A month ago my mother could talk - in a low voice - in full sentences and would respond accurately to questions, ask questions, etc. Now she is not communicating at all with us, not even registering if she knows who we are. Is this the dementia accelerating, or a typical result of the stroke that paralyzed her left side, 6 weeks ago. is it common that the responsiveness and communication 'come and go' with stroke victimes? I appreciate any insights you might be able to share.