Although originally described in 1949 in patients with liver disease and labelled as “liver flap”, numerous other causes of asterixis exist aside from severe liver disease (1,2). As early as 1950s, asterixis was observed among some patients with heart failure and pulmonary insufficiency but without known significant liver disease (3). Azotemia has also been associated with asterixis.
Don’t forget about medication-associated asterixis . Commonly used drugs such as gabapentin, pregabalin, phenytoin, and metoclopramide have been associated with asterixis (1,4) . Even antibiotics such as ceftazidime and high dose trimethoprim-sulfamethoxazole may be culprits (1,5). There are many psychiatric drugs including lithium, carbamazepine, clozapine, and valproic acid that have been implicated (1,6) as well. Some reviews have also included hypomagnesemia and hypokalemia on the list of causes of asterixis (1).
Although asterixis is essentially a negative myoclonus with episodic loss of electrical activity of muscle and its tone, its exact pathophysiology remains unclear (7).
Bonus Pearl: Did you know that the origin of the word asterixis is An (negative)-iso (equal)-sterixis (solidity) which was shortened by Foley and Adams, its original discoverers, to what we now refer to as “asterixis” (1).
References
1. Agarwal R, Baid R. Asterixis. J Postgrad Med 2016;62:115-7. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4944342/
2. Pal G, Lin MM, Laureno R. Asterixis: a study of 103 patients. Metab Brain Dis; 2014:29:813-24. https://link.springer.com/article/10.1007%2Fs11011-014-9514-7
3. Conn HO. Aterixis—Its occurrence in chronic pulmonary disease, with a commentary on its general mechanism. N Engl J Med 1958;259:564-569. https://www.nejm.org/doi/full/10.1056/NEJM195809182591203
4. Kim JB, Jung JM, Park MH. Negative myoclonus induced by gabapentin and pregabalin: a case series and systemic literature review. J Neurol Sci 2017;382:36-9. https://www.sciencedirect.com/science/article/pii/S096758681830225X
5. Gray DA, Foo D. Reversible myoclonus, asterixis, and tremor associated with high dose trimethoprim-sulfamethoxazole: a case report. J Spinal Cord Med 2016; Vol. 39 (1), pp. 115-7. https://www.ncbi.nlm.nih.gov/pubmed/26111222
6. Nayak R, Pandurangi A, Bhogale G, et al. Aterixis (flapping tremors) as an outcome of complex psychotropic drug interaction. J Neuropsychiatry Clin Neurosci 2012;24: E26-7. https://neuro.psychiatryonline.org/doi/pdf/10.1176/appi.neuropsych.101102667.
7.Ugawa Y, Shimpo T, Mannen T. Physiological analysis of asterixis: silent period locked averaging. J Neurol Neurosurg Psych 1989;52:89-9. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1032663/pdf/jnnpsyc00523-0104.pdf
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