n Lack of normal voluntary control of bladder or bowels (although good modern techniques make this much better) n Lack of movement and loading, reducing bone stimulation and leading to osteoporosis n Lack of normal protective motor reflexes in a fall, making falls more likely to result in significant injury.

Sensory loss may result in the following: n Pressure area ulcers n Damage to skin from heat or sharp objects n Lack of normal sexual function n Lack of awareness of significant injury, infection or other problems.

Autonomic dysreflexia Autonomic dysreflexia describes an abnormal reflex or response in the autonomic nervous system unique to patients with spinal cord injury above

7a. Slowed heart rate

7b. Descending inhibitory signals blocked at spinal cord injury

Level of spinal cord injury = T6 or above X

2. Afferent stimulus

1. Full bladder or stimulus from the bowel

3. Massive sympathetic response

Figure 1: Disruption of autonomic reflexes following spinal injury Spinal cord

(sympathetic fibres)

Sympathetic chain

T11 - L2 Pelvic nerve (parasympathetic) Striated sphincter S2-S4

Pudendal nerve (somatic)

Figure 2: Spinal cord and neural connections for the bladder, allowing micturition and storage (8)

16 Bladder

Bladder neck and proximal urethra

5. Hypertension

4. Widespread vasoconstriction

6. Baroreceptors in blood vessels detect hypersensitive crisis – signal brain

the major sympathetic outflow tract at around T6. Any stimulus that would normally be painful arising below the level of spinal cord injury stimulates a sympathetic response, which results in widespread vasoconstriction and rapid rise in blood pressure, sometimes to extremely dangerous levels in excess of 250–300mmHg. The normal reflex within the baroreceptors in the neck attempts to modify this and is able to slow the heart, but it is not able to effect feedback on this due to the division of the cord at this level (Fig. 1).

Causes of autonomic dysreflexia n Bladder irritation (most common) – from overstretch or irritation of the bladder wall: n Urinary retention n Urinary tract infection n Blocked catheter or overfull collection bag n Bowel distension or irritation: n Constipation/impaction n Bowel gas n Manual evacuation n Tight or restrictive clothing or pressure to skin from sitting on wrinkled clothing n A normally painful stimulus below the level of injury (eg. prolonged pressure by a sharp object in a shoe or chair, cuts, bruises or fractures) n Pressure sores n Ingrown toenails n Burns (eg. sunburn, burns from using hot water) n Sexual activity n Menstrual cramps n Labour and delivery n Acute abdominal conditions (gastric ulcer, colitis, peritonitis).

n Symptoms and signs of autonomic dysreflexia n Pounding headache (caused by elevation in blood pressure) n Sweating above the level of injury n Flushed (reddened) face or blotching of the skin, especially above the spinal lesion level n Cold, clammy skin below the level of the spinal injury n Goose bumps n Slow pulse (less than 60 beats per minute) n Hypertension (blood pressure greater than 200/100mmHg) n Restlessness n Nausea.

Treatment of autonomic dysreflexia n The priority of treatment is to remove the painful stimulus: check the most common problems first (bladder and bowel problems). n Ideally treat the patient in quiet warm comfortable surroundings. n Treat the patient sitting up in order to avoid increasing cerebral pressure. n If there is no apparent treatable cause, then consideration should be given to urgent reduction in blood pressure by medication. n Nifedipine capsules, which should be chewed and then swallowed, are commonly used. Normally one or two 5mg tablets can control the situation, although larger doses have been used. Other drugs may include glyceryl trinitrate (GTN) spray, but care should be exercised if there is a history of use of sildenafil or similar impotence drugs (not uncommonly taken in this group). Failure of immediate treatment should raise the possibility of hospital admission, as the condition can lead to serious consequences such as stroke (6,7).

Bladder and bowel dysfunction Control of bladder and bowel function is important in order to maintain dignity and independence. Bladder and bowel function are inevitably damaged in spinal cord injury. Although most physiotherapists and doctors do not commonly get involved in this area of care, it is important to understand these aspects of spinal injury and to be aware of the consequence of illnesses such as gastroenteritis or urinary tract infection on an athlete with spinal injury. Many Paralympic medical teams include specialist nurses who provide a valuable resource for the team in this area. In complete spinal lesions, in general a lesion aboveT6 results in a reflex bladder that recovers but has no sensation of filling or control over emptying. As the bladder works purely as a reflex, stimulation such as tapping over the bladder or sudden movement such as transferring may set off a reflex bladder contraction. Not uncommonly, however, there is an uncoordinated contraction of the bladder outflow muscle valve (detrusor sphincter dyssynergia), resulting in high residual urine or increased pressure causing backflow into the kidneys, and it is often better to consider intermittent regular self-catheterisation.

sportEX medicine 2009;42(Oct):13-19