Shakespeare: "Macbeth" (Judi Dench) - sleepwalking scene

This scene is from the 1979 tv version of the Trevor Nunn production by the Royal Shakespeare Company starring Judi Dench as Lady Macbeth. This is Act 5 Scene 1, the scene where the doctor and the waiting gentlewoman witness Lady Macbeth sleepwalking. I picked this clip because it is the point of no return for Lady Macbeth, her actions in the play have finally caught up to her and she is starting to show signs of going mad. Her conscience is going into overload for the death of Banquo among others and this scene sets up for her suicide later on in the play. Throughout the play she is the person who is most willing to kill people in order for Macbeth to gain the throne. She pushes Macbeth to commit numerous crimes and when he is reluctant she questions whether or not he is truly a man. In the end the guilt was too much for her and she spirals into madness.

Did the performance of this scene match what you pictured in your mind as you read the text? What was the same and what varied?

During this scene in the play there is a part where Lady Macbeth exclaims, "O,O,O!" which Judi Dench turned into a prolonged screech(4:10) of anguish. Which do you thing was more effective?