Spinal Cord Injury: An Overview By Kristyn Campbell, MD, and Chester Ho, MD he World Health Organization sometimes also the trunk. Paraplegia is com- defines spinal cord injury (SCI) as monly caused by an SCI in the thoracic or lum- damage to the spinal cord, conus bar regions. medullaris or cauda equina.1 The estimated global incidence of SCI is 40 to Damage to the spinal cord can 80 cases per million annually.1 In Canada, the resultT in loss of sensation and motor control prevalence is approximately 1,298 cases per to the limbs and trunk as well as loss of auto- million.1 Trauma causes include motor vehicle nomic control. This in turn can result in abnor- accidents, falls and violence. Non-traumatic SCIs mal bowel and bladder control, sexual function, may be caused by degenerative changes of breathing, blood pressure, heart rate and tem- the spine, neoplastic tumours, vascular insults, perature control. The extent of these symptoms autoimmune disorders and infections. The inci- depends on the level at which the spinal cord dence of traumatic SCI is higher in adult men, injury occurred as well as the extent to which with at least a 2:1 ratio of male to female injur- the spinal cord is damaged. Tetraplegia (previ- ies.1 The incidence of non-traumatic SCI is also ously known as quadriplegia) is the term used higher in men. Traumatic SCI is most likely to to describe a loss of sensation and motor con- occur in young adults (15 to 29 years) and the trol in all four limbs and the trunk. Tetraplegia elderly (over 60 years), whereas non-traumatic usually results from a cervical SCI. Paraplegia SCI is more common in the elderly. Tetraplegia is used to describe a loss of sensation and/ is slightly more common than paraplegia and or motor control in only the lower limbs and accounts for 52% to 57% of SCI injuries.2 10 Wound Care Canada Volume 16, Number 2 · Winter 2018 How is spinal cord motor function is preserved lateral motor level on either injury classified? in the sacral segments S4–5. side of the body. For AIS C, The extent of SCI is described B = Sensory Incomplete: less than half of key muscle using the International Sensory, but no motor func- functions below the single Standards for Neurological tion is preserved below NLI have a muscle grade ≥ 3. Classification of Spinal the neurological level and D = Motor Incomplete: Motor incomplete status as Cord Injury published by includes the sacral segments defined above, with at least the American Spinal Injury S4–5 (light touch or pin half (or more) of key muscle Association (ASIA). The classifi- prick at S4–5 or deep anal functions below the single cation is based on a systematic pressure) AND no motor NLI having a muscle grade sensory and motor examination function is preserved more ≥ 3. of neurological function. The than three levels below the E = Normal: If sensation and neurological level of injury (NLI) motor level on either side of motor function as test- is the lowest segment of the the body. ed with the International spinal cord with intact sensation C = Motor Incomplete: Motor Standards for Neurological and antigravity muscle strength, function is preserved at the Classification of Spinal Cord provided there is normal motor most caudal sacral segments Injury (ISNCSCI) are graded and sensory function above. for voluntary anal contrac- as normal in all segments, A level of injury from C1 to T1 tion (VAC) OR the patient and the patient had prior results in tetraplegia. A level of meets the criteria for sensory deficits, then the AIS grade injury below T2 results in para- incomplete status (sensory is E. plegia. function preserved at the The severity of the injury is most caudal sacral segments described by the American [S4–S5] by light touch, pin Complications Spinal Injury Association prick or deep anal pressure), Following a Spinal Cord Impairment Scale (AIS), which and has some sparing of Injury includes five scales from A to E: motor function more than In additional to motor and sen- A = Complete: No sensory or three levels below the ipsi- sory impairments, SCI also caus- Volume 16, Number 2 · Winter 2018 Wound Care Canada 11 es many other impairments and prone to leaking, but intravescial Neurogenic Bowel chronic complications, including pressure remains low. The Impact psychosocial consequences The Implications SCI impairs bowel function such as adjustment, depression, Urinary tract infections are the and can result in poor col- vocation, and caregiver burden most common complication in onic motility, delayed transit issues, can be significant and people with SCIs and are often time, chronic constipation and complex. For the purpose of this heralded by increased spasticity, review, we focus on physiologic- fecal incontinence. Similar to fever, incontinence, autonomic al consequences, which include neurogenic bladder, SCI above dysreflexia and vague abdom- but are not limited to the fol- the sacral segments results in inal discomfort. Other urinary lowing. a UMN bowel pattern, while complications include vesicou- lesions at the sacral segments Neurogenic Bladder reteral reflux, renal and bladder lead to an LMN bowel pattern. calculi, hydronephrosis and In a person with a UMN bowel, The Impact chronic renal failure. voluntary defecation cannot be SCI above the sacral segments initiated, and the anal sphinc- results in an upper motor neur- The Interventions on (UMN) bladder. In a UMN Management of neurogen- ter may be spastic, leading to bladder, there is detrusor muscle ic bladder aims to drain the stool retention. Intrinsic and hyperactivity, with patients pre- bladder sufficiently, to ensure reflex-mediated colonic peri- senting with urgency, frequency continence and to maintain stalsis are intact, however, which and incontinence. Intravesical normal intravesical pressure to allows stool to move through pressures may be elevated. protect the upper urinary tract. the colon and rectum reflexive- Injuries involving the sacral Intermittent catheterization ly in response to distension. In segments from S2 to S4 cause is commonly used for bladder a person with an LMN bowel, a lower motor neuron (LMN) management, but where inter- voluntary defecation and the bladder. In an LMN bladder, the mittent catheterization is not reflexes are impaired. This leads bladder is areflexic and atonic— feasible, some may choose to to an even slower colonic transit so the person cannot voluntarily have an indwelling urethral or time. The anal sphincter is often empty the bladder—and it is suprapubic catheter. atonic and prone to leakage of 12 Wound Care Canada Volume 16, Number 2 · Winter 2018 stool, so incontinence may be a Spasticity occurs in the muscles Focal chemo-denervation with problem. below the level of injury in SCIs botulinum toxin type A is help- The Implications above the cauda equina. ful when specific muscles can be targeted. Intrathecal baclofen is Bowel continence plays a large The Implications another option for those with role in a person’s ability to Spasticity may be painful and diffuse, severe spasticity that is return to former social roles and interfere with activities of daily not well managed with other activities. Neurogenic bowel living, ambulating, positioning conservative treatment options. may also cause chronic con- and transfers. However, spas- stipation, hemorrhoids, rectal ticity may also be helpful for Bone Health prolapse, acute ileus or bowel ambulation and transfers by obstruction. providing more rigid support The Impact An imbalance between bone The Interventions from the lower limbs. Worsening resorption and formation Management of a UMN bowel spasticity is often related to occurs following SCI, leading to involves using stool-softening other complications, such as a increased bone resorption in the laxatives, colonic stimulants to urinary tract infection—hence bones below the level of injury. assist in stool propulsion, and a the importance to rule this out. This may result in symptomatic suppository with digital stimu- The Interventions hypercalcemia typically in the lation to trigger the colonic Non-pharmacological treat- first three to fourth months after reflexes to stimulate evacua- ments for spasticity include SCI, causing symptoms such tion of stool. Management of proper positioning, stretch- as nausea, lethargy, abdomin- an LMN bowel involves using ing and serial casting. al pain, polyuria and anorexia. a bulking agent to achieve a Pharmacological treatments Bone mineral density declines stool consistency that allows for include oral baclofen and other by six weeks post-injury, and manual disimpaction from the anti-spasticity medications. bone loss continues for years. rectum. Adequate fibre and fluid intake also assist with devel- oping bulky, formed stool. A bowel program is individualized to each patient but generally occurs at the same time every day and should take less than one hour to complete. The goals of a bowel program are to effi- ciently evacuate the colon to prevent incontinence, constipa- tion and complications such as hemorrhoids. Spasticity The Impact Spasticity is a common com- plication of SCI characterized by hyperreflexia, velocity-de- pendent increased resistance to passive stretch and involuntary muscle contractions or spasms. Volume 16, Number 2 · Winter 2018 Wound Care Canada 13 upper limbs from their work, activities of daily living, and mobilization in a wheelchair. Repetitive motions and recur- rent microtrauma can result in overuse injuries, most com- monly in the shoulder, causing rotator cuff impingement, sub- acromial bursitis, osteoarthritis, bicipital tendonitis or capsulitis. The Implications These are common caus- es for chronic pain after SCI. Contractures may lead to diffi- culties in positioning, pressure injuries, or limit the use of a joint if delayed motor recovery occurs. Functionally, these may limit activities such as dressing, hygiene and transfers. Overuse injuries may also limit mobiliza- tion and activities of daily living.