Unilateral Reversible Posterior Leukoencephalopathy Syndrome after Coiling of an Aneurysm

BACKGROUND: Reversible posterior leukoencephalopathy syndrome (RPLS) is radiologically characterized by symmetrical subcortical areas of vasogenic edema that are preferentially parieto-occipital, and it typically resolves after appropriate treatment. CASE REPORT: We present a patient with strikingly unilateral RPLS that developed 21 days after coiling of an anterior communicating artery aneurysm and several days of triple-H therapy. Cortical and subcortical vasogenic edema and enhancement developed only in the left hemisphere, with a pattern suggesting RPLS. After 7 months the lesions had nearly completely resolved. CONCLUSIONS: The pathophysiological mechanism underlying RPLS is still not well understood, which makes it difficult to explain the unilateral appearance in this case. Since the imaging findings may be confused with other conditions such as ischemia, recognition of RPLS after coiling is necessary in order to avoid inadequate treatment.