Spasticity management

After damage to the brain or spinal cord, muscles can become involuntarily tight — resisting movement more the faster you try to move them. It develops over weeks rather than immediately, and it is not the same as weakness, though the two usually appear together.

Not all spasticity should be reduced. Some people stand and transfer using the stiffness in their legs, and removing it leaves them less able, not more. Treatment is offered when tightness limits function, prevents washing or dressing, causes pain, or is pulling a joint towards a fixed contracture.

Botulinum toxin is injected into specific overactive muscles. It suits focal problems — a clenched hand, an inturned foot, a flexed elbow. Weakening begins within days, reaches full effect in one to three weeks, and wears off over roughly three months, at which point it can be repeated 1.

Oral medication such as baclofen or tizanidine acts on the whole body, which is why it suits widespread spasticity and why its main limitation is drowsiness. Intrathecal baclofen delivers the drug straight to the spinal cord through an implanted pump, giving a much smaller dose for much less sedation, and is considered when spasticity is severe and generalised. Serial casting and splinting are used where a joint is already losing range.

Botulinum toxin makes a muscle weaker. It does not teach a limb to move, lengthen a tendon that has already shortened, or restore a grip. What it does is create a period of several weeks in which stretching, splinting and functional training can achieve something they could not achieve against the tightness.

If that therapy is not arranged, the window closes unused and the injection is repeated indefinitely with nothing accumulating between rounds. We do not inject without the programme that follows it already scheduled.

Muscles are located with ultrasound or electrical stimulation rather than by surface landmarks alone. Which muscle is producing a given posture is often not obvious, and injecting the wrong one wastes both the dose and the three months that follow it.

Tone is scored with the Modified Ashworth Scale before treatment and again afterwards, alongside what actually changed — whether the hand opens for washing, whether the foot clears the floor when walking. A tone score that improves while nothing else does is not a result worth repeating.

The muscles are located with ultrasound or electrical stimulation, the toxin is injected, and the appointment takes under an hour. Most people notice nothing immediately.

Weakening begins within a few days, reaches full effect at one to three weeks, and wears off over roughly three months 1. The therapy block is scheduled into that window rather than left to chance.

That this weakens muscles rather than restoring control, that the effect is temporary by design, and that repeating it indefinitely without therapy in between accumulates nothing.

And that some spasticity is useful — a person who stands using the stiffness in their legs may be less able after it is removed. That possibility is assessed before injecting rather than discovered afterwards.