Studying the evolution and the magnetic resonance findings of reversible posterior leukoencephalopathy in children

Abstract

-Purpose: To describe the evolution and the magnetic resonance imaging (MRI) findings of the reversible posterior leukoencephalopathy (RLPS) in children. Method: Nine children with neurologic symptoms and sudden increase of the arterial pressure were studied by brain MRI. Results: All children evaluated had lesions seen on FLAIR-weighted images of the parietal-occipital regions. Other regions were also involved. Four patients presented restriction on diffusion-weighted images and only two with reduction of the apparent diffusion coefficient (ADC), whitch evolved with neurologic sequels and persistence of the lesions on the control examination. The other patients had complete regression of the lesions after therapy. Conclusion: MRI is important to suggest the diagnosis of RPLS in patients with arterial hypertension and unspecific neurologic symptoms. Moreover, the outcome is not favorable all the time and the association of D-WI with ADC can be an instrument capable of predicting irreversible lesions.KEY WORDS: magnetic resonance imaging, leukoencephalopathy, arterial hypertension. Estudo da localização e evolução da leucoencefalopatia posterior reversível em crianças usando ressonância magnéticaRESUMO -Objetivo: Avaliar a evolução e aspectos na ressonância magnética (RM) da leucoencefalopatia posterior reversível (LPR) em crianças. Método: Nove crianças com sintomas neurológicos e aumento súbito da pressão arterial foram estudadas por exame de RM encefálica. Resultados: Todas as crianças avaliadas tinham lesões vistas nas regiões parieto-occipitais em imagens ponderadas na seqüência FLAIR. Outras regiões também foram envolvidas. Quatro crianças apresentaram restrição na seqüência difusão e apenas duas com redução do coeficiente de difusão aparente (ADC), o qual evoluiu com lesões seqüelares em exame de controle; os outros pacientes tiveram regressão completa das lesões após terapia específica. Conclusão: A RM é um método importante para o diagnostico de LPR em pacientes com hipertensão arterial e sintomas neurológicos não específicos. Devido à evolução não ser favorável em todos os casos, a associação da difusão com ADC pode ser utilizada para predizer lesões irreversíveis.

Hematopoietic stem cell transplantation for natural killer-cell lineage neoplasms

“…The MRI of brain typically reveals bilateral white matter edema, primarily in the parietal and occipital regions without infarction which is reversible after correction of the precipitating event. In children, it can involve other territories or cortical graymatter of the brain, and partial resolution or persistence of the lesions can occur [5].…”

“…The pathophysiology of RPLS is considered to be disturbed autoregulation of cerebral vasculature and maintenance of the blood-brain barrier due to acute hypertension: vasospasm resulting in ischemia and cytotoxic edema; and vasodilatation, capillary leakage, leading to vasogenic edema. The relative lack of sympathetic innervation in the vertebrobasilar vasculature may predispose the parietal occipital region to the development of cerebral edema in hypertensive encephalopathy [4][5][6][7].…”

Static magnetic field blood pressure buffering, baroreflex vs. vascular blood pressure control mechanism

“…The aim of the present study was to confront verapamil vascular blood pressure buffering with that after sinocarotid baroreceptors exposed to an SMF in conjunction with actual BRS and microcirculatory blood flow. The answer to the question of which blood pressure buffering mechanism is more effective vascular or baroreflex mediated, may help to develop new therapeutic strategies to potentiate the most effective blood pressure buffering mechanism and use them in clinically important cardiovascular conditions with sudden high elevations in blood pressure, which has been identified as an independent cardiovascular risk factor (Nakamura et al 1999, Hata et al 2000, 2002, Pickering 2000, Stauss and Persson 2000, Pickering et al 2005, Ferraz-Filho et al 2006, Stead et al 2006.…”

Verapamil buffering effect on the abrupt elevation in blood pressure, linkage with microcirculatory blood flow

“…, 2003). Both abrupt elevations in blood pressure and chronic high blood pressure can jeopardize the vessel wall and the heart and deteriorate the regional haemodynamic autoregulation system (Ferraz‐Filho et al. , 2006); they can cause extensive target organ damage and increase the risk of ischaemic stroke (Kumagai et al.…”