Chronic acquired hepatocerebral degeneration: case reports and new insights.

Chronic acquired hepatocerebral degeneration (CAHD) is a heterogeneous disorder that can occur with a primary neurologic, hepatic, or combined presentation. Little has been added to the understanding of this disorder since the detailed, early clinical and pathological descriptions. The spectrum of clinical presentations can be neuropsychiatric (apathy, lethargy, excessive somnolence), a movement disorder (ataxia, tremor, chorea, parkinsonism, myoclonus, dystonia), or both. Cortical laminar necrosis and polymicrocavitation in the cortex and basal ganglia are combined with cerebral and cerebellar atrophy. Microscopically, Alzheimer type II astrocytes and cytoplasmic glycogen granules are characteristic. Recent neuroradiological observations in patients with liver failure have shown a specific magnetic resonance (MR) imaging appearance with a hyperintense T1 signal in the pallidum, putamen, and, rarely, mesencephalon. Using clues from a similar MR appearance in patients receiving total parenteral nutrition as well as animals given parenteral manganese, and the knowledge that manganese is cleared by the hepatobiliary system, deposition of manganese in the brain is postulated in patients with CAHD. In this review we describe three cases of CAHD with detailed clinical and radiological documentation and discuss the aforementioned pathogenetic mechanisms.