WHC including MHE | ISHEN | Description | Suggested operative criteria | Comment |
Unimpaired |
| Tested and proved to be normal | ||
Minimal | Covert |
| Abnormal results of established psychometric or neuropsychological tests without clinical manifestations | No universal criteria for diagnosis Local standards and expertise required |
Grade I |
| Despite oriented in time and space (see below), the patient appears to have some cognitive/behavioral decay with respect to his or her standard on clinical examination or to the caregivers | Clinical findings usually not reproducible | |
Grade II | Overt |
| Disoriented for time (at least three of the following are wrong: day of the month, day of the week, month, season, or year) ± the other mentioned symptoms | Clinical findings variable, but reproducible to some extent |
Grade III |
| Disoriented also for space (at least three of the following wrongly reported: country, state [or region], city, or place) ± the other mentioned symptoms | Clinical findings reproducible to some extent | |
Grade IV |
| Does not respond even to painful stimuli | Comatose state usually reproducible |