Acquired hepatocerebral degeneration

Discussion

The relationship between the brain and the liver has been well established since many years. Among the neurological problems based on chronic liver diseases, the most common and widely recognized one is the reversible syndrome of HE which can be divided into 2 main forms: minimal HE and overt HE.3,7 The first one, which used to be referred to as latent or subclinical HE according to the old terminology, is now replaced with the term minimal HE. It is characterized by mild impairment of visuospatial function, attention and psychomotor speed.7,8 The second form is referred to as a syndrome of neuropsychiatric, neuropsychological and neurological disturbances arising as a complication of liver disease. Despite previous studies suggesting the condition is reversible, there is growing evidence that reversibility is incomplete.7,8

Both confusion episodes of our patient were compatible with overt HE attacks. However, it is noteworthy that in the follow-up period lasting for 3 years, neither of these episodes repeated nor the patient developed any neurological sign or symptom or impairment of cognitive functions. She even got a promotion which is the best evidence of her successful cognitive performance. The absence of liver cirrhosis could be the reason for the benign course of the disease, since most of the cases diagnosed AHD and described in the literature were suffering from cirrhosis but further investigation are necessary to confirm this hypothesis.8

The pathogenesis of the disease is poorly understood, but it is assumed that the chronic exposure of the brain to toxic substances, especially to manganese, bypassing the liver is the main cause of the disease.3,9 Typical MR findings show an abnormally high signal on T1-weighted imaging in the basal ganglia, particularly globus pallidus. This high signal is now believed to be due to manganese deposition, and postmortem studies have shown levels up to 7 times normal in globus pallidus confirming the main role of manganese in the pathogenesis of the disease.8 Magnetic resonance imaging findings of our patient were typical for AHD.

Although AHD has been long assumed to be irreversible, growing evidence shows that orthotropic liver transplantation (OLT) is the best treatment option which improves both motor and cognitive functions.3,10 Additionally, patients who could not be submitted to OLT can be treated by reducing the flow through the portosystemic shunts or by obliteration of them.11 The MRI findings, medical history including Budd-Chiari syndrome and operation on TIPS, overt HE attacks with triphasic waves on EEG are all in accordance with AHD.

In conclusion, we would like to draw attention to the time course of the disease; the time between the outset of the degenerative process in the brain during the disease and the clinical manifestation of typical picture can take many years. Because of the lack of a gold standard for assessing AHD, we propose to make cranial MRI of patients that represent with confusion state, especially those with triphasic waves in the EEG and surgically or spontaneously induced portosystemic shunts in the past history, in order to detect candidates of AHD. Finally, we hope that early diagnosis of AHD and prospective follow-up of patients will add crucial information about the course of the disease and make it possible to develop effective treatment strategies.