Brief Answer: Marijauna unlikely the cause... Detailed Answer: Hi, I see you have posted this question to a neurologist. I am a physician associated with Department of Neurology for more than 3 years and worked with many epilepsy patients. Since your query has been unattended for sometime now, I shall take this opportunity to answer it. Well, there are no robust clinical studies that proves cannabis (active ingredient of marijuana as a cause of seizure. Therefore I do not think cannabis was a reason directly. Further if valproate level was well under therapeutic index, that should have prevented convulsion what ever may have been the precursor. If the last episode was a recent one, I feel your neurologist should consider using a second anticonvulsant after performing an EEG. Hope this helps. Let me know if you need clarifications. Regards

---