Reversible white matter lesions in a patient with fulminant hepatitis and acute renal failure

Reversible hyperintense lesion after balloon occlusion test

We report a unique case of a reversible high signal intensity lesion observed on a magnetic resonance (MR) image accompanied by transient neurological deficits related to a balloon occlusion test. This abnormality was considered to be vasogenic edema caused by the disruption of the blood-brain barrier (BBB) due to a long history of uncontrolled hypertension and transient ischemia induced by the balloon occlusion test.

Does uremia protect against the demyelination associated with correction of hyponatremia during hemodialysis? A case report and literature review

Rapid correction of chronic hyponatremia is known to cause demyelination syndromes, which are attributed to the rapid shift of water out of the brain. In uremic patients with hyponatremia, depending on the dialysate sodium concentration and delivered Kt/V, serum sodium levels may be rapidly corrected inadvertently during the hemodialysis (HD) session. It is not known whether uremic patients are as susceptible to the development of demyelination as patients with normal renal function. Since urea diffuses slowly across the blood-brain barrier, it can act as an effective osmole between plasma and the brain if levels are changed abruptly. During HD, blood urea levels drop suddenly and significantly and cerebral edema may develop (dialysis disequilibrium syndrome). This effect may counteract the fluid shift out of the brain during correction of hyponatremia. Therefore, theoretically, uremic patients may be less prone to develop demyelination. We present a patient with renal failure whose hyponatremia was corrected rapidly during HD to illustrate the potential problem. The patient tolerated rapid correction of hyponatremia without sustaining any neurologic damage. We performed a literature search looking for similar case reports and reviewed the scientific evidence behind the above hypothesis.