Stage | Clinical | Reflexes | Neurologic signs | EEG changes |
0 | None | Normal | Psychological testing only | Normal |
I | Confused, mood changes, altered sleep habits, loss of spatial orientation, forgetful | Normal or hyperreflexic | Tremor, apraxia, impaired handwriting | Normal or diffuse slowing to theta rhythm, triphasic waves |
II* | Drowsy, inappropriate behavior, decreased inhibitions | Hyperreflexic | Dysarthria, ataxia | Abnormal generalized slowing, triphasic waves |
III* | Stuporous, obeys simple commands | Hyperreflexic, upgoing toes (Babinski sign) | Rigidity | Abnormal generalized slowing, triphasic waves |
IV | Comatose, arouses with painful stimuli (IVa), or no response (IVb) | Usually absent | Decerebrate or decorticate | Abnormal, very slow delta activity |
EEG: electroencephalography.
* Asterixes is a common feature of stages II and III encephalopathy in adults but may be difficult to assess in children.