Patients with manifest hepatic encephalopathy can reveal impaired thermal perception

Objectives Previous evoked potential studies indicated central impairments of somatosensory function in patients suffering from hepatic encephalopathy ( HE ). The aim of this study was to quantify the somatosensory perception in patients with minimal and overt HE . Materials and Methods Forty‐two patients with liver cirrhosis and HE up to grade 2 and 12 age‐matched healthy controls underwent a comprehensive graduation of HE including the West Haven criteria , the critical flicker frequency ( CFF ), and neuropsychometric testing. Quantitative sensory testing, standardized by the German Research Network on Neuropathic Pain , was performed on both hands. Results Pain and mechanical detection thresholds were unchanged in HE . Tests of thermal processing revealed that patients with HE of grade 2 perceive cold at lower temperatures (cold detection threshold) and need a higher temperature difference to distinguish between warm and cold (thermal sensory limen). These impairments correlated with the CFF . A correction for attention deficits by performing partial correlations using neuropsychometric test results canceled these correlations. Conclusions The present findings demonstrate an impairment of temperature perception in HE . The extent of this impairment correlates with HE severity as quantified by the CFF . The attenuation of the correlations after correction for attention deficits suggests a strong role of attention deficits for the impaired thermal perception. Thus, it provides initial evidence for a central impairment of thermal processing in HE due to alterations in high‐level processes rather than due to peripheral neuropathic processes, which are a frequent complication in patients with liver cirrhosis.