Cerebral imaging changes in patients with chronic renal failure treated conservatively or in hemodialysis.

BACKGROUND: Nonuremic patients with apparently normal memory and behavior, studied by means of cerebral computed tomography and found to have cerebral atrophy (CA), evidenced functional intellectual deficits when they underwent psychometric testing. The finding of CA has been repeatedly reported in limited case groups of uremic patients who also demonstrated functional intellectual deficits on the basis of the same tests. This retrospective study considered all diagnostic cerebral computed tomography scans done in our department between 1981 and 1998. Fifty-five uremic patients in conservative treatment (CT) and 111 patients in hemodialysis treatment (HT) were selected on the basis of the following two criteria: primary nephropathy as the cause of uremia and an age < or =55 years to exclude involutive brain changes occurring with age. AIMS: The aims of the study were to determine the percent of uremic patients with CA, the characteristics of their CA (cortical or subcortical), and eventual associated morphological lesions. RESULTS: CA was detected in 50.9% (cortical atrophy in 47.3% and subcortical atrophy in 3.6%) of the uremic patients in CT and in 77.5% of those in HT (cortical atrophy in 65.7% and subcortical atrophy in 7.7%). The average degree of CA was 0.872 in the patients in CT and 1.765 in the patients in HT. Thirty-four of the patients in the CT group and 46 in the HT group were hypertensive: these patients had a more severe degree of CA than the nonhypertensive subjects. In the CT group, the degree of CA in the hypertensive patients was 1.205 versus 0.428 for the nonhypertensive subjects. In the HT group, the degree of CA was 2.087 for the hypertensive patients versus 1.538 for the nonhypertensive patients. Of the overall population, 7.8% had ischemic lesions, 9.6% had endocranial calcifications, and 5.4% evidenced periventricular white matter hyperintensities. CONCLUSIONS: The high percent of CA found in young uremic patients increased in subjects in HT and, even more so in hypertensive patients. Vascular calcifications, focal ischemia and leukoaraiosis, well-known expressions of a chronic state of cerebrovascular insufficiency, were also found in HT patients; hypertension alone is a recognized accelerator of vascular damage. Thus, early and severe atherosclerosis and related hypoperfusion can be considered as the paramount causes of parenchymal cerebral damage in uremia.

[Antiphospholipid antibody syndrome]. / Sindrome da anticorpi antifosfolipidi.

Antiphospholipid antibodies (aPL) are an eterogeneous group of immunoglobulins, that include lupus anticoagulant and anticardiolipin antibodies. Patients with aPL are at high risk of venous and arterial thrombosis, thrombocytopenia and recurrent fetal loss. Antiphospholipid antibodies should be suspected in case of unexplained thrombophilia and prolongation of coagulation assays (aPTT); infact although such antibodies present an anticoagulant effect in vitro, in vivo the interfere with physiological anticoagulant reactions and may have a procoagulant effect. This paper deals with a case report characterized by a poor sintomatology, a short bleeding, but a spread of abnormal laboratoristic findings that give us the opportunity to investigate an uncommon syndrome.

[Amyloidosis and renal failure]. / Amiloidosi ed insufficienza renale.

A heterogeneous group of disorders associated with abnormal extracellular deposition of fibrillar proteins is defined amyloidosis. The renal involvement may occur in the absence of a recognized underlying disease or the kidney is affected as a result of systemic amyloidosis. Even if the diagnosis can only be confirmed by demonstrating the presence of amyloid deposits in the tissues, the development of a radiolabelled serum amyloid P component as a diagnostic nuclear tracer and the reduced urinary excretion of glycosaminoglycans as a decrease in the synthesis of functioning glomeruli and trapping by amyloid fibrils allow new diagnostic insight for the future. Patients maintained on haemodialysis or continuous ambulatory peritoneal dialysis for long develop amyloid deposits composed of beta 2 microglobulin that are predominantly osteoarticular, associated with carpal tunnel syndrome, large-joint pain, stiffness and pathological fractures. Systemic amyloidosis and some local forms are progressive and no treatment specifically resolves the amyloid deposits but therapy may reduce amyloid precursor proteins and improve survival.