What exactly is a Trapped Nerve?
Nerves may be trapped at several points along their course. Those points of entrapment outside of the spine are rare. The focus of this page is upon nerves becoming trapped in the spine. The term trapped covers a range of situations causing symptoms of irritation to frank loss of function, presenting as pain, pins & needles, numbness or weakness.
These symptoms may arise from:
- In the exit route from the spine (Foramen) nerves may become tethered by scarring, by excessive bulging of the disc wall (“Slipped Disc”) or by overgrowth or arthritis of the facet joint or distortion of this outlet tunnel by slippage of one vertebra on another or bone spurs from the facet joint or vertebral rim or ligaments or cysts pressing on the nerve or surgical damage / complications. These may cause “Lateral Recess Stenosis” (narrowing).
- In the midline of the spinal canal the disc may bulge or disrupt (“Slipped Disc”) thus irritating, tethering or compressing the nerve(s) descending or beginning to exit the spinal canal. This may be worsened by in-folding of ligaments in the back of the spinal canal as the discs lose height in the front or the facet joints become overgrown or from cysts which crowd towards the midline reducing available canal space. These may cause “Axial Stenosis” (narrowing).
- The effect of these factors may be increased by the irritation caused by the by-products leaking from some high intensity zones.
- The origin of the presenting symptoms of low back pain or sciatica need to be differentiated from similar symptoms arising from irritated Cluneal Nerves.
In reality, this is a ‘catch-all’ term for a range of medical problems that relate to irritation or compression of the nerve by the ‘discs’ , soft tissue or bones or high intensity zones in the spinal column or in the exit route as they leave the spine.
Where does it hurt?
A “Trapped or Irritated” Nerve can occur anywhere along the length of the spinal column from the neck to the lower back. The condition may arise in the neck (cervical spine), back of chest (thoracic spine) or lower back (lumbar spine). The symptoms may be a combination of pain in the local area of the spine and pain radiating outwards from that point into the arm, waist or leg respectively.
- So in the neck, there may be midline neck pain with pain radiating to the shoulder and down the arm to the fingers.
- In the thoracic region, there may be midline posterior chest pain with pain radiating around the ribs to be felt as deep chest pain or pain in the abdomen.
- In the lumbar spine, there may be midline lower back pain with pain radiating to the flank, buttock and down the leg to the toes.
As the trapping or irritation becomes more pronounced so the nerve function gradually fails with numbness and muscle weakness or hypersensitivity developing in the area of the pain. On occasions the compression becomes so pronounced that the muscle function deteriorates markedly manifesting as weakness but because the nerve is so compressed and immobilised, that the pain diminishes. Consequently, the patient thinks they are improving when in fact the condition is worsening.
How is a Trapped Nerve diagnosed?
One of the complications in diagnosing a Trapped Nerve is that whilst the apparent pain or problem may manifest itself in one part of the body, the actual cause of the problem can lie in a different part of the spinal column. For this reason, medical professionals pay close attention to the pattern and the way in which the symptoms are developing as a first step in evaluating the problem. Then they move on to more focused diagnostic investigations such as MRI, CAT, Dexa scans and EMGs. However, these inert studies can be misleading – hence the need for aware state diagnosis.
Is the pain in your lower back?
Various combinations of pain in the lower back, buttock, groin or leg can arise either from irritation within the disc itself, or when the disc causes irritation and tethering / trapping of the adjacent nerves. The leg pain, when it spreads below the knee is termed Sciatica, occurs when the nerve becomes increasingly trapped or irritated in the lumbar spine. As the compression increases this may cause numbness or pins and needles in the leg and be associated with weakness such as “foot drop” (difficulty lifting the toes and foot up) or weakness when pushing off with the foot.
Is the pain in your neck?
Neck pain, headaches and pain in the face, shoulders, arms and hands may be created when the nerve is trapped or irritated in the neck. As compression increases, it may cause numbness or ‘pins & needles’ in the face, shoulder, arm or hand and may also be associated with weakness of shoulder, elbow, wrist or hand movements. Any one of these symptoms, or a combination of them, can indicate a Trapped Nerve.
Is the pain in the middle of your back, chest or abdomen?
Pain in the middle of your back, chest wall, sternum, abdomen or deeply in your chest may be created when the nerve is trapped in the thoracic spine. This may cause numbness or ‘pins & needles’ in the rib cage or abdomen and may also be associated with weakness of the chest wall or abdomen on one side. Any one of these symptoms, or a combination of them, can indicate a Trapped Nerve.
How is the first Trapped Nerve attack treated?
The major symptoms of a trapped nerve, arising from the first attack, generally settle down over the first 6 weeks and half of the remainder will usually settle down over the next 6 weeks. Treatment during this period is focused on reducing the irritation by prescribing: anti-inflammatory drugs (Steroids or Non-Steroidal Anti-Inflammatory therapy – Ibuprofen, Diclofenac , Naproxen or Acemethacin), control of pain with paracetamol and separate Codeine and correcting posture and regaining deep muscle control of the spine by Muscle Balance Physiotherapy. Additional pain control may require Amitryptaline, Nortryptaline or Pregabolin.
How are repeated Trapped Nerve attacks treated?
Repeated attacks or enduring symptoms need more radical treatment and these may be grouped in to three treatment pathways; Conservative Therapy, Conventional Open Surgery and Endoscopic Minimally Invasive Spine Surgery. (To see these diagrammatically, please click here for lumbar treatment pathways and here for cervical treatment pathways).
- Conservative therapy consists of Muscle Balance Physiotherapy, CT Guided Nerve Root Block injections, Facet Joint Injections (Caudal Epidurals are only rarely conducted unless for short-term relief) Cognitive Behavioural Therapy and Coping Courses, plus a restricted lifestyle, and the hope that the symptoms will abate over time. Some patients will be offered Dorsal Column Stimulation where the clinician is unable to define the pain source and some patients are left in a wheelchair existence.
- Conventional Open Surgery, carries greater risk than conservative therapy and cannot guarantee success. The surgical options are tabulated below and details of these treatments may be explored through the list on the left.
- Endoscopic Minimally Invasive Spine Surgery (Foraminoplasty) has shown encouraging results in over 80% of 4,950 Foraminoplasties carried out in the Spinal Foundation in patients suffering Slipped discs, Failed Back Surgery, Failed Fusion Surgery, “Instability”, Spondylosis and Back pain, Lateral Recess Stenosis and Axial Stenosis, Spondylolytic Spondylolisthesis and Disc infections. 10 years from Foraminoplasty, 72% were successful. 50% of this group suffered from failed back surgery.
|Success At Year 2
|6% (Recurrent protrusions 3 – 13%)
|Leg but not back pain 90%
|8% (Instability & Scarring)
|Poor Data 75%
|11 – 18% (International Controlled Trials)
|Total Disc Replacement
|16 – 45%
|Spinous Process Fractures, settlement, infection
|Endoscopic Transforaminal Decompression