From the Guidelines
Asterixis can be caused by several conditions beyond hepatic encephalopathy, including uremia, respiratory failure, electrolyte disturbances, certain medications, Wilson's disease, and severe heart failure, as evidenced by recent studies 1.
Causes of Asterixis
The causes of asterixis can be broadly categorized into:
- Metabolic disorders: such as uremia, respiratory failure with carbon dioxide retention, and electrolyte disturbances (particularly hypomagnesemia, hypocalcemia, and hypokalemia) 1
- Medications: certain medications, especially anticonvulsants like phenytoin, valproic acid, and carbamazepine 1
- Other conditions: Wilson's disease, and severe heart failure 1
Diagnosis and Management
When evaluating a patient with asterixis, it's essential to check renal function, arterial blood gases, electrolytes, and medication history alongside liver function tests to determine the cause 1.
- A clinical and paraclinical diagnostic work-up for investigations of a differential or associated diagnosis with HE is essential in any initial evaluation of neurological symptoms in cirrhotic patients 1
- Treatment should focus on addressing the underlying condition rather than the asterixis itself, as the symptom will resolve when the primary disorder is corrected 1
Key Considerations
- Asterixis is not pathognomonic of HE and can be observed in other diseases, such as uremia 1
- The presence of asterixis is strongly suggestive of metabolic encephalopathy, but a differential diagnosis should be considered 1
- A thorough medical history, neurological examination, and laboratory tests are necessary to determine the underlying cause of asterixis 1
From the Research
Causes of Asterixis
Besides hepatic encephalopathy, asterixis can be caused by various other factors, including:
- Medications 2
- Renal disorder 2
- Pulmonary insufficiency 2
- Stroke and other brain lesions, such as malignancy, subdural hematoma, and epidural abscess 2
- Other generalized encephalopathies 2, 3
Patterns and Presentations
Asterixis can occur in different patterns, including:
- Unilateral or bilateral presentation 2
- Easier to elicit in the upper extremities or lower limbs 2
- Solely or predominantly unilateral presentation 2
Clinical Significance
Asterixis is an important clinical sign that can be associated with a wide range of potential causes, both in neurology and general medicine 3. Its presence can indicate underlying electrolyte and acid-base disturbances, which are common in patients with end-stage liver disease 4, 5. Additionally, hypokalaemia has been suggested to be an active contributor to hepatic encephalopathy, and correcting low potassium levels may be important in patients with cirrhosis 6.