There is evidence of downward transtentorial herniation (crossing the plane of the incisura from above) related to lateralized mass effect or from symmetric (bilateral) mass effect.   [Yes/No]

There is evidence of dilatation of the 3rd ventricle causing central incisural herniation of the tuber cinereum into and/or beyond the plane of the incisura. The basis for this may be hydrocephalus with dilated 3rd ventricle or intracranial hypotension.   [Yes/No]

There is evidence of downward incisural displacement originating from mass effect in the caudal 3rd ventricle, or pineal gland or splenium (corpus callosum).   [Yes/No]

There is evidence of upward transtentorial herniation (crossing the plane of the incisura from below) related to central or lateralized mass effect or from posterior fossa lesion(s).   [Yes/No]

There is intra of extra axial mass effect(s) producing symmetric or lateralized cerebellar tonsillar displacement into the cisterna magna (caudal tonsillar surface at or minimally below the plane of the foramen magnum possibly compressing the cervicomedullary cord.   [Yes/No]

There is evidence of developmental tonsillar ectopia or Chiari-1 malformation.   [Yes/No]

There is concurrent evidence of downward incisural plus downward tonsillar herniation without evidence of any lesion to explain the combined herniations; this complex is consistent with intracranial hypotension.   [Yes/No]

No other concurrent significant abnormality is present.   [Yes/No]