Is it possible to have csf leak 3wks post esi. l4-l5. bad headache/foggy/no fever. painful epidural even with lidocaine before placed. nsai helps.

Headache: it can happen .usual time frame is 3-5 weeks if you having any back pain or any leg numbness tingling or problems with bowel or bladder control i suggest you see a doctor asap for just a headache take ibuprofen

Be patient: Its doubful that you have developed a CSF leak weeks after an Epidural Steroid Injection. but the headace from such a small leak at the time of the injection can persist for weeks. Be patient. Take NSAIDS and try to rest a bit more than usual. If the headaches still present in three more weeks see the doctor who prescribed the ESI. Hope this Helps.