Spasticity, dystonia and tone management: Case

Summary and immediate impression

This child presents a classic tone-management decision in spastic diplegic cerebral palsy. The adductor and calf spasticity are limiting both function, with scissoring and a tip-toe gait, and care, with difficult nappy changing, so the tone is a legitimate treatment target under the goal-directed principle. Her GMFCS level of two, her good selective motor control and her minimal dystonia together point toward focal botulinum toxin type A as first-line therapy, with selective dorsal rhizotomy as a definitive option to discuss with the family using the randomised-trial evidence. [1]

Assessment, goals and the first-line plan

I would start with the goal-directed principle: tone is treated only when it limits function, comfort, care or participation, and for this child the adductor spasticity limits care and hygiene while the calf spasticity limits gait function, so both are legitimate targets. I would set SMART goals with the family using Goal Attainment Scaling, naming the concrete outcomes they want, such as easier nappy changing, a heel strike in gait, and a longer walking distance. [2]

My assessment would separate the spastic from the dystonic phenotype, because the therapy follows the phenotype. I would use the Modified Tardieu Scale, comparing the angle of catch at a fast velocity with the passive range at a slow velocity, to confirm that the tone is dynamic spasticity a toxin can soften rather than a fixed contracture that needs surgery. I would grade the tone, test the deep tendon reflexes and clonus, document the selective motor control, and state her GMFCS level of two, which frames the functional goal and the modality. I would examine the hips for pain and limited abduction and review her surveillance hip radiograph, confirming the migration percentage is below the thirty percent at-risk threshold. [1][3]

My first-line therapy for her focal adductor and calf spasticity is focal botulinum toxin type A, layered on a daily stretching and positioning program, an ankle-foot orthosis for the equinus, and serial casting if the range remains limited after injection. I would inject the overactive muscles individually, counsel the family that the onset is two to seven days, the peak is around four weeks and the wear-off is at twelve to sixteen weeks, and schedule the next cycle no sooner than twelve weeks to avoid neutralising antibodies, because the three toxin products are not interchangeable. I would book a reassessment at four to six weeks with Goal Attainment Scaling and the Tardieu angle. [1][5]

Selective dorsal rhizotomy and the multidisciplinary plan

Selective dorsal rhizotomy is the definitive operation for this child, and she is a strong candidate because she is at GMFCS two, has good selective motor control, has minimal dystonia, has no major orthopaedic deformity, and has a motivated family. The surgeon identifies the dorsal sensory rootlets from L2 to S1 and cuts a proportion of them, often around twenty-five to sixty-seven percent, to remove the afferent input that drives the spasticity in the legs, with the aim of a durable reduction in spasticity and a reduced need for later orthopaedic surgery rather than a new GMFCS level. [6]

The evidence is the cleanest in paediatric tone care. The McLaughlin meta-analysis of three randomised controlled trials showed that selective dorsal rhizotomy with therapy outperformed therapy alone for spastic diplegia in the younger child, and the Tedroff systematic review confirms a durable reduction in spasticity and later orthopaedic surgery. I would be honest that loss of spasticity is not the same as a gain in function, that the operation unmasks underlying weakness, and that the family must commit to months of intensive postoperative physiotherapy and strengthening or the child can lose ground. [6][7]

The multidisciplinary plan runs throughout childhood regardless of the surgical decision. The physiotherapist and the orthotist hold the range and shape the gait, the orthopaedic surgeon reconstructs any fixed deformity, the rehabilitation engineer shapes the seating and the standing frame, and the hip and spine surveillance continues to skeletal maturity with a migration-percentage threshold for orthopaedic referral. I would coordinate the team and the family around the shared goals. [1][2]

Safety netting and the long-term course

I would teach the family the safety-netting principles that apply across the tone population. If this child were ever to receive an intrathecal baclofen pump in the future, its withdrawal is a medical emergency that presents with rebound rigidity, high fever, seizures and rhabdomyolysis and is treated by restoring the infusion, giving enteral baclofen and a benzodiazepine, and admitting to intensive care. If a dystonia-dominant picture were ever to emerge, the pathway would shift to oral trihexyphenidyl and baclofen and then to intrathecal baclofen or globus pallidus internus deep brain stimulation. [8][11]

I would tell the family that the prognosis of her function is set by the GMFCS, which is stable over years, and that her ambulant trajectory at GMFCS two is favourable with the right therapy and surgery. I would emphasise that the goal is to preserve and improve her walking, ease her care, prevent the hip and spine complications of unmanaged tone, and plan a coordinated transition to adult rehabilitation care in the late teenage years. I would arrange genetic counselling and family support where relevant, and I would advocate for equitable access to the funded therapies and the multidisciplinary team. [2][3]

Marking domains

• Diagnosis and reasoning: separates spasticity from dystonia with the Modified Tardieu Scale, states the GMFCS level of two, and applies the goal-directed principle to confirm the tone is a legitimate target. [1][3]
• Management — definitive: chooses focal botulinum toxin type A with correct non-interchangeable dosing and a twelve-week interval, and discusses selective dorsal rhizotomy with the McLaughlin and Tedroff evidence. [5][6]
• Safety netting: teaches the intrathecal baclofen withdrawal emergency and the dystonia pathway to deep brain stimulation. [8][11]
• Communication: counsels the family on the goal-directed plan, the multidisciplinary surveillance, and the transition to adult care. [2]