The term spinal cord injury (SCI) occurs when there is damage or trauma (lesion) to the spinal cord itself or to the vertebral column, this can also include a number of diseases such as Transverse Myelitis, Polio and Spina Bifida.

The injury disrupts nerve transmission resulting in impaired or loss of function leading to a reduction in mobility, sensation and reflex activity below the level of injury. The most common types of SCI include contusions (bruising), compressions, lacerations and central cord syndrome (specific damage to the nerve tracts of the cervical region of the cord). The majority of traumas leading to broken backs, necks or vertebral fractures do not cause spinal cord damage, spinal cord damage occurs in 10-14% of incidents.

Dependent on the level of the lesion the resulting paralysis is known as either paraplegia (if lesion occurs in either the thoracic, lumbar or sacral regions) or tetraplegia, also known as quadriplegia, if it involves the cervical region. The injury is also described as “complete” or “incomplete”. Complete injuries result in a total loss of function and sensation below the level of injury; incomplete, the patient may have sensation but little or no movement or viceversa. Complete does not necessarily mean that the cord has been severed.

Since 1990, in order of frequency, the most common neurological categories are - tetraplegia, incomplete (31%); paraplegia, complete (28.2%); paraplegia, incomplete (23.1%) and tetraplegia, complete (17.5%). There appears to be a trend of increase in paraplegia incomplete and decrease in tetraplegia complete.

Spinal cord injury can occur at any level; or at multiple levels, but the structure and architecture of the spine leads to levels that are more prone to be the site of injury. The most common levels are that of C-4, C-5 and C-6 followed by T-12 and C-7. It is estimated that there are approximately 40,000 people living with the effects of a SCI in the UK. An epidemiological survey in London and the south-east of England suggests that the annual incidence is 3 new people per 100,000 population, other studies report rates of 1.3-5 per 100,000. The most common causes of SCI in the UK and Ireland in the year 2000 were - falls (42%), road traffic accidents (37%), sports (12%), trauma/assault (6%) and other causes (3%).

The highest numbers of people suffering injuries fall into the 16-30 year age group (56%); males suffer the majority of SCI's at approximately 80%. The average age at SCI is around 31 years old.