Severe grades of Hepatic Encephalopathy (HE) go along with a variety of motor symptoms like ataxia, „mini-asterixis“ and asterixis. Recently, it has been shown that „mini-asterixis“ in HE is due to a general slowing of motor cortex drive (Timmermann et al., Neurology 58: 295–298) and thalamo-cortical coupling (Timmermann et al., Neurology 61: 689–692). However, it remained unclear whether HE patients show ataxia already at low grades that could be detected in clinical scoring.
We therefore tested 17 patients with liver cirrhosis proved by clinical examination, laboratory findings and ultrasound/cat-scan of the liver. As a control group we studied 8 age-matched healthy controls. All subjects were neuropsychologically tested using a computerized test battery and the critical flicker frequency, a reliable measure for HE. Grading of HE, according to the „West-Haven criteria“, was performed by a neurologist and hepatologist. Patients were then assessed by an experienced Movement Disorders Specialist blinded to the results of the HE grading. Two scales were used: The Fahn Tremor scale and the International Ataxia rating scale.
All 8 control subjects did neither show deficits in the neuropsychological assessment nor in the tremor or ataxia scale. Grading of HE revealed in 12 patients no hint for any HE, in three patients subclinical HE (SHE) and in 2 patients HE grade 1 (HE). Patients with liver cirrhosis, but without any HE, but also the SHE and HE1 patients showed significantly higher ratings on the tremor scale and on the ataxia scale compared to controls. Furthermore, patients without HE were rated significantly lower in the tremor and ataxia rating scales compared to SHE patients.
Taken together the present study revealed ataxia and tremor in patients with liver cirrhosis with mild and subclinical HE, but also in patients without any signs of HE. These results indicate that ataxia and tremor as a marker for cerebral dysfunction in the motor system emerge already at very early stages of HE.
