New England Journal of Medicine. You can do an image in clinical medicine, a brief report, or a clinical problem solving case. Oh, and if you work at MGH you can do a CPC. They do a lot of neurology cases.
Alternative ideas for what to do with that interesting case are resident and fellows section submissions in Neurology. Can turn it into a clinical reasoning article, or really truncate things and submit for a neuroimaging (100 word) report.