Spinal Stenosis

Spinal Stenosis Overview

Spinal stenosis is a progressive "wear and tear" or degenerative process.   A range of anatomic structures including the facets, ligamentum flavum, and intervertebral discs may contribute to the symptoms. Degenerative stenosis results in narrowing of the spinal canal and lateral recess and foramen. Although degenerative changes are ubiquitous in the aging population, most individuals do not have symptoms despite these radiographic abnormalities.

Lumbar Stenosis

Symptomatic lumbar stenosis typically occurs in patients in the fifth to seventh decades of life with a reported incidence from 1.7% to 10%, and as the population ages, a greater number of patients will need to be treated for this condition. Although there may be a structural predisposition to stenosis (congenital short pedicles), symptomatic narrowing of the spinal canal almost always is seen in association with osteoarthritic changes of the lumbar spine. Males and females seem to be affected equally with spinal stenosis; however, women are afflicted with associated degenerative spondylolisthesis four times more often than men. The hallmark symptom is neurogenic claudication. Neurogenic claudication refers to pain radiating to the lower extremities that begins and worsens as the patient walks and resolves as the patient bends forward or sits. Also, patients with stenosis complain of mechanical back pain and radiculopathy that may be unilateral or bilateral.

Spinal Stenosis in the Neck

Cervical stenosis

Cervical stenosis is a condition in which the spinal canal is too small for the spinal cord and nerve roots.  This can cause damage to the spinal cord, a condition called myelopathy, or pinch nerves as they exit the spinal canal (radiculopathy). Occasionally, damage to the spinal cord and nerve roots may occur, resulting in a condition called myeloradiculopathy. Stenosis is most often caused by a number of factors which combine to cause a critical level of spinal cord compression, at which time symptoms may develop. Factors contributing to the development of cervical stenosis include: congenital short pedicles (the bones which form the sides of the spinal canal), degenerative arthritis causing excessive bone growth, and thickening of the ligamentum flavum. However, it is important to note that cervical stenosis does not always get worse and cause progressive symptoms. Many people have mild stenosis and never become symptomatic, or have mild symptoms which are not bothersome enough to seek treatment. Even if symptoms occur which are severe enough to seek treatment, they can usually be controlled with a combination of medication and physical therapy. If surgery is ultimately necessary, there are two basic surgeries that are performed. Depending on the cause and location of the stenosis, surgery may be performed from the front, known as anterior cervical fusion. Surgery may also be performed from the back of the neck, commonly called a posterior laminectomy or laminoplasty.

Types of Spinal Stenosis

• Mild Stenosis
• Moderate Stenosis
• Severe Spinal Stenosis
• Congenital
• Degenerative Spinal Stenosis
• Spinal Canal Stenosis
• Lateral Recess Stenosis
• Central Stenosis

Causes 

Lumbar stenosis Causes

The lumbar spinal canal is the space in the lower spine that carries nerves to your legs. It is very narrow. It gets even more narrow if the bone and tissue around it grow over the course of many years. This narrowing is called "stenosis." As the lumbar spinal canal narrows, the nerves that go through it are squeezed. This squeezing may cause back pain, and leg pain and weakness. Arthritis, falls, accidents, and wear and tear on the spine's bones and joints can also cause narrowing of the spinal canal. These factors play a part in stenosis among many adults.

Natural History of Cervical Stenosis

Patients are likely to develop further neurologic symptoms. The natural history is of neck pain, radiculopathy, and myelopathy. Response to nonoperative treatment by DePalma 1972 21% complete resolution of neck pain, 50% partial relief, and 28% no response. Rothman and Rashbaum 1978 found 23% had partial or total disability at 5 years. Radiculopathy at 10-25 years follow-up Gore 1987, 43% complete resolution and 32% continued moderate-severe symptoms. The classic myelopathy picture is stepwise progression. Non-operative care Pro-Clarke 1956 75% progressed episodically, 20% steadily worsened, and 5% rapidly progressed. Seymon and Lavender 1967 67% steady progression of symptoms.

Symptoms



Lumbar stenosis symptoms

People with stenosis may have back or leg pain or numbness. Your legs might also feel cramped, tired or weak. These symptoms usually start when you are standing or walking. Often, the symptoms get better if you sit, crouch or lie in the fetal position (on your side with your knees tucked up to your chest). It's thought that these positions "open" the lumbar canal and take the pressure off the nerves that go to the legs. In severe cases, stenosis can cause bowel or bladder problems.

Cervical stenosis symptoms

Symptoms of cervical stenosis with myelopathy People with this condition may note one or more of the following symptoms: Heavy feeling in the legs, Inability to walk at a brisk pace, Deterioration in fine motor skills (such as handwriting or buttoning a shirt), Intermittent shooting pains into the arms and legs (like an electrical shock), especially when bending their head forward (known as Lermitte’s phenomenon). Arm pain (radiculopathy) Often it is the arm pain that prompts someone with this condition to seek medical treatment, and then the myelopathy is discovered through medical history and physical exam. Cervical stenosis is usually suspected based on the patient’s history and physical examination. Your doctor may order X-rays of the neck. X-rays may show bone spurs or narrowing of the space between vertebral bodies, caused by collapse of the discs. A more specialized type of imaging, magnetic resonance imaging (MRI) may also be obtained. The MRI will show the condition of the intervertebral discs, the ligaments, and the spinal cord and nerves. The MRI is the most common way to diagnose the presence of nerve compression. Other types of imaging studies such as CT scans and myeolograms may also be used in certain cases to help make the diagnosis.

Diagnosis and Common Questions



Lumbar diagnosis

X-rays often demonstrate multilevel spondylosis, which may not be associated with stenosis of the spinal canal. Radiographic findings that are more suggestive of spinal stenosis include degenerative spondylolisthesis and degenerative lumbar scoliosis. The diagnosis of lumbar spinal stenosis can be confirmed with use of magnetic resonance imaging (MRI). Magnetic resonance imaging provides superior visualization of the soft-tissue elements of the spinal canal and is especially useful for the evaluation of abnormalities of the intervertebral disc. Its diagnostic accuracy is superior to myelography and plain CT scan, and it is as accurate and sensitive as CT-myelogram. The combination of axial and sagittal images allows for complete evaluation of the central spinal canal and the neural foramen. The importance of correlating radiographic abnormalities with clinical symptoms and signs must be emphasized. Asymptomatic individuals over 60 years may have MRI anatomical stenosis. EMG/NCV can be an excellent adjunct in stenosis. In patients with diabetes and lumbar spinal stenosis, EMG can be useful for differentiating between radiculopathy and diabetic neuropathy affecting the peripheral nerves. EMG also can be useful for differentiating acute denervation from chronic inactive changes in spinal nerves. Normal EMG does not rule out stenosis. However, the more typical EMG pattern is that of a polyradiculopathy, often with bilateral involvement of multiple levels.

Cervical Stenosis diagnosis

Cervical stenosis with myelopathy affects the nerves. Myelopathy affects the nerve tracts that run inside the spinal cord (long tracts) and deficits in these long tracts can be picked up on physical exam. For example: Muscular tone in the legs will be increased.  Deep tendon reflexes in the knee and ankle will be accentuated (hyperreflexia).  Forced extension of the ankle may cause the foot to beat up and down rapidly (clonus).  Scratching the sole of the foot may cause the big toe to go up (Babinski reflex) instead of down (normal reflex).  Flicking the middle finger may cause the thumb and index finger to flex (Hoffman’s reflex).  Compromised coordination may be evidenced by difficulty walking placing one foot in front of the other (tandem walking) Diagnostic tests for cervical stenosis with myelopathy An MRI scan and/or a CT with myelogram can show the tight canal and associated spinal cord pinching. The condition may be present at one or several levels in the spine. Often, cervical stenosis with myelopathy is associated with some degree of cervical instability, and flexion/extension lateral cervical spine x-rays are useful to rule out abnormal motion and instability. Somatosensory Evoked Potentials (SSEP), an electrical study, is done by stimulating the arms/legs and then reading the signal in the brain. A delay in the length of time that it takes to get to the brain indicates that there is a compromise of the spinal cord.

MRI Signal changes in the spinal cord

What is it?

Ohshio 1993 correlated histopathology changes and MRI signal of the cord. High T2 mildly altered areas are cord edema. Sharply demarcated high T2 implies more severe histological lesion. Low T1 and high T2 together are severely altered lesions of the gray matter with necrosis, myelomalacia, or spongiform changes.

How common is it?

Asymptomatic stenosis series (Bednarik) High T2 only in 35%. Low T1 with High T2 was 0%. Symptomatic series with mild myelopathy (Matsumoto) High T2 in 65% and low T1 with High T2 0%. In Surgical series Morio signal changes in 97%. Low T1 and high T2 6%. Low T1 only 0%. Suri 2003, high T2 33%, Low T1 with High T2 67%.

Does cord signal changes predict outcome of conservative care?

Matsumoto 2000, 52 treated in collar for three months, when re-examined with MRI signal change regressed in 18%, and no change in 70%.

Does cord signal change predict results of surgery?

Suri 2003 146 patients treated by anterior or ant/post decompression. Patients without cord changes had significantly better motor outcomes than patient with low T1 and high T2 signal changes. No differences in neurologic recovery in patients without cord changes and high T2 only. Post-op MRI in 44 with pre-op cord changes showed regression in T1 20% and T2 12%. Padadopoulos 2004 42 patients treated by decompression, focal high T2 changes had better recovery than multi-segmental high T2. Patients with focal high T2 had same recovery as those without cord changes.

Is low T1-high T2 cord changes an indication for surgery?

This represents potentially irreversible histopathologic changes in the cord that correlates with severity of myelopathy. Surgical outcomes are better if these changes not present. Yes it is an indication for surgery but ideally operate before these changes occur.

Is High T2 cord changes an indication for surgery?

Yes, High T2 represents potentially reversible cord changes. It may respond to conservative care. Surgical outcomes no different in high T2 signal than no cord changes. This is a controversial indication for surgery.

Treatments

Lumbar stenosis treatment -What can I do to relieve the pain and numbness? Once you know you have lumbar spinal canal stenosis, you have several choices for treatment. Your treatment will depend on how bad your symptoms are. If your pain is mild and you haven't had it long, you can try an exercise program or a physical therapy program. This can strengthen your back muscles and improve your posture. Your doctor may also prescribe medicine to help reduce inflammation (soreness and swelling) in your spine.If you have more severe symptoms, you may need to see a spine surgeon. The surgeon may recommend surgery to take the pressure off the nerves in your lower spine. This surgery works well for many people.

An initial course of non-surgical therapy is recommended. Pain reduction with activity modification and relative rest. Strict bed rest no longer advocated. Patients become active as soon possible. Avoid heavy lifting and trunk extension. An elastic lumbar binder for a short period of time. Medications include Nonsteroidal anti inflammatory drugs, Muscle relaxants occasionally, Gabapentin and tricyclic antidepressants for neuropathic pain, Oral corticosteroids for acute flare-ups used briefly. Narcotics prescribed sparingly, cause constipation and habit forming. Therapy modalities and chiropractic treatment have no prospective randomized studies proving their benefit. Chiropractic manipulation is useful when the symptoms are posture dependent. Usually not recommended, but if desired, avoid extension manipulation. Epidural steroid injections reduce the radicular pain with analgesic and anti-inflammatory effects, and may facilitate progression to physical therapy. Acute radicular pain is best treated with a nerve-root block (NRB). Studies show 72% short-term benefit, 28% 2 year success with NRB, and 71% who initially requested surgery decided not to after NRB. Physical therapy is mainly flexion-based exercises, including exercises on a stationary bicycle and inclined treadmill, aquatic therapy, stretching and strengthening, and patient education on posture and daily activities. Non-surgical treatment can minimize the progression of symptoms but is unlikely to affect the underlying pathology. With non-surgical treatment four years later, the pain level is unchanged in the majority of patients and 42% were satisfied with the outcome. Although conservative measures may be of little long-term benefit, nonsurgical is the first line of treatment for lumbar stenosis, reserving surgery for intolerable pain, a progressive neurologic deficit, cauda equina syndrome (which is rare), and patients for whom conservative measures have failed.

Conservative Treatment Cervical Stenosis

An initial course of non-surgical therapy is recommended. Most often, early cervical stenosis can be treated with stretching and strengthening exercises, over the counter medications, and lifestyle modifications. Acute neck pain may be treated with a cervical collar for 6-12 weeks. Physical therapy such as modalities and electrical stimulation followed by isometric exercises may be added . Sometimes, acute flare-ups may be treated with a brief course of medications, including Nonsteroidal antiinflammatory drugs, Muscle relaxants occasionally, and Gabapentin or tricyclic antidepressants for neuropathic pain, Oral corticosteroids for acute flare-ups may be used briefly. Narcotics prescribed sparingly, cause constipation and habit-forming.  Epidural steroid injections reduce the radicular pain with analgesic and anti-inflammatory effects, and may facilitate progression to physical therapy. Traction is contra-indicated in myelopathy. Physical therapy is mainly stretching and strengthening, and patient education on posture and daily activities. In patients with myelopathy, non-surgical treatment can minimize the progression of radicular symptoms in the arms but is unlikely to affect the underlying pathology. With non-surgical treatment four years later, the pain level is unchanged in the majority of patients and only 42% were satisfied with the outcome. Although conservative measures may be of little long-term benefit, conservative options are the first line of treatment for cervical stenosis, reserving surgery for intolerable pain, a progressive neurologic deficit and patients for whom conservative measures have failed.

As a 61 year old real estate agent Mrs. T. is always on the go.  She began experiencing myelopathic symptoms. She has a long-term complaint of neck pain usually controlled with ibuprofen (Motrin™) and some home exercises. Occasionally, she wears a soft cervical collar to calm her neck spasms. In the past two months, however, she finds that her fingers are becoming clumsy, and she has to take frequent breaks. In addition, Mrs. T. is finding that she is not as agile buttoning her shirts in the morning. She is not complaining of any pain in the arms or legs. Interestingly, her legs are a bit wobbly, but she attributes that to some arthritis that has set in over the years.  Mrs. T. has had no problems urinating on her own, and no change in her bowel habits or control. Examination showed diminished reflexes in the arms and hyper-active reflexes in the legs. The MRI scan clearly showed that she suffered from multifocal cervical stenosis. Treatment may include physical therapy, medication, pain-blocking injections, or surgery.  She elected surgery that thankfully was without problem. After three months, she felt that her fingers were working better and she no longer felt wobbly in the legs. She returned to knitting, producing a blue baby bonnet for her newborn grandson.

Risk Factors for Spinal Stenosis

Is lumbar spinal canal stenosis the same as a ruptured disk? Lumbar spinal canal stenosis is not the same as a ruptured disk. A ruptured (also called "herniated") disk usually pinches 1 or 2 nerves at a time. The pain caused by a ruptured disk in the lumbar spine is usually easy to diagnose. This pain has a special name: "sciatica." Sciatica usually causes back pain that shoots down one leg. This pain can happen any time, not just when you stand up or start walking.

Spinal Stenosis Surgical Results

Lumbar decompression

Minimally invasive decompression through a narrow tubular retractor, by means of laminotomy and medial facetectomy. Under-cutting of the facet joint may relieve the nerve root pressure and maintain stability of the facet joints. In most cases, disc bulging or a small herniation, plays a role in the compression of the neural structures. Most common is severe arthritic facets causing compression in the lateral recess. Surgical decompression of the nerve root emerging from the thecal sac along its entire course distal to the pedicle by under-cutting the facet joints.

Jerry thought he would never play golf again at first the numbness in Jerry's right leg only lasted a few minutes.  A year later, Jerry was told not to play golf and to see a spinal specialist as soon as possible. By then, his left leg would go completely numb and felt weak every day. Bone spurs built up on his vertebra were causing the pain. Fortunately, the orthopedic spine surgeons in San Antonio, caught it in time and were able to perform minimally invasive spine surgery with a medical device that makes a small window onto the spine. The incision was less than one-half inch and required no sutures or stitches. Jerry was up and walking around just two short hours after the surgery. Within a few months, he was back to normal activity. Now, you might see him enjoying his golf game. Procedures like minimally invasive spine surgery are commonly performed for nerve pain here in San Antonio, rather than larger incision surgery.

Surgical Treatment of Central Stenosis

Until recently, total laminectomy was the standard method of decompression in central spinal stenosis. Since most compression of the neural structures occurs only at the level of the disc, has led to bilateral laminotomy, which preserves the central part of the lamina, thus causing less instability.

Discectomy: In stenosis, the disc often plays an important role in the compression of the neural structures. In most cases, the disc bulges into the spinal canal, but no true disc herniation is present. When the disc bulges only slightly, discectomy should be avoided. In the typical forms of degenerative stenosis, the disc is not involved in neural compression.

Arthrodesis: In central spinal stenosis alone, spinal fusion is needed in the following situations: when more than two thirds of the facet joints are resected; when there is abnormal instability of the motion segment; and in the presence of moderate or severe idiopathic scoliosis.

Surgery for Lateral Recess Stenosis

In most cases, disc bulging or a small herniation, plays a role in the compression of the neural structures. Most common is severe arthritic facets causing compression in the lateral recess. Surgical decompression of the nerve root emerging from the thecal sac along its entire course distal to the pedicle by means of laminotomy and medial facetectomy. Under-cutting of the facet joint may relieve the nerve root pressure and maintain stability of the facet joints.

As a 66 year old insurance analyst Rosa is always on the go. She began experiencing aches in her right leg, with walking or standing. Over the months it became difficult to do everyday things. Rosa was hardly able to walk at all. "I had to stop working," she says, "because the pain was too much." Rosa's MRI scan clearly showed that she suffered from lumbar stenosis. Treatment may include physical therapy, medication, pain-blocking injections, or surgery. "I told the doctor that I wanted to take out the problem," Rosa says. "Not just to feel better, but to actually recover my health." Surgery it was. Rosa's surgery was performed and afterwards Rosa slowly sat up. She put her feet on the floor, stood carefully, and took a step. And then another. The pain was gone. It's now two years later, and nothing can keep Rosa down. "I can walk everywhere I want to go. I walk as much as I can. Everything is like it was before the problem began."

Yukawa and Bridwell reported exercise testing on treadmill and bicycle before and after decompression for lumbar stenosis. Exercise outcomes were significantly improved in more than 90% with one or more levels of decompression. Yamashita et al reported patients with unilateral rather than bilateral leg pain had better functional and less leg pain after surgery.  Katz et al found the best predictor of less pain and greater walking capacity was good health and low cardiovascular comorbidity before surgery. Katz et al at 7-10 years found 1/3 had severe back pain after laminectomy. Lumbar decompression, fusion, and instrumentation is best with spondylolisthesis with instability. Iguchi et al found more than 50% of decompression patients had continued good functional result ten years later.

Cervical stenosis surgical treatment

Cochrane review 2002, on role of surgery in cervical spondylotic radiculomyelopathy, conclusions were that the data was inadequate to provide reliable conclusions on the balance of risk and benefit from cervical surgery. Surgery is indicated for progressive or significant arm pain or neurologic deficit with compression, instability at compressed level, or signal change in the cord (Low T1 High T2). Perssen 1997 81 patients with long-lasting radiculopathy surgically treated found pain, and neuro deficit showed improvement at three months, one year results compared to conservative care about equal. Myelopathy treatment Kadanka 2005 3 year PRT recommend non-operative care for older age, and canal area >70square mm, and recommend surgery if clinically worse myelopathy with small transverse area of spinal cord. The goal of surgery is to halt the neuropathic progression of myelopathy, relieve pain, prevent recurrence, and stabilize the unstable segments.

Surgical Treatment of Cervical Stenosis Myelopathy

There are several surgical procedures used to treat cervical spinal stenosis from the front or the back of the neck.  Both types of operations have the same goal - to relieve the pressure on the spinal cord by making the spinal canal larger. In some cases, laminectomy to remove the posterior roof of the spinal canal allows more room for the spinal cord. In other cases, an operation from the front such as a discectomy and fusion or a corpectomy (remove the body) and strut graft. This operation allows the surgeon to remove the vertebral body of the vertebra, along with any bone spurs  pushing into the spinal cord. Decompression for stenosis is a gratifying procedure, improving the quality of life for many patients who are prematurely disabled.

Treatment for cervical stenosis with myelopathy

The only effective treatment for myelopathy is surgical decompression of the spinal canal. If the patient also has a radiculopathy (myeloradiculopathy), conservative treatment may help relieve the arm pain. Myelopathy is a generally progressive condition that develops slowly. Symptoms may not progress for years, and then difficulties with coordination may suddenly increase. Unfortunately, the symptoms rarely improve without spine surgery to decompress the affected area. Surgical decompression may or may not improve the symptoms. Typically, the main goal of the spine surgery is to arrest the progressive nature of the condition and stabilize the patient’s neurological condition. Surgical decompression can be performed through an anterior (front) approach or posterior (back) approach. The type of approach is generally dependent on the surgeon’s preference and where the majority of the compression is located (in the front or back). Often, multiple levels need to be decompressed, so the spine surgery tends to be more involved than that for disc herniations or foraminal stenosis.

Minimal Surgery for Cervical  Foraminal Stenosis

In some cases, a small foramina disc herniation, or commonly severe arthritic facets causing compression in the lateral foramen. Surgical decompression of the nerve root emerging from the thecal sac along its entire course distal to the pedicle by means of key-hole laminotomy and Under-cutting of the facet joint may relieve the nerve root pressure and maintain stability of the facet joints.

Cervical Laminoplasty for Treatment of severe cervical spinal stenosis

Laminectomy

During cervical laminectomy the spinous process and lamina on both sides are removed. This enlarges the spinal canal by removing its roof and takes pressure off of the cervical spinal cord and spinal nerve roots. This procedure is more suitable for patients with stiff spines.

Laminoplasty

What is Laminoplasty? For patients with narrow spinal canals this procedure immediately relieves pressure on the nerves by creating more space beneath the lamina. This technique is often called open door laminoplasty because the lamina is made to swing open over the spinal nerves.   In laminoplasty, the laminae are reattached to preserve cervical is stability. This procedure may be done for younger patients with a supple spine.

Why do I need Laminoplasty?

To relieve the narrowing of spinal canal over multiple levels, due to thickening of spinal ligaments, bony outgrowths and calcification compressing the spinal cord, resulting in numbness, pain and weakness of the limbs, as well as difficulty walking normally.

Laminoplasty Procedure

An incision is made on the back of the neck, a groove is made on one side of the cervical lamina creating a hinge. The other side of the lamina is cut all the way through. The tips of the spinous processes are removed to create room for the bones to open wide like a door. The lamina is bent open to remove pressure on the spinal cord and roots. Small wedges of bone are placed in the opened lamina like wedging a door open. Small metal plates may be used to stabilize the door. The spinal cord rests comfortably behind the open door laminoplasty.

A neck collar may be worn for a month after surgery. Hospital stay may be several days.

What are Risks of Laminoplasty?

• General anesthesia risks
• Early risks of wound infection, hoarseness of voice, bleeding, and weakness of limbs
• Late risks are infection of implants, neck stiffness, and rarely displacement of implant or instability of the spine.