Spasticity as Sequela of Stroke

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.

This study aims to evaluate the efficacy of a combined treatment approach for post-stroke upper limb spasticity using phenol neurolysis and botulinum toxin (BoNT). Spasticity is a common post-stroke complication that leads to muscle stiffness and significantly hinders functional recovery. While botulinum toxin is the standard treatment, its high cost often limits its application, particularly for large proximal muscles. The researchers will compare two treatment strategies in 60 adult stroke survivors: Group A (Combined Therapy): Patients will receive ultrasound-guided phenol neurolysis for the proximal nerves (pectoralis and musculocutaneous nerves) and botulinum toxin for the distal forearm flexors. Group B (Standard Care): Patients will receive botulinum toxin alone for all affected muscles in the upper limb. All procedures will be performed under ultrasound guidance to ensure anatomical precision. The study will also utilize Transcranial Magnetic Stimulation (TMS) to assess changes in cortical excitability (RMT, MEPs, and cortical silent period). The primary goal is to determine if this combined approach effectively reduces muscle stiffness (measured by the Modified Ashworth Scale) while potentially reducing the total dose of botulinum toxin required per patient.

Stroke is the leading cause of acquired disability in adults. Stroke causes death in 10% of patients, disability and functional handicap in 60% of cases. Sequelea of hemiplegia include spasticity resulting in great difficulty and slowness in walking, gait instability, increasing the risk of falls. Deambulation may need help (cane, crutch, tripod cane, walker). Lower limb spasticity includes hypertonia of extensors (gluteus maximus, quadriceps, posterior gastrocnemius) resulting in equinovarus. A neurology deficit may be present on ipsilateral lower limb flexors. Hence the patient walks with rubbing of the tip of the foot (tip-toeing gait), resulting in a "mowing wheatslike" movement of the leg as described in the French literature. Walking is then slowed down, unstable, with increased risk of falls. In post stroke, during the period of rehabilitation and beyond, it is advisable to wear sports shoes although custom-made shoes improve walking and are reimbursed by the French social security system after prior agreement. Most of patients only wear conventional shoes.

A scientific study is being done to test a special treatment for people who have spasticity or tight muscles. This treatment is called "stereotactic radiosurgery dorsal rhizotomy." It uses very accurate beams of radiation to target certain nerves in the back to help loosen up the muscles. In this study, people are put into two groups by chance: one group gets the real treatment, and the other group gets a "fake" treatment that doesn't do anything. This fake treatment is called a "sham." Doing this helps make sure the study is fair and the results are true. After the people in the study get their treatment, the researchers will watch and see how they do. They will check if their muscles are less stiff and if they have any side effects. By looking at the results from both groups, the researchers can find out if the special treatment really helps people with spasticity. Patients who got the "fake" treatment will be eligible to receive the "real" treatment after 6 months.

Stroke is a global health problem, with an incidence in Europe of 147/100,000 people per year. It is estimated that 43% of them present spasticity throughout the first year, causing disability, hindering mobility and functionality, which can generate comorbidity problems, which in turn hinders its improvement over time. Recently, high quality studies have conclude that there is a moderate level of evidence with large effect size in reducing spasticity with dry needling, as well as being cost-effective in stroke patients in both the subacute and chronic phases. However, due to the limitation of manual evaluations of spasticity, and it is necessary to look for measurement alternatives that complement it, such as the analysis of the electromyographic activity and the muscular structure measured with ultrasound. These data could provide objective, useful and complementary information to clinical assessments to be more specific and effective in the treatment of stroke patients. This randomized controlled trial aim to analyse the effect of dry needling in this parameters in patients with stroke and spasticity, as well as correlated with gait variables. Each participant will be randomly assigned to the dry needling group or to the sham dry needling group, where participants receive a total of 4 sessions of ultrasound-guided dry needling or sham ultrasound-guided dry needling in the gastrocnemius medialis over 4 weeks, one per week. Measures of spasticity, electromyographic activity and muscle structure via ultrasound will made at baseline (T0) and immediate after each intervention (T1,T2,T3,T4). Gait variables will be made at baseline and after the last intervention (T0 and T4).

Spasticity, or greater muscle resistance, is a major disabling condition following stroke. Recovery of lost motor function in patients with stroke may be affected by spasticity, which most commonly develops in elbow and ankle muscles. However, despite its clinical relevance, the natural development of spasticity over the first 3 months after stroke is not clearly understood. Indeed, common clinical measures of spasticity such as the Modified Ashworth Scale (MAS) do not take into account the neurophysiological origin of spasticity and lack reliability and objectivity. The objective of this study is to examine the natural history of the development of spasticity among patients with stroke over the first 3 months using a new neurophysiological measure (TSRT, the tonic stretch reflex threshold angle) and its velocity sensitivity (mu) in comparison to MAS and other common clinical tests. In addition, detailed brain imaging will be used to understand the relationship between damage to brain regions relevant to the development of spasticity and TSRT/mu values. It is hypothesized that 1) TSRT/mu will indicate the presence of spasticity earlier than MAS/clinical tests; 2) TSRT/mu measures will be more closely related to motor impairments and activity limitations than MAS; 3) the lesion severity (identified by imaging) will be related to the change in TSRT/mu values. Outcomes will be measured in a pilot cohort of 12 patients hospitalized for first-ever stroke. Measurements will be taken at the bedside within the 1st week of the patient's admission and will be done once per week for 12 weeks with a follow-up at week 16. Brain Imaging will be done around the 6th week post-stroke.