Our review shows that a wide array of neurologic complications can occur after liver transplantation. Clinical correlation of the neuropathologic lesions may be difficult, as multiple lesions of variable etiologies may coexist, and significant systemic and metabolic complications may obscure the symptoms related to an underlying lesion in the central nervous system. Nevertheless, a reasoned approach to the recognition and diagnosis of these lesions is offered. In the early post-transplantation period, noninfectious lesions predominated. Of these, anoxic-ischemic changes and vascular events (hemorrhages and/or infarcts) occurred most frequently. Anoxic events occurred a mean of 10 days after transplantation and were often preceded by transient or varying degrees of hypotension. Hemorrhagic events and infarcts occurred a median of 27 and 5 days, respectively, after transplantation. It should be noted, however, that the projected onset of these events may vary somewhat, e.g., a brain infarct developed 47 days after liver transplantation in case 2. Although defects in coagulation may predispose to hemorrhagic lesions, a source for the infarct is usually not apparent. Central pontine myelinolysis is also an early-occurring lesion: most cases are seen within 10 days of transplantation. Extrapontine involvement frequently coexisted with or was present without pontine lesions. Hyponatremia or wide variations in serum sodium generally preceded the CNS lesion. Focal areas of high signal density by CT scan in the pons was highly suggestive of central pontine myelinolysis. Cyclosporine may cause white matter changes in the brain despite normal serum cyclosporine levels.(ABSTRACT TRUNCATED AT 250 WORDS)