Spasticity is a neuromuscular condition in which muscles are continuously contracted. The stiff or rigid muscles inhibit normal activity, including walking, movement and speech. Spasticity in children has numerous potential causes, most of which include some form of damage to the nervous system, such as brain damage caused by a lack of oxygen, brain trauma, stroke or spinal cord injury.
Certain metabolic disorders also may cause spasticity. When nervous system damage takes place before birth, the resulting nerve and muscle problems, including spasticity and loss of muscle control, are known as cerebral palsy. The neural damage that causes spasticity typically takes place in the cerebral cortex, the region of the brain that controls movement or the nerves that travel from the brain to the spinal cord.
Spasticity can take many forms, including the inability to bend limbs because of overactive deep tendon reflexes, joints that stay bent at unusual angles, crossing of the arms or legs (called scissoring), repetitive jerky movements (called clonus), abnormal posture and speech problems.
These problems vary in severity, from mild muscle stiffness and increased muscle tone to painful, uncontrollable, and debilitating muscle spasms. Long-term spasticity can result in permanent contracture of muscles, in which muscles shrink and lock joints in a single position.
Complete physical examination and neurological testing are necessary to assess the extent of spasticity. Physical & occupational therapists also will examine the child to determine exactly which muscles are involved.
There are several forms of treatment for spasticity. Physical & occupational therapy is an important treatment that likely will be required regardless of other treatment choices. This involves a daily regimen, which parents can do at home with their children, of joint movement, exercise, and stretching that alleviates the severity of the symptoms. Therapy also may include fixing a joint with a cast or brace to oppose the spastic muscle.
In addition, a range of medications, including baclofen, tizanidine, benzodiazepines and dantrolene sodium may be used. These medications are taken orally, but in severe chronic cases, a pump that administers baclofen directly to the fluid that surrounds the spinal cord may be surgically implanted. Another form of treatment commonly used is called chemodenervation and involves the injection of botulinum toxin type A to loosen the spastic region.
Surgery for severe chronic spasticity includes orthopedic and neurological approaches. Orthopedic surgeries may involve altering tendon, muscle and bone to restore movement and flexibility. These approaches may be done in children to maintain function as a child grows.
Neurological surgeons employ another type of procedure called selective dorsal rhizotomy, in which the nerves that carry sensory information to the spastic limbs are cut where they emerge from the spinal cord. These nerves play a key role in the generation of spasticity. The procedure often is used in children with cerebral palsy and has been shown to improve leg function. The decision to treat spasticity surgically depends on the extent and severity of the condition and the child’s other medical concerns. Often only one part of the body will be treated surgically because it will make specific movements necessary for daily living easier.