What is spasticity?

Spasticity is a state of increased muscle tone that occurs after damage to the parts of the nervous system that control movement. Affected muscles feel tight and stiff, resist being stretched, and can produce involuntary movements or postures. Spasticity occurs after stroke, in multiple sclerosis, in cerebral palsy, after spinal cord injury, after traumatic brain injury, and in some other neurological conditions.

Why it happens. Movement is normally controlled by a balance between excitatory and inhibitory signals from the brain and spinal cord to the muscles. When parts of the controlling pathways are damaged, the inhibitory signals are reduced, and muscles become over-active in response to stretch and other stimuli. The result is the typical features of spasticity: increased resistance to passive movement, exaggerated reflexes, and sometimes painful muscle contractions.

Why treatment matters. Beyond discomfort, spasticity can interfere with mobility, hygiene, dressing, sleep, and the work of caregivers. Untreated spasticity over time can lead to permanent shortening of muscles and joint contractures that are much harder to address than the spasticity itself. Early and ongoing management is the standard.

The therapy options.

Physiotherapy and occupational therapy: stretching, positioning, splinting, and functional training are foundational. They are used at every stage of spasticity management, alongside medical therapy.

Oral medicines: baclofen, tizanidine, dantrolene, and diazepam can reduce spasticity throughout the body. They commonly cause sedation at doses high enough to produce substantive benefit, which limits how aggressively they can be used.

Botulinum toxin injection: for focal or multifocal spasticity (specific muscles or muscle groups), botulinum toxin injected directly into the affected muscles can be very effective. The effect lasts about three to four months and treatment is repeated. Botulinum toxin is the preferred approach for focal spasticity in modern practice.

Intrathecal baclofen: for severe generalised spasticity that does not respond adequately to oral and focal therapy, a small pump can deliver baclofen directly into the spinal fluid. This delivers high doses to the spinal cord with minimal sedation.

Procedural and surgical options: selective dorsal rhizotomy is a neurosurgical procedure used in selected children with cerebral palsy. Orthopedic surgery may be needed if joint contractures have already developed.

Emerging therapy: medicines targeting other pathways involved in muscle tone (including the myostatin pathway and alpha-adrenergic pathway) are in late-stage trials, with the goal of effective spasticity reduction without sedation.

What to expect. With appropriate combination of physical therapy, medical therapy, and (where needed) injections or procedures, most people with spasticity can achieve meaningful improvement. The right combination depends on the cause, distribution, and severity of the spasticity, and on what activities the spasticity is interfering with most.