Obligatory medical device diagnostics.
- Abdominal ultrasonography (ultrasound examination of the abdominal organs) – for basic diagnosis.
- Computed psychometry – gold standard; very time consuming compared to flicker frequency.
- Flicker frequency analysis
- Very accurate form of diagnosis with high sensitivity
- There is a correlation between the critical flicker frequency and the severity of hepatic encephalopathy: the human eye can perceive flicker only below a frequency of approximately 39 Hz. In the context of hepatic encephalopathy, the critical flicker frequency (CFF/critical flicker frequency) is decreased.
Optional medical device diagnostics – depending on the results of the history, physical examination and obligatory laboratory parameters – for differential diagnostic clarification.
- Computed tomography of the skull (cranial CT, cranial CT or cCT) – to exclude apoplexy (stroke) in comatose patients.
- Encephalogram (EEG; recording of brain electrical activity) [triphasic waves (stages II and III of hepatic encephalopathy) or delta activity (stage IV)]