Fig. 9 .

An axial slice of the cerebrum from a cadaver shows that the distance from the subarachnoid space to the lateral ventricular wall as well as the distance from the Sylvian fissure to the third ventricular wall is almost equal in each region ( solid lines ). Cerebrospinal fluid (CSF) and interstitial fluid travel a long distance when the distal part of the Sylvian fissure is not present between the third ventricle and the convexity of the subarachnoid space ( dashed line ). Reprinted with the permission from Reference³¹⁰⁾ modified Figure 1 . [Sato O: [Reconsideration of research into cerebrospinal fluid], in Arai, H, Ishikawa, M, Mori, E ( eds ): iNPH: Idiopathic Normal Pressure Hydrocephalus . Kyoto, Kinpodo, 2014, pp 8–18 (Japanese)].