With information above, what should be my course of action?

Someone has to take her to a DSHS and they'll refer her to their Mental Health

Department.

As you are not a trained professional in mental health or medicine you can only GUESS at the cause of her behavior. A doctor visit is warranted and she may not have a choice since she slapped your father. Call the police and have her taken in for mental evaluation. She's violent and a potential danger to herself and others. She goes willingly or by authority of officer. Most folks, when faced with the choice, go to a doctor. In Calif it's called Health & Safety code 5150.

You can try something called an intervention.  That is when the whole family gets together as a family and gently confront your mother on what is happening to her and that she needs help.  Tell her you will all be supportive of her and that she has nothing to worry about.  Explain to your mother that seeing a doctor will make her feel so much better and she will be able to live normally again.  Be gentle, kind, and loving, as I am sure you will be.  Good Luck.  Also, pray.

First of all I would like to say how sorry I am to you and your family for having to go through this difficult time...It is never easy to sit and watch in frustration, while a loved one is going through a personality change right before your eyes.

Now, a question or two - Was your mom diagnosed with PSTD or is that your family making the diagnosis on their own?  PSTD presents in many ways, and there are some things in which you describe, that can be associated with PSTD, but some of which can be from another illness.

Also, I would like to comment that although this is a good forum to "vent" and try to get some answers -  however, it is in no way a substitute for a "physician's medical diagnosis" please keep that in mind.

Your mother needs a full examination by medical personnel...There are so many other issues that may be the underlying cause of her behavior...Some of which may be, "Thyroid; hormones; vitamin deficiency; sleep deprivation - which can cause delusions; even brain tumors" - only a Doctor is qualified to make a diagnosis...And, it is essential she go.

My suggestion is to call up the town Social Worker - which is usually in your local Senior Citizen Community Center/Town Hall...Explain your circumstances - and she/he will come out to your house for a full evaluation, to ascertain what may be the problem...She/he will then bring the paperwork and recommendations to the Physician...This is probably the best place to begin...As they are fully equipped to handle any crisis, they will know how to circumvent your mother's apprehension and non compliance with wanting to see a physician.

Please make a concerted effort to do something before it progresses any further...And, again - good luck and my heart goes out to all of you at this time.

Take Care~

Who diagnosed you mother with PTSD?  What you are describing are psychotic symptoms.  You can have psychotic symptoms with PTSD, but your question does not provide any information that warrants diagnostic criteria for PTSD.  When did she begin to manifest her symptoms of paranoia and extreme agitation?  Has she been depressed and are her symptoms becoming more extreme or exacerbating?  If you are that concerned that she may cause herself or someone else grave harm and is at imminent risk, take her to the nearest ER and tell them she maybe in danger of harming herself or someone else, she will than be committed for evaluation. 

Unfortunately, to be declared her guardian through a court procedure requires her to have a psychiatric evaluation.  The only way you maybe able to accomplish this is by having her committed through a petition and certificate...which again your best bet for immediate intervention is an ER.  I wish you luck.