Two pilot studies will gauge impact of interventions on neuroplasticity and hip-fracture surgery outcomes in older adults

 

UT Health San Antonio researchers will be launching two pilot studies to learn whether specific interventions help older adults build stronger neural pathways and recover better from hip fracture surgery.

The two separate pilot studies each received a $50,000 grant from the San Antonio Claude D. Pepper Older Americans Independence Center.

Does blood-flow restriction exercise boost neuroplasticity?

One of the pilot studies aims to determine whether the use of blood-flow restriction training affects neuroplasticity in older adults. The study is led by principal investigator Gustavo Almeida, PT, PhD, assistant professor in the Department of Physical Therapy and the Department of Orthopaedics, who has been researching the impact of blood-flow restriction exercise in older adults with osteoarthritis (OA) of the knee.

“We have enough evidence that blood-flow restriction using minimal weights improves strength and muscle volume to the same level of resistance training using a lot of weights. That is done. But what is happening behind all these gains?” Almeida said.

“The idea was that most of the time older adults do not exercise at the intensity needed for muscle gains,” Almeida said. “That’s when blood-flow restriction training comes in handy: The training can be done with no or little weight and it has been shown to improve muscle strength and volume. We thought maybe it’s also improving the speed of the connection between the brain and muscle contraction, which helps to improve neuromuscular performance.”

The six-week study will include two groups of 10 subjects 65 years and older. Both groups will exercise two-to-three times per week, with one group using the cuff-style blood-flow restriction bands and the other group exercising without the bands. Study participants will perform activities such as getting up from a chair, leg extensions and leg curls.

“We are going to look at the corticomotor activation, or excitability, of the muscle representations in the brain, which is a more mechanistic way to see how blood-flow restriction training is improving the lives of older adults,” Almeida said. “We are expecting to see whether people improve their neuromuscular performance using a battery of physical function tests.”

Co-principal investigator Anjali Sivaramakrishnan, PT, PhD, assistant professor in the Department of Physical Therapy, will use non-invasive transcranial magnetic stimulation to measure whether study subjects in the intervention group who perform blood-flow restriction exercises experience changes in the neural pathways compared to the control group.

“This is a new area that has a lot of potential,” Sivaramakrishnan said. “We don’t know if blood-flow restriction exercise can actually cause changes in outcomes related to the brain.”

“If someone is walking well after BFR exercise, does that strengthen the connectivity between the brain and muscles? That would give a good mechanistic understanding of how blood-flow restriction training works, how it affects not just muscles and other structures but even has changes in the central nervous system. That would suggest it has way more potential than what was thought about.”

 

Seeking better outcomes for hip-fracture surgery patients

Almeida is a co-investigator on a second Pepper-funded pilot project led by principal investigator, Professor Boris Zelle, MD, in the Department of Orthopaedics in the Joe R. & Teresa Lozano Long School of Medicine. 

The pilot study, which will be conducted over the course of one year, seeks to determine whether a comprehensive nutritional intervention with supplementation of conditionally-essential amino acids, minerals and multivitamins as well as diet counseling may improve outcomes for in older adults undergoing hip fracture surgery. “The study’s long-term goal is to minimize patients’ risks of functional decline, complications and mortality through implementation of interdisciplinary multimodal interventions,” Zelle said.

“Older adults undergoing hip fracture surgery remain at relatively high risk for perioperative morbidity and mortality. I really think that this pilot study will lay the groundwork for future multi-level interventions that can help this steadily growing patient population to recover from surgery and maintain a functional and active lifestyle,” Zelle said. He noted that in addition to improved nutrition, increasing access to PT services and OT services are crucial elements of a multidisciplinary approach to rehabilitation.

In addition to Almeida, co-investigators include Associate Professor Ana Allegretti, PhD, OTR, ATP, of the Department of Occupational Therapy, and Associate Professor Monica Serra, PhD, who will provide diet counseling to study participants. The hip fracture pilot study is part of a larger collaboration of the research team, which is seeking to improve outcomes for older patients undergoing hip fracture surgery. Other related studies will help form the basis of the group’s efforts to develop a multidisciplinary intervention.

“We would like to come up with an intervention that will work for all patients who find themselves in this unfortunate situation,” Allegretti said. “The main focus is to address the rehabilitation issues early on and throughout the first year post-operative, when the complication and mortality rates are the highest.”