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Spinal Cord Injury Medicine. 1. Epidemiology and Classification

      Abstract

      Ho CH, Wuermser LA, Priebe MM, Chiodo AE, Scelza WM, Kirshblum SC. Spinal cord injury medicine. 1. Epidemiology and classification.
      This self-directed learning module reviews the demographics of traumatic and nontraumatic spinal cord injuries (SCIs). It is part of the study guide on SCI medicine in the Self-Directed Physiatric Educational Program for practitioners and trainees in physical medicine and rehabilitation. This article specifically focuses on the changing demographics of traumatic SCI, the classification of SCI, the common causes of nontraumatic SCI, and the incidence and prevalence of myelomeningocele.

      Overall Article Objective

      To summarize the demographics and classification of traumatic and nontraumatic spinal cord injuries in adults and children.

      Key Words

      1.1 Educational Activity: To discuss the epidemiologic factors relevant to a 70-year-old man who fell and sustained a neurologically incomplete C4 injury

      SINCE 1973, THE NATIONAL Spinal Cord Injury Database (NSCID) has been collecting data on people with new spinal cord injuries (SCIs) from the facilities participating in the Model Spinal Cord Injury System (MSCIS). Analyses of these data have shown changing trends in traumatic SCI. Such epidemiologic data can guide us on the use of resources for preventing and treating SCI.
      The case of this 70-year-old man who fell illustrates several significant trends in traumatic SCI: the increasing average age of onset, the increasing incidence of falls as one of the leading causes of SCI, the increasing incidence of cervical injuries, and the continuing trend of people with incomplete tetraplegia as the largest group by neurologic classification.
      National Spinal Cord Injury Statistical Center
      Spinal cord injury: facts and figures at a glance.

       Increasing Age at Onset of SCI

      Between 1973 and 1979, the average age at injury was 28.7 years, with most of the injuries occurring between the ages of 16 and 30 years. The average age has since been increasing steadily to an average age of 37.6 years between 2000 and 2003.
      • Jackson A.B.
      • Dijkers M.
      • DeVivo M.J.
      • Paczatek R.B.
      A demographic profile of new traumatic spinal cord injuries: change and stability over 30 years.
      With the exception of violence as a cause of injury, this increase in the average age at injury has been found in all other etiology groups (motor vehicle crashes, falls, sports). A closer look at the data showed that, although the relative order of prevalence of SCI in the various age groups (0–15, 16–30, 31–45, 46–60, 65+y) has remained unchanged, the absolute percentage for each group has significantly changed over the last 3 decades. The prevalence in older adults above the age of 65 years has increased from 4.7% between 1973 and 1979 to 10.9% since 2000, whereas the prevalence among children between the ages of 0 and 15 years has decreased from 6.4% to 2.0% in the same periods
      • Jackson A.B.
      • Dijkers M.
      • DeVivo M.J.
      • Paczatek R.B.
      A demographic profile of new traumatic spinal cord injuries: change and stability over 30 years.
      (table 1). This trend of increasing average age of injury is significant; the larger percentage of elderly people with SCI has implications on the need to consider specific aging-related and geriatric needs in the rehabilitation of these people.
      Table 1Changes in Age at Onset of SCI
      Characteristic1973–19792000–Present
      Average age at injury (y)28.737.6
      Percentage of people >60y at injury4.710.9
      NOTE. Data from the National Spinal Cord Injury Statistical Center.
      National Spinal Cord Injury Statistical Center
      Spinal cord injury: facts and figures at a glance.
      • Jackson A.B.
      • Dijkers M.
      • DeVivo M.J.
      • Paczatek R.B.
      A demographic profile of new traumatic spinal cord injuries: change and stability over 30 years.

       Changes in Etiology

      The most common cause of SCI between 2000 and 2003 continued to be motor vehicle crashes (table 2). They account for 50.4% of all the causes for all age groups during the time period, compared with a similar rate of 48.7% between 1973 and 1979.
      • Jackson A.B.
      • Dijkers M.
      • DeVivo M.J.
      • Paczatek R.B.
      A demographic profile of new traumatic spinal cord injuries: change and stability over 30 years.
      However, the rates for falls have progressively increased over the last 3 decades, from 16.5% in the 1970s to 23.8% between 2000 and 2003.
      • Jackson A.B.
      • Dijkers M.
      • DeVivo M.J.
      • Paczatek R.B.
      A demographic profile of new traumatic spinal cord injuries: change and stability over 30 years.
      Even though falls were still the second most common cause of SCI across all age groups, it was the only cause with a rate that has steadily increased over the last 3 decades. When data were stratified by age group, it was apparent that falls were by far the most common cause of SCI in people over age 60 years. Successful fall prevention education for the elderly may mitigate the prevalence of SCI in this population.
      Table 2Changes in Etiology of SCI
      Etiology of SCI1973–19792000–Present
      Motor vehicle crashes48.750.4
      Falls16.523.8
      Sports14.49
      Violence13.311.2
      NOTE. Values are percentages. Data from National Spinal Cord Injury Statistical Center.
      National Spinal Cord Injury Statistical Center
      Spinal cord injury: facts and figures at a glance.
      • Jackson A.B.
      • Dijkers M.
      • DeVivo M.J.
      • Paczatek R.B.
      A demographic profile of new traumatic spinal cord injuries: change and stability over 30 years.
      Examination of the other causes of SCI shows that the rates associated with sports have decreased over the decades, from 14.4% between 1973 and 1979 to 9% between 2000 and 2003. Violence as an etiology as reported by the NSCID initially increased from 13.3% between 1973 and 1979 to a peak of 21.8% in the 1990s. However, it has since declined to 11.2% between 2000 and 2003. When compared with international statistics, with the exception of acts of violence as causes of SCI, the etiologies of SCI were similar in other countries, including Denmark, Taiwan, and Spain.
      • Jackson A.B.
      • Dijkers M.
      • DeVivo M.J.
      • Paczatek R.B.
      A demographic profile of new traumatic spinal cord injuries: change and stability over 30 years.

       The Increasing Incidence of Cervical Injuries

      Throughout all the time periods observed, cervical injuries occurred more often than thoracic and lumbar injuries. Furthermore, there was an increasing percentage of cervical injuries from 53.5% between 1973 and 1979 to 56.5% between 2000 and 2003. This increase was statistically significant but also has financial implications, because the lifetime costs for the care of people with tetraplegia were much higher than for those with paraplegia. For all age groups since 2000, people with incomplete tetraplegia made up the highest number (34.5%), followed by complete paraplegia (23.1%), complete tetraplegia (18.4%), and incomplete paraplegia (17.5%).
      National Spinal Cord Injury Statistical Center
      Spinal cord injury: facts and figures at a glance.

       Other Trends

      NSCID data show that from the 1970s to the 1990s, the percentage of whites with SCI decreased from 76.8% between 1973 and 1979 to 59.9% between 1990 and 1999. However, the percentage has risen to 67.4% between 2000 and 2003. At the same time, the increase in percentage among African Americans and Hispanics from the 1970s to the 1990s was reversed between 2000 and 2003.
      • Jackson A.B.
      • Dijkers M.
      • DeVivo M.J.
      • Paczatek R.B.
      A demographic profile of new traumatic spinal cord injuries: change and stability over 30 years.
      During the periods when the percentage of ethnic minorities with SCI rose, there was a striking correlation with an increase in acts of violence as causes for SCI.
      The percentage of females with SCI has increased since the 1970s, from 18.2% between 1973 and 1979 to 21.8% between 2000 and 2003. When the data from the Shriners Hospitals for Children SCI database were combined with the NSCID from 1973 to 2002, analysts noted that males were a consistently decreasing proportion of new SCI patients.
      • DeVivo M.J.
      Epidemiology of traumatic spinal cord injury.
      Therefore, this finding appeared to reflect a trend observed across different age groups.
      The NSCID has provided the most comprehensive and helpful epidemiologic data on SCI in the United States, noting the changing trends of traumatic SCI over the last 3 decades. However, the data represent only the facilities participating in the MSCIS. Furthermore, over the decades, the profile of the participating facilities has changed. Therefore, it is not clear how generalizable these data are to the general U.S. population. Such factors should be taken into account when interpreting these data.

      1.2 Clinical Activity: To classify the injury for a 70-year-old man with diabetes mellitus who fell from a ladder

       Sensation

      Examining the patient at 72 hours after injury, you note the following: sensation is normal to pin prick and light touch over the face and neck, in the supraclavicular region anteriorly, and over the acromioclavicular joints bilaterally. Sensation to pinprick is diminished, but present, at the lateral antecubital fossa bilaterally and in all dermatomal segments below. Light touch is intact throughout except at midcalf and below bilaterally. Proprioception is absent at the toes bilaterally.

       Motor Function

      Motor examination results are in table 3.
      Table 3The Patient’s Muscle Grades by Location 72 Hours Postinjury
      SideElbow FlexionWrist ExtensionElbow ExtensionDeep Finger FlexionFinger Abduction
      Right1/51/53/53/53/5
      Left0/50/51/51/51/5
      Hip FlexionKnee ExtensionAnkle DorsiflexionGreat Toe ExtensionAnkle Plantarflexion
      Right3/54/54/53/54/5
      Left2/52/52/51/52/5

       Reflexes

      Areflexia is observed in biceps, brachioradialis, and tricep reflexes bilaterally; hyperreflexic without clonus at the patella tendons; and areflexic at the Achilles’ tendon. There is an extensor response to plantar stimulation bilaterally.

       Rectal Examination

      The patient’s sensation to light touch is present at the anocutaneous junction with absent voluntary anal contraction. There is increased sphincter tone and a present bulbocavernosus reflex.
      Based on these examination findings, this patient’s neurologic classification according to the American Spinal Injury Association (ASIA) International Standards for Neurological Classification of Spinal Cord Injury
      American Spinal Injury Association
      is as follows: sensory level of injury, C4 bilaterally; motor level of injury, C4 bilaterally; and degree of completeness, ASIA Impairment Scale (AIS) grade C. This combination of findings follows a pattern of central cord syndrome with an underlying peripheral neuropathy.
      In 1982, ASIA published its first edition of the Standards for Neurological Classification of Spinal Injured Patients.
      American Spinal Injury Association
      This document arose from a need to more precisely define neurologic levels and the extent of incomplete injuries. The ASIA standards focused on key muscles and key sensory points to be tested during the neurologic assessment. Ten key muscles were selected, 5 in the upper limb and 5 in the lower limb (table 4). Each muscle represents a single myotome from C5 through T1 and L2 through S1. The muscles were chosen to be testable with the patient supine and with minimal movement of the spinal column. Likewise, key sensory points were selected to represent each sensory dermatome from C2 through S4-5. A standardized form to be used as a flow chart for classifying spinal injuries was also developed by ASIA (fig 1).
      Table 4The 10 Key Muscles Tested to Determine an ASIA SCI Classification
      Muscle GroupRoot Level
      Upper limb
       Elbow flexorsC5
       Wrist extensorsC6
       Elbow extensorsC7
       Long finger flexorsC8
       Small finger abductorsT1
      Lower limb
       Hip flexorsL2
       Knee extensorsL3
       Ankle dorsiflexorsL4
       Long toe extensorL5
       Ankle plantarflexorsS1
      Figure thumbnail gr1
      Fig 1The standard ASIA method for classifying SCI by neurologic level. Source: American Spinal Injury Association.
      American Spinal Injury Association
      Reprinted with permission.
      Over the next 10 years, refinements were made to definitions of neurologic levels, key muscles and key sensory points, the zone of partial preservation, and the Frankel Scale. In 1992 the fourth edition of the Standards was published. In this edition, the most important change incorporated was the definition of complete versus incomplete injuries using the sacral sparing basis for definition of completeness. An injury was defined as neurologically incomplete if there was any sparing present at the lowest sacral segments. This edition also included recommendations for use of the FIM instrument for assessment of disability. The Frankel Scale was further modified and was termed the ASIA Impairment Scale (AIS). Also in 1992, the International Medical Society of Paraplegia (now the International Spinal Cord Society) endorsed these standards, creating the International Standards for Neurological and Functional Classification of Spinal Cord Injury.
      American Spinal Injury Association, International Medical Society of Paraplegia (ASIA/IMSOP)
      The International Standards document has evolved and improved over the past 20 years. These standards have become accepted as the appropriate method for describing the neurologic impairment of SCI for clinical and research use. The standards have been used in numerous clinical trials and have been incorporated into the International Core SCI Data Set.

      International Spinal Cord Society (ISCoS). Available at: http://www.iscos.org.uk. Accessed October 31, 2006.

      Although not all patients fit the International Standards matrix perfectly, most patients can be adequately classified using this approach.
      Appendix 1 also lists the most common terms used in SCI medicine. Appendix 2 describes the steps to classify the SCI, and appendix 3 outlines the AIS. An ASIA Standards Teaching Package

      American Spinal Injury Association. Available at: http://www.asia-spinalinjury.org. Accessed October 31, 2006.

      and Additional Teaching Manuals (2003, Revised)

      American Spinal Injury Association. Available at: http://www.asia-spinalinjury.org. Accessed October 31, 2006.

      have been developed as a companion volume to the current standards. The teaching package provides a detailed explanation of the examination elements, rationale for inclusion, scoring instructions, and background references. It is available online from the ASIA Website.

      American Spinal Injury Association. Available at: http://www.asia-spinalinjury.org. Accessed October 31, 2006.

      In the sample case the stocking-glove loss of sensation is most likely caused by the history of diabetes mellitus and is unrelated to the patient’s SCI. Although reflexes are an important part of the neurologic examination they are not used for classification in the International Standards.

      1.3 Educational Activity: To identify the common causes of nontraumatic SCI pertinent to a 30-year-old woman who presents with subacute onset of paraplegia associated with a T6 sensory level

      Nontraumatic SCI affects a vast number of people and is a growing population for admission to inpatient rehabilitation. The percentage of inpatient rehabilitation admissions for SCI for nontraumatic injuries has been growing. In a comparison of traumatic and nontraumatic SCI, Chapman
      • Chapman J.
      Comparing medical complications from nontraumatic and traumatic spinal cord injury.
      found that nontraumatic SCI was more likely to present with a neurologically incomplete lesion and was associated with a lower frequency of secondary conditions such as spasticity, deep vein thrombosis, and autonomic dysreflexia. However, among an older population, other comorbidities and generalized deconditioning more significantly affected functional outcome. In patients with nontraumatic SCI, there tended to be a longer period between diagnosis and rehabilitation than in traumatic SCI. Nontraumatic SCI patients had a lower rate of discharge home (73%), with favorable discharge seen in patients who had incomplete injury, were married, and had an established bowel and bladder management program and intact skin.
      Excluding multiple sclerosis (MS) and degenerative central nervous system (CNS) diseases, causes for nontraumatic SCI have included neoplasms (25%), vascular disease (25%), inflammatory disease (19.5%), and spinal stenosis (18.6%).
      • Citterio A.
      • Franceschini M.
      • Spizzichino L.
      • Reggio A.
      • Rossi B.
      • Stampacchia G.
      Nontraumatic spinal cord injury: an Italian survey.
      In another study,
      • McKinley W.O.
      • Huang M.E.
      • Tewksbury M.A.
      Neoplastic vs. traumatic SCI: an inpatient rehabilitation comparison.
      spinal stenosis (21%) and spinal cord tumors (14%) were the most common causes of nontraumatic SCI. Spinal stenosis patients with cord compression were more commonly paraplegic (73%) and neurologically incomplete (90%) than their traumatic SCI counterparts.
      • McKinley W.O.
      • Tellis A.A.
      • Cifu D.X.
      • et al.
      Rehabilitation outcome of individuals with nontraumatic myelopathy resulting from spinal stenosis.
      Inflammatory disorders of the spinal cord were commonly represented among SCI patients who participate in rehabilitation. MS was most commonly seen in young adults, although pediatric and elderly presentations are common and may affect the spinal cord. Pediatric disease was usually relapsing-remitting and with a longer time course to disability, although disability occurs at an earlier age. Negative prognostic indicators among children were a short interattack interval, a high relapse rate, a relapsing-progressive course, a shift to the secondary progressive phase, and early accumulation of disability.
      • Ghezzi A.
      Clinical characteristics of multiple sclerosis with early onset.
      Elderly presentation, representing 4% to 10% of cases, was often primary progressive with pyramidal or cerebellar involvement seen in more than half. Progression to disability is faster in elderly patients than younger patients. Differential diagnoses included cerebrovascular disease, hypertension-related encephalopathy, cerebellar degenerative diseases, other neurodegenerative diseases, and nutritional disorders. Diseases that mimic MS included Devic’s neuromyelitis optica and acute disseminated encephalomyelitis. Devic’s neuromyelitis optica was diagnosed clinically and by magnetic resonance imaging (MRI), with evidence of myelitis and optic neuritis. Poorer prognosis was seen clinically in people with relapses in the first 2 years of the disease, with older age, and in women.
      • Bergamaschi R.
      • Ghezzi A.
      Devic’s neuromyelitis optica: clinical features and prognostic factors.
      Antiphospholipid syndrome can clinically mimic MS. In MS, MRI is an accepted tool for monitoring disease progression, with the number of new lesions seen on T2 images and degree of brain atrophy being predictive of subsequent disease in primary progressive patients.
      Transverse myelitis (TM) is another common inflammatory disorder of the spinal cord. It can be primary or may be secondary to vasculitis or rheumatologic disorders such as systemic lupus erythematosis or Sjögren’s syndrome. TM has a female-to-male ratio of 4:1, with peaks in the second and fourth decades. The time course of progression is longer than 48 hours and less than 6 weeks. At nadir, half have paraplegia, all have neurogenic bladder, and 80% to 94% have sensory symptoms. Over time, one third recovered, one third had neurologic deficits, and one third had paraplegia. Poor recovery was predicted by rapid progression, back pain, and spinal shock.
      Transverse Myelitis Consortium Working Group
      Proposed diagnostic criteria and nosology of acute transverse myelitis.
      SCI from epidural abscess in immunocompromised and diabetic patients is not rare. Epidural hematoma can be associated with anticoagulation, vascular malformations, or myelodysplastic diseases. Arterial disease associated with thrombosis or embolism to spinal arteries may cause spinal cord ischemia and injury.
      Infarction of the spinal cord can occur in many other vascular diseases, including vasculitis and diabetes. Idiopathic syringomyelia can also cause spinal cord damage.
      SCI in patients after thoracoabdominal aneurysm repair was reported in 9% to 18% of cases. Increased occurrence was associated with rupture, dissection, or prolonged surgery.
      • Rectenwald J.E.
      • Huber T.S.
      • Martin T.D.
      • Ozaki C.K.
      • Devidas M.
      • Welborn M.B.
      • Seeger J.M.
      Functional outcome after thoracoabdominal aortic aneurysm repair.
      Improved outcome has occurred with preoperative planning with spinal angiography, reattachment of intercostal arteries, good distal aortic perfusion, spinal cord hypothermia, intraoperative cerebrospinal fluid drainage, and intraoperative neurophysiologic monitoring.
      • Tabayashi K.
      Spinal cord protection during thoracoabdominal aneurysm repair.
      Radiation myelopathy may occur months after treatment. This myelopathy involves an injury to the white matter that predominates in the lateral spinal cord. Etiology remains elusive, with injury to glial cells and vascular injury remaining as the most likely mechanisms.
      • Okada S.
      • Okeda R.
      Pathology of radiation myelopathy.
      Spinal cord tumors can be primary or metastatic, intradural, or extradural. In patients with intramedullary tumors, favorable functional outcome was observed in 94.1% of patients with vascular tumors, in 61.3% of patients with low-grade neuroepithelial tumors, and in 53.3% of patients with malignant tumors.
      • Sandalcioglu I.E.
      • Gasser T.
      • Asgari S.
      • et al.
      Functional outcome after surgical treatment of intramedullary spinal cord tumors: experience with 78 patients.
      The strongest predictors of functional outcome were the tumor type and the preoperative neurologic status.
      • Sandalcioglu I.E.
      • Gasser T.
      • Asgari S.
      • et al.
      Functional outcome after surgical treatment of intramedullary spinal cord tumors: experience with 78 patients.
      In patients with metastatic spine disease, quality-of-life measurements have been generally favorable except for those patients who have high emotional distress.
      • Levack P.
      • Graham J.
      • Kidd J.
      Listen to the patient: quality of life of patients with recently diagnosed malignant cord compression in relation to their disability.
      Comprehensive inpatient rehabilitation that included mobility, activities of daily living, bowel and bladder care, and patient and family training and equipment prescription was important for nontraumatic injuries. The prognosis of the underlying disease process will guide the rehabilitation goals. Inpatient rehabilitation lengths of stay were shorter, but FIM efficiency and home discharge rates were comparable with those of traumatic spinal cord patients.
      • McKinley W.O.
      • Huang M.E.
      • Tewksbury M.A.
      Neoplastic vs. traumatic SCI: an inpatient rehabilitation comparison.

      1.4 Educational Activity: To discuss the epidemiologic factors related to a girl born with spina bifida at the L2 level with a lower motoneuron injury

      Embryonic development of the CNS starts with the formation of the neural tube at approximately day 18. Neural tube defects or, as they are most accurately termed, spinal dysraphism, result in failure of the ectodermal, mesodermal, and neuroectodermal tissues to develop properly. In the United States, spinal dysraphism incidence has dramatically decreased to about 3.2 per 10,000 live births.
      Centers for Disease Control (CDC)
      Spina bifida incidence at birth—United States, 1983-1990.
      Recent trends show a uniform incidence in all ethnic groups with no geographic variation. The reduction in incidence is largely believed to be associated with better national nutritional habits. Folic acid supplementation of 0.4mg a day is recommended for all women of childbearing age to reduce the risk.
      From the Centers for Disease Control and Prevention
      Recommendations for folic acid to reduce the number of spina bifida cases and other neural tube defects.
      The risk to siblings of those with spinal dysraphism increases to 2% to 5% with 1 affected sibling and to 10% to 15% with 2 affected siblings. In those with spina bifida, allergy to latex has a prevalence of up to 40%. It is immunoglobulin E mediated and may be mild with urticaria or more severe with laryngeal edema and bronchospasm; it is recommended that latex exposure be minimized as much as possible.
      • Tosi L.L.
      • Slater J.E.
      • Shaer C.
      • Mostello L.A.
      Latex allergy in spina bifida patients: prevalence and surgical implications.
      Cognitive dysfunction, obesity, and precocious puberty are also commonly seen in people with myelomeningocele.
      • Molnar G.E.
      Spina bifida.
      In spinal dysraphism’s most common form, myelomeningocele, neural elements are exposed, causing complete neurologic deficits. They can present anywhere throughout the spine but are most commonly seen in the thoracolumbar regions, resulting in paraplegia. After birth, in the presence of a myelomeningocele, immediate surgical closure is usually undertaken within 24 hours. Goals of the operation are to preserve neurologic function and to prevent infection. In a meningocele, the dural sac is exposed and the neural elements may be intact without neurologic deficits. Prompt closure is suggested for the same reasons as with myelomeningocele.
      • Kaufman B.A.
      Neural tube defects.
      Occult spinal dysraphism refers to closed spinal deficits including spinal lipomas, diastematomyelia, and a tethered spinal cord. These conditions are suspected when a cutaneous marker such as a dimple with a pinhole tract, a hairy patch, or nevus is discovered. Neurologic deficits at the time of birth may or may not be present, but further investigation should ensue. Spinal lipomas may present with a subcutaneous fatty mass without any neurologic deficits but may gradually change over the first years of life and should be closely monitored. Surgical treatment is usually focused on untethering of the spinal cord. The lipomas are not typically removed, because neural tissue is usually enmeshed within them and removal would potentially create a more severe deficit.
      • Molnar G.E.
      Spina bifida.
      Spina bifida occulta is strictly a defect in bony closure of the posterior elements without neurologic deficit and is usually an incidental finding.
      In people with myelomeningocele, hydrocephalus is seen in approximately 90% of patients and usually manifests itself after surgical closure. Most of these people will also require ventriculoperitoneal (VP) shunting, which is placed at the same time as the surgical closure. Classic symptoms of elevated intracranial pressure such as headache, nausea, vomiting, and lethargy may be present in shunt malfunctions and must be reviewed with the patient and his/her caregivers. Adolescents, however, may have a more subtle presentation, which may be irritability, worsening performance at school, and generalized weakness. Chiari II malformations are usually the underlying etiology of hydrocephalus, because they are present in almost all cases. Dysphagia, stridor, vocal cord paralysis, cranial nerve palsies, and central respiratory dysfunction may occur in about 20% of cases, and symptoms will primarily occur in the first several months of life.
      • Charney E.B.
      • Rorke L.B.
      • Sutton L.N.
      • Schut L.
      Management of Chiari II complications in infants with myelomeningocele.
      These symptoms are usually treated with VP shunting but sometimes will need a posterior fossa decompression to relieve pressure exerted on the brainstem. Cognitive dysfunction is also prevalent, with approximately 30% of people having below-normal intelligence.
      Hydrosyringomyelia (syrinx) or cystic fluid–filled cavities within the spinal cord are common in myelomeningocele, but the precise prevalence is not known. The syrinx cavity can present in any portion of the spinal cord but is most common in the cervical segments. Classic presentation of syrinx formation includes cervical pain, new weakness, spasticity, and scoliosis. A syrinx may be asymptomatic and may not present clinically until adulthood. Possible etiologies could exist from a tethered spinal cord, which will place traction on the spinal cord over time and contribute to syrinx formation. Tethering of the spinal cord is usually from scar formation or traction of neural tissue attached to the dura. Symptoms of tethered cord are very similar to syrinx. If severe, surgical procedures can be performed to release the tethered area, but scar tissue will often allow them to recur in 15% to 20% of cases.
      • Tamaki N.
      • Shirataki K.
      • Kojima N.
      • Shouse Y.
      • Matsumoto S.
      Tethered cord syndrome of delayed onset following repair of myelomeningocele.
      Scoliosis affects most people with myelomeningocele as well, especially when at the thoracic levels. Neuromuscular weakness, lower-extremity contractures, and primary vertebral abnormalities all contribute to the formation of scoliosis. Syrinx formation, uncompensated hydrocephalus, or tethered cord syndrome, as mentioned before, should be considered when a scoliosis abruptly worsens, especially in someone who is skeletally mature. Curvature generally less than 25° should be monitored closely. Greater curvature may require a thoracolumbosacral orthosis brace to prevent further curvature. Severe curves will occasionally require surgery.

      APPENDIX 1. Glossary of key terms used in SCI

      Key muscle groups: The 10 muscle groups that are tested in the standardized spinal cord examination.
      Motor level: The most caudal key muscle group that is graded 3/5 or greater with the segments cephalad to that level graded normal (5/5) strength.
      Sensory level: The most caudal dermatome to have normal sensation for both pinprick and light touch on both sides.
      Neurologic level of injury: The most caudal level at which both motor and sensory modalities are intact.
      Complete injury: The absence of sensory and motor function in the lowest sacral segments.
      Incomplete injury: Preservation of motor or sensory function below the neurologic level of injury that includes the lowest sacral segments.
      Sacral sparing: Presence of motor function (voluntary external anal sphincter contraction) or sensory function (light touch, pinprick at S4/5 dermatome, or anal sensation on rectal examination) in the lowest sacral segments.
      Zone of partial preservation: All segments below the neurologic level of injury that have preserved motor or sensory findings; used only in complete SCI.

      APPENDIX 2. Steps to classifying injury severity in a patient with SCI
      • Kirshblum S.C.
      • Donovan W.H.
      Neurologic assessment and classification of traumatic spinal cord injury.

      • 1
        Perform sensory examination in 28 dermatomes bilaterally for pinprick and light touch, including S4/5 dermatome, and test for anal sensation.
      • 2
        Determine sensory level (right and left).
      • 3
        Perform motor examination in the 10 key muscle groups, including anal contraction.
      • 4
        Determine motor level (right and left).
      • 5
        Determine neurologic level of injury.
      • 6
        Classify injury as complete or incomplete.
      • 7
        Categorize ASIA Impairment Scale (A–E).
      • 8
        Determine zone of partial preservation if ASIA A.

      APPENDIX 3. The AIS
      American Spinal Injury Association

      A = Complete: No sensory or motor function preserved in the lowest sacral segments (S4/5).
      B = Sensory incomplete: Sensory but no motor function preserved below the neurologic level including the sacral segments S4/5.
      C = Motor incomplete: Motor function is preserved below the neurologic level, and more than half of the key muscles below the neurologic level have a muscle grade less than 3. There must be some sparing of sensory and/or motor function in the segments S4/5.
      D = Motor incomplete: Motor function is preserved below the neurologic level, and more than half the key muscles below the neurologic level have a muscle grade greater than or equal to 3. There must be some sparing of sensory and/or motor function in the segments S4/5.
      E = Normal: Sensory and motor functions are normal. Patient may have abnormalities on reflex examination.

      References

      1. Key reference.
        • National Spinal Cord Injury Statistical Center
        Spinal cord injury: facts and figures at a glance.
        J Spinal Cord Med. 2005; 28: 379-380
        • Jackson A.B.
        • Dijkers M.
        • DeVivo M.J.
        • Paczatek R.B.
        A demographic profile of new traumatic spinal cord injuries: change and stability over 30 years.
        Arch Phys Med Rehabil. 2004; 85: 1740-1748
      2. Key reference.
      3. Key reference.
        • American Spinal Injury Association
        International standards for neurological classification of spinal cord injury. ASIA, Chicago2002 (revised 2000)
        • American Spinal Injury Association
        Standards for neurological classification of spinal injured patients. ASIA, Chicago1982
        • American Spinal Injury Association, International Medical Society of Paraplegia (ASIA/IMSOP)
        International standards for neurological and functional classification of spinal cord injury. ASIA, Chicago1992 (revised 1992)
      4. International Spinal Cord Society (ISCoS). Available at: http://www.iscos.org.uk. Accessed October 31, 2006.

      5. American Spinal Injury Association. Available at: http://www.asia-spinalinjury.org. Accessed October 31, 2006.

        • Chapman J.
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