Guest Discussants: Sayed E Wahezi, MD, Andrew Lederman, MD, Eric H Elowitz, MD Feature Editor: Jaspal Ricky Singh, MD
What is radiculopathy?
Radiculopathy is a condition brought about a compressed or irritated nerve in the spine that can cause pain, numbness, tingling, or weakness along the path of the nerve. Radiculopathy can occur in any part of the spine, but it is most common in the low back (lumbar radiculopathy) and the neck (cervical radiculopathy). Patients involved in heavy labor or contact sports are more prone to develop radiculopathy than those with a more sedentary lifestyle.
Spinal disks are located between each vertebra of the spine, acting as shock absorbers when the body moves. A disk is made up of a tough fibrous outer surface, with a soft, gel-like inner substance.
A forceful movement can injure the lumbar spinal disks, or repetitive straining can gradually damage them over time. With a mild injury, the disk can be stretched or pinched. With a more severe injury, the outer surface can be weakened, allowing the substance inside to push towards the outside. This is known as a bulging or herniated disk. Disk herniation reduces the amount of space in the spinal canal and compresses the exiting nerve. Doctors call this “mechanical radiculopathy.”
With further damage, the outer surface can tear, and the disk fluid inside might leak out. This tear is called complete herniation or extrusion. The disk material may then irritate nearby nerves (known as inflammatory neuritis) as they exit the spinal cord. Doctors refer to this condition as “chemical radiculopathy.”
How is radiculopathy diagnosed?
The diagnosis of radiculopathy starts with a medical history and physical examination. During the medical history, the doctor asks questions about the type and location of symptoms, how long they have been present, and what makes them better and worse.
By knowing the exact location of the patient’s symptoms, the doctor tries to determine the nerve that is responsible. Neurological tests are performed to determine loss of sensation and motor function. Abnormal reflexes and muscle weakness may indicate a source of the radiculopathy. Imaging may also be done.
Plain X-rays can often see the presence of trauma or osteoarthritis and early signs of tumor or infection. A magnetic resonance imaging (MRI) or computed axial tomography (CAT) scan looks at the soft tissues, nerves, muscles, etc., around the spine to determine possible compression of the nerves. In some cases, the doctor may order an electromyogram (EMG), which can show if there is damage to the nerve.
How is radiculopathy treated?
Most radiculopathy symptoms go away with conservative treatment—for example, anti-inflammatory medications, physical therapy, chiropractic treatment, and avoiding activity that strains the neck or back. Symptoms often improve within 6 weeks to 3 months. If radiculopathy symptoms do not improve with conservative treatments, patients may benefit from an epidural steroid injection (ESI), which reduces the inflammation and irritation of the nerve. Read more about ESIs.
If the symptoms continue despite all of the above treatment options, surgery may be an option. The goal of the surgery is to remove the compression from the affected nerve. Depending on the cause of the radiculopathy, this can be done by a diskectomy or micro-diskectomy. A diskectomy removes the part of the disk that has herniated out and is compressing a nerve. In a micro-diskectomy (or microdecompression) spine surgery, a small portion of the disk and disk material impinging the nerve root is removed to provide more room for the nerve to heal.
In the June 2015 issue of Pain Management & Rehabilitation Journal, three physicians shared differing opinions about treatment for lumbosacral radiculopathy with muscular weakness and loss of reflexes. A patient’s case is presented here, followed by a debate as to the best treatment plan. Drs Sayed Wahezi and Andrew Lederman will argue that a conservative treatment plan will help the patient regain full function. Dr Eric H Elowitz suggests that surgery will provide the best outcome.
Logan, a healthy, 28-year-old man, injured himself while skiing. The same evening as the accident, Logan experienced pain that traveled from his right lower back, buttock, and thigh to his right calf. Also, he had a slight limp and decreased strength in his big toe.
Logan comes into the spine clinic 5 days after the injury. At this time, he is almost pain-free and says that he is not getting any weaker.
Logan’s physical examination indicates he has no Achilles reflex on his right leg. He is unable to complete a single-leg heel raise on his right side. Logan can flex his ankle and his extensor hallucis longus (EHL) strength is 4 out of 5. (The EHL muscle is responsible for extending the big toe: its strength is a predictor of L5 nerve root radiculopathy.)
An MRI of Logan’s lumbar spine shows an extruded disk between the L5 and S1 vertebrae, which is compressing the S1 nerve root.
Sayed E Wahezi, MD, and Andrew Lederman, MD, respond
Logan’s treatment plan is up for debate because current research supports both nonsurgical and surgical intervention.
Logan has persistent weakness, and his pain is going away. We recommend an ESI because Logan likely has chemical radiculitis. The painful symptoms already have subsided, and motor recovery will likely follow. If a compressed nerve were the cause, pain would likely persist.
A bulging disk is a contained herniation, whereas a complete herniated disk is extruding (or leaking). With an extruding disk herniation, the gelatinous nucleus does not create significant nerve compression, but rather a chemical irritation. Resolution of symptoms can occur on their own or with ESIs, but studies show that patients with complete herniated disks have a better chance of recovery than those with bulging disks.
Logan’s case is an example of a complete herniated disk. The herniated disk is the cause of Logan’s muscle weakness. Understanding the composition of the extruded disk material is critical to understanding our case.
Herniated disk material is primarily the gel-like substance that cushions the vertebrae. Due to its chemical composition, this material promotes inflammation. When it comes into contact with the nerve root, nerve pain occurs. We will demonstrate that Logan’s symptoms indicate chemical radiculitis as the cause of his radiculopathy.
As in Logan’s case, radiculopathy with muscle weakness is likely caused by defective nerve conduction. Chemical radiculitis causes nerve damage due to the direct contact of the thick disk material with the nerves, causing inflammation and decreasing normal neural transmission. The nerve heals as the disk herniation recedes from the nerve and the chemical irritants go away. Chemical radiculitis usually responds well to conservative treatment, while mechanical radiculitis may not.
A complete disk herniation, as in Logan’s case, often improves without surgery because of the absorption of the disk material back into the body. In clinical practice, most disk herniations with muscle weakness are caused by inflamed nerves, rather than compression. In fact, most patients’ symptoms improve with conservative treatment alone. Although the presence of muscle weakness as a result of a herniated disk can be a sign of severity, the literature does not conclusively support the immediate necessity of surgery.
Epidural steroid injections (ESIs), physical therapy, and oral anti-inflammatory medicine are necessary in treating chemical radiculopathy because they all help reduce inflammation. ESIs decrease the chemical irritation to neighboring nerve roots.
Some investigators have even demonstrated the effectiveness of ESIs without steroids, which supports the theory that diluting or “washing away” inflammation-inducing material adjacent to a nerve also could reduce symptoms. Physical therapy may improve spinal blood flow as well as cerebrospinal flow, adding to the washout concept. Finally, oral anti-inflammatory medicine improves the local inflammation.
The decision to perform surgery is a clinical one; we must consider the type of herniation, partial or complete herniation, as well as the patient’s pain state. Evidence supports a trial of conservative therapy when there is mild weakness (greater than 3 out of 5) before considering surgery because the duration of symptoms before surgery does not change the rate of postoperative motor recovery.
In Logan’s case, he has chemical radiculitis with mild muscle weakness. His MRI, which depicts a disk extrusion, and his pain that went away on its own, both support this diagnosis. An ESI may reduce local inflammation, ultimately leading to resolution of his chemical radiculitis.
In our current environment of cost-conscious medicine, we must consider the cost of the services we offer our patients. A head-to-head cost analysis favors conservative, non-surgical treatments, including ESI, physical therapy, and potentially oral medications, for this patient.
Disk extrusions often improve on its own, so Logan’s case is not unusual. A trial of ESI has a better chance of improving short-term outcomes than worsening long-term outcomes. Furthermore, Logan’s other factors support conservative therapy: young age, new symptoms, mild muscle weakness, and the limited number of muscles involved, all favor a good prognosis without surgical intervention.
If we were treating this patient, we would closely monitor Logan’s weakness and schedule Logan for an ESI. At this point, we are comfortable watching Logan’s neurologic function, and if there is no return of strength or even progression of weakness in the ensuing 4-6 weeks, we would then consider surgery.
Eric H Elowitz, MD, responds
The management of Logan’s condition can be quite controversial. Although his muscle weakness can sometimes appear trivial to the examiner, it can have an adverse impact on function and self-image in active patients. Herniated lumbar disks, one of the most common problems seen by physicians, can produce back pain and other symptoms, including lower extremity pain, numbness, and weakness.
The treatment recommendations for a patient with a herniated disk are based on the initial physical examination, as well as MRI images. Therapeutic options include physical therapy, EPIs, oral steroidal and nonsteroidal anti-inflammatory medications, and surgery. Although herniated lumbar disks are common, there is no standard for the timing and order of these therapeutic options.
Logan is a young, active man with radiculopathy. He is unable to perform a single-leg heel raise, and his MRI scan indicates an extruded disk herniation with S1 nerve root compression. Patients with muscle weakness are clearly more of a treatment concern than those who present with pain alone. In fact, Logan no longer has pain. In treating patients with herniated disks and radiculopathy, the goals of treatment may vary. Patient expectations, age, and activity level all play into the proposed therapy.
Although most patients with herniated disks should initially be treated nonsurgically, early surgical intervention can be indicated in selected patients. I believe that, in Logan’s case, a minimally invasive microdiskectomy would be the best treatment.
Significant variation exists in diskectomy rates. The Spine Patient Outcomes Research Trial (SPORT) assessed the efficacy of surgery in patients with herniated lumbar disks. Eligible patients were assigned to either the surgery or nonsurgical treatment groups; however, patients could crossover between groups. Patients in both the nonsurgical as well as in the surgery groups achieved substantial improvement over 2 years. A follow-up study of patients at 4 years found that those who underwent surgery achieved greater improvement than patients who did not undergo surgery.
In our scenario, Logan has muscle weakness caused by extruded disk herniation. There are few studies in the literature that specifically address the timing of surgery in such patients. Studies evaluated the recovery of motor function after a microdiskectomy.
Overall, there was a full recovery in muscle strength in 84% of patients with mild muscle weakness and 61% with severe muscle weakness. Regarding the timing of surgery, all patients with a severe deficit undergoing surgery within 1 month of the onset of weakness had a complete recovery in contrast to those undergoing surgery after 70 days, where most had an incomplete recovery of muscle strength. This finding would argue for early surgery in patients with a severe deficit.
A review of patients with muscle weakness who underwent surgery showed a significant improvement in strength. Maximal recovery occurred within 6 weeks in most the patients.
In evaluating patients with radiculopathy and muscle weakness, I take several factors into consideration. Clearly, the degree of weakness as well its functional impact on Logan must be weighed. One can assume that Logan is a high-level functioning young man who would find even a mild residual muscular weakness and loss of reflexes to be unsatisfactory. In such a patient, I would be much more inclined to recommend surgery earlier rather than later to decompress the nerve root.
Another factor is the MRI findings. I would lean more toward early surgery in patients with a disk herniation or an extruded fragment that is causing significant nerve root compression. In patients with smaller herniations or less-obvious nerve root compression, I would feel more comfortable in nonsurgical measures initially.
Another factor arguing for surgery in Logan’s case is the safe and minimally invasive nature of modern-day microdiskectomies. This surgery is provided on an outpatient basis, and most patients can return to work within a week. The recurrence rates are low, generally in the 3-5% range, and the complication rate is extremely acceptable.
Clearly, the treatment of any patient with a herniated lumbar disk has to be customized to their clinical presentation and with a clear goal in mind. For Logan, the goal would be an improvement in his motor strength to prevent permanent disability. As such, I would recommend an early microdiskectomy rather than nonsurgical treatment to maximize his chance of a complete recovery. With early decompression, the nerve root would be given an opportunity to heal and subsequent treatment, such as a physical therapy, may have a better chance of success in regaining his strength. Ultimately, the decision would have to be one shared between the physicians involved and Logan with a clear understanding of the treatment goals.
Compressed nerve: Sometimes called a pinched nerve, this condition is caused when if a spinal disk weakens or tears and puts pressure on a spinal nerve.
Motor function: The ability of the nerves to convey sensory and motor impulses to the body.
Radiculitis: Terminology used to describe the neurological symptoms felt as a nerve is pinched, compressed, irritated, or inflamed.
Radiculopathy: A set of conditions in which one or more do not work properly, resulting in pain, weakness, numbness, or difficulty controlling specific muscles.
Spinal nerve: A nerve that carries motor, sensory, and autonomic signals between the spinal cord and the body. There are 31 pairs of spinal nerves, one on each side of the vertebral column.
Vertebrae: The bones that make up the spinal column. In between each vertebra lies a disk.
The complete list of references supporting this article can be found in the original journal article.