similar symptoms to type 1. But type 2 follows a distinct nerve injury. It is also known as causalgia.
Treatment may include physiotherapy, pain management programmes, pain medication, Transcutaneous electrical nerve stimulation (TENS) or spine cord stimulation.