From the Guidelines
The diagnostic workup for hepatic encephalopathy (HE) should include a thorough clinical and paraclinical evaluation to exclude differential or associated diagnoses.
Key Components of Diagnostic Workup
- Recent medical history, including infections, trauma, and psychotropic drug use
- Complete medical history, including diabetes, neurovascular diseases, and epilepsy
- Neurological examination, including cognitive, motor, sensory, and cranial nerve testing
- Common blood tests, such as electrolytes, glucose, calcium, and inflammatory markers
- Brain imaging, preferably MRI, for differential diagnosis, especially during the first episode of HE or when an intracranial lesion is suspected 1
Exclusion of Differential Diagnoses
The diagnostic workup should aim to exclude other causes of altered mental status, such as infections, hyponatremia, renal dysfunction, and intracranial bleeding 1.
Use of Scoring Systems
The West Haven HE criteria and the Glasgow Coma Scale can be used to characterize brain failure in critically ill patients with cirrhosis 1.
Laboratory Tests
While ammonia level testing is not routinely recommended 1, other laboratory tests, such as blood glucose, electrolytes, and inflammatory markers, can help identify potential precipitating factors or alternative causes of altered mental status 1.
Imaging Studies
Brain imaging, such as MRI or CT scans, can help exclude intracranial lesions or other structural causes of altered mental status 1.
Electroencephalogram (EEG)
An EEG may be considered to exclude non-convulsive seizures, especially in patients with a history of seizure disorders or those who do not respond to empirical therapy for HE 1.
From the Research
Diagnostic Approaches
The diagnostic workup for hepatic encephalopathy (HE) involves a combination of clinical evaluation, laboratory tests, and imaging studies. The following are some of the key diagnostic approaches:
- Clinical examination and history taking to identify precipitating factors and assess the severity of neurological dysfunction 2
- West Haven criteria to assess the severity of neurological dysfunction 2, 3
- Neuropsychometric tests, such as the psychometric hepatic encephalopathy score, to diagnose minimal hepatic encephalopathy (MHE) and covert hepatic encephalopathy (CHE) 2, 3
- Electrophysiological evaluation to diagnose MHE and CHE 2
- Brain imaging studies to rule out other causes of encephalopathy and to assess for cerebral edema 3
Diagnostic Classification
HE can be classified into different types, including:
- Minimal hepatic encephalopathy (MHE): characterized by subtle cognitive impairment, only detectable by psychometric tests or electrophysiological evaluation 2, 4
- Covert hepatic encephalopathy (CHE): includes MHE and Grade I HE, characterized by mild cognitive impairment and no overt clinical signs 2
- Overt hepatic encephalopathy (OHE): characterized by personality changes, progressive disorientation, and altered level of consciousness, ranging from mild confusion to coma 2, 3
Laboratory Tests
Laboratory tests, such as ammonia levels, may be used to support the diagnosis of HE, but are not definitive 3. The diagnosis of HE is often made based on a combination of clinical evaluation, laboratory tests, and response to empiric treatment 3.