My hand musles stiff and face difficukty in moving why thus so and are these side effects of lexapro (escitalopram)?

Unlikely Lexapro (escitalopram) : If you are stiff in one hand and cannot move facial muscles, you need to go by ambulance to er as soon as possible as you may have had a stroke, especially with the risk factors you have listed.

Get to your doctor: This could be related to medicines, Lexapro (escitalopram) being one, but is best evaluated comprehensively by your doctor.