emg-controlled virtual reality to improve upper extremity function in chronic stroke patients

Conditions: Stroke; Upper Extremity Dysfunction

Summary: this is a single subject design study to investigate the effectiveness of electromyography-controlled virtual reality and serious gaming treatment on upper extremity functionality in patients in the chronic recovery stage after stroke. the treatment consists of 18 sessions, 3 times per week, 2 hours each session. the investigator's hypothesis is that this treatment will improve upper limb functionality in our study population, this outcome will be measured with fugl-meyer upper-extremity (fma-ue) and action research arm test (arat) tests and kinematic analysis. in addition, we expect to see an increase in the strength of the affected limb and an increase in the embodiment of the upper limb trained.

background the world health organization (who) defines stroke as rapidly developing clinical signs of focal or global disturbance of cerebral function, with symptoms lasting more than 24 hours or leading to death and with no apparent non-vascular cause. the incidence of stroke in sweden is 300 cases per 100.000 inhabitants in a year of whom 200 suffer the first incidence of stroke leading to 18.000 new stroke victims. of these, about 20% will die within the first month and about 1/3 of the survivors will remain significantly disabled after 6-12 months. the upper extremity function is impaired after stroke in approximately 70-80% of patients in the acute phase and in 40% in chronic phase. this impairment limits the voluntary, well-coordinated, and effective movements as well as a person's level of activity and participation in their social and physical environment. this longstanding disability also affects the quality of life. improved upper extremity function is one of the suggested areas for research by survivors of stroke. objectives primary objective: investigate the effectiveness of electromyography-controlled augmented reality, and serious gaming on upper extremity functionality in patients in the chronic recovery stage after stroke, measure with fma-ue and arat tests secondary objectives: * investigate changes in the movement quality when performing a daily task using kinematic analysis and perceived difficulties in daily activities. * measure how strength changes on the affected limb after the treatment. measure by a dynamometer. * measure with embodiment questioner if the treatment makes some changes on the embodiment of the affected limb. * measure with thermography the skin temperature differences between the affected and non-affected limb pre- and post-treatment. tertiary objectives: the tertiary objectives of this study are to investigate the effect of training on electromyography-based pattern recognition accuracy and targeted achievement control scores, changes in kinematics, and changes in abilhand, barthel index, muscle tone, and sensation scores in the affected limb over the recovery period. study design inclusion and exclusion criteria for prospective patients will be addressed at the first measurement session. baseline measurements will start at week 1 and, if necessary, inclusion and exclusion criteria will be reassessed. patients will undergo a single subject design (a-b-a-fu). intervention stages are as follows: a (baseline). 2-3 weeks of no intervention with measurements taken once or twice per week, with a minimum of 3 assessments. b (intervention). 6 weeks of intervention three times per week with measurements taken once per week (18 sessions). a (reversal). 2-3 weeks of no intervention with measurements taken once or twice per week, with a minimum of 3 assessments. fu (follow-up). follow-up measurements taken after 3 months without treatment. treatment administration surface electrodes and a tracking marker are placed on the subject's affected upper extremity. electrodes are placed on active muscle sites along the affected extremity determined by palpation. if no active sites can be determined, electrodes are placed along with major muscle groups regardless of activation. electrodes are fixed to an electromyography recording device, and signal acquisition and processing software (biopatrec) is used to record electromyography (emg) signals and display feedback. emg signals are observed, and the most active electrode locations are documented and used for further experiments. the subject should attempt to perform different hand and arm movements with the extremity indicated by a nearby computer screen while the computer records emg signals from the arm (referred to as offline training). agonist-antagonist movement pairs should always be used in combination when selecting movements. treatment sessions should start with one movement pair at a time and progress to multiple and simultaneous movements as treatment progresses and the patients perform better with the system. the computer system recognizes the different movements while the computer system records closely related emg signals and will perform the subject's intended movements with a computer-simulated upper extremity. the subject will then use previously recorded movements to control a computer-simulated limb and attempt to match limb positions indicated on the computer screen. the system will measure how fast and how efficiently the subject reaches the target position with the simulated extremity targeted achievement control (tac test). tac tests will initially involve control over one degree of freedom at a time, e.g. rotation of the wrist or open/close hand movements. as the patient gains better control of their affected extremity and learn to use the system, the difficulty of the tac tests will be increased by adding additional and simultaneous movements. duration of the treatment: each intervention session should take approximately two hours. the intervention stage of the trial will last six weeks with three sessions per week, total of 18 sessions.

Eligibility criteria:
inclusion criteria: * able to sign an informed consent document * detectable muscle signals in the affected upper limb. * age between 18 and 80 years of age * montreal cognitive assessment test score of at least 22 * at least 6 months after stroke * experiencing upper-limb weakness, paralysis, or other loss of functionality * having a score below 50 on the fugl-meyer assessment - upper extremity score * modified ashworth score (0-5) of less than 3 pts * able to communicate and follow instructions needed for assessment and intervention adherence exclusion criteria: * patients who are blind * presence of a condition or abnormality that in the opinion of the investigator would compromise the safety of the patient or the quality of the data * patients who have open wounds or other acute complications on their arms

Keywords: electromyography virtual reality