Spastic diplegia is a form of spastic cerebral palsy that predominantly affects muscle control in the legs. Individuals with spastic diplegia experience increased muscle tone—known as spasticity—which leads to stiffness, tightness, and a characteristic scissored gait.
What Is Spastic Diplegia?
Spastic diplegia arises from damage to the upper motor neurons in the brain, often occurring before, during, or shortly after birth. This damage disrupts signals that normally regulate muscle relaxation and contraction, causing the leg muscles to remain hypertonic (overly tense). While “spastic” denotes excessive muscle tone, “diplegia” specifies that the condition primarily involves both lower limbs.
Underlying Causes and Risk Factors
Spastic diplegia results from non-progressive brain injury or malformation in regions that control voluntary movement.
- Upper motor neuron lesions impair communication between the brain and spinal cord.
- Reduced gamma-aminobutyric acid (GABA) uptake in spinal nerves prevents proper muscle relaxation.
- Premature birth and low birth weight significantly increase the risk.
Genetic factors and perinatal complications—such as lack of oxygen during delivery ( HIE )—also contribute to the development of spastic diplegia.
Recognizing the Symptoms of Spastic Diplegia
Early identification of spastic diplegia supports timely intervention and better long-term outcomes.
- Scissored gait: legs cross at the knees during walking.
- Toe walking and pointed feet due to calf muscle tightness.
- Hyperreflexia: exaggerated stretch reflexes in the lower limbs.
- Delayed motor milestones: late sitting, crawling, or walking (often after 18 months).
- Mild involvement of arms or hands in some cases, but leg symptoms dominate.
Diagnosis and Early Intervention
Most children receive a diagnosis of spastic diplegia by age three, based on clinical evaluation and developmental history.
- Neurological examination assesses muscle tone, reflexes, and coordination.
- Imaging (MRI or CT) identifies the location and extent of brain injury.
- Gait analysis evaluates walking patterns and joint alignment.
- Functional assessments classify mobility level using scales like GMFCS (Gross Motor Function Classification System).
Early diagnosis paves the way for targeted therapies that optimize motor skills and prevent secondary musculoskeletal issues.
Treatment Strategies for Spastic Diplegia
A multidisciplinary approach maximizes independence, strength, and flexibility.
- Physical Therapy
- Stretching routines to reduce spasticity and increase range of motion.
- Strength-building exercises focused on hip, knee, and ankle stability.
- Orthotic Support
- Ankle-foot orthoses (AFOs) and knee-ankle-foot orthoses (KAFOs) help align joints and improve gait.
- Medical Interventions
- Botulinum toxin injections temporarily relax spastic muscles.
- Oral medications (e.g., baclofen) reduce overall muscle tone.
- Complementary Therapies
- Therapeutic massage, yoga, and hydrotherapy enhance relaxation and mobility.
- Chiropractic care may assist with spinal alignment and posture.
Living with Spastic Diplegia: Prognosis and Support
Outcomes vary widely depending on the severity of brain injury and the effectiveness of early intervention.
- Many individuals achieve independent walking or use assistive devices.
- Wheelchair mobility may be necessary for more severe cases.
- Ongoing physical and occupational therapy supports functional gains throughout life.
- Community resources, adaptive sports, and support groups foster social engagement and self-esteem.
With tailored care plans and evolving therapies, people with spastic diplegia can lead active, productive lives.
Emerging Therapies and Future Directions
Research continues to expand options for managing spastic diplegia and improving quality of life.
- Selective dorsal rhizotomy (SDR) offers surgical reduction of spasticity by cutting nerve roots in the lower spine.
- Intrathecal baclofen pumps deliver targeted medication directly to the spinal fluid, minimizing systemic side effects.
- Stem cell therapies and neuroplasticity-enhancing interventions are under investigation for long-term nerve repair.
Staying informed about clinical trials and specialized treatment centers can connect families with cutting-edge care.
Spastic diplegia is a sub-type of spastic cerebral palsy. Spastic cerebral palsy is the most common form of cerebral palsy, with rough estimates speculating that between 70% and 80% of all cases are spasticity-dominant. Spastic diplegia is a form of cerebral palsy that manifests primarily in the legs “Spastic” is a general term used to describe a higher-than-average degree of tightness, tone and tension in the muscles.
Spastic cerebral palsy is usually the result of an upper motor neuron lesion in the brain (often through injury or damage inflicted in the womb or during birth), though the motor cortex and corticospinal tract may also be affected. The lesion impairs the brain’s ability to send signals to the nerve receptors housed in the spine, which in turn limits the nerves’ ability to receive gamma amino butyric acid. Gamma amino butyric acid normally triggers the nerves to send messages to the muscles that cause them to work together; when one group of muscles contracts, another relaxes. The lack of this important organic compound in these damaged nerves instead causes them to send a signal to the connected muscles to tense up, or become hypertonic. In people with spastic diplegia, the nerve receptors that control the legs are damaged, making the legs rigid and weak. Premature infants are at an increased risk of developing spastic diplegia.
Spastic diplegia causes the legs to be overly stiff. Usually, people with spastic diplegia have a distinct, scissored walk. The legs cross over in a scissoring motion and the toes are pointed upwards due to the contractions in the muscles. People with spastic diplegia may also have some symptoms in their hands, though not nearly as pronounced as the symptoms in the legs and feet.
Spastic diplegia can cause deformities in the legs, so braces are commonly used to help support the legs of children with the condition. Most cases are diagnosed by the age of three. Physical therapy is also affective in helping people with spastic diplegia strengthen their muscle tone and increase their range of motion. Massage, yoga and chiropractic therapy can also help loosen the rigidity in the legs.
The degree of disability and level of functioning are dependent on how extensive the brain and nerve receptors are. Many people with spastic diplegia lead independent, productive lives, while others require assistance or the use of a wheelchair for mobility.
References:
U.S. National Library of Medicine