By Jodee Redmond from In The Cloud Copy
The results of a new study using laboratory rats to model cerebral palsy with spasticity (muscle stiffness) accompanied by dystonia (involuntary muscle contractions) may give researchers the answers they need to develop better treatments in humans. This was the first study to examine dystonia and spasticity as two separate issues in rats. It indicated that gender appears to have a role in motor symptoms. The researchers discovered that male rats have a greater tendency to develop spasticity and female rats have a higher risk for dystonia.
What is Cerebral Palsy?
Cerebral palsy (CP) is not just one disorder. It refers to several disorders affecting the patient’s muscle tone, movement, and posture. CP is caused by damage to the fetus’s brain as it develops before birth.
The signs of CP become evident during early life or the preschool years. Symptoms of this disorder include the following:
- Abnormal pain perceptions
- Abnormal reflexes
- Difficulty swallowing
- Eye muscle imbalance (eyes don’t focus on the same object)
- Floppiness in the extremities and trunk region
- Involuntary movements
- Learning difficulties
- Mental health concerns
- Muscle stiffness leading to reduced range of motion
- Oral diseases
- Posture abnormalities
- Rigidity in the limbs and trunk
- Unsteadiness when walking
- Urinary incontinence
The symptoms may become more or less serious as the child gets older. Muscle shortening and rigidity may become worse without aggressive treatment.
It’s common for people living with CP to have muscle stiffness and involuntary movements. Researchers have found that opportunities for studying how these symptoms impact patients have been few because there are several types of brain injuries that cause CP, such as infections, premature birth, and exposure to low oxygen levels in the late stages of pregnancy.
Difficult for Researchers to Identify Symptoms in Lab Rats
The issues leading to brain injuries can be closely controlled in a laboratory setting. It is hard for researchers to researchers to tell the difference between dystonia and spasticity at times. As a result, they find it challenging to come to clear conclusions about disease systems.
The researchers developed a rat model that displayed dystonia and spasticity. These symptoms could be detected using electrophysiological markers (amount of electrical energy) each one of them produces.
Study Exposed Lab Rats to Hypoxia for Several Minutes
For the study, the rats were exposed to low oxygen levels (hypoxia) for 12 minutes. These conditions were set to resemble the disability produced by caused by asphyxia during pregnancy. (Rats seven or eight days old correspond to 37 weeks of pregnancy in humans.) A control group was established with normal oxygen exposure.
When the young rats were 27-29 days old (comparable to adolescence in people), the researchers examined them for dystonia and spasticity. They found that hypoxia exposure varied in the laboratory rats only based on gender. The male rats had a motor impairment and they had measurably higher levels of spasticity after exposure to hypoxia.
Female rats did not show higher spasticity scores after hypoxia. They did show higher dystonia scores when they were awake.
The researchers stated that these results need clinical confirmation. They did suggest that gender could indicate how a pre-birth brain injury could present itself.
Learn more about this research here.
Read the original study here.