Consciousness disturbance in patients with chronic kidney disease: Rare but potentially treatable complication. Clinical and neuroradiological review.

In patients with chronic kidney disease, particularly those in end-stage kidney failure and undergoing dialysis treatment, brain complications may arise, and their potential reversibility mainly hinges on timely diagnosis and intervention. Neurological symptoms may be non-specific ranging from slight or pronounced consciousness disturbance till coma, and imaging is the main tool to guide diagnosis and may reveal the underlying pathophysiological mechanism. Kidney impairment, causing a surge in blood pressure, increases the risk of Posterior Reversible Encephalopathy Syndrome and, leads to neurochemical alterations that result in uremic encephalopathy. In end-stage kidney failure patients, Posterior Reversible Encephalopathy Syndrome predominantly occurs in atypical locations, often involving the bilateral basal ganglia, and exhibit larger volumes compared to patients without kidney dysfunction. Uremic encephalopathy may involve the basal ganglia, white matter, and cortical or subcortical regions; in the latter case, imaging features resemble the typical location of Posterior Reversible Encephalopathy Syndrome. Dialysis Disequilibrium Syndrome, Osmotic Demyelination Syndrome, and Wernicke's encephalopathy are uncommon complications associated with dialysis. Each syndrome manifests distinct imaging patterns: Dialysis Disequilibrium Syndrome shows bilateral, patchy, diffuse white matter alterations; Osmotic Demyelination Syndrome causes central pontine and less often extrapontine lesions (involving bilateral basal ganglia, thalamus, and cerebral peduncles); Wernicke's encephalopathy determines symmetrical abnormalities in the thalamus, mammillary bodies, periaqueductal gray matter, midbrain tectal plate but the nature of brain edema associated with these complications remains controversial. Besides, in rare cases, overlapping imaging features may occur, and only the accurate patient's clinical history reconstruction along with laboratory examination results can lead to a better evaluation of MRI findings and underlying causes allowing prompt therapy.