The purpose of the study is to measure the outcomes of a standard care, an ultrasound guided mini-invasive percutaneous procedure, performed on recent stroke patients on reduces pain, increases function & quality of life

The primary objective of the project is to reduce shoulder and/or knee pain in patients who have had a stroke so that they can more readily engage in rehabilitation.

Secondary objectives are to reduce analgesic medications, increase independence and improve range of motion, to promote non-drug treatment measures in the medical toolkit, and to include an interdisciplinary care team in patient selection for interventions.

Hemiplegic shoulder pain (HSP) is the most common pain disorder after stroke and one of the four most common complications. The estimated incidence ranges from of 30%-70%. HSP is associated with reductions in function, interference with rehabilitation efforts , and a reduced quality of life .Onset of HSP is rapid, occurring as soon as a week after stroke in 17% of patients.While ubiquitous, the management of HSP represents a complex treatment pathway that has insufficient evidence supporting one particular treatment.

The pain associated with HSP may be due to heterogeneous causes. In the acute setting, decreased ROM in the shoulder may represent several processes including the early onset of spasticity, capsular pattern stiffness, glenohumeral pathology, or a component of complex regional pain syndrome (CRPS). Effective management of the HSP with decreased ROM requires assessment of each possible contributor. The suprascapular nerve provides up to 70% of the sensory fibers to the shoulder. Targeting the suprascapular nerve to reduce pain from stroke has been study with both nerve blocks and radiofrequency ablation. Cryoneurolysis to treat shoulder pain has also been proposed in recent years.

The lack of early recognition and treatment of HSP can lead to worsening limb function, increased pain, and may impair the rehabilitation and recovery process Early intervention may reduce the risk and onset of contracture, which can lead to significant impairments and a reduced quality of life. The incidence of developing at least one contracture in stroke patients within six months of their stroke is estimated at 52%.Contractures are a source of pain and limited ROM, and limit function while stretching has not been shown to be clinically effective. Patients with contractures and limited volitional control of their shoulder muscles, can experience maceration, skin dehiscence, impaired hygiene, and difficulty dressing, thus more invasive surgery may be required.

Knee osteoarthritis is ubiquitous in the aging population. Many stroke patients may have been pre-stroke poor candidates for a total knee arthroplasty due to medical frailty. Participants recovering from stroke, with pre-existing arthritis perceived that their arthritis "held them back" from an expected stroke recovery trajectory.In this study; "This slowed stroke recovery was attributed to daily pain, frustration, mobility limitations, and the required extra coping due to arthritis. As a result, comorbid arthritis increased the complexity of stroke recovery and rehabilitation."

This group has been global pioneers in the use of cryoneurolysis to treat spasticity.The process first involves isolating the nerves with ultrasound guidance and e-stimulation for motor nerves. A diagnostic nerve block is then performed to assess if spasticity is reduced, and range of motion and ease of movement occurs, as well as pain reduction. After a successful nerve block the patient then goes on to have cryoneurolysis which is performed using a small 1.2 to 1.3 mm diameter cryoprobe that is inserted percutaneously to targeted peripheral nerves. It has an established history over more than fifty years for lasting pain relief from months to years, when used for sensory nerves. Cryoneurolysis is possible due to the process of throttling a gas through an orifice from high to low pressure resulting in a rapid expansion of the gas and a drop in temperature, known as the Joule-Thomson effect. The rapid cooling generates an ice ball or oval between 3.5 and 18 mm that is formed at the tip of the with compressed CO2 or N2O at temperatures typically between -60 to -88° C. The ball or oval creates a targeted zone of axon and myelin disruption. This results in loss of axon continuity due to Wallerian degeneration of the targeted nerve extending outward from the lesion over a limited distance. However, the basal lamina, epineurium and perineurium of the targeted nerve remain intact and serve as a conduit or tube for neural regeneration.

Development of the ViVe algorithm to create a team based assessment tool to isolate the sources of Hemiplegic pain. This allows us to select patient that would benefit from cryoneurolysis to both the suprascapular nerve as well as the nerves to the spasticity muscles of the upper limb. Similarly, cryoneurolysis has been shown to be effective in managing osteoarthritis, a limiting factor for stroke rehabilitation.

There are 50,000 new strokes in Canada every year. Direct costs for 12-month stroke survivors are 4 times higher than direct costs for patients with stroke without spasticity during the first year after the event.

It has been demonstrating that cryoneurolysis has long lasting effects Over 100 patients, mostly with chronic neurologic disorders, received cryoneurolysis as a part of their standard care in this center and their outcomes are being measured and assessed . The number of these patients exceeding rapidly and it is essential to assess treating patients much earlier, in acute phase, to assess the reduction in pain, disability, and lengths of stay.

PURPOSE The purpose of this study is to measure the outcomes of a standard care procedure called cryoneurolysis. This will include any changes in pain and spasticity in an inpatient setting and for adult patients with an acute neurological condition who suffer from Hemiplegic Shoulder Pain (HSP) and or osteoarthritis of the knee and will receive this procedure as a part of their treatment and based on available guidelines.

Inclusion Criteria:

1. Adult inpatients at any hospital in the Greater Victoria Area or referred to Victoria General hospital for rehabilitation with the chief complaint of an acute neurological condition (within sixteen weeks) including but not limited to stroke and traumatic brain injury. People that have had a stroke or neurological event within sixteen weeks but have been discharged to outpatient rehab at Victoria General Hospital are also candidates

2. In addition to their chief complaint, are also affected by one or both of the following

   1. Hemiplegic shoulder pain,
   2. Knee pain due to osteoarthritis

3. Patients who are already candidate for cryoneurolysis.

4. Ability to attend testing sessions, comply with testing protocols and provide either written or verbal informed consent. If necessary, a witness will be asked to sign the consent form and confirm the participant signature. For those patients who do not have the capacity to sign the consent form(Based on evaluation by PI or the recorded assessment by their physician in their medical charts) the designated care provider or family member will be asked to sign the ICF on behalf of them. Evaluation of the capacity to understand and communicate are part of routine assessment and are done routinely and each visit by physicians.

5. Able to understand and complete study-related questionnaires (must be able to understand and speak English or have access to an appropriate interpreter as judged by the investigator).

Exclusion Criteria:

1. Have undergone any previous peripheral nerve procedures in their affected side, for the treatment of spasticity or pain. Relevant treatments included but not limited to previous cryoneurolysis, previous chemical neurolysis, neurectomy or arthroplasty.
2. Patients who received botulinum toxin in the past 4 months in the same targeted muscles for cryoneurolysis

Adult patients with an acute neurological disorder, within 16 weeks, who have been referred to the Victoria General Hospital for rehabilitation and are already candidate for cryoneurolysis to manage their shoulder and/or knee pain.