I told myself if I passed the CNRN exam I would create a post that detailed what I reviewed in preparation since it was so hard for me to find any recent info on the topic while I was trying to prepare. I used several resources and threw a lot of money at it, not having any idea how to focus my prep. That said, I can share what I studied but it's not necessarily a recommendation because, though I passed, I still felt I was failing the test the entire time. So, I didn't feel prepared, but apparently I was.
My background is about 2 years in Neuro ICU at a Level I Trauma Center and 1.5 years in neurointerventional radiology. That experience gave me a good foundation of knowledge in brain anatomy, trauma, post-surgical, stroke and cerebrovascular anatomy/injury. Resources I used for other areas:
AANN Neuroscience Nursing Certification Review Focused CE Series: this was interesting but I don't feel it helped me at all in preparation for the test. The extremely high cost of the course is not justifiable if you want it solely as test prep. If you only had the minimum one year experience in nursing and planned to take the test, then maybe it would be helpful in exposing you to other areas of neuro nursing beyond your current scope.
AANN CNRN Self-Assessment Examination: This test is only 70 questions and I passed with a lower score than I got on the actual test. I guess this is helpful if you just want some practice questions, but again, the cost is very high for what you get in return.
CNRN Exam Secrets Study Guide by Mometrix: This is more of a pamphlet, the individual topic areas are so general as to feel almost useless, but it does contain a breadth of topics that might help you understand where you need further study. The practice test is crazy hard, but if like me you really like practice questions to get you critically thinking, it still helps.
What I thought helped the most (and was the cheapest!)
The Clinical Practice of Neurological and Neuroscience Nursing, ie The Hickey Book: I used the test outline and looked up each area in this book. For me that meant just some areas like chronic neurological, immune/infection, and diseases. Made notes on things like treatment/meds, plan of care.
AANN Clinical Practice Guidelines: These are free for members! It's a lot to slog through, but it's bullet points and pretty straightforward. Again, note treatment/meds, nursing actions.
Dr. Najeeb Lectures on YouTube: I really liked the Circle of Willis lecture and I think his lectures are great for visual learners.
That sums it all up. I don't think there's one best resource, but using the test outline to guide your study into the areas you are lacking is my best advice. I'll also note that I am a good test taker, so I had that on my side as well.
Thank you thank you thank you!