There can be many conditions that can affect the memory. Things like lupus are certainly possible, but difficult to say without examination.
An elevation of CK by itself is non-specific. It can be indicative of muscle damage anywhere in the body, as well as possible heart damage (which certainly would have been considered in the emergency room). Various medications, like cholesterol medications, can also lead to an elevation in the CK.
If there is consideration of a rheumatological cause, you can consider an ANA test. Further followup would be dependent on the results.
I would consider a referral to a neurologist. Testing the metabolic panel, blood count, thyroid, vitamin b-12 level as well as brain imaging studies (i.e. an MRI) should all be considered as part of the workup.
Followup with your personal physician is essential.
This answer is not intended as and does not substitute for medical advice - the information presented is for patient education only. Please see your personal physician for further evaluation of your individual case.