The study was published in ‘Nature Communications’. People are primarily treated with drugs, but in some cases, doctors use deep brain stimulation (DBS). In DBS, the surgeon inserts a thin metal coil into the brain, which can be used to send electrical pulses. DBS is effective in treating tremors, but reducing difficulties with walking and freezing is a challenge.
Studies in rats suggest that DBS treatment of walking problems in Parkinson’s could be adapted by targeting specific neurons in the brainstem – potentially benefiting more than 7 to 10 million people living with the disease worldwide could.
Based on previous animal studies of the motor circuits that are responsible for the planning, control, and execution of voluntary movements, scientists hypothesize that walking may underlie the chills in Parkinson’s. This would require DBS to stimulate neurons in the pedunculopontin nucleus (PPN), which is located in the brainstem. The PPN was believed to send signals from the brain to the spinal cord that led to body movement.
Over time, about a quarter of patients have so much trouble walking that they often freeze and collapse on the spot, and many are locked up in the house.
“However, preliminary results of clinical trials of PPN with DBS had a very variable effect on recovery of movement, particularly in patients who experience chills while walking. It is therefore debated whether Where should an optimal stimulus occur within the brainstem. Our study brings new knowledge to the table about the best area for DBS to alleviate this particular symptom,” said corresponding author Professor Ole Kihn in the Department of Neuroscience.
Previous results from the group showed that stimulation of so-called excitatory neurons in the PPN can initiate locomotion in normal rats. This raised the possibility that these nerve cells could actually be used to treat movement symptoms in mice with features of Parkinson’s disease.
“We use a technique to target a specific group of cells in the PPN to determine which areas are best stimulated to reduce these particular symptoms. The results show that motor improvement is optimal if we Those that excite we call excitatory neurons in the caudal region of the PPN,” explained Ole Kihn.
“We believe that clinical trials with brainstem DBS are the right strategy to allow patients to walk properly again. But variable clinical outcomes occur because DBS is targeted to specific groups of neurons in the caudal PPN. To do this would require high precision. This is a very delicate area because if we stimulate excitatory neurons in regions other than the caudal PPN, it will instead cause complete immobilization.”
In Parkinson’s disease, the nerve cells that produce dopamine progressively die. Since the 1960s, doctors have relied on medication to replace the missing dopamine, but it is extremely difficult to fully control symptoms as the disease progresses.
“In many people, agitation symptoms in the later stages of this disease do not respond well to medical treatment, so there has been a lot of research into alternative treatments, including the search for optimal targets for deep brain stimulation, ” explained postdoc Deborah Masini, first author of the new study, which included several different strategies to substantiate their findings.
“When we stimulated these specific neurons in the caudal region of the PPN, the animals were able to walk normally, long distances and with a normal walking speed, unlike before stimulation, where they would display symptoms of Parkinson’s disease.” ,” said Deborah Masini.
“We systematically compared the excitability of different locations and cell types in a series of complementary experiments. And they all point to the same conclusion. This strongly indicates that these excitatory neurons in the caudal PPN exhibit loss of movement. are an ideal target for recovery,” she said. ,
The researchers hope that the new study may aid clinicians when they choose the exact location for DBS in the brainstem.
“The mice in our study only partially represent a complication of this disease, but the results are very telling. Much of what we initially learned about how to treat Parkinson’s disease comes from animal models.” , which includes the drug we use for patients today. In this sense, it is a valid approach, and we hope that our study can help provide better treatments for human patients,” says Deborah Masini he said. (ANI)
First published:February 21, 2022, 11:59 pm