“…Normal GBM thickness has been estimated in several reports (Coleman, Haynes, Dimopoulos, Barratt, & Jarvis, 1986;Das, Pickett, & Tungekar, 1996;Dische et al, 1985;Haas, 2009;Jovanovic GB, 1990). Since there is a lack of a general consensus on diagnostic criteria, it is recommended that a GBM normal range should be established for each laboratory (Dische et al, 1985;Tiebosch et al, 1989). This normal range is a necessary pre-requisite that facilitates the subsequent accurate diagnosis of TBMN.…”