Spinal Cord Injury (SCI)

SCI is typically caused by a traumatic blow to (or penetration of) the spine that fractures or dislocates vertebrae. The trauma causes the resulting bone fragments, material in the spinal discs, or ligaments to bruise or tear into spinal cord tissue, damaging it or, in some cases, severing the cord entirely and resulting in partial or complete paralysis. The NICHD supports basic research related to SCI and promotes the development and application of devices, including prosthetics and wheelchairs, and the use of biomechanical modeling to improve the quality of life for people regardless of their injury. 

Common Name

  • Spinal cord injury (SCI)

Scientific Names

  • Tetraplegia (pronounced te-truh-PLEE-jee-uh and formerly called quadriplegia [pronounced kwod-ruh-PLEE-jee-uh])
  • Paraplegia (pronounced par-uh-PLEE-jee-uh)

Spinal Cord Injury (SCI): Condition Information

What is SCI?

SCI is usually associated with what is commonly called a broken neck or broken back. Generally speaking, SCI is damage to the spinal nerves, the body's central and most important nerve bundle, as a result of trauma to the backbone. 

Most cases of SCI take place when trauma breaks and squeezes the vertebrae, or the bones of the back. This, in turn, damages the axons—the long nerve cell "wires" that pass through vertebrae, carrying signals between the brain and the rest of the body. The axons might be crushed or completely severed by this damage. Someone with injury to only a few axons might be able to recover completely from their injury. On the other hand, a person with damage to all axons will most likely be paralyzed in the areas below the injury.1

An SCI is described by its level, type, and severity. The level of injury for a person with SCI is the lowest point on the spinal cord below which sensory feeling and motor movement diminish or disappear.

The level is denoted by the letter-and-number name of the vertebra at the injury site (such as C3, T2, or L4).

  • There are seven cervical vertebrae (C1 through C7), which are in the neck.
  • There are 12 thoracic vertebrae (T1 through T12), which are located in the upper back. There are five lumbar vertebrae (L1 through L5), which are found in the lower back.
  • Below those are five sacral vertebrae, which are fused to form the sacrum. Finally, there are the four vertebrae of the coccyx, or tailbone.1

There are two broad types of SCI, each comprising a number of different levels:

  • Tetraplegia (formerly called quadriplegia) generally describes the condition of a person with an SCI that is at a level anywhere from the C1 vertebra down to the T1. These individuals can experience a loss of sensation, function, or movement in their head, neck, shoulders, arms, hands, upper chest, pelvic organs, and legs.
  • Paraplegia is the general term describing the condition of people who have lost feeling in or are not able to move the lower parts of their body. The body parts that may be affected are the chest, stomach, hips, legs, and feet. The state of an individual with an SCI level from the T2 vertebra to the S5 can usually be called paraplegic.2

In addition, there are two degrees of SCI severity:

  • Complete injury is the situation when the injury is so severe that almost all feeling (sensory function) and all ability to control movement (motor function) are lost below the area of the SCI.
  • Incomplete injury occurs when there is some sensory or motor function below the damaged area on the spine. There are many degrees of incomplete injury. 1

The closer the spinal injury is to the skull, the more extensive is the curtailment of the body's ability to move and feel. If the lesion is low on the spine, say, in the sacral area, it is likely that there will be a lack of feeling and movement in the thighs and lower parts of the legs, the feet, most of the external genital organs, and the anal area. But the person will be able to breathe freely and move his head, neck, arms, and hands. By contrast, someone with a broken neck may be almost completely incapacitated, even to the extent of requiring breathing assistance.3

Citations

  1. National Institute of Neurological Disorders and Stroke. Spinal cord injury: Hope through research. Retrieved June 19 , 2013 , from https://www.ninds.nih.gov/Disorders/Patient-Caregiver-Education/Hope-Through-Research/Spinal-Cord-Injury-Hope-Through-Research
  2. National Spinal Cord Injury Association. Understanding spinal cord injury. Retrieved May 21, 2012, from https://unitedspinal.org/what-is-spinal-cord-injury-disorder-scid/ External Web Site Policy
  3. Shepherd Center, KPKinteractive, American Trauma Society, National Spinal Cord Injury Association, & Christopher & Dana Reeve Foundation. Levels of Injury. Retrieved June 26, 2013, from https://www.spinalinjury101.org/details/levels-of-injury External Web Site Policy

What are the symptoms of SCI?

According to the American Association of Neurological Surgeons, there are many different symptoms or signs of SCI. Some of the more common signs of SCI include1:

  • Extreme pain or pressure in the neck, head, or back
  • Tingling or loss of sensation in the hand, fingers, feet, or toes
  • Partial or complete loss of control over any part of the body
  • Urinary or bowel urgency, incontinence, or retention
  • Difficulty with balance and walking
  • Abnormal band-like sensations in the thorax—pain, pressure
  • Impaired breathing after injury
  • Unusual lumps on the head or spine

Citations

  1. American Association of Neurological Surgeons. Spinal cord injury facts. Retrieved June 21, 2012, from https://www.aans.org/en/Patients/Neurosurgical-Conditions-and-Treatments External Web Site Policy

How many people are affected by SCI?

According to the National SCI Statistical Center, annually there are about 12,000 new cases of SCIs in the United States,1 which amounts to about 40 cases per million people. The last studies of the incidence of SCI were conducted in the 1990s, however, and so it is not known whether incidence has changed in recent years. In 2010, about a quarter of a million people in the United States were living with an SCI.

The majority of SCIs occur in young to middle-aged adults. From 1973 to 1979, the average age at injury was 28.7 years, and most injuries occurred between the ages of 16 and 30. However, demographic changes since the mid-1970s have resulted in an increase of 9 years in the median age of the U.S. population. Similarly, the average age for an SCI has increased over time. From 2005 to 2010, the average age was 40.7.2

Who is at risk for SCI?

SCIs are typically the result of accidents and therefore can happen to anyone.

Factors that increase the risk of SCI:

  • Driving or riding in a car. Using a seatbelt can reduce the possibility of an SCI by 60%; using a seatbelt plus having a functioning airbag can cut the odds of this injury by 80%.3,4
  • Being male. 80% of spinal cord injury patients are male.5
  • Operating machinery without using safety equipment6
  • Improper or unsafe use of a ladder, which can result in a fall from the ladder7
  • Using drugs or alcohol while driving, operating machinery, or playing sports8
  • Having arthritis, osteoporosis, or another bone or joint disorder9

Citations

  1. National Spinal Cord Injury Statistical Center. (2011). Spinal cord injury facts and figures at a glance. Retrieved May 22, 2012, from https://www.nscisc.uab.edu/PublicDocuments/nscisc_home/pdf/Facts%202011%20Feb%20Final.pdf External Web Site Policy (PDF - 197 KB)
  2. National Spinal Cord Injury Statistical Center. (2011). Spinal cord injury facts and figures at a glance. Retrieved May 22, 2012, from https://www.nscisc.uab.edu/PublicDocuments/nscisc_home/pdf/Facts%202011%20Feb%20Final.pdf External Web Site Policy (PDF - 197 KB)
  3. Clayton, B., MacLennan, P. A., McGwinn, G., Jr. Rue, L. W., III, Kirkpatrick, J. S. Cervical spine injury and restraint system use in motor vehicle collisions. Spine 2004 February;29(4):386-389.
  4. Thompson, W. L., Steill, I. G., Clement, C. M., Brison, R. J. (2009). Association of injury mechanism with the risk of cervical spine fractures. Canadian Journal of Emergency Medicine, 11(1):14-22.
  5. Centers for Disease Control and Prevention. (2010). Spinal Cord Injury (SCI): Fact Sheet. Retrieved June 21, 2012, from http://www.cdc.gov/TraumaticBrainInjury/scifacts.html
  6. Centers for Disease Control and Prevention. (2011). Machine safety. Retrieved June 26, 2012, from http://www.cdc.gov/niosh/topics/machine/default.html
  7. Hasler, R. M., Exadaktylos, A. K., Bouamra, O., Benneker, L. M., Clancy, M., Sieber, R. et al. (2011). Epidemiology and predictors of spinal injury in adult major trauma patients: European cohort study. European Spine Journal, 20(12):2174-2180.
  8. Beers, M. H., & Kaplan, J. L. (Eds.). (2006). The Merck manual of diagnosis and therapy. 18th ed. Whitehouse Station, NJ: Merck Sharp & Dohme Corp.
  9. PubMed Health. (2010). Spinal cord trauma. Retrieved June 26, 2012, from https://medlineplus.gov/ency/article/001066.htm

What causes spinal cord injury (SCI) and how does it affect your body?

SCIs result from damage to the vertebrae, ligaments, or disks of the spinal column or to the spinal cord itself.

A traumatic SCI may stem from a sudden blow to the spine that fractures, dislocates, crushes, or compresses one or more vertebrae. Car crashes are the leading cause of SCI among people younger than 65. Falls cause most SCIs in persons age 65 and older.

Since 2005, SCI has been caused by1:

  • Car crashes (40.4%)
  • Falls (27.9%)
  • Violence, including gunshot wounds (15%)
  • Sport-related accidents (8%)
  • Other/unknown (8.5%)

What happens in your body when your spinal cord is injured?

When an SCI occurs, the spinal cord starts to swell at the damaged area, cutting off the vital blood supply to the nerve tissue and starving it of oxygen. This sets off a cascade of devastation that affects the entire body, causing the injured spinal tissue to die, be stripped of its insulation, and be further damaged by a massive response of the immune system.2

  • Blood flow. The sluggish blood flow at the injury site begins to reduce the flow of blood in adjacent areas, which soon affects all areas of the body. The body begins to lose the ability to self-regulate, leading to drastic drops in blood pressure and heart rate.
  • Flood of neurotransmitters. The SCI leads to an excessive release of neurotransmitters, or biochemicals that let nerve cells communicate with each other. These chemicals, especially glutamate, overexcite nerve cells, killing them through a process known as excitotoxicity. The process also kills the vital oligodendrocytes that surround and protect the spinal axons with the myelin insulation that allows the spinal nerves to transmit information to and from the brain.
  • Invasion of immune cells. An army of cells of the immune system speeds to the damaged area of the spine. While they help by preventing infection and cleaning up dead cellular debris, they also promote inflammation. These immune cells stimulate the release of certain cytokines that, in high concentrations, can be toxic to nerve cells, especially those needed to maintain the myelin sheath around axons.3
  • Onslaught of free radicals. The inflammation caused by cells in the immune system unleashes waves of free radicals, which are highly reactive forms of oxygen molecules. These free radicals react destructively with many types of cellular molecules, in the process severely damaging healthy nerve cells.
  • Nerve cell self-destruction. A normally natural process of programmed cell death, known as apoptosis, goes out of control at the injury site. The reasons are not known. Days or weeks after the injury, oligodendrocytes die from no apparent cause, reducing the integrity of the spinal cord.

Additional damage usually occurs over the days or weeks following the initial injury because of bleeding, swelling, inflammation, and accumulation of fluid in and around the spinal cord.

Citations

  1. National Spinal Cord Injury Statistical Center. (2011). Spinal cord injury facts and figures at a glance. Retrieved May 21, 2012, from https://www.nscisc.uab.edu/PublicDocuments/nscisc_home/pdf/Facts%202011%20Feb%20Final.pdf External Web Site Policy (PDF - 197 KB)
  2. National Institute of Neurological Disorders and Stroke. (2012). Spinal cord injury: Hope through research. Retrieved May 22, 2012, from https://www.ninds.nih.gov/Disorders/Patient-Caregiver-Education/Hope-Through-Research/Spinal-Cord-Injury-Hope-Through-Research
  3. Edwards, S. P. The Dana Foundation. (2006). The other side of cytokines: The paradoxical effects of TNF-alpha. Retrieved June 27, 2012, from http:// www.dana.org/Publications/Brainwork/Details.aspx?id=43669 External Web Site Policy

How is SCI diagnosed?

SCIs are not always immediately recognizable. The following injuries should be assessed for possible damage to the spinal cord1:

  • Head injuries, particularly those with trauma to the face
  • Pelvic fractures
  • Penetrating injuries in the area of the spine
  • Injuries from falling from heights

If any of these injuries occur together with any of the symptoms mentioned above (acute head, neck, or back pain; decline of feeling in the extremities; loss of control over part of the body; urinary or bowel problems; walking difficulty; pain or pressure bands in the chest area; difficulty breathing; head or spine lumps), then SCI may be implicated.2

A person suspected of having an SCI must be carefully transported—to prevent further injury the spine should be kept immobile—to an emergency room or trauma center. A doctor will question the person to determine the nature of the accident, and the medical staff may test the patient for sensory function and movement. If the injured person complains of neck pain, is not fully awake, or has obvious signs of weakness or neurological injury, diagnostic tests will be performed.

These tests may include3:

  • A CT ("cat") scan. This approach uses computers to form a series of cross-sectional images that may show the location and extent of the damage and reveal problems such as blood clots (hematomas).
  • An MRI (magnetic resonance imaging) scan. An MRI machine "takes a picture" of the injured area using a strong magnetic field and radio waves. A computer creates an image of the spine to reveal herniated disks and other abnormalities.
  • A myelogram. This is an X-ray of the spine taken after a dye is injected.
  • Somatosensory evoked potential (SSEP) testing or magnetic stimulation. Performing these tests may show if nerve signals can pass through the spinal cord.
  • Spine X-rays. These may show fracture or damage to the bones of the spine.

On about the third day after the injury, doctors give patients a complete neurological examination to diagnose the severity of the injury and predict the likely extent of recovery. This involves testing the patient's muscle strength and ability to sense light touch and a pinprick. Doctors use the standard ASIA (American Spinal Injury Association) Impairment Scale for this diagnosis. X-rays, MRIs, or more advanced imaging techniques are also used to visualize the entire length of the spine.

The ASIA Impairment Scale has five classification levels, ranging from complete loss of neural function in the affected area to completely normal4:

  • A: The impairment is complete. There is no motor or sensory function left below the level of injury.
  • B: The impairment is incomplete. Sensory function, but not motor function, is preserved below the neurologic level (the first normal level above the level of injury) and some sensation is preserved in the sacral segments S4 and S5.
  • C: The impairment is incomplete. Motor function is preserved below the neurologic level, but more than half of the key muscles below the neurologic level have a muscle grade less than 3 (i.e., they are not strong enough to move against gravity).
  • D: The impairment is incomplete. Motor function is preserved below the neurologic level, and at least half of the key muscles below the neurologic level have a muscle grade of 3 or more (i.e., the joints can be moved against gravity).
  • E: The patient's functions are normal. All motor and sensory functions are unhindered.

To illustrate, a person classified as C-level on the ASIA scale functions better than a person at the B level. Time was, a patient might have been labeled a C4 quadriplegic. Today, however, using the ASIA scale, the classification might be C4 ASIA A tetraplegic. Regarding muscle-strength grades, zero is the lowest, corresponding to complete absence of muscle movement. Five is the highest, representing full, normal strength.5,6

Citations

  1. National Institute of Neurological Disorders and Stroke. (2012). Spinal cord injury: Hope through research. Retrieved June 26, 2012, from https://www.ninds.nih.gov/Disorders/Patient-Caregiver-Education/Hope-Through-Research/Spinal-Cord-Injury-Hope-Through-Research
  2. University Specialty Clinics. (n.d.). Spinal cord injury. Retrieved June 26, 2012, from http://neurosurgery.med.sc.edu/patientcare/spinal_cord_injury.asp External Web Site Policy
  3. PubMed Health. (2010). Spinal cord trauma. Retrieved June 26, 2012, from https:// www.ncbi.nlm.nih.gov/pubmedhealth/PMHT0030151/
  4. The Spinal Cord Injury Zone. (2009). What is ASIA impairment scale. Retrieved June 26, 2012, from http://www.spinalcordinjuryzone.com/answers/9243/what-is-asia-impairment-scale External Web Site Policy
  5. Shepherd Center. (n.d.) Diagnosing the severity of a SCI. https://www.shepherd.org/patient-programs/spinal-cord-injury/diagnosing-the-severity-of-a-spinal-cord-injury External Web Site Policy
  6. Radiopaedia. (n.d.). ASIA impairment scale. Retrieved June 26, 2012, from http://radiopaedia.org/articles/asia-impairment-scale External Web Site Policy

What are the treatments for spinal cord injury (SCI)?

Unfortunately, there are at present no known ways to reverse damage to the spinal cord. However, researchers are continually working on new treatments, including prostheses and medications, which may promote regeneration of nerve cells or improve the function of the nerves that remain after an SCI.

SCI treatment currently focuses on preventing further injury and empowering people with an SCI to return to an active and productive life.

At the Scene of the Incident

Quick medical attention is critical to minimizing the effects of head, neck, or back trauma. Therefore, treatment for an SCI often begins at the scene of the injury.

Emergency personnel typically:

  • Immobilize the spine as gently and quickly as possible using a rigid neck collar and a rigid carrying board
  • Use the carrying board to transport the patient to the hospital

In the Emergency Room

Once the patient is at the hospital, health care providers focus on:

  • Maintaining the person's ability to breathe
  • Immobilizing the neck to prevent further spinal cord damage

Health care providers also may treat an acute injury with:

  • Surgery. Doctors may use surgery to remove fluid or tissue that presses on thespinal cord (decompression laminectomy); remove bone fragments, disk fragments, or foreign objects; fuse broken spinal bones; or place spinal braces.1
  • Traction. This technique stabilizes the spine and brings it into proper alignment.
  • Methylprednisolone (Medrol). If this steroid medication is administered within 8 hours of injury, some patients experience improvement. It appears to work by reducing damage to nerve cells and decreasing inflammation near the site of injury.
  • Experimental treatments. Scientists are pursuing research on how to halt cell death, control inflammation, and promote the repair or regeneration of nerves.2 See "Is there a cure for SCI?"

People with SCI may benefit from rehabilitation, including3,4:

  • Physical therapy geared toward muscle strengthening, communication, and mobility
  • Use of assistive devices such as wheelchairs, walkers, and leg braces
  • Use of adaptive devices for communication
  • Occupational therapy focused on fine motor skills
  • Techniques for self-grooming and bladder and bowel management
  • Coping strategies for dealing with spasticity and pain
  • Vocational therapy to help people get back to work with the use of assistive devices, if needed
  • Recreational therapy such as sports and social activities
  • Improved strategies for exercise and healthy diets (obesity and diabetes are potential risk factors for persons with SCI)
  • Functional electrical stimulation for assistance with restoration of neuromuscular function, sensory function, or autonomic function (e.g., bladder, bowel, or respiratory function).5

Citations

  1. PubMed Health. (2010). Spinal cord trauma. Retrieved June 27, 2012, from https:// www.ncbi.nlm.nih.gov/pubmedhealth/PMHT0030151/
  2. National Institute of Neurological Disorders and Stroke. (2012). Spinal cord injury: Hope through research. Retrieved May 22, 2012, from https://www.ninds.nih.gov/Disorders/Patient-Caregiver-Education/Hope-Through-Research/Spinal-Cord-Injury-Hope-Through-Research
  3. National Institute of Neurological Disorders and Stroke. (2012). Spinal cord injury: Hope through research. Retrieved May 22, 2012, from https://www.ninds.nih.gov/Disorders/Patient-Caregiver-Education/Hope-Through-Research/Spinal-Cord-Injury-Hope-Through-Research
  4. Tator, C. H., & Benzel, E. C. (Eds.). (2000). Contemporary management of spinal cord injury: From impact to Rehabilitation, 2nd ed. Rolling Meadows, IL: American Association of Neurological Surgeons.
  5. Evans, R. W., Wilberger, J. E., & Bhatia, S. Traumatic disorders. In: Goetz, C. G. (Ed.). (2007). Textbook of clinical neurology (3rd ed.), chap. 51. Philadelphia, PA: Saunders Elsevier.

What conditions are associated with SCI?

SCI is associated with many secondary conditions that have significant impacts on medical rehabilitation management, long-term outcome, and quality of life.

  • Secondary conditions associated with SCIs include1,2:
    • Breathing problems
    • Bowel and bladder problems, including overactive bladder and incontinence
    • Heart problems
    • Pressure sores
    • Sexual function problems
    • Pain
    • Blood clots
    • Impaired muscle coordination (or spasticity)
    • Pneumonia
    • Autonomic dysreflexia (or hyperreflexia), which causes a potentially lethal increase in blood pressure
    • Increased likelihood of certain cancers, including bladder cancer

Citations

  1. McKinley, W. O., Tewksbury, M. A., & Godbout, C. J. (2002). Comparison of medical complications following nontraumatic and traumatic spinal cord injury. The Journal of Spinal Cord Medicine, 25(2):88-93.
  2. Gunduz, H. & Binak, D. F. (2012). Autonomic dysreflexia: An important cardiovascular complication in spinal cord injury patients. Cardiology Journal, 19(2):215-219.

Spinal Cord Injury (SCI): NICHD Research Goals

NICHD research related to SCI is focused on increasing the health, productivity, independence, well-being, and recovery of all people living with SCI. The intent is to develop social, physical, and behavioral rehabilitation treatments for people with spinal-injury disabilities while also performing and supporting basic research in such fields as neurology, neurophysiology, osteology, biochemistry, motor control, and neuromechanics as a foundation for these developments.

The NICHD's research efforts on SCI include a range of overlapping areas:

  • Understanding of the biochemistry of the normal, wounded, and healing spinal cord
  • Developing new tools that can scan and provide images of living tissue to diagnose the extent of SCI
  • Understanding the mechanisms of bladder and bowel infections and how to prevent them
  • Understanding the mechanisms and means of prevention of other secondary complications of SCI, such as pressure sores, blood clots, pneumonia, spasticity, sexual dysfunction, and neuropathic pain
  • Investigating the biochemistry of nerve regeneration
  • Improving the quality of life of individuals with SCI (e.g., improved accessibility for activities of daily living [ADLs]; improved upper limb function or functional mobility)
  • Helping people with SCI adapt their behavior to the loss of sensory, motor, and organ-control function
  • Assessing the efficacy and outcomes of medical rehabilitation therapies and practices in spine-injured people
  • Developing improved assistive technologies for the SCI population
  • Understanding whole-body−system responses of spine-injured people to physical impairments and functional changes
  • Developing more precise methods of measuring impairments, disabilities, and both societal and functional limitations
  • Training research scientists in the field of rehabilitation

Spinal Cord Injury (SCI): Research Activities and Scientific Advances

Through its intramural and extramural organizational units, the NICHD supports and conducts a range of research on spinal cord injury (SCI), especially in the area of rehabilitation. Short descriptions of some of this research are included below.

Institute Activities and Advances

Several NICHD and organizational units support research and other activities related to SCIs and spinal cord development.

  • The NICHD's National Center for Medical Rehabilitation Research (NCMRR) is the primary NICHD entity that supports research to advance the understanding of treatments and devices to assist movement in patients with SCIs.
  • The NICHD's Pregnancy and Perinatology Branch (PPB) supports studies to understand and treat birth defects that affect the spinal cord, such as spina bifida.
  • The NICHD's Division of Intramural Population Health Research (DIPHR) supports and conducts research relevant to human development and spinal cord health through studies of nutrients in the prevention of birth defects. For example, studies are investigating the importance of folic acid in preventing neural tube defects.
  • Researchers in the NICHD's Division of Intramural Research (DIR) are developing methods for improved imaging of the central nervous system. These methods will assist not only in studying normal patterns of development, but also in evaluating and studying SCIs and spinal cord diseases.

Some recent findings related to SCIs are described below.

Folate Found to Encourage Healing in SCIs

The B vitamin folate seems to stimulate healing in the damaged spinal cord tissue of rats by touching off a change in DNA, according to a laboratory study funded by the NICHD's NCMRR and three other NIH Institutes. The greater the doses of folate the researchers administered (up to a maximum of 80 micrograms of the B vitamin per kilogram of body weight), the more regrowth of axons occurred. The scientists found that folate fueled an intracellular process in which DNA is superficially altered by the attachment of chemical compounds known as methyl groups. This natural biochemical process is called DNA methylation. The regrowth of axons in rats suggests that more research on folate metabolism and DNA methylation could open new paths to healing damaged spinal cords—not to mention the healing of other forms of trauma to nerve tissue, as in the brain. The research represents an advance in the new field of epigenetics, in which changes are made to DNA to alter its function without changing the structure of genes, a seemingly counterintuitive exercise given the long-established notion that the only way DNA's function can be changed is to alter its composition through mutation.

The researchers went a step further and investigated how folate repairs damaged nerve tissue. Traumatized axons, they found, start to produce surface receptors for folate. Folate is attracted to the receptors and fits into them like a hand in a glove and then is absorbed into the axon. After absorbing folate, the nerve cells begin producing enzymes that fasten methyl groups to DNA. When the scientists chemically blocked folate from binding to the nerve cells, or blocked the methylation enzymes, they found that the nerve-healing process tapered off.1

Brain Control of Wheelchairs, Prostheses, and Computers

Researchers funded by a grant from the NCMRR, which is part of the NICHD, demonstrated that a tiny microelectrode array implanted in the brain cortex can help a person with tetraplegia achieve repeatable and accurate point-and-click control of a computer interface nearly 3 years after implantation of the device. The goal of these researchers, who were working in a human clinical trial at Massachusetts General Hospital in Boston, was to make progress in developing a system called BrainGate2 that can help those with SCIs and other nervous system injuries to turn brain impulses into electrical signals that can control external devices such as computers, wheelchairs, and prostheses or robotic appendages. For 5 days, the scientists tested a 4×4 mm array of 100 microelectrodes that had been implanted 1,000 days previously in the motor cortex of a patient with longtime tetraplegia from a brainstem stroke. Across the 5 days, spiking signals were obtained from 41 of 96 electrodes and were successfully decoded to provide neural cursor point-and-click control with a mean task performance of 91.3% ± 0.1% (mean ± standard deviation) correct target acquisition.

The ultimate aim of BrainGate2 is to help people with SCI, stroke, muscular dystrophy, amyotrophic lateral sclerosis, limb loss, or other serious conditions to restore their mobility and independence. In addition to the brain-implanted sensor that records signals directly related to imagined limb movement, the system consists of a decoder, which includes a set of computers and embedded software that turns the brain signals into a useful command for an external device, which could be a standard computer desktop or other communication device, a powered wheelchair, or a prosthetic or robotic limb.

Working together, the system components can turn thought into action. For example, the user thinks about moving a cursor on a computer, and the brain emits a signal that is captured by the implanted sensor. The sensor signals the decoder, which translates it into a command for the computer to move the cursor.2

Strengthening SCI Patients' Leg Muscles Through Electrical Stimulation

The mass, strength, and endurance of the thigh muscles of people with tetraplegia and paraplegia can be significantly increased through the electrical stimulation of the area's nerves and muscles combined with resistance training, according to a small longitudinal study, conducted at the Department of Cell Biology at the Emory University School of Medicine in Atlanta, which was supported by the NICHD. During the study, the experimenters also measured the femoral artery's diameter and blood flow.

In the study, five male patients, ages 31 to 41, who had chronic complete paralysis below the level of injury (C5 vertebra to the T10) completed 18 weeks of home-based neuromuscular electrical stimulation (NMES) resistance training. While seated, the participants trained their quadriceps muscle group twice a week with four sets of 10 dynamic knee extensions against resistance. All measurements were made before training and after 8, 12, and 18 weeks of training. Ultrasound was used to measure the femoral artery diameter and blood flow. Blood flow was measured before and after 5 and 10 minutes of occluding blood circulation with a cuff and during a 4-minute isometric electrical stimulation fatigue protocol.

The training led to substantial increases in muscle mass and ability to lift weight, as well as a 60% reduction in muscle fatigue. However, training did not increase the diameter of the femoral artery and the volume of blood flow—both of which typically diminish with SCI.

In summary, NMES resistance training improved muscle size and reduced fatigue without a corresponding increase in the blood supply. This suggests that the effects of SCI on artery size and blood flow are not linked directly with muscle mass and resistance to fatigue. It also shows that muscle fatigue in SCI patients can be improved without increases in arterial diameter or in blood flow capacity.3

Training a Key Researcher to Study the SCI Population in High-Risk Communities

A 5-year NICHD award is connecting registered nurses with Ph.D. degrees to the scholarly training, mentorship, and support necessary to become a skilled independent researcher in SCI, while also providing help to those living SCI. At the completion of training, candidates are expected to create and oversee a large randomized controlled trial (RCT) focusing on people with SCI who are living in a local community whose residents are at high risk for this injury. It is anticipated that this research project will provide empirical data to develop programs that will improve the health and quality of life of this vulnerable population.

The training will take place at the Medical University of South Carolina in Charleston, a facility that features senior experts in the areas of community-based participatory research (CBPR), research in health disparities, and applied SCI research. The trainee is connected with mentors who have complementary expertise in the measurement and interpretation of health and social outcomes after SCI and in the development and implementation of RCTs of community-based health promotion interventions with vulnerable populations using a CBPR approach. The mentoring team will be responsible for monitoring the trainee's progress during the 5-year program.

The planned research project, to be conducted in partnership with a local center for independent living, as well as the Medical University of South Carolina, includes strategies to identify and address obstacles in the physical and social environment that affect health after SCI. The overall goals are to reduce rehospitalizations and the development of secondary conditions, to improve community participation in the program, and to increase satisfaction with life after SCI. The study is employing the novel approach of having community-based peer navigators who have SCI. These navigators will proactively mitigate barriers and facilitate access to health care and other community-based services for other people in the community with SCI. (NIH/NICHD K23. Project Dates: 2/01/2010 to 3/31/2015. Susan Newman, Ph.D., RN, CRRN. Grant/Project No. 5K23HD062637-03)

Microimaging of Living Nerve Tissue

NICHD scientists in the DIR Section on Biophysics and Biomimetics invented a breakthrough living-tissue imaging technique known as diffusion tensor magnetic resonance imaging (DTI). This technique allows researchers to better understand the function and organization of the central nervous system in its normal, diseased, and injured states, and thus it contributes to improving the diagnosis of neurological and developmental disorders. DTI measures how water diffuses along gradients in three directions. Water takes the path of least resistance, even as it travels through biological structures such as cell membranes. By imaging the path and rate of flow of biosystem water in tiny three-dimensional sectors called voxels, a highly detailed image of normal and abnormal nerve microstructures can be constructed. The resulting "picture" looks like tissue "stains" on a lab slide, but these pictures are "developed" without chemical contrast agents or dyes.

DTI is the most successful imaging technique to date for identifying ischemic regions in the brain during acute stroke. It is also used to follow changes in normally and abnormally developing white matter, including demyelination, the loss of axons' myelin sheath that often happens in SCI. NICHD researchers also pioneered the use of DTI-derived color maps to encode the orientation of nerve fibers. One example of this type of work, published in 2006 in the American Journal of Neuroradiology, can be found at: http://www.ajnr.org/content/27/4/786.full?ref=starshemale.com External Web Site Policy

More recently, NICHD scientists invented and have been developing several advanced live-tissue magnetic resonance methods to measure fine microstructural features of nerve fascicles, which are bundles or tracts of nerve cells or fibers. Previously, these fascicles could be measured only by optical microscopy, and then only by using laborious dead-tissue histological methods. The scientists also recently developed a DTI method to measure the distribution of axon diameters within large white-matter fascicles, dubbing this method AxCaliber MRI. After careful validation studies, the researchers recently reported the first in vivo measurement of the distribution of axon diameters within the corpus callosum in the rodent brain. This measurement is important neurophysiologically and developmentally because the axon diameter determines the velocity of nerve conduction and thus the rate of information transfer along nerve pathways. See the article at: https://science.nichd.nih.gov/confluence/download/attachments/117212440/barazanybasserassaf_brain09.pdf (PDF - 902 KB).

Understanding Spinal Cord Injury and Bone Loss

People who experience spinal cord injury often have the added problem of osteoporosis and bone loss. As a result, patients with spinal cord injury are more prone to bone fractures and other serious medical complications such as increased pain, amputation, and prolonged hospitalization for treatment. Unfortunately, a lack of understanding of what causes spinal cord injury-related osteoporosis makes it difficult to diagnose, treat, and prevent. In short-term animal studies, bone loss was associated with increases in a specific protein called sclerostin. To assess whether these research results could lead to new ways to help humans with spinal cord injury, scientists studied this same protein in a group of men who had suffered spinal cord injury at least two years previously.

The results from the earlier animal studies suggested that researchers may find high levels of the sclerostin protein in patients with complete spinal cord injury who could not walk. However, what scientists discovered was the opposite—the amount of the protein was significantly lower in the men who were wheelchair bound, compared with those who could walk. Additionally, the researchers found that men with spinal cord injury but who could walk had very similar sclerostin levels to men without any spinal cord injury. Scientists theorized that sclerostin may increase shortly after spinal cord injury, while bone loss is occurring rapidly, and then fall to low levels once most of the damage is already done. Additional research is needed to determine whether sclerostin is simply a marker of osteoporosis or whether blocking the effects of the protein soon after an injury could help prevent or reduce long-term bone loss.4

Other Activities and Advances

To achieve its goals for research on SCI, the NICHD supports a variety of other activities. Some of these activities are managed through the Institute's components; others are part of NIH-wide or collaborative efforts in which the NICHD participates. Some of these activities are listed below.

  • The Medical Rehabilitation Research Infrastructure Network (MRRIN), funded through the NCMRR, the National Institute of Neurological Disorders and Stroke, and the National Institute of Biomedical Imaging and Bioengineering, builds research infrastructure in medical rehabilitation. The Network provides investigators with access to expertise, courses and workshops, technologies, and other collaborative opportunities from allied disciplines such as neuroscience, engineering, applied behavior, and the social sciences. The Network provides rehabilitation researchers access to resources to study a wide range of conditions, including SCI, stroke and traumatic brain injury, musculoskeletal and joint disorders, developmental disorders, and degenerative disorders.
  • Among its many activities, the NCMRR supports research on SCIs and musculoskeletal disorders, as well as assistive devices, through its Spinal Cord and Musculoskeletal Disorders and Assistive Devices (SMAD) Program. A large portion of this program's activities focus on developing and supporting the application of devices to improve the human-environment interface and to restore or enhance an individual's capacity to function in his or her environment. This type of applied research and rehabilitation technology includes, but is not limited to, prosthetics, wheelchairs, biomechanical modeling, and other topics that aim to enhance mobility, communication, cognition, and environmental control.
  • The NICHD's PPB initiated the Maternal-Fetal Surgery Network to understand if surgery done in utero was comparable to standard post-natal surgery. The primary study in the Network is the Management of Myelomeningocele Study (MOMS), which aims to understand which treatment—the standard postnatal surgery or prenatal surgery—is more effective in treating myelomeningocele, the most frequent and severe form of spina bifida, and for improving short- and long-term outcomes for those with the condition. The results of the study were so positive that a clinical trials organization named MOMS the "Clinical Trial of the Year" in 2012; visit http://www.nichd.nih.gov/news/releases/Pages/052312-MOMS.aspx for more information.
  • The Paul D. Wellstone Muscular Dystrophy Collaborative Research Centers program is supported by the NICHD's IDDB  and several other NIH Institutes. The Centers promote basic, translational, and clinical research and provide important resources that can be used by the national muscle biology and neuromuscular research communities, including those conducting research on SCIs and spinal cord health.
  • The NICHD held a 2-day workshop on Personal Motion Technologies for Healthy Independent Living to discuss the clinical needs of older and/or disabled persons and how sensor technologies can be used to monitor personal motion in their everyday lives. The Workshop provided critical information and discussion on how such devices could be used to monitor patients with SCIs.
  • The NICHD also sponsored the 2-day workshop on Pregnancy in Women with Disabilities to review the current body of evidence on the management of pregnancy in women with physical disabilities. The Workshop identified key gaps in knowledge and recommendations for priority avenues for future research.

Citations

  1. Iskandar, B. J., Rizk, E., Meier, B., Hariharan, N., Bottiglieri, T., Finnell, R. H., et al. (2010). Folate regulation of axonal regeneration in the rodent central nervous system through DNA methylation. Journal of Clinical Investigation, 120, 1603-1616. PMID: 20424322
  2. Simeral, J. D., Kim, S. P., Black, M. J., Donoghue, J. P., & Hochberg, L. R. (2011). Neural control of cursor trajectory and click by a human with tetraplegia 1000 days after implant of an intracortical microelectrode array. Journal of Neural Engineering, 8, 025027. PMID: 21436513
  3. Sabatier, M. J., Stoner, L., Mahoney, E. T., Black, C., Elder, C., Dudley, G. A., et al. (2006). Electrically stimulated resistance training in SCI individuals increases muscle fatigue resistance but not femoral artery size or blood flow. Spinal Cord, 44, 227-233. PMID: 16158074
  4. Morse, L. R., Sudhakar, S., Danilack, V., Tun, C., Lazzari, L., Gagnon, D. R., et al. (2012). Association between sclerostin and bone density in chronic spinal cord injury. Journal of Bone and Mineral Research, 27(2), 352-359. PMID: 22006831

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