Grade

Neurocognitive manifestations

0/MHE

Increased incidence of motor-vehicle accidents, decreased quality of life, abnormal psychometric or neuropsychological examination 

1

Mild cognitive and behavioral impairment that is different from patient’s baseline. Manifested by disordered sleep, impaired attention span, mild confusion with intact orientation to time and space. Mild asterixis possible

2

Lethargy, moderate confusion, slurred speech, asterixis, dyspraxia, personality changes, disorientation to time

3

Stupor with intact arousability to stimuli, gross disorientation to time and space, incoherent speech. Clonus, nystagmus, Babinski sign, or rigidity may be seen on physical examination

4

Comatose state that does not respond to any stimuli, including pain