Cerebral palsy is a condition in which muscle movement is stiff or uncoordinated. CP, as it is commonly known, is caused by damage to various parts of the brain. Spastic diplegia is one of nine different forms of Cerebral Palsy; each form is distinguished by the amount and type of movement impairment present. According the National Institute for Neurological Disorders and Stroke, two-thirds of people with CP have some type of mental impairment as well as movement impairment.
Spastic diplegia was the initial form of cerebral palsy diagnosed. During the 1860s, William Little, an English doctor, first wrote about children who were afflicted with a mysterious disorder which made their limbs stiff. The disorder became known as Little’s disease for several years. Gradually, researchers determined that Little’s disease was spastic diplegia—just one of the forms cerebral palsy can take.
The March of Dimes reports that spastic forms of cerebral palsy account for seventy to eighty percent of cases. The form of CP called spastic diplegia is common and can be less severe than some other forms. The term spastic means that the muscles are stiff and make moving awkward. Diplegia means that both sides of the body are affected by a form of paralysis; "di" is from the Greek word for two and "plegia" is derived from the Greek word for some form of paralysis. The term diparesis, which has a similar meaning, is sometimes also used; paresis is another term derived from Greek that means paralysis.
The reference to paralysis may be somewhat misleading. A person with spastic diplegia is not completely paralyzed, but his or her movements are impaired. This impairment can range from mild and hardly noticeable to severely disabling. Spastic diplegia affects the leg muscles more than the arm and facial muscles.
Distinct Symptoms of Spastic Diplegia
Individuals with spastic diplegia walk with a distinct “scissored” gait. The legs cross over and move stiffly back and forth like the blades of a pair of scissors. This occurs because some leg muscles are more affected by the disorder than others are. The knees and feet of a person with spastic diplegia may be twisted at abnormal angles. The muscles in the feet are stiff, causing the person’s toes to point towards the sky.
The hands of someone with spastic diplegia also move awkwardly, but are usually not as impaired as in some other forms of CP.
People with spastic diplegia generally have normal intelligence. Language skills are usually normal as well.
Possible Complications from Spastic Diplegia
Spastic forms of CP can lead to deformities of the limbs. A condition called equinus ankle may occur in spastic diplegia, although it is more common in spastic hemiplegia. Because of the spastic muscles in the leg, unequal pressure is exerted on the foot and ankle joints. This can cause toe walking and further impede the patient’s ability to move freely.
In children under five years old, the use of braces is the most common treatment for ankle and foot deformities caused by CP. Older children may sometimes benefit from surgery.
Causes of Cerebral Palsy Spastic Diplegia
For decades doctors usually attributed spastic diplegia and other forms of cerebral palsy to complications that had occurred during delivery. Today, thanks to a large study funded by the National Institute of Neurological Disorders and Stroke, researchers have discovered that less than a tenth of CP cases are caused by injury at birth. Many cases of CP are caused by infections or other trauma while the baby is still in the womb. A few cases of CP are caused by head injury or infection after birth.
Other risk factors for CP include low birthweight and prematurity. Thanks to modern medical advances, babies born prematurely now have a greater chance of surviving than ever before, but being born too early can lead to medical problems which increase the risk of spastic diplegia and other forms of CP. Multiple births can also put the infants at higher risk for CP, as can certain maternal medical conditions.
Damage to the white matter of the brain resulting in lesions called periventricular leukomalacias is common in premature babies. Periventricular leukomalacias interfere with blood flow and result in less oxygen being delivered to vital areas of the brain; this interferes with the nervous system’s communication with the muscles. Between 60 to 100 percent of infants who have periventricular leukomalacias will develop cerebral palsy—generally the spastic diplegia form. The severity of the CP depends on the extent of the brain damage experienced.
Women who have an infection while they are pregnant have a higher risk of having a baby with cerebral palsy. Researchers think that increased levels of cytokines—immune system cells, which are caused by a maternal infection, can lead to damage of the unborn baby’s nervous system. The cytokines produce inflammation to fight the infection, but the inflammation can damage the unborn baby’s still developing nervous system; the risk to the baby from a maternal infection is highest during the first twenty weeks of the pregnancy.
Women with seizures, mental retardation, or thyroid problems are a little more likely to give birth to a child with cerebral palsy. Being exposed to a poisonous substance during pregnancy, especially in the first two trimesters, can also put the unborn baby at higher risk for CP. In addition, a condition known as Rh incompatibility is an increased risk factor for spastic diplegia and other forms of cerebral palsy.
Rh incompatibly means that the mother and baby have different Rh blood types. The presence of the fetus’s Rh negative blood cells in a woman with positive Rh blood cells (or vice a versa), triggers an immune response as the mother’s blood cells manufacture antibodies against the baby’s blood cells. This condition is dangerous and can increase the risk of cerebral palsy and other health problems; fortunately, doctors in the United States routinely monitor for Rh incompatibility. When treated, Rh incompatibility is unlikely to cause a problem.
Age at Diagnosis
Most cases of spastic diplegia are diagnosed before the child is three. Developmental delay can be an early sign of CP in infants, and it is the sign parents most often notice and bring to the attention of their pediatrician. Babies with CP may have unusual muscle tone. They may be rigid or stiff or they may seem floppy and unable to hold their head at a normal angle. The stiffness is caused by increased muscle tone (hypertonia), while floppiness is caused by decreased muscle tone (hyptonia). Sometimes a baby may begin appearing overly relaxed and then become increasingly stiff; this generally occurs at age two to three months.
Treatments for Spastic Diplegia
Physical therapy is the standard treatment is used for all CP patients; this was the first form of therapy developed for CP. Physical therapy prevents spastic muscles from becoming contracted (unable to move) and it strengthens muscles which would otherwise become weak from disuse. There are several different methods of physical therapy used for spastic diplegia.
Other treatments for spastic diplegia and other forms of CP range from medicines that reduce muscle tension to orthopedic surgery to correct CP induced deformities. Braces and other orthopedic supports are helpful for some patients.
Today, some spastic diplegia patients are finding relief (not a cure) from alternative therapies such as massage, yoga and chiropractic adjustments. Massage therapists believe that gentle massage helps spastic diplegia patients relax and sleep better.
Research on all forms of CP is ongoing. Researchers hope to both find a cure for spastic diplegia and to prevent it from occurring.
“Ankle Equinus: in CP” Wheeless’ Textbook of Orthopaedics. Retrieved March 29, 2009 from the World Wide Web: http://www.wheelessonline.com/ortho/ankle_equinus_in_cp
“Cerebral Palsy: Hope Through Research” National Institute of Neurological Disorders and Stroke. Retrieved March 27, 2009 from the World Wide Web: http://www.ninds.nih.gov/disorders/cerebral_palsy/detail_cerebral_palsy....
“Cerebral Palsy” March of Dimes. Retrieved March 28, 2009 from the World Wide Web: http://www.marchofdimes.com/pnhec/4439_1208.asp#types
“Cerebral Palsy” MayoClinic.com Retrieved March 27, 2009 from the World Wide Web: http://www.mayoclinic.com/health/cerebral-palsy?DS00302
Zach, Terrence, MD. and James C. Brown MD. “Periventricular Leukomalacias” updated February 14, 2008. eMedicine. Retrieved March 30, 2009 from the World Wide Web: http://emedicine.medscape.com/article/975728-overview