From the FDA Drug Label
Diazepam is a useful adjunct for the relief of skeletal muscle spasm due to reflex spasm to local pathology (such as inflammation of the muscles or joints, or secondary to trauma), spasticity caused by upper motor neuron disorders (such as cerebral palsy and paraplegia), athetosis, and stiff-man syndrome The cause of spasticity in cerebral palsy is upper motor neuron disorders. Key points:
- Spasticity is caused by upper motor neuron disorders
- Cerebral palsy is an example of an upper motor neuron disorder that can cause spasticity 1
From the Research
Spasticity in cerebral palsy is primarily caused by damage to the motor cortex and pyramidal tracts in the developing brain, resulting in abnormal muscle tone and reflexes. This brain damage disrupts the normal balance between excitatory and inhibitory signals to muscles, leading to increased muscle tone and hyperactive stretch reflexes 2. The upper motor neuron damage affects the communication between the brain and spinal cord, causing muscles to receive improper signals that make them contract too much or remain in a constant state of contraction.
Key Points
- Spasticity typically affects the antigravity muscles (flexors in the arms and extensors in the legs), creating characteristic postures and movement patterns.
- The severity of spasticity varies depending on the extent and location of brain damage, which typically occurs during fetal development, birth, or early infancy due to factors like oxygen deprivation, stroke, infection, or genetic abnormalities.
- Spasticity often worsens with growth, stress, excitement, illness, or certain body positions, and requires comprehensive management through physical therapy, medications like baclofen or diazepam, and sometimes surgical interventions to improve function and prevent complications like contractures and deformities 3, 4, 5, 6.
Management
- Treatment options include intramuscular onabotulinumtoxinA, systemic and intrathecal muscle relaxants, selective dorsal rhizotomy, and physical and occupational therapies 2.
- Botulinum toxin type A has been shown to be effective in treating spastic equinus foot in cerebral palsy, with a statistical superiority over placebo on gait improvement 6.