RecruitingNot ApplicableNCT06958289

Cryoneurolysis for Spasticity Treatment: Long-term Clinical Outcomes and Mechanisms in the Central Nervous System

Cryoneurolysis for Spasticity Treatment: Quantifying Long-term Clinical Outcomes and Exploring Mechanisms Within the Central Nervous System

Sponsor

Sue Peters

Enrollment

25 participants

Start Date

Aug 1, 2025

Study Type

INTERVENTIONAL

Conditions

Spasticity as Sequela of Stroke

Summary

Spasticity can make regular daily activities difficult or impossible. Cryoneurolysis is a new technique to treat spasticity that is currently being tested. For this technique, a needle is inserted alongside a nerve implicated in spasticity. The needle then freezes and causes the nerve to break down. The nerve breaking down seems to provide relief for spasticity. The investigators are interested in testing the long-term effects of cryoneurolysis on the function of the brain over six months after treatment. The investigators are testing the brain's function using transcranial magnetic stimulation (TMS) which involves a magnet activating specific parts of the brain that cause muscles to fire; magnetic resonance imaging (MRI) which uses to examine brain structure; functional near-infrared spectroscopy (fNIRS) to examine brain function. The investigators believe that there will be a change in these measures that are related to the long-lasting effects of cryoneurolysis. Cryoneurolysis is not a part of standard care after stroke but is approved in Canada for patients. It has been used extensively in the past for treating pain. TMS is a way of studying how the brain sends signals to muscles to make movement. During these sessions, a researcher will use a magnet to turn on specific neurons in the brain that will cause muscles to contract. The investigators can study the way eyes and muscles respond to better understand how the brain is sending information about moving the body to the muscles. FNIRS is a new way of studying how the brain works. During these sessions, a researcher will fit the participant with a cap that has several lights on it. The light travels through hair, scalp, and skull where it interacts with blood in the brain. By studying the changes in the colour of the blood in the brain, researchers can understand which parts of the brain are active during specific tasks. Magnetic Resonance Imaging (MRI) involves a powerful magnet that takes very detailed pictures of the brain. These images help the investigators to understand how a stroke is related to spasticity. Also, these images are helpful to make the stimulation with TMS more accurate. Study participation will require five visits to the Parkwood Institute Main Building and one visit to St. Joseph's Hospital. The entire study will take place over roughly six months. The investigators are recruiting 25 people with stroke who are eligible for cryoneurolysis to participate in the study.

Eligibility

Min Age: 18 Years

Inclusion Criteria7

have increased range of motion or reduced spasticity with diagnostic nerve block,
have no undesired loss of function with a diagnostic nerve block,
score 2 or higher in the Modified Ashworth scale,
have at least flickers of movement in the upper extremity,
have not received botulinum-A neurotoxin within the past 3 months,
if on anti-spastic medication, maintaining anti-spastic medications on a stable schedule over the course of the follow up period, and
they can understand and follow instructions in English.

Exclusion Criteria4

have contraindications to TMS (i.e., history of seizure, pregnancy) or 3T MRI (i.e., certain metallic implants),
are unable to provide informed consent (i.e., severe cognitive impairment),
receive any toxin injections for spasticity (Botulinum-A Toxin or equivalent) within 3 months of initial baseline assessments or at any time over the course of the follow-up period.
Have previously undergone any nerve-specific interventions (phenol neurolysis, radio-frequency ablation, or cryoneurolysis) for spasticity on a nerve that will be targeted for this study.

Interested in this trial?

Get notified about updates and connect with the research team.

Interventions

DEVICECryoneurolysis

Each participant will receive cryoneurolysis which involves the application of extreme cold directly to, or near targeted nerves under ultrasound guidance. This cold causes axonotmesis to occur, thereby completely preventing the treated nerve from propagating any signal. Cryoneurolysis produces an effect called Wallerian degeneration, where the treated nerve's axon is destroyed but the epineurium and perineurium are left intact. Therefore, the axon can regenerate, following the same path as prior to treatment.