Complete transection of the cord results in
(1) loss of all sensations below the level of lesion;
(2) voluntary movements below the level of lesion;
(3) initial loss of muscle tone and reflexes followed by their recovery and exaggeration later. Immediately after injury, there is a period of spinal shock, which may last from a few days to several weeks.
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During this period, all somatic and visceral reflex activities are abolished. Thereafter, the reflex activities are returned and the muscles become spastic with exaggerated tendon reflexes.
In transaction above S2, voluntary control over the bladder and bowel functions are lost. Immediately following the injury, there is abolition of the micturition reflex resulting in a flaccid neuro- pathic bladder with overflow incontinence. Following recovery, the reflex excitability of the detrusor returns and the bladder capacity is reduced.
The micturition reflex is exaggerated, resulting in the spastic neuropathic bladder. The micturition reflex is triggered whenever the bladder gets distended and hence the bladder is called an automatic bladder. A few patients develop the ability to empty the bladder reflexly by triggering mass reflex, i.e., by tapping or scratching the skin above the pubis or external genitalia.
In transection above T2 i.e. above the thoracolumbar sympathetic outflow, the sympathetic and somatic thermoregulatory mechanisms do not remain under hypothalamic control. Some local vasodilatation and sweating may still be possible through spinal reflexes, but these are too weak for effective control of body temperature. Such patients have to depend largely on conscious behavioral thermoregulatory mechanisms.
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In transection below C5 the patient becomes quadriplegic. When the transection takes place between the cervical and lumbosacral enlargements, the patient becomes paraplegic.
In paraplegia, when extensor spasms predominate, it is known as paraplegia-in-extension, which indicates that the transaction is functionally incomplete. Paraplegia-in-flexion takes place when the transection is complete in which flexor spasms predominate.
In transection above Cs, the patient is unable to survive due to paralysis of respiratory muscles following involvement of phrenic nerve nucleus.