Hi thank you for trusting HCM I read your query and the information you provided leads to any viral infections I read that you undertake LP with high pressure at first so definitely it needs imageric evaluation at leat CT or ideal MR to better understand what was going with menings Joint paint is uncommon to neurologic disorders but it can be taken as fever syndrome Cystitis may be called as entrance way of infection so LCS much be further evaluated not just biological evaluation Neurologic exam can give further information so provide it if you have done that It is something systemic, arteritis (giant cell) or vasculitis Hope I have been of help Feel free to ask for further questions or doubts Best regards Dr Eris Ranxha Neurologist