(dailyRx News) A traumatic brain injury won't cause Parkinson's disease. Instead it may make patients more susceptible to developing the neurodegenerative disorder.
Scientists have found that the loss of one specific type of neuron cases the added Parkinson's risk following a traumatic brain injury.
Dr. Marie-Francoise Chesselet, senior author of the study, and a professor of neurology and chair of the University of California Los Angeles department of neurobiology, said that it was discovered that with a moderate traumatic brain injury, the loss of neurons was too small to cause Parkinson's disease. However, it was enough to increase risk for Parkinson's.
She said that when the neurons are decreased, any additional insult to the brain will attack fewer neurons. In that case the threshold for symptoms of a disease, in this case Parkinson's, would be reached much quicker.
In a pre-clinical study, investigators found that a moderate traumatic brain injury in rats caused a 15 percent loss in brain cells known as nigrostriatal dopaminergic neurons shortly after the trauma. Over the course of the following 26 weeks, that loss continued, progressing to 30 percent after the initial injury.
When these particular neurons are lost, the result can be movement problems, tremors and rigidity found in Parkinson's disease.
Researchers also found that the pesticide paraquat, one of the most widely used herbicides, caused neurons to be lost at a pace that was about twice as fast. The pesticide previously was linked to making individuals more susceptible to developing Parkinson's disease.
The research was published in journal Neurotrauma.