Evidence based practice is definitely used with stroke patients and patients with complex diagnoses. I currently have a patient with flaccid hemiplegia. I have implemented mirror therapy with her and the following citation below was utilized when determining best treatment.
Thieme, H., Bayn, M., Wurg, M., Zange, C., Pohl, M., & Behrens, J. (2013). Mirror therapy for patients with severe arm paresis after stroke - a randomized controlled trial. Clinical Rehabilitation, 27(4), 314-24. doi:http://dx.doi.org/10.1177/0269215512455651