Surgical Treatment of Spasticity in Children

What is spasticity & which conditions cause it?

Spasticity is a symptom, not a diagnosis. It results from injury to the brain or spinal cord and accompanies many neurological conditions.

Simply put, spasticity is an abnormal increase in resistance when a muscle is moved passively, especially at higher speeds. It reflects injury to the upper motor neuron system (cerebral cortex, corticospinal tracts, spinal cord).

In children, spasticity most commonly occurs in:

• Cerebral palsy (CP) – the most frequent cause.
• After severe traumatic brain injury.
• After pediatric ischemic or hemorrhagic stroke.
• After spinal cord injury or congenital malformations (e.g., myelomeningocele).
• Less commonly, hereditary spastic paraplegias or metabolic disorders.

In many children, spasticity coexists with other movement disorders (such as dystonia), which strongly influences treatment selection.

How common is it in children & at what ages?

Most common in cerebral palsy; often not evident at birth but becomes apparent during early childhood development.

Cerebral palsy (CP) affects approximately 2–3 per 1,000 live births. Up to 60% of children with CP have spasticity as a dominant clinical feature.

Spasticity typically:

• is not obvious in the first months of life,
• emerges around 1 year of age as standing and walking are expected,
• may increase during early childhood,
• often stabilizes or improves by ages 6–7 with appropriate intervention.

Importantly, spasticity should not progressively worsen during adolescence. If deterioration occurs, other contributors—such as dystonia, orthopedic deformities, or pain—should be reassessed.

What is the underlying mechanism in the brain & spinal cord?

Spasticity results from an imbalance between excitatory and inhibitory signals within the spinal cord.

Under normal conditions, the brain modulates sensory input reaching the spinal cord, allowing smooth and coordinated muscle contraction.

In spasticity:

• sensory input to the spinal cord (Ia afferents) becomes excessively excitatory,
• inhibitory control from the basal ganglia, cerebellum, and descending pathways is reduced,
• the spinal cord responds with exaggerated, autonomous muscle contraction.

Two principal neurosurgical strategies interrupt this cycle:

• Selective Dorsal Rhizotomy (SDR): reduces excessive sensory (afferent) input from posterior roots.
• Intrathecal baclofen (ITB): enhances inhibitory GABA-B activity within the spinal cord.

How does it present clinically—symptoms & impact?

Excessive spasticity interferes with walking and function, reduces independence, and increases pain and fatigue during movement.

Common manifestations in children include:

• Stiff, scissoring legs during gait, difficulty abducting hips and knees.
• Toe-walking, increased lumbar lordosis, scoliosis.
• Spasms or jerks when limbs are stretched.
• Difficulty with dressing, diaper changes, and sitting.
• Pain, cramps, and fatigue after minimal activity.
• Challenges with daily care (washing, transfers, repositioning).

Untreated spasticity may also limit the effectiveness of physiotherapy and lead to permanent deformities (contractures, dislocations, painful foot deformities).

How is severity classified & assessed?

Assessment relies on clinical scales and functional classifications, guiding both monitoring and treatment selection.

Commonly used tools include:

• Modified Ashworth Scale (MAS) – grades tone during passive movement (0–4); scores ≥2 indicate clinically significant spasticity.
• GMFCS (Gross Motor Function Classification System) – classifies overall motor function from level I (independent walking) to V (wheelchair dependence).
• Functional outcome measures for hand use, daily activities, and quality of life.

Surgical decisions are never based on a single score alone, but on the child’s overall profile: therapeutic goals, presence of dystonia, cooperation, family support, and ability for long-term follow-up.

What are conservative & orthopedic treatment options?

Surgery is never standalone—effective care requires a structured rehabilitation program.

Conservative management typically includes:

• Specialized physiotherapy—stretching, strengthening, gait training.
• Occupational & speech therapy when indicated.
• Orthotic devices (ankle-foot orthoses, seating systems, standing frames).
• Oral medications (e.g., baclofen, diazepam, tizanidine), carefully monitored for sedation or other side effects.
• Botulinum toxin injections for focal muscle groups when localized problems exist.

Orthopedic surgery (tendon lengthening, osteotomies, joint stabilization) is often organized as single-event multilevel surgery (SEMLS) to minimize repeated hospitalizations.

Neurosurgical treatment (ITB or SDR) does not replace physiotherapy—it enhances its effectiveness and may slow progression of deformities.

What is the intrathecal baclofen pump (ITB) & who is it for?

A programmable implant that delivers baclofen directly into the cerebrospinal fluid, achieving strong effect with fewer systemic side effects.

Baclofen is a GABA-B receptor agonist that reduces spasticity when adequate spinal concentrations are achieved. Oral therapy is often limited by sedation or hypotension.

With an intrathecal pump (ITB), very small doses are delivered directly into the CSF via a catheter. Key points include:

• Primarily used in spastic quadriplegia (GMFCS IV–V, MAS ≥2) when tone interferes with care, comfort, sleep, or wheelchair positioning.
• A test dose is often performed to assess responsiveness.
• Advantage: reversibility—the pump can be adjusted, turned off, or removed.
• Limitations: need for regular refills, ongoing follow-up, and risk of mechanical complications (catheter kinking/breakage, pump malfunction).

Serious complications requiring immediate recognition include:

• Baclofen withdrawal syndrome: abrupt increase in tone, itching, irritability, fever, rhabdomyolysis—requires urgent oral baclofen and system correction.
• Overdose: somnolence, respiratory depression—managed with supportive care and dose adjustment.

What is Selective Dorsal Rhizotomy (SDR) & who is the ideal candidate?

A spinal procedure that permanently reduces abnormal sensory input, leading to sustained reduction of lower-limb spasticity.

Selective Dorsal Rhizotomy (SDR) is performed via a lumbar laminectomy. Posterior sensory roots are divided into rootlets, electrically stimulated, and those with abnormal responses are partially sectioned (typically 30–50%).

The ideal SDR candidate typically includes:

• child aged 5–8 years,
• spastic diplegia predominantly affecting the legs,
• good baseline lower-extremity strength,
• minimal fixed contractures or severe deformities,
• ability to participate in intensive postoperative physiotherapy,
• absence of significant dystonia.

Advantages of SDR include durable long-term effect and a single-stage procedure. The key limitation is irreversibility, making careful patient selection essential.

Short-term effects may include transient urinary retention, sensory changes, or weakness. Long-term impact on spinal growth remains under study and is always weighed against the natural scoliosis risk associated with cerebral palsy.

Other procedures (peripheral neurotomies, DBS)—when are they considered?

Adjunctive interventions for focal spasticity or significant associated dystonia.

Peripheral neurotomies

In severe focal spasticity of specific muscle groups, partial sectioning of the motor branch of a peripheral nerve may be performed under stimulation, permanently reducing tone in that region.

Deep Brain Stimulation (DBS)

DBS is not routine for isolated spasticity, but can be highly effective for associated dystonia. In selected children with mixed spasticity and dystonia, ITB may address spasticity while DBS targets dystonia.

What is the prognosis & expected benefit?

The goal is not simply lower tone, but better function and quality of life.

With appropriate selection and multidisciplinary care, ITB and SDR can provide:

• Reduced spasticity and painful spasms.
• Improved sitting and standing posture.
• Easier daily care for families.
• Better sleep, comfort, and endurance.
• In selected children, improved gait quality and independence.

Outcomes depend on baseline neurological status, GMFCS level, rehabilitation intensity, and family engagement, as well as comorbidities such as epilepsy or cognitive impairment.

Practical considerations & guidance for families

Decisions about spasticity surgery are long-term journeys requiring time, information, and ongoing support.

• Request a clear explanation of ITB versus SDR and why one is recommended.
• Discuss realistic functional goals, not only tone reduction.
• Prepare for intensive physiotherapy after SDR or regular pump refills after ITB.
• Engage your support network (rehabilitation centers, social services).
• Do not hesitate to seek a second opinion before irreversible surgery.