Posts Tagged ‘paraplegia’

Spinal Epidural Abscess: A basic primer

Friday, March 11th, 2011

Epidural abscess compressing the spinal cord -courtesy of aafp.org

In a previous blog, I introduced the topic of neck and back pain which can have a host of causes, most of which are mechanical.  This blog attempts to explore an infectious etiology of neck and back pain that can be potentially devastating, resulting in paralysis and even death.

The spine is a complicated structure involving bones, discs, ligaments, muscles, blood vessels and nerves.  It’s two main functions are to provide axial support for the upright stature of the human body and fluid movement of the body parts while also protecting or housing a critical component of the central nervous system, the spinal cord. Oversimplified, the spinal cord is a conglomeration of nerve fibers that act as the “information highway” between the peripheral nerves supplying sensory and motor function to the body parts and the brain. The spinal cord transmits chemical messages from the brain, telling the body what to do and how to function, even functions we are not conscious of doing (digestion, breathing, etc.), and it receives input from all of our senses and interprets the data.  Without the spinal cord or if the spinal cord is affected by an injury, there is disconnect; we lose feeling and movement as well as control of some of our normal unconscious body functions.  The location of the spinal cord damage dictates the level at which the disconnect occurs.  To help you understand the anatomy of the spine, here’s a short video describing the basic anatomy of the spine.

httpv://www.youtube.com/watch?v=Zeo0Im7h4Go

 

An epidural abscess is a collection of pus that occurs as the result of an infectious process involving any part of the  spinal cord from the base of the head to the tailbone; the abscess is located within the protective boney compartment housing the spinal cord, the spinal canal, and the thick outer covering of the spinal cord, the dura.  The dura is comprised of 3 layers, the outer one being very tough, the middle one being very vascular, and the inner one being very “tender.”

Signs and Symptoms:

In the early stages of the infection, a patient will often complain of neck or back pain very specific to the location of the infection, but the pain can be referred due to nerve root irritation.  As the infection grows, it spreads along the axial plane of the spinal canal, but the pressure and swelling of the purulent collection also tends to compress the spinal cord, resulting in numbness, tingling and functional loss below the level of the compression.  This progression can be indolent or rapid, depending on both the virulence of the pathogen and the person’s immune system.  Without emergent treatment, the pus collection can “choke off” the spinal cord and its blood supply, leading to permanent spinal cord injury and paralysis.

How does the infection get there?

Patients who have undergone spinal surgery are at an increased risk of these types of infections, especially during the immediate post-operative period.  Surgical wounds can become infected allowing bacteria to track deep into the tissues and the spine through the operative plane.  If hardware (spinal instrumentation) has been used, these man-made devices become reservoirs or fomites for attachment of the bacteria, and it is extremely difficult to eradicate bacterial pathogens from the hardware.

The bloodstream is another source of migration for bacterial pathogens from peripheral sites (infected gums, endocarditis, bladder infection, skin abscesses/boils) to the spine.  Individuals particularly at risk are those with depleted immune systems (e.g. diabetics, patients with auto-immune diseases on chronic steroids, HIV, etc.) and IV drug abusers (directly inject materials into veins).  Having spinal hardware from a previous spine surgery will increase the risk of seeding to that instrumented site should bacteria become blood-borne.

Direct inoculation can occur if  poor technique is utilized during epidural spinal injections or epidural anaesthesia.  There can also be contiguous spread from adjacent infected tissues (e.g. diskitis, osteomyelitis).

What are the most common pathogens?

Staph aureus, a common skin pathogen, is the most common cause.  It is known to cause skin abscesses/boils, wound infections, sinus infections, bladder infections and even pneumonia!  The relatively recent incidence of MRSA (a very resistent variety of Staph aureus) in the community has changed the way medicine treats common skin ailments; its effect on the incidence and treatment of epidural abscesses has yet to be determined.  If an epidural abscess is suspected, antibiotic coverage for MRSA is now automatically included in the initial treatment due to the bacterial virulence and resistance to treatment.

E. coli ( a common bowel pathogen and cause of bladder infection), fungi (like yeast), and even Mycobacterium tuberculosis are also causes of epidural abscess.  One can also contract mixed infections with aerobic and anaerobic bacteria, depending on the source of the infection (intra-abdominal abscess, perforated appendix).

How is an epidural abscess diagnosed?

The clinician must have a high index of suspicion and keep an open mind.  A thorough history often leads to clues such as recent fevers, a recent skin abscess or cellulitis, IV drug abuse, recent dental extraction or procedure, and neck or back pain without a specific inciting incident.  Physical examination of the patient often reveals point tenderness directly over the affected area of the spine, worse with percussion or tapping on the boney prominences, and often worse in the recumbent position.

Visualization of the spine is best accomplished with an MRI of the spine (above, below and including the tender area); it is non-invasive and very detailed regarding the soft tissues.  Patient weight can be a factor in accessing these machines; they often have a maximum weight limit of 300 lbs.  Many morbidly obese patients, who often have type II diabetes, are at risk for epidural abscesses; they often have to be transported to external facilities for “open MRI” studies.  Claustrophobia can also be a restricting factor, often requiring patient sedation or anaesthesia.  Excruciating pain while lying flat can also be prohibitive.  An alternative study to visualize the spinal cord is a CT-myelogram during which the epidural space is accessed with a spinal needle and dye is injected for visualization under computed tomography.  The CT-myelogram is a higher-risk study and can also be limited by a patient’s weight and sensitivity to contrast dye.  A lumbar puncture should NOT be done since it can lead to spinal cord herniation and permanent spinal injury.

What is the treatment for an epidural abscess?

There are two schools of thought regarding treatment.  One school favors emergent surgical debridement of the abscess along with intravenous antibiotics; this also allows for identification and sensitivity testing of the organism.  The other school suggests that intravenous antibiotics alone can be sufficient if no signs of spinal cord impingement are present; if symptoms progress to the development of neurologic symptoms, then surgery becomes more urgent.

What is the prognosis in epidural abscess?

Prognosis depends on the patient’s underlying medical condition and the degree of spinal cord involvement at the time of diagnosis/intervention.  Obviously, the earlier the intervention and treatment, the better the prognosis; hence, I favor surgical debridement as soon as possible.  Delays in diagnosis often lead to permanent and life-altering neurologic damage and functional loss or even death.  These delays and the permanent neurologic sequellae suffered often become the basis for medical malpractice litigation.

The daily struggle of raising a disabled child

Thursday, February 24th, 2011

Parents must cope with daily concerns of special needs children

Like many parents, I am blessed to have healthy children.  I take it for granted that my kids are smart, active, well-adjusted.  I don’t even have to think about their health other than the occasional cold or earache or sprained ankle. Others are not so fortunate.

This past weekend I was reading in Maryland Family Magazine an article about a local college professor who wrote a book about raising a son with severe autism.  After writing the book, he assumed that a major publisher would have interest. He ended up being turned down by some agents who told him that without a happy ending or a cure, there was no way they could market the story. Apparently, the public wants stories about disability to have a Hollywood ending. (A publisher finally did come along that agreed to publish the book).

This, in turn, made me think of a good friend of mine (I’ll call her Jane), who has a disabled son (autism spectrum) in addition to three normal children. I hesitate to use the words normal and disabled for two reasons:  1) we live in a politically correct world where deciding what label to apply to anything means stepping into a social minefield; and 2) on the spectrum of mental or physical ability, it can be difficult to say what exactly is normal versus abnormal. I never want to suggest that children with limitations are abnormal. Some parents even bristle at the term “disabled.” Others use the more cumbersome term “neurotypical” rather than the term “normal.” You can see that it can be hard to discuss the topic of disability when we don’t even have terms we can all agree on.

Jane and I often discuss our kids and parenting. She has been very candid with me in describing how incredibly hard it is to raise a disabled child. She believes that no one really wants to hear the negative side of raising a child with special needs. Like the publishing agents that the professor encountered, some people only want to hear about the inspirational side of the story. Truth is, there is not always a happy ending or miracle cure when raising a disabled child, be it autism or cerebral palsy or paraplegia. These are life-long disabilities. There are happy moments, of course, as well as accomplishments both major and minor, but for parents raising a disabled child, it is a daily struggle to make sure that the child gets the medical care and therapy and attention that he or she needs. Parents undertake this monumental and thankless task not because they hope for some Hollywood ending, but because they love their child and they do what they need to do, even if they never knew they had such strength and determination in them.

It’s not all negative, of course. Jane tells me all the time how much she loves her son and how he has taught her so much about herself and about life. She says she cannot imagine who she would be without her son. At the same time, however, she also feels a lot of pain and loss and regret about what she and her family have had to sacrifice in order to care for her disabled son. The daily struggle can truly be overwhelming at times. Jane believes that parents often feel unable to express these feelings for fear of being branded a less-than-stellar parent. As she told me, “There isn’t a safe place to express one’s own doubts about being able to effectively take care of another person who requires so much care. It’s daunting, hard and stressful and for some reason it’s not completely OK to admit that.”  Jane is careful about the sentiments she expresses in public versus those she tells to her friends:

There is the aspect of autism that you are allowed to talk about versus not allowed. I’m allowed to admit it’s hard, but I can’t really say how hard or I’m too negative. I’m just supposed to say it has changed my perspective and I’m blessed.  It has changed my perspective but I’m not blessed. Shut up about being blessed.

While disabilities are all different and every parent’s story is unique, there is a common thread that runs through them all – raising a disabled child takes its toll on the parents and the family as well as the child. The challenges can be enormous. Some of the more common challenges include:

  • Financial:  Finding ways to afford medical care, therapy, services;  working with insurance companies and various state agencies;
  • Educational:  Struggling with teachers and school administrators to make sure that your child is getting an appropriate education and Individualized Education Program or IEP.
  • Medical:  Finding doctors who are willing to take the time to listen to your concerns and diagnose your child; getting referrals to specialists; sorting through the myriad hoops of insurance; finding therapies that work for your child;
  • Social:  The loss of normal everyday activities like going out to dinner, taking trips, seeing friends; not having anywhere to turn to talk about what they are going through.
  • Marital:  A couple often experiences difficulty because of all the other stresses that are created by having a disabled child, as well as the substantial time investment that is required.
  • Family: Other children in the family can be affected because mom and dad have to devote so much time to the disabled child and because the family’s usual routine and activities are disrupted; money can often be tight.
  • Psychological: Many mothers experience feelings of guilt, wondering if it was something they did during pregnancy that caused their child to have this disability.
  • Legal: Figuring out what rights you and your disabled child have, what services you are entitled to.

I can’t say enough about those parents who take on these challenges on a daily basis.  It is difficult to even imagine the level of devotion and commitment that is required.  I welcome all parents to share their stories — the good and the bad — so that the rest of us can try to better understand the reality of raising a disabled child.  In future blogs I will talk about some of these challenges in more detail and where parents can turn for assistance.

Image from metroparent.com

New Microchip Promises to Make Life Much Easier for Paraplegic Patients

Friday, February 11th, 2011

Hope for those with paraplegia?

Researchers in the U.K. have developed a revolutionary microchip muscle stimulator that will enable patients with paraplegia to exercise multiple muscles at the same time. According to the Engineering and Physical Sciences Research Council (EPSRC), the microchip developed by Professor Andreas Demosthenous from University College of London and his team is truly unique.

The microchip chip is small enough (approximately the size of a child’s fingernail) that it can be implanted directly into the spinal canal. Unlike previous models, the new implant incorporates the muscle stimulator and the electrodes into a singular unit.  The unit is properly sealed to protect against moisture, which could lead to corrosion of the electrodes.

The creation of the implant has been made possible by new laser processing technology, which enabled researchers to micro-pack all components into one unit. With this new laser technology, researchers were able to cut much tinier electrodes from platinum. The electrodes are then folded into a 3D shape that resembles pages in a book. Each electrode can be wrapped around a nerve root. The electrode is then welded to the microchip located in the spinal cavity.

Because the implant comes with multiple electrodes, which can be connected to multiple nerve roots, it is capable of controlling entire muscle groups. In patients with paraplegia, the devise can be used to stimulate or trigger multiple paralyzed muscles at the same time. Researchers also claim that the new device will also be used in patients with bladder or bowel incontinence.  Because the device has multiple electrodes, some electrodes can be connected to nerve roots that control bladder muscles or nerves that control bowel capacity.

Although all of this may sound a bit scifi, the implant will be available for pilot studies sometime this year. If you or someone you know is paraplegic, this research is worth following. It clearly promises to offer life-chaining benefits to patients with paraplegia. If you know of other research on similar devices, we’d love for you to share that information with our readers. We’ll try to keep an eye on the progress and implementation of this device from the UK and keep you posted if and when developments occur.

Neck & Back Pain: When is it something more serious?

Wednesday, December 22nd, 2010

Statistically, 4 out of every 5 adults under the age of 50 have experienced at least one episode of neck or back pain.  For most people, the symptoms resolve in a reasonable period of time with or without intervention.  For others, the symptoms become chronic, often leading to surgical procedures and even disability.  Sometimes, there is a specific identifiable incident that incited the pain while in other cases, no particular injury or overuse syndrome could be identified.  Neck and back pain are one of the most common complaints leading to medical evaluations in the emergency room, urgent care center or primary care physician’s office; they are also a significant cause of lost time from work, lost wages and productivity, and high expenditure from a healthcare perspective.

Neck and back pain are symptoms of an underlying problem.  The majority of the causes (~97%) are purely mechanical, that is related to the mechanics of movement of the neck or back, involving the bones, muscles, ligaments, discs and joint spaces.  They include such diagnoses as lumbar strain/sprain, degenerative disc disease, herniated discs, spinal stenosis, spondylolisthesis, osteoporotic compression fracture and traumatic fractures.  Some of these, obviously, are more serious with potential neurologic sequellae than others.  Any condition that results in compression of the spinal cord can cause permanent neurologic injury, including paralysis; these include fractures, stenosis and significant spondylolisthesis. Causes include acute traumatic injuries (car accidents, falls, direct blows), overuse syndromes, poor lifting techniques, poor posture, chronic degenerative arthritis leading to spinal stenosis and spondylolisthesis, and osteoporosis.

The remaining 3% of causes of neck and back pain are considered non-mechanical, but they can be further divided into non-mechanical spinal conditions (1%) and visceral (internal organ-related) conditions (2%).  Of the non-mechanical spinal conditions, neoplasias/malignancies comprise 0.7% while infections and inflammatory arthritides (inflammation of joints due to infectious, metabolic, or constitutional causes) comprise the remaining 0.3%.  Of the 2% visceral complications, etiologies are potentially due to vascular problems (aortic aneurysms, retroperitoneal hemorrhage, coronary syndromes, etc.), prostatitis, endometriosis, pelvic inflammatory disease, kidney stones/infections, pancreatitis, cholecystitis or ulcer perforation.  Thus, the sub-categories of non-mechanical neck and back pain have very small incidences in the global sense, but they are potentially more serious with more ominous consequences, including paralysis and death, making them diagnoses not to be missed or ignored.

So, how can one tell the difference between mechanical versus non-mechanical neck or back pain?

As a general rule, mechanical neck/back pain, since it is related to movement, is typically worse with movement or specific body positions and better with rest or lying supine without the burden of one’s weight causing an axial load on the vertebral column.  Non-mechanical neck/back pain is relatively constant and not related to body position or movement.  Pain in either case can be sharp or dull/aching, and each can have instances in which there is neurologic involvement causing pain to radiate along the nerves that exit the spinal column.  In the neck, nerve pain typically radiates to the arms causing pain, numbness and sometimes weakness.  In the upper to mid-back, nerve pain typically radiates to the anterior chest and abdomen.  In the lower back, nerve pain typically radiates into the pelvis, genital area, and especially the legs.  Radicular pain can be either one-sided or bilateral, the latter of which is more ominous and indicative of spinal cord compression as opposed to a single peripheral nerve root.

What are the “red flags” that raise concern for more serious problems?

There are specific risk factors that, when present, raise concerns for more systemic disease processes.  A history of cancer, for instance, increases the likelihood of the pain being related to a metastatic lesion or tumor.  Presence of a fever increases the likelihood of the pain being related to an infectious etiology.  Unexplained weight loss increases the likelihood of the pain being related to either a primary malignancy or metastatic cancer.  A history of intravenous drug use or even diabetes increases the risk for an acute or chronic infectious cause.  Blood in the urine can indicate a malignancy or other kidney-related problem.  Swollen glands can be indicative of a malignancy or infectious problem.  Anemia can be indicative of an underlying malignancy or vascular problem.  Rashes are often associated with rheumatologic or auto-immune problems that often involve the joints.  Chronic steroid use or other immunosuppression can increase the risk of infectious causes or osteoporosis with compression fracture.  Obviously, a history of trauma increases the risk of fracture, disc rupture/herniation and ligamentous injury leading to spinal instability, but it can also be a cause of intra-abdominal injuries or retroperitoneal injuries that present as back pain.  Any time there are neurologic deficits (numbness, tingling, weakness, muscle atrophy, etc.) beyond sciatica, the risk of nerve compression or spinal cord compression becomes higher.  Abdominal pain associated with back pain can be related to an intra-abdominal process (infection, abscess, aneurysm, ulcer perforation, etc.).  Neck pain that is associated with headache, fever and neck rigidity is often indicative of menigitis.

Overall, there are a plethora of potentially serious causes of neck and back pain.  One can see that the diagnosis of more serious conditions can be a little more complicated, especially since they are much rarer than the  common, everyday, garden-variety mechanical back pain without complications.  There are, however, a variety of clues that can lead one to an accurate and relatively rapid diagnosis.  The intention of this blog has been to introduce the topic and the dilemma faced by a provider when diagnosing these conditions.  Since the topic is broad and more complicated, a series of blogs dedicated to some of the more devastating etiologies of neck and back pain will follow.  The key to diagnosing any condition is an accurate and in-depth history and physical examination with keen attention to specific clues that are typically present.