Patients who survive an episode or several episodes of hepatic coma are sometimes left with residual neurologic abnormalities such as tremor of the head or arms, asterixis, grimacing, choreic movements and twitching of the limbs, dysarthria, ataxia of gait, or impairment of intellectual function. These symptoms may worsen with repeated attacks of stupor and coma. In few patients with chronic liver disease, permanent neurologic abnormalities become manifest in the absence of discrete episodes of hepatic coma. Patients deteriorate neurologically over a period of months or years. Examination of their brains discloses foci of destruction of nerve cells and other parenchymal elements in addition to a widespread transformation of astrocytes, changes very much similar to those of Wilson disease.
Probably the first to describe this acquired type of hepatocerebral degeneration was van Woerkom, whose report appeared only 2 years after Wilson’s original description of the familial form. A full account of the cases reported since that time as well as the extensive experience of our colleagues with this disorder is contained in the article by Victor, Adams and Cole.
The first symptom may be a tremor of the outstretched arms, fleeting arrhythmic twitches of the face and limbs (resembling either myoclonus or chorea), or a mild unsteadiness of gait with action tremor. As the condition evolves over months or years, a characteristic dysarthria, ataxia, wide-based, unsteady gait, and choreoathetosis, mainly of the face, neck, and shoulders, are joined in a syndrome. Mental function is slowly altered, taking the form of a dementia with a seeming lack of concern about the illness. A coarse, rhythmic tremor of the arms appearing with certain sustained postures, corticospinal tract signs (“hepatic paraplegia”), and diffuse EEG abnormalities complete the clinical picture. Other less-frequent signs are rigidity, grasp reflexes, tremor in repose, nystagmus, asterixis, and action or intention myoclonus. In essence, each of the neurologic abnormalities observed in patients with acute hepatic encephalopathy are also part of chronic hepatocerebral degeneration, the only difference being that the abnormalities are evanescent in the former and irreversible and progressive in the latter.
As a rule, all measurable hepatic functions are altered but the chronic neurologic disorder correlates best with an elevation of serum ammonia (usually >200 mg/dL). Unlike Wilson disease, where the cirrhosis usually remains occult for a long time, there is no question about its presence in the acquired syndrome; jaundice, ascites, and esophageal varices are manifest in most of the acquired cases. Wilson disease, which enters into the differential diagnosis, is usually not difficult to differentiate on clinical grounds, although the distinction in some cases requires the critical evidence of familial occurrence, Kayser-Fleischer rings (never found in the acquired type), and certain biochemical abnormalities (diminished serum ceruloplasmin, elevated serum copper, and elevated urinary copper excretion, discussed in Chap. 39).