Research Reveals Cause of ‘Freezing’ Gait in Parkinson’s

By Dennis Thompson
HealthDay Reporter

MONDAY, Sept. 12, 2022 (HealthDay News) — Researchers assume they’ve found out why Parkinson’s illness causes an individual’s limbs to turn out to be so stiff that at occasions they’ll really feel frozen in place.

Using a robotic chair outfitted with sensors, a analysis crew has linked the activation of leg muscle groups in Parkinson’s sufferers with a area of the mind referred to as the subthalamic nucleus.

This oval-shaped mind space is concerned in motion regulation, and information from the chair present that it controls the beginning, end and measurement of an individual’s leg actions, in response to analysis printed Sept. 7 in Science Translational Medicine .

“Our outcomes have helped uncover clear modifications in mind exercise associated to leg actions,” stated senior researcher Eduardo Martin Moraud, a junior principal investigator on the University of Lausanne in Switzerland.

“We may verify that the identical modulations underlie the encoding of strolling states — for instance, modifications between standing, strolling, turning, avoiding obstacles or stair climbing — and strolling deficits corresponding to freezing of gait,” Moraud stated.

Parkinson’s illness is a degenerative dysfunction of the nervous system that primarily impacts the physique’s motor features.

Parkinson’s sufferers have hassle regulating the scale and velocity of their actions, in response to the Parkinson’s Foundation. They wrestle to start out or cease actions, hyperlink completely different actions to perform a process like standing up, or end one motion earlier than they start the subsequent.

The subthalamic nucleus is a part of the basal ganglia, a community of mind buildings recognized to manage a number of features of the physique’s motor system, stated Dr. James Liao, a neurologist with the Cleveland Clinic who reviewed the findings.

“This examine is the primary to convincingly show that the basal ganglia management the vigor of leg actions,” Liao stated. “The significance is that this hyperlinks dysfunction of the basal ganglia to the shuffling gait deficit of Parkinson’s illness.”

To analysis Parkinson’s impact on strolling, researchers constructed a robotic chair wherein an individual may both voluntarily lengthen their leg from the knee or the chair may do it for them.

Researchers recruited 18 Parkinson’s sufferers with extreme motor fluctuations and issues with their strolling gait and their steadiness. Each affected person was implanted with electrodes that would monitor electrical alerts from their subthalamic nucleus and likewise present deep mind stimulation to that mind area.

Impulses coming from the subthalamic nucleus had been tracked as sufferers used the chair and later as they stood and walked.

“The truth that every one these strolling features are encoded in that area of the mind makes us consider that it contributes to strolling operate and dysfunction, thereby making it an fascinating area for therapies and/or for predicting issues earlier than they come up,” Moraud stated. “We may leverage that understanding to design real-time decoding algorithms that may predict these strolling features in real-time, utilizing mind alerts solely.”

In truth, the researchers did create a number of laptop algorithms that distinguished the mind alerts from a daily stride from those who happen in sufferers with an impaired gait. The crew additionally may establish freezing episodes in sufferers as they carried out quick strolling checks.

“The authors demonstrated that intervals of gait freezing will be predicted from recorded neural exercise,” Liao stated. “Accurate predictions will permit algorithms to be developed to vary [deep brain stimulation] patterns in response to intervals of gait freezing, shortening and even eliminating freezing episodes utterly.”

Moraud stated these findings may assist inform future applied sciences geared toward enhancing the mobility of Parkinson’s sufferers.

“There are huge hopes that the subsequent era of deep mind stimulation therapies, which can function in closed loop — that means that they are going to ship electrical stimulation in a sensible and exact method, primarily based on suggestions of what every sufferers wants — might assist higher alleviate gait and steadiness deficits,” Moraud stated.

“However, closed-loop protocols are contingent on alerts that may assist management the supply of stimulation in real-time. Our outcomes open such potentialities,” he added.

Dr. Michael Okun, nationwide medical adviser of the Parkinson’s Foundation, agreed.

“Understanding the mind networks underpinning strolling in Parkinson’s illness might be necessary to the long run growth of therapeutics,” Okun stated. “The key query for this analysis crew is whether or not the data they’ve gathered is sufficient to drive a neuroprosthetic system to enhance Parkinson’s strolling means.”

More data

The Parkinson’s Foundation has extra about strolling and motion difficulties related to Parkinson’s.

SOURCES: Eduardo Martin Moraud, PhD, junior principal investigator, University of Lausanne, Switzerland; James Liao, MD, neurologist, Cleveland Clinic; Michael Okun, MD, nationwide medical adviser, Parkinson’s Foundation, New York City; Science Translational Medicine, Sept. 7, 2022