Rule of 4️⃣s trick from my Neurology guide 🧠📘#medstudent #medschool #usmle #usmlestep1 #step1

[0:00]You will never forget this brainstem trick again, which all stems from the number four, the rule of fours. So, we have four cranial nerves that arise from above the pons, in the midbrain, four cranial nerves from the pons, and four cranial nerves below the pons in the medulla. Now, where M here signifies our medial structures that all conveniently start with the letter M, and there's four of them. We have our medial longitudinal fasciculus, our motor cranial nuclei, our motor pathway or cortical spinal pathway, as well as our medial menisco or dorsal column. Now, we also have an S here in red, which signifies our side or lateral structures. And conveniently, these also start with S, and there's also four of them. This is our spinocerebellar, spinothalamic, our sensory cranial nerve nuclei of the trigeminal nerve, as well as the spinothalamic pathway. And guys, a quick trick to remember your medial cranial nuclei is that they're all divisible by 12. Three, four, six, and 12. There you have it.