The first mechanical blow, and what continues after it for hours and weeks. It is the second part that most research aims at.
This is educational context. It is not a diagnosis, not a prognosis, not a treatment plan and not advice about any individual person. For anything urgent, seek professional help rather than an answer from a website.
Two lengths of cord side by side. On the left the traffic runs the whole way, down one side and up the other. On the right a bruise with a core in the middle of it, the two arrows stopping at its edge and crossed out beyond it. Under them, the four groups of function an injury can change, each with its own drawing.
Damage from an outside force: a road collision, a fall, sport, violence, a wound. The force acts on the spine and through it on the cord.
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Non-traumatic injury
Damage with no outside blow: a tumour, an infection, a problem with blood supply, an inflammatory or degenerative disease. The consequences for function can be the same; the course in time is often different.
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Movement
Voluntary movement: strength, control, the ability to hold a position. It is the function most studies measure, and it is only one of several.
What may change after an injuryStrength can change; control can change while strength is preserved; tone can increase. These are different changes and different scales measure them.
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Sensation
Touch, temperature, pain and the sense of where a limb is. Losing sensation is not only about not feeling: it is also a wound noticed late.
What may change after an injuryDifferent kinds of sensation travel by different paths, so they can change unevenly — and that unevenness is what gives a clinician the pattern.
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Autonomic function
What a person does not steer consciously: blood pressure, temperature, bladder, bowel and sexual function. These changes are rarely visible from outside and they often decide the shape of a day.
What may change after an injurySome of these changes are dangerous rather than inconvenient — and they are asked about constantly and reported on rarely.
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Breathing
The work of the diaphragm and the intercostal muscles, and the strength of a cough. The diaphragm is driven from the cervical segments C3–C5.
Five three-bone motion segments, each deformed by its own force with the cord drawn through it: bent forward, bent back, crushed along its axis with the cord narrowed, pulled apart, and twisted. Below them nine drawings of how it happens — a crash, a fall, a dive, an assault, a site injury, an infection, a tumour, a blocked vessel and a worn disc.
Direct, sustained pressure on the cord — from a fragment, a displaced vertebra, a haematoma or a tumour.
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Contusion
A blow without a tear. The commonest form: the column looks continuous from outside, the tissue inside is damaged, and a cavity can form in the centre over time.
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Transection
An anatomical tear in the tissue. A complete transection is uncommon, which is why "the cord was severed" is not a description of every injury: in most cases the tissue is still there and it is the conduction that is lost.
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Distraction
A pull along the axis, when vertebrae move apart and the cord between them is stretched.
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Flexion and hyperextension
The neck or back moving beyond its ordinary range, forward or backward. A common mechanism in collisions and falls, especially in the neck.
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Rotation
The vertebrae twist against one another beyond the ordinary range. It is often combined with bending, and it damages ligaments and joints first.
Road traffic crashes
One of the most common causes of traumatic spinal cord injury worldwide. The force arrives suddenly and in several directions at once.
Falls
A fall from a height or on the level is the other large group of causes, and its share grows with age.
Sport and diving
A head-first entry into shallow water, contact sport, a fall at speed. The neck is the region most often involved.
Violence
Gunshot and stab wounds. The share of this cause differs widely between countries and periods.
Injuries at work
A fall from a height on a site, a blow from a heavy object, a crush. The mechanism is the same as in any other injury; the setting differs.
Infection
Inflammation or an abscess inside the canal compresses the cord with no blow at all. This is a non-traumatic cause.
Tumours
A growth in the canal or in the cord itself gradually takes up room and presses on the tissue. The signs more often build slowly.
Vascular causes
A disturbance of the blood supply to the cord — a blockage or a bleed. The tissue loses its oxygen with no mechanical blow.
Degenerative change
Narrowing of the canal with age, a disc herniation, bone overgrowth. The canal becomes tighter and the cord is under steady pressure.
On the left the mechanical damage of the moment: tissue with a crack through it and the forces that made it. On the right, four numbered drawings of what continues — a torn vessel with cells escaping, a vessel narrowed and the tissue beyond it pale, a membrane under attack, and an axon losing its sheath. A time line under both, from the first days into the months.
What happened at the moment of injury: mechanical damage to tissue, vessels and fibres. It has already happened and cannot be undone.
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Secondary injury
The biological processes that begin minutes after the blow and continue for hours, days and weeks. This is where most research aims: unlike the primary damage, this stage is still in progress.
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Subacute phase
The weeks after an injury. Inflammation and tissue remodelling are still going on and the scar is still forming.
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Oxidative stress
After an injury the tissue carries an excess of reactive molecules that damage cell membranes. It is one of the steps of the secondary injury.
Six numbered drawings with arrows between them: the first mechanical damage, bleeding into the tissue, tissue swelling against its own boundary, blood flow falling away, immune cells arriving, and fibres and cells damaged. Along the bottom, the phases of time since the injury, including the one for records that do not say.
Blood leaks into the tissue and the tissue swells. Pressure inside the canal rises — and that pressure does damage of its own.
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Reduced blood flow and inflammation
Blood flow falls and cells run short of oxygen. Inflammatory cells arrive, and their work both clears debris and harms neighbouring tissue.
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Damage to fibres and cells
Fibres lose their myelin sheath and break down; nerve cells die. A scar forms at the site, and often a cavity beside it.
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Acute phase
The first days after an injury. This is the window that research aiming to limit secondary damage is pointed at.
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Chronic phase
Months and years after an injury. The tissue has settled, and research here asks a different question from research in the acute phase.
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Subacute phase
The weeks after an injury. Inflammation and tissue remodelling are still going on and the scar is still forming.
Phase not classified
A state of our data, not a state of a body. Many registry records do not state time since injury in a field this map reads, and then the phase stays unclassified. Guessing would put a study in the acute or the chronic column on this programme's say-so.
This layer names the axes the corpus is indexed by. Where an axis holds no records, the panel says so and says what would change it — the gap is part of the answer.
The same corpus, entered a different way: by question, by place, by connection, and by what changed recently. Every one of these reads the records this step has been pointing at.
124 medical statements · 6 authorities · 124 stand on an address that answered · 0 have been read against the source by a person
The last of those numbers is nought, and it is printed rather than left to be assumed. These explanations are ordinary anatomy and ordinary clinical vocabulary, written for this product, and each one names the authority it stands on; nobody has yet sat down and compared them, sentence by sentence, with the text at those addresses.