Spine imaging for chronic neck pain: a brief review

It is estimated that at least 15% of the US adult population suffer from chronic neck pain. While cervical intervertebral discs, cervical facet joints, atlanto-axial and atlanto-occipital joints, ligaments, fascia, muscle, and dura have all been shown to be potential causes for neck pain, it is often difficult to identify the exact cause of the pain. Spine imaging is often helpful in identifying targets for intervention.

Plain radiographs, MRI and CT scans have all been utilized as imaging modalities for diagnosing neck pain. Indications for radiographic imaging include age >50 with new symptoms, constitutional symptoms such as fevers or unexplained weight loss, moderate to severe pain lasting more than six weeks, progressive neurologic findings, infectious risk such as IVDA or immunosuppression, and history of malignancy.

Plain films often include a cervical series of seven views, including odontoid, lateral, AP, two oblique views, lateral view in flexion, and lateral view in extension. However, as the flexion and extension views have not been shown to lead to findings that changed clinical management, often they are excluded. Lateral views demonstrate vertebral alignment, screens for osteoarthritis and disc space narrowing, and may demonstrate bony pathology such as compression fracture. Oblique views are used to diagnose foraminal encroachment. AP views best show lateral spine deviation, while odontoid views are appropriate in acute trauma.

MRI and CT are more sensitive than plain films for diagnosing disc herniation, spinal cord compression, infection and malignancy. While MRI is preferred for soft tissue processes such as tumor, central stenosis, and disc herniation, CT is better for facet osteoarthrisis or other osseous changes. CT scans are not able to identify intramedullary pathology such as spinal cord tumors, and have the downside of significant radiation exposure.

In addition to spine imaging, fluroscopically guided diagnostic procedures such as cervical facet joint block have been shown to be helpful in establishing the etiology of neck pain. By injecting local anesthetic into the facet joint, the amount of immediate relief experienced by the patient is useful in determining if the facet joint is the source of pain. Cervical facet joint interventions such as therapeutic cervical medial branch blocks and radiofrequency neurotomy of medial branches in the cervical spine have fair evidence in terms of efficacy of pain relief. Intraarticular injections, on the other hand, had limited evidence for efficacy.

Fluroscopically guided epidural steroid injections have also been shown to be effective in providing short term relief of cervical radicular pain. Long term benefits are less certain, with few studies comparing the intervention to a true placebo group.

Spine imaging for chronic neck pain is helpful in both diagnosis and, when coupled with fluoroscopically guided pain procedures, provides therapeutic relief of this prevalent condition. Even general anesthesia providers should have a basic understanding of these concepts, as many of our patients are likely to have undergone similar evaluations and procedures.


References:

Falco FJ, Manchikanti L, Datta S, Wargo BW, Geffert S, Bryce DA, Atluri S, Singh V, Benyamin RM, Sehgal N, Ward SP, Helm S 2nd, Gupta S, Boswell MV. Systematic review of the therapeutic effectiveness of cervical facet joint interventions: an update. Pain Physician. 2012 Nov-Dec;15(6):E839-68.

House LM, Barrette K, Mattie R, McCormick ZL. Cervical Epidural Steroid Injection: Techniques and Evidence. Phys Med Rehabil Clin N Am. 2018 Feb;29(1):1-17. doi: 10.1016/j.pmr.2017.08.001. Epub 2017 Oct 16.

Isaac, Z. (2018). Evaluation of the patient with neck pain and cervical spine disorders. In Sullivan, DJ and Lee, SI (Ed), UpToDate.

Managing and Monitoring Pediatric Pain with a Mobile App

Pain management is a crucial component of surgical recovery for any patient, but there are unique concerns and challenges that comes with managing pain in pediatric patients. While the inherent vulnerability of children is deeply felt by clinicians and families alike, postoperative pain is nevertheless undertreated in this population. A major driver of this issue is that many common procedures require little time in the hospital, leaving most of the recovery to happen at home. Neglected postoperative pain creates short-term issues of sleep disruption, stress, and delayed recovery but can also lead to serious long-term consequences, or even disability.1

A central barrier to effectively managing pain following a procedure is reliably assessing a young patient’s pain level.2 This task most often falls to parents and other caregivers, and is deceptively difficult. Research reveals two major challenges in pain reporting: a child’s ability to identify and name their pain, and the reliability of measurement instruments to consistently guide a clinical response. Opioids are unsurprisingly a central tool for effectively treating pain in children. For acute pain in particular, they are a powerful option that can provide uniquely immediate relief. However, there are known risks and side effects associated with opioid use that merit heightened caution when opiods are being used by children. Understanding a child’s experience of pain is key to responding with the appropriate balance of analgesics, and this can place an immense amount of pressure on caregivers at home.

Self-reporting is the clinically preferred way to assess pain in children.3 However, this approach to pain measurement can be difficult among children for reasons that any parent could probably guess—a child may be afraid that sharing about their pain will cause them to return to the hospital, for example, or their social environment might cause them to overstate or understate their pain level. Commonly used instruments take various forms of visual and verbal rating scales, but the evidence is mixed on which tools are the most rigorous and widely applicable across the many developmental stages of childhood.


What if there was a way to solicit a child’s experience of pain through a familiar, less clinical and engaging instrument? This is where the recently developed Panda pain management mobile app is poised to make a difference. The Panda app seeks to improve pediatric postoperative pain management through an engaging and easy-to-use platform. Parents or other caregivers use the app’s walkthrough design to assess and record important aspects of their child’s pain. Then, the app guides them in making decisions about when and how to administer pain medication, tracking when medication is administered to keep families on schedule for future dosages. Users receive medication alerts directly from their phone, much like the many apps families already use to schedule and track their commitments and routines.

 

Panda was developed by researchers at the University of British Columbia and has already seen promising results in the controlled setting of in-hospital use. Parents piloting the app with the guidance of clinical staff reported that the app was easy to use and could see themselves using it in the home setting.4 The app is currently being evaluated for in-home use.

Providing families with an easy-to-navigate tool to not just identify pain in children following surgery, but also connect those pain measurements to a medication schedule, could be an important step in better addressing this neglected area of pain management. Pain management is a complex aspect of clinical care for patients regardless of age, and the special concerns of pediatric patients demand innovation beyond merely adapting adult guidelines for younger patients. There are exciting possibilities for the use of smartphone apps like Panda in better describing and alleviating pain in children. Tools that fit neatly into a familiar routine, like a smartphone app, may reduce some of the stress parents face in managing complex pain without clinical support.


References

[1] Porter FL, Grunau RE, Anand KJ: Long-term effects of pain in infants. J Dev Behav Pediatr 1999; 20:253–61Porter, FL Grunau, RE Anand, KJ

[2] Chou, Roger, et al. “Management of Postoperative Pain: a clinical practice guideline from the American pain society, the American Society of Regional Anesthesia and Pain Medicine, and the American Society of Anesthesiologists’ committee on regional anesthesia, executive committee, and administrative council.” The Journal of Pain 17.2 (2016): 131-157.

[3] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3983412/

[4] https://www.researchgate.net/publication/316853501_Feasibility_of_Panda_a_Smartphone_Application_Designed_to_Support_Pediatric_Postoperative_Pain_Management_at_Home

Herniated Lumbar Disc

Herniated Lumbar Disc also known as Lumbosacral Radiculopathy (“slipped disc”, “ruptured disc”) is a medical term for the pain (lower back and legs), numbness, tingling and weakness associated with a herniated disc in the lumbar (lower back) region. Patients often undergo significant suffering and reduction in quality of life with this condition. It is the most common type of disc herniation. Lumbosacral disc herniation occurs in the lower back region, typically between the fourth and fifth lumbar (L4-L5) or fifth lumbar and first sacral (L5-S1) vertebral bodies but can occur in any disc of the lumbar spine. The essence of the condition is a tear in the fibrous outer ring of the disc between vertebrae which then allows for the central component (nucleus pulposus) to protrude out. This nucleus pulposus carries a cascade of inflammatory chemicals that often irritate and compress lumbar spinal nerves causing symptoms. This can occur spontaneously or from trauma, lifting, and straining of the lower back.

Symptoms of this condition depend on the location and severity of the herniation. In terms of location, there are five lumbar vertebral bodies with discs between them (these are the ones that can herniate) with 2 spinal nerves exiting at each level. Vertebral discs provide support and mobility for the lower back region. Severity is often caused by how much of the disc has herniated and subsequently compressed the surrounding lumbar spinal nerve. Patients’ symptoms can range from mild sensory changes in the lower back, buttock, thigh, foot or toe to numbness, tingling, paresthesia, sharp shooting pain, muscle weakness, and leg paralysis. Severe symptoms, including loss of bowel or bladder function, should warrant immediate medical evaluation.

Diagnosis and Management

Diagnosis of lumbar disc herniation is a clinical one often resulting from the history provided by the patient along with specific physical examination findings. Examination includes a thorough neurological examination to uncover motor, reflex, and sensory changes. This will often lead to the “culprit” lumbar nerve root that is affected by a lumbar disc herniation. Other signs include diminished leg reflexes and a positive straight leg raise. There is no “gold standard” for diagnosing lumbar disc herniation but often imaging, specifically MRI, is very helpful. Imaging may point to the existence of a specific location of disc protrusion. A positive correlation with symptoms may aid in the diagnoses. There is a high degree of variability in the symptoms experienced by patients. Most concerning is worsening pain and weakness in the leg. Other possible diagnoses for back/leg symptoms are lumbar facet syndrome, myofascial pain syndrome, and spinal stenosis.

Generally, lumbar disc herniations will heal on their own with conservative measures (including rest, ice, heat, anti-inflammatory medications). If symptoms do resolve, they often do in a period of weeks to a couple of months. Initial treatment involves conservative measures including education, light exercise, medications (a short course of anti-inflammatories), physical therapy, body mechanics, lumbar traction, and weight control. More invasive treatments include interventional pain injections (lumbar epidural steroid injections, spinal cord stimulation) and/or surgery (most commonly lumbar decompression or laminectomy). Lumbar epidural steroid injections involve depositing a small quantity of steroid and local anesthetic mediation, using X-ray image guidance, onto the affected lumbar spine nerve. These may often be repeated every 3-6 months depending on the symptoms. Indications for surgery include patients with ongoing leg pain despite 6-8 weeks of conservative treatment along with signs of motor or saddle weakness.

Herniated Cervical Disc

Background/description

Herniated Cervical Disc also known as Cervical Radiculopathy (“slipped disc”, “ruptured disc”) is a medical term for the pain (neck and arms), numbness, tingling and weakness associated with a herniated disc in the cervical (neck) region. Patients often undergo significant suffering and reduction in quality of life with this condition. It is the second most common type of disc herniation, following lumbar (back) disc herniation. Cervical disc herniation occurs in the neck region, usually between the lower cervical vertebral bodies but can occur in any disc of the cervical spine. The essence of the condition is a tear in the fibrous outer ring of the disc between vertebrae which then allows for the central component (nucleus pulposus) to protrude out. This nucleus pulposus carries a cascade of inflammatory chemicals that often irritate and compress cervical spinal nerves causing symptoms. This can occur spontaneously or from trauma, lifting, and straining of the neck.

Symptoms of this condition depend on the location and severity of the herniation. In terms of location, there are seven cervical vertebral bodies with discs between them (these are the ones that can herniate) with 2 spinal nerves exiting at each level. Vertebral discs provide support and mobility for the neck region. Severity is often caused by how much of the disc has herniated and subsequently compressed the surrounding cervical spinal nerve. Patients’ symptoms can range from mild sensory changes in the neck and arms: numbness, tingling, paresthesia to sharp shooting pain, muscle weakness, and arm paralysis. Severe symptoms should warrant immediate medical evaluation.

Neck Pain

Diagnosis and Management

Diagnosis of cervical disc herniation is a clinical one often resulting from the story (history) provided by the patient and the physical examination findings. Examination includes a thorough neurological examination to uncover motor and sensory changes. This will often lead to the “culprit” cervical nerve root that is impingement by a cervical disc herniation. Other signs include increase in arm reflexes and a maneuver known as Spurling’s, where downward pressure is applied by a physician on a patient’s neck to recreate arm tingling and numbness. There is no “gold standard” for diagnosing cervical disc herniation but often imaging, specifically MRI, is very helpful. Imaging may point to the existence of specific locations of disc protrusion and if correlating with the symptoms may aid in the diagnoses. There is a high degree of variability in the symptoms experienced by patients. Most concerning as worsening pain and weakness in arm. Other possible diagnoses for neck/arm symptoms are nerve entrapment medical conditions such as carpal tunnel (median nerve) syndrome and cubital tunnel (ulnar nerve) syndrome. These can often be diagnosed clinically with the support of a nerve conduction study.

Most cervical disc herniations will heal on their own with conservative measures (include rest, ice, heat, anti-inflammatory medications). Most of the time the symptoms involve pain, numbness, and weakness in the arm. If symptoms do resolve, they often do so in a period of weeks to a couple of months. Otherwise, initial treatment often begins with conservative measures including education, light exercise, medications (short course of anti-inflammatories), physical therapy, body mechanics, cervical traction, and weight control. More invasive treatments include interventional pain injections (cervical epidural steroid injections) and/or surgery (most commonly anterior cervical discectomy and fusion – ACDF). Cervical epidural steroid injections involve depositing a small quantity of steroid and local anesthetic mediation, using X-ray image guidance, onto the affected cervical spine nerve. These may often be repeated every 3-6 months depending on the symptoms. Indications for surgery include patients with ongoing arm pain despite 6-8 weeks of conservative treatment along with signs of motor weakness.

Sacroiliac Disease

Background/Description

Sacroiliac (SI) disease (also known as SI joint dysfunction, SI syndrome) is an inflammation in the joint connecting the pelvis (iliac bones) to the sacrum. It is often caused by a dysfunction in the mobility of the joint (too much movement, too little movement). This dysfunction can be a debilitating source of back pain and suffering for patients. This highly complex joint is surrounded by numerous muscles, ligaments, and cartilage that intricately function with one another to provide stability in normal everyday movements. Symptoms include lower back or buttock pain, groin or hip pain. This pain can be sharp or dull and often worsens with activity and movement. Some patients also complain of tingling and numbness in the pelvic region. Standing, sitting, lying in a prolonged position often worsens this numbness and pain. If symptoms are severe and chronic enough this can often lead to depression, social isolation, and insomnia.

Diagnosis and Management

Often overlooked as a source of pain, sacroiliac disease is part of many possible sources of lower back/buttock pain or dysfunction. Imaging studies (X-ray, CT, MRI) are often not specific enough to diagnose SI disease. More commonly, it is diagnosed by a physician with a series of physical examination signs known as provocative testing. A detailed history relayed by the patient is also an important part of diagnosis. The most specific way of diagnosing this joint disease is to undergo a diagnostic Sacroiliac joint injection (X-ray, ultrasound) by a physician with additional training in pain medicine. A substantial relief in pain from this injection is a specific indicator of pathology in the Sacroiliac joint.

Management of sacroiliac disease and treating its resultant back pain includes conservative and invasive treatments. Conservative measures include anti-inflammatory medications, ice/heat, rest, and physical therapy. Manipulative, massage, and manual therapy are additional measures in this category. More invasive treatments include steroid injections and in severe cases, surgery. Steroid injections are low risk procedures (with image guidance) that deposit strong anti-inflammatory medication directly into the joint. This is often followed by a series of physical and manual therapy sessions to encourage adequate movement and mobility of the joint. Periodic steroid injections are often adequate in providing patients with significant pain relief and in improving quality of life. New technologies have emerged in the field of neuromodulation in cases where injections and surgery have not sufficiently reduced pain. These interventions utilized low and high frequency signals to provide a means of overriding the SI joint pain generator. A patient should ask her physician questions about all these possible treatments in order to start the path of healing and recovery.

Selective Cannabinoids: A Potential Adjuvant for Chronic Neuropathic Pain?

Neuropathic pain is an elusive target for anesthesia pain specialists. A small class of anti-epileptic and antidepressant mediations has been the mainstay of medical therapy for neuropathic pain, and it has been put forward that only one in three patients who suffer from this particularly recalcitrant condition has an analgesic response to treatment.

In searching for potential new therapies for neuropathic pain, selective cannabinoids (synthetic cannabinoids containing only tetrahydrocannabinol [THC]) have emerged in the past decade as a drug class of interest. Cannabinoid receptors play a role in pain modulation by inhibiting pain responses, and also interact with various other receptor systems such as GABA, opiate, serotonergic and adrenergic, many of which are current targets for neuropathic pain medications.

A recent meta-analysis attempted to examine the efficacy of selective cannabinoids in treating neuropathic pain refractory to first and second-line agents. A database search was conducted for randomized control trials (RCT) comparing selective cannabinoids (dronabinol, nabilone, and nabiximols) containing synthetic THC, or a combination of extracted THC and CBD, versus placebo or standard treatment.

Selective Cannabinoids11 RCTs were selected for inclusion. All studied neuropathic pain patients, but there was variability in the etiology of this pain and its distribution. Variation also existed in which cannabinoid was used (1 dronabinol trial, 3 nabilone, and 7 nabiximols) and for how long (2 to 15 weeks), as well as the dosages. Primary outcome in all studies was pain score, with a multitude of secondary outcomes including physical function, quality of sleep, anxiety, and patient satisfaction. Not all secondary outcomes were examined across all studies (e.g. only three included physical function).

Metanalysis of the 11 RCTs showed that with regard to the primary outcome of pain scores (measured on the numerical rating scale and measured at least two weeks after therapy initiation), there was a statistically significant but clinically small reduction in pain scores in the selective cannabinoids group (mean difference −0.65 points; 95% CI, −1.06 to −0.23 points; P = .002, I2 = 60%).

For secondary outcomes, quality of sleep and patient satisfaction were significantly improved. Only one of the three studies that examined physical function reported an improvement. Six out of the seven studies that examined quality of sleep found an improvement. Only one of the three studies that examined anxiety reported an improvement. Five of the six studies that examined patient satisfaction reported positive results.

Adverse effects of selective cannabinoids studied by the 11 included RCTs were mostly mild to moderate. Most common were dizziness/lightheadedness, somnolence, and dry mouth. Rarely there were severe adverse effects requiring withdrawal from the trials: confusion (2 patients), headache (1 patient), agitation and paranoid ideation (2 patients).

Overall, the small clinical reduction in pain scores must be weighed against the potential for adverse effects. Sleep quality and patient satisfaction are likely secondary benefits. Weaknesses of this meta-analysis include wide heterogeneity of trials and likely publication bias. Further research is needed to standardize dosages and duration of treatment, as well as better define adverse effects.

References

  1. Meng H, Johnston B, Englesakis M, Moulin DE, Bhatia A. Selective cannabinoids for chronic neuropathic pain: a systematic review and meta-analysis [published online May 19, 2017]. Anesth Analg. doi:10.1213/ANE.0000000000002110

Causes of Neck Pain

Neck pain can be caused by a variety of factors, mostly benign but some serious. A careful history, physical and appropriate diagnostic studies can help a doctor determine the diagnosis and plan an appropriate course of treatment that hopefully results in neck pain relief.

A careful history should include questions pertaining to causative and related events such as infections, injury, stress or medications. The duration, nature of the pain, origin and associated symptoms such as weakness, numbness and tingling are important in determining a diagnosis. Alleviating or aggravating factors as well as surgical history are also important factors in determining the cause of the neck pain.

During physical examination to evaluate neck discomfort, your physician will first inspect your neck for any visual abnormalities. She/he will may then palpate the soft tissues and bony structures of your neck to check for signs of infection or other structural issues. Reproduction of neck pain with certain motions during the physical exam may assist your physician in determining a diagnosis. One example of this is the compression test, where your physician may press down on your head to reproduce the pain associated with nerve compression or a pinched nerve in your neck.

The anatomy of the neck, or cervical spine, is complex. It consists of seven cervical vertebrae (bones that provide structural support and house the spinal cord in the neck), eight cervical nerves that are derived from the spinal cord in the neck, inter-vertebral disks that lie between the vertebral bodies and act as a cushion, as well as joints that hold the vertebrae together and allow motion. These joints are lined by cartilage. Ligaments also help support the bony structure of the neck. The cervical nerves also divide into more nerves that innervate much of the head, the neck, the arms and other parts of the upper body. This elaborate structure and the complex signal processing mechanisms of the nerves, can be affected by numerous pathological states. In other words, there are numerous conditions that can cause neck or cervical spine pain.

One of the most common causes of neck pain is injury. This can result from an acute process such as an accident or repetitive stress and strain. Most neck pain causes are a result of such injuries or trauma. A very common neck injury is whiplash syndrome resulting from an automobile accident, especially a rear end collision. Whiplash refers to the injury secondary to sudden hyperextension of the neck from an indirect force i.e. one not directly applied to the neck. Symptoms of whiplash injury may not occur for up to 24 hours after the injury because it may take this long for bleeding and swelling to develop as a response to the injury. About one in ten patients experience loss of consciousness and almost all patients develop neck pain and stiffness. The neck pain may radiate to the arms. A fair number also develop headaches and shoulder pain.

Severe whiplash injury may result in damage to a cluster of nerves known as the cervical sympathetic chain, resulting in nausea, dizziness and ringing in the ears. Long term complications resulting from damage to the cervical sympathetic chain include a condition known as complex regional pain syndrome.

The diagnostic work up of neck trauma may involve X-rays to evaluate the cervical spine for bony damage and/or soft tissue injury. An MRI or a CT scan may be warranted for a more detailed diagnostic workup especially when symptoms persist or there are significant neurological symptoms. CT and MRI are more helpful than X-rays in evaluating soft tissues, disk abnormalities and nerve root compression, also called a “pinched nerve”. Electromyography is a diagnostic test that may be utilized to test for nerve compression/damage as well.

Myofascial pain syndrome is a common cause of chronic neck pain. It results in pain that is referred from trigger points, which are tender knots in the muscle. These trigger points restrict full lengthening of muscles and can weaken them. Pressing on a trigger point can cause pain at the site as well as in a referred pattern, i.e. pain away from the cause of the pain. They appear to results after an acute episode of muscle stress or strain. The muscle contracts, decreasing blood flow to the area. Nerve fibers connect the trigger point to the spinal cord and cause the pain to travel. Other symptoms such as sweating and erection of body hair, or piloerection, may also result. The pain is typically described as steady, deep and aching.

Myofascial pain can be exacerbated by viral illness, exposure to cold, strenuous exercise, typing, driving, carrying heavy shoulder bags and certain sleeping positions. This condition may coexist with other cervical spine disorders and can mimic these disorders as well, such as a herniated disk. Medical management of myofascial pain involves non-steroidal anti-inflammatory drugs and certain types of anti-depressants known as tricyclic anti-depressants, or TCAs. Procedures performed on trigger points include passive stretching after applying vapo-coolant or injection of the trigger points with local anesthetics and sometimes steroid. When symptoms are resistant to such management, epidural steroid injections or specific nerve blocks can be considered. Home remedies include passive stretching while taking a hot shower and applying moist hot packs.

Torticollis is a severe contracture of neck muscles that typically results in the head being painfully twisted to one side with the chin pointing to the opposite side. This pattern is secondary to the involvement of the SCM, or sternocleidomastoid muscle, one of the two most commonly involved muscles in the neck and upper back. Torticollis can be congenital (present at birth) or secondary to injury to the muscles and tissues of the neck. It can also be the result of disease to the central nervous system. Torticollis may result in permanent contracture of the neck muscles.

In trying to classify torticollis, your physician may order x-rays and if there is a specific neurologic deficit associated with the condition, an MRI or CT scan may be warranted.

Spasmodic torticollis can be treated with medications known as anticholinergics. Valium has also been used. Haldol has also been used for more severe cases.

The two most common muscles involved in this condition, the SCM and the trapezius muscles, share innervation by the spinal accessory nerve. Blocking this nerve can improve symptoms in many instances. The muscles themselves may also be injected directly with local anesthetic. Other nerve blocks and trigger point injections may be necessary if additional muscles are involved. Injections and nerve blocks are coupled with physical therapy to enhance recovery. For severe cases that are resistant to such therapeutic maneuvers, spinal cord stimulation and specific surgical procedures may be required.

Cervical spondylosis refers to degenerative changes in the joints and intervertebral disks of the cervical spine. These changes occur over time from wear and tear and result in neck pain. Specific changes include dehydration of intervertebral disks resulting in disk bulging, leakage of disk material, inflammation and compression of nerve roots and bone spur formation. Along with nerve roots, the spinal cord itself can be compressed. Ligament and joint hypertrophy or enlargement, can also lead to nerve compression and irritation. The most common nerve roots affected are at C5 and C6 which represents the mid-cervical level.

The neck pain can be poorly localized, exacerbated with movement and be accompanied by muscle spasm. X-rays, MRI or CT scans can assist in the diagnosis by excluding other causes of neck pain such as infection or cancer. Nerve root compression can result in numbness or tingling in the arm and in severe cases, weakness or paralysis of the arm. Treatment includes conservative therapy such as NSAIDS and physical therapy. Cervical epidural steroid injections and other specific nerve blocks may be warranted. Surgery is reserved for cases where significant symptoms such as worsening arm weakness or paralysis develop.

Compression of the cervical spinal cord itself is known as cervical myelopathy. The compression can be secondary to enlarged ligaments, herniated discs, radiation treatment, a diminished blood supply, cancer or infection. While a posterior compression typically results in sensory loss, motor loss and weakness can result from an anterior compression. The spinal cord compression can initially be painless but can result in foot numbness and unsteadiness while walking.

For patients with cervical myelopathy with radicular symptoms of less than one month in duration with no significant finding on x-ray, MRI or CT scan, conservative treatment with a soft collar and non-steroidal anti-inflammatory drugs is indicated. For symptoms lasting more than a month in duration, cervical isometric exercise, trans-cutaneous electrical nerve stimulation, anti-depressants, anticonvulsants, muscle relaxants and cold or hot packs are indicated.

In cervical myelopathy that results from spondylosis, spinal stenosis, herniated disc(s), arthritis or myofascial pain, cervical epidural steroid injections have found to be effective. Surgery is reserved for worsening neurologic deficits along with significant cord compression.

Facet joints are the connections between the vertebral bodies of the spinal canal. They provide structural support to the spinal column and allow limited motion. Cervical facet joint disease can cause localized symptoms or radicular/radiating pain. It can be difficult to differentiate from disk disease and can often occur with disk disease. Facet arthropathy can arise from acute injury but most commonly occurs secondary to chronic changes in the facet joints brought on by disk degeneration, spondylosis, repetitive stress and strain and weight bearing.

Cervical facet joint irritation may be associated with muscle spasms and headaches. Facet joint symptoms may also be like those of cervical disk nerve root irritation resulting in neck pain and radiating pain to the shoulders and arms. Cervical facet joint disease can occur concomitantly with nerve root irritation caused by cervical disk disease.

Extending or rotating the neck stresses the facet joints and reproduces the symptoms. Tenderness is often present when the area above the facet joints is pressed. X-ray, CT and MRI scans may show abnormalities of the facet joints.

Initial treatment of facet symptoms is conservative. Nonsteroidal anti-inflammatory drugs, tricyclic antidepressants, physical therapy and transcutaneous electrical nerve stimulation may afford relief. Facet joint injections with local anesthetic and steroid may be beneficial if conservative therapies fail. Injections should only be attempted if the symptoms can be supported by the findings on imaging studies.

If the injections provide only temporary relief of symptoms, ablation of the nerve supply to the joints can be achieved with radiofrequency techniques, thermocoagulation or phenol injection. Severe cases can be treated with surgical techniques such as cervical fusion with bone graft or spinal hardware/implants.

In summary, causes of neck pain can vary from short lived conditions that are simple to manage and treat to serious and even life threatening states that require immediate intervention by specialty physicians. Neck pain can involve other parts of the upper body such as the head, shoulders, upper back and arms. Appropriate diagnosis by a physician trained to manage such conditions, along with the appropriate diagnostics studies such as MRI can help determine the underlying cause or causes. Most cases of neck pain can be managed conservatively but a good number may require interventional procedures. Some may require surgery.

What is a Pinched Nerve?

A pinched nerve typically refers to nerve compression due to a variety of factors. Local degenerative changes in or near the spinal column involving intervertebral discs, facet joints and ligaments can cause nerve root compression. These can be due to disc bulges or herniations, facet hypertrophy, ligament hypertrophy, osteochondral spurs or spondylolisthesis or slippage of a one vertebral body over another.

Pinched nerves can occur anywhere in the body where nerves travel through bony and ligamentous structures. Some of the most common sites of nerve compression are the neck and the lower back.

“Pinched Nerve” or nerve compression is typically diagnosed by a physician or chiropractor after careful history taking from the patient. This is followed by a physical exam where the pain may be reproduced after certain motions. A physician may order additional studies such as an MRI to look for pathologic changes in or near the spine that may be causing the nerve compression.

Nerve root compression symptoms typically include pain, inflammation and often shooting pain down the arm or leg. Treatment includes conservative measures such as over-the-counter pain relievers, rest and physical therapy. Most cases have symptomatic resolution over time and only conservative treatment measures are needed.

If pinched nerve symptoms persist after conservative therapy, interventional pain management injections may be warranted. These are typically performed under fluoroscopy which is a “live” x-ray. It allows the physician to see bone and some other anatomical structures in different “frames” while performing a procedures or surgery.

The most common interventional pain management procedures for nerve root compression near the spine is called a selective nerve root block. During this procedure, the physician guides a fine needle under fluoroscopy near the pinched nerve. The fluoroscopy helps the physician guide the needle close to the nerve compression while avoiding anatomical structures that might be damaged if penetrated by the tip of the needle. Once the tip of the needle is close to the nerve root compression, steroid is injected next to the pinched nerve but not into the nerve. The purpose of the steroid is to decrease inflammation and improve symptoms. If symptoms do not resolve, the procedure can be repeated. Typically, it is repeated up to two times with each procedure separated by a time interval of two weeks.

If symptoms are severe to the point where the nerve root compression causes unbearable, unremitting pain, neurological symptoms such as arm or leg weakness or in the case of a pinched nerve in the lower back, loss of bowel or bladder control, surgery is the preferred intervention.

The most common spinal decompressive surgery has traditionally been microdiscectomy. It is considered a minimally invasive surgery in which the herniated intervertebral disc fragments that are causing the nerve root compression are removed. A newer, even less invasive technique involves using a narrow, hollow tube through which instruments are passed to remove the disc fragments. Visualization during this “endoscopic” surgical procedure is aided by a digital camera positioned on the end of the instrument along with a light source. This technique is meant to minimize the surgical trauma to the patient, reduce the incidence of complications and to shorten the recovery time.

Interventional pain management procedures such as selective nerve root block and surgical procedures such as microdiscectomy for pinched nerves are typically followed by a course of physical therapy in order to assist in the patient’s recovery and allow her/him to get back to their daily routine.

Ketamine for Chronic Pain Management

Ketamine is a phencyclidine derivative which acts primarily as an N-methyl-D-aspartate (NMDA) antagonist. Its unique anesthetic profile includes relative hemodynamic stability due to its sympathomimetic properties (though in some patients who are catecholamine deplete, it can cause myocardial depression), preservation of respiratory drive, bronchodilatory properties, and significant non-opiate mediated analgesic properties. It is an attractive adjuvant in patients with chronic pain, who are often opiate-tolerant. At sub-anesthetic doses, ketamine has been shown to be opiate-sparing in the perioperative setting, as well as reducing post-operative nausea and vomiting. Sub-anesthetic, or “low-dose” ketamine, is defined as <2mg/kg intramuscularly or 1mg/kg intravenously. For continuous infusions, <1.2mg/kg/hr has been suggested

In sub-group analyses, ketamine’s opiate sparing effects were greatest in upper abdominal and thoracic procedures. It was still effective, though less so, in orthopedic and lower abdominal surgery. It did not significantly reduce opiate consumption in ear, nose and throat and oral surgery. Furthermore, the more painful the surgery (i.e. high VAS scores), the greater ketamine’s opiate sparing effect.

In addition to sparing opiates in chronic pain patients, ketamine may help prevent chronic postsurgical pain by diminishing central sensitization via its NMDA blocking effects. Anywhere from 10-50% of patients have persistent pain after surgery, much of which may be attributed to iatrogenic nerve injury. Blocking central sensitization could help prevent these injuries from persisting in the form of chronic pain. In one systemic review, the relative risk of developing chronic pain after surgery was reduced by 25% (NNT 12) at 3 months and 30% at 6 months.

Short term use of ketamine has been described in the treatment of neuropathic pain, migraine, fibromyalgia, ischemic pain, whiplash injury, and TMJ disease. The mechanism of action is likely NMDA antagonism and potentially enhancement of descending inhibition, though ketamine also acts on other central receptors, including opioid, with their contributing roles still uncertain. Ketamine has also showed promise in reducing opioid-induced hyperalgesia.

Long term benefit of ketamine has been best studied in complex regional pain syndrome (CPRS). Several studies have showed reduction of pain scores for up to 3 months with a several-day course of intravenous ketamine.

The safety of long-term ketamine use is ill-defined, and the logistics of delivery are a barrier. Ketamine has poor oral bioavailability, and while intramuscular, sublingual, nasal and rectal formulations exist, they have yet to be widely used or studied. Caveats for long-term ketamine use include urologic complications such as cystitis and bladder contractions, hepatic dysfunction, and psychologic side effects including addiction.

While further studies are warranted in long-term use of ketamine for chronic pain, there is ample evidence in its efficacy as a perioperative adjuvant. It behooves anesthesiologists to be familiar with its use, particularly in the chronic pain population.

References:

Gorlin AW, Rosenfeld DM, Ramakrishna H. Intravenous sub-anesthetic ketamine for perioperative analgesia. J Anaesthesiol Clin Pharmacol [serial online] 2016 [cited 2017 Jun 6];32:160-7

 

Peltoniemi, M.A., Hagelberg, N.M., Olkkola, K.T. et al. Ketamine: A Review of Clinical Pharmacokinetics and Pharmacodynamics in Anesthesia and Pain Therapy. Clin Pharmacokinet (2016) 55: 1059.