Spinal Cord Injury

STARTLING STATISTICS

  • The majority of spinal cord injuries occur in young males between 25 – 45 years who are at the peak of their productivity.
  • 40% of spinal cord injuries in New Zealand are a result of motor vehicle accidents.
  • The average cost of care for each high level tetraplegic is NZ$212,000 per year.
  • New Zealand has one of the highest rates of SCI in the western world with the associated rehabilitation and hospital costs being among the highest for all injuries.

THE SPINE

Five segments of the vertebral column

The spinal column houses the spinal cord and is often referred to as the vertebral column. This vertebrae are classified in five segments as detailed below.

Cervical vertebrae
Seven vertebrae make up the cervical spine with eight pairs of cervical nerves. The individual cervical vertebrae are abbreviated C1, C2, C3, C4, C5, C6 and C7.
Thoracic vertebrae
The Thoracic spine is located in the chest area and contains 12 vertebrae. The ribs connect to the thoracic spine and protect many vital organs. Individual vertebrae are abbreviated to T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11 and T12.
Lumbar Vertebrae
These five bones are the largest vertebrae in the spinal column. These vertebrae support most of the body’s weight and are attached to many of the back muscles. Individual vertebrae are abbreviated to L1, L2, L3, L4, and L5.
Sacrum vertebrae
The sacrum is a triangular bone located just below the lumbar vertebrae. It consists of four or five sacral vertebrae in a child, which become fused into a single bone in adulthood.
Cocyx
The bottom of the spinal column is called the coccyx. This consists of 3-5 bones that are again fused in an adult.

THE SPINAL CORD

Spinal cord overview

The spinal cord is part of the nervous system and runs the length of the back, extending from the base of the brain at the medulla to about the waist at the conus medularis. The spinal cord is housed within the spinal column. Within the column, the cord is surrounded by cerebral spinal fluid. This fluid acts as a buffer to protect the spinal cord from damage sustained by striking the inside of the vertebral column.

Spinal cord illustration

The diagram below illustrates the main anatomical features of the spinal cord. The function of the main areas highlighted are listed below.

  • Spinal Nerve – Carries nerve impulses
  • Dorsal Root Ganglion – Receives impulses from other areas such as the skin for transmission to the brain.
  • Central Canal – Fluid filled space running the length of the spinal cord
  • Grey Matter – Contains nerve cell bodies.
  • White Matter – contains the axons of the spinal cord.

SPINAL CORD FUNCTION

The spinal cord carries out two main functions, and is effectively a superhighway for communication of signals.
Firstly, it connects a large part of the nervous system to the brain. Nerve impulses are transmitted to the spinal cord through sensory neurons. These impulses are then transmitted by the spinal cord to the brain. This pathway is known as the ascending tract of nerves. In the reverse process, impulses are generated in the brain, which are transmitted down the cord and leave by the motor neurons. This pathway is known as the descending tract of nerves.

Secondly, the spinal cord acts as a co-ordinating centre in order to produce simple reflexes such as the withdrawal reflex.

The area within the spinal column beyond the end of the spinal cord is called the cauda equina. The nerves that branch out from the spinal cord to the other parts of the body are called lower motor neurons (LMNs) and dorsal root sensory neurons.

SPINAL CORD INJURY

The impact after spinal cord injury depends on the severity of the injury and the location of the spinal cord segments injured.
Completeness
There are two types of injury which are known as complete and incomplete.

In a complete injury, the spinal cord is damaged across the whole of its width so that there is no function below the level of injury.

In an incomplete injury, the injury does not spread across the whole of the spinal cord; some areas away from the injury remain intact or at least intact enough to retain some function. People with incomplete injuries have some sensation and/or movement control below the level of injury.

SPINAL LEVELS

The higher the location of the injury in the spinal cord, the greater the proportion of the body affected. Thus, injuries higher up the spinal cord cause relatively greater paralysis and dysfunction than lower spinal injuries: injuries in the cervical region cause paralysis in both the arms and then legs (known as tetraplegia or quadriplegia) whereas injuries in the thoracic region cause paralysis in the legs, which is called paraplegia.

FAQs

Dr. Leanne McAlister, an expert in the field of Spinal Cord Injuries, answers the most common questions that arise when a loved one is injured.

What are the options for bladder management?

For a male the options are Self Intermittent Catheterisation (SIC), a Suprapubic Catheter (SPC) or an External Collecting Device (ECD/Uridome/Uritip). For women options include SIC or SPC. In very basic and general terms if there is adequate hand function and trunk control, SIC would be the usual option. If there is not adequate hand function and/or trunk control, or if there are other reasons why SIC is not appropriate, a SPC or ECD (in men only) is considered. An ECD can only be used if there is automatic emptying of the bladder when full (like a newborn baby) which is usually possible if the spinal cord injury (SCI) is above about T12/L1.

If with any of the above management options there is significant problems, then surgical procedures and various implants may be helpful, but require careful assessment, planning and thought before embarked upon.

Why do I get Spasm?

Before SCI, a normal function of the spinal cord is reflex activity. Usually however this reflex activity is only obvious when your body needs to instantly react without you thinking – for example when your hand draws back without conscious thought if you place it in hot water. For those with SCI above about T12/L1 these reflexes still occur – but now the messages from the brain that modulates these reflexes don’t get through the damaged part of the spinal cord well, causing spasticity – or over exaggeration of these reflexes. If the SCI is below about L1, spasticity is very unlikely.

Will I be able to get an erection/ejaculate/orgasm?

Most men and women with SCI experience changes in sexual function after injury. For men there can be problems gaining and/or maintaining erections, lost or decreased sensation and inability to ejaculate. For women, changes include less vaginal lubrication and decreased sensation. For men, paraplegics are more at risk of erectile dysfunction than tetraplegics. However the good news for men is that Viagra and other medications for erectile dysfunction, vacuum pumps and penile rings can help most men achieve and maintain erections for intercourse.

If these don’t work, there a whole range of other approaches to sex and intimacy that those with SCI and their partners can find very satisfying. It can be relatively easy for women with SCI’s to maintain normal sexual activities. However, there are often changes to the way women feel or respond to stimulation. Many can still achieve orgasm. Often areas of the body that still have sensation become more sensitive and new erogenous zones are found. Communication with partners and their lovers is the key to enable those with SCI and their partners to explore different ideas and approaches to sex and intimacy.

Are there any treatments that can fix a damaged spinal cord?

At the moment – unfortunately there isn’t. However there is a lot of research interest being shown in regard to the possibilities of medications given at the time of spinal cord injury to limit the damage, and the use of stem cell implants to repair damaged spinal cord some time after the injury has occurred. The research is certainly still in its infancy, but it is progressing.

What are the options for bowel management?

For those with injuries above T12/L1, bowel management usually relies on the preservation of the ‘evacuation reflex’. A suppository, or digital stimulation can help trigger the reflex to empty the rectum. Laxatives may or may not be required to aid the passage of bowel material through the bowel to the rectum. Those with injuries below L1 are usually unable to utilise this reflex and the bowel needs to be emptied manually. Usually fibre is required to aid stool passage to the rectum. There may be overlap around injury levels of T12/L1 where the picture can be one or the other, or a combination of both. For some, a colostomy – where a section of the bowel is brought to the abdomen wall and the stool matter collected in a bag – is becoming a increasingly utilised option.

Why do I suffer from pain?

For many people with a SCI chronic pain can be a major issue. The source of pain can be many. Aches and pains particularly in shoulders and upper back due to wheelchair use are common and may respond to local therapy such as physiotherapy and massage. Spasticity can also lead to pain and anti spasticity medications may be useful. Often the most troublesome pain is due to pain generated in the damaged part of the spinal cord. This ‘neuropathic’ pain is mediated by the damaged spinal cord. It is often described as ‘electric shock like’ or a ‘hot burning poker’.

There are various modalities for treatment of this type of pain including medications, TENS machines (electrical stimulation) and as a last resort surgical procedures. If useful, these treatments usually only dampen the pain and are unlikely to eliminate it completely. An important part of treatment involves diversion tactics such as keeping active and relaxation techniques.

How will I be able to return to the work force?

Getting back to work is proven to be good for people with SCI. Those with SCI who work have fewer health problems, better physical and mental health, a wider social group and generally better quality of life. For some, their old job may not be suitable to do with SCI, but this is just an opportunity to consider something different. There are many different vocational rehabilitation organisations which can aid return to work and retraining if needed.

Questions on Stem Cells

CatWalks goal is to support research that will lead to a cure for Spinal Cord Injury. Internationally, there are many areas of investigation. One promising area is the cell-based approach in which damaged spinal cord cells are replaced.

There are many potential candidates for these cells. Currently, the use of cells derived from the patients themselves are thought to be the most promising candidates, such as those derived from nerve tissue at the back of the nose.

Other cells from the patient, such as from the bone marrow, hold possibilities and need further investigation. These are known as adult stem cells. Cells derived from the discarded umbilical cord and placenta without any harm to the newborn baby may also be of value. These are known as foetal stem cells.

Other sources of cells, such as embryonic stem cells, are possibilities for the future, but a number of issues must be addressed before these become a real option.

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