High Quality Content by WIKIPEDIA articles! Spontaneous cerebrospinal fluid leak syndrome (SCSFLS) is a medical condition in which the cerebrospinal fluid (CSF) held in and around a human brain and spinal cord leaks out of the surrounding protective sac, the dura, for no apparent reason. The dura, a tough, inflexible tissue, is the outermost of the three layers of the meninges, the system of meninges surrounding the brain and spinal cord. (The other two meningeal layers are the pia mater and the arachnoid mater).