Hi and welcome back..sorry you had yo come back with these issues returning.....I had surgery same year as you...and I am ok....I do not have four little ones to run after, and can only imagine if I did....I know the more I do the worse I can feel, but I also know my issues/symptoms may be due to other related conditions I have.....I also have tethered cord, EDS, CCI,....to name a few and I know they can cause many of the same symptoms as Chiari.
I do not remember what your background was concerning related conditions.....
Drop attacks to me signal a CSF obstruction.....you may have developed a syrinx so a MRI of cervical spine, thoracic and lumbar should be done to see why you are having drop attacks.....I had those prior to surgery and none since.
Congrats on having two more babies <3